Review: Intend Infinity Dual-Crown USD Fork

Jul 25, 2019
by Mike Kazimer  
Intend Infinity fork review


Intend Bicycle Components is one of the smallest suspension and component companies in the world, so it's understandable if the name isn't immediately familiar. The company, which is essentially a one-man operation, is headed up by Cornelius Kapfinger, an engineer who formerly worked with Trickstuff, the German brand best known for their beautifully machined, uber-expensive brakes. He's since branched out on his own, and now produces cranks, stems, disc rotors, and suspension components, like the Intend Infinity upside-down fork that's reviewed here.

Inverted, or upside-down (USD) suspension forks aren't a new development in the mountain bike world, but despite an ever-growing list of valiant attempts, they haven't been able to surpass the popularity of the much-more common right-side-up design. That doesn't stop companies from trying to crack the code, and Cornelius has tossed all of his engineering know-how at the Infinity to try and make his mark in the suspension world.

Intend Infinity Details

• Intended use: DH
• Wheel size: 29", 27.5" or 26"
• Air-sprung
• Travel: Up to 215mm
• 20x110mm steel through-axle
• Adjustable rebound and low-speed compression
• Colors: blue or black
• Weight: 2,510 g / 5.5 lb (29")
• Price: €2,049
• 3 month delivery time
www.intend-bc.com

Available with up to 215mm of air-sprung travel, the Infinity's upper tubes measure 45 millimeters in diameter, and slide on 35mm stanchions. You can get the fork configured for 29”, 27.5”, or even 26” wheels, but there is a maximum headtube length of 140mm, including the headset. Why's that? It's because the Infinity doesn't use a traditional steerer tube – instead, a there's a small extension on each crown, and a threaded bolt, which is accessed from the underside of the lower crown, cinches everything together. That helps keep the weight down, and our test fork checked in at only 2,510 grams, which is roughly 100 grams lighter than a RockShox BoXXer, and 200 grams lighter than a Fox 49.

The Infinity is priced at 2,049 Euro, but be prepared to wait up to 3 months for delivery – each fork is hand-assembled after an order is submitted. For riders in Canada and the US, you're out of luck, unless you're planning a European vacation – due to insurance reasons Intend doesn't ship to North America.


Intend Infinity fork review


Design Details

The Infinity's air pressure is adjusted via a Schrader valve on the top of the left leg, which is the case with nearly every air-sprung fork on the market. The amount of end-stroke ramp-up can be adjusted by removing the top cap by using a cassette tool and screwing on a plastic spacer, or oil can be added to accomplish the same result. According to Intend, the Infinity's negative air spring volume is larger than most forks on the market in order to create a sensitive beginning stroke with plenty of mid-stroke support.

Rebound is adjusted on the top of the right leg. On my test fork, the rebound knob was 3D printed, and there weren't any clicks to help keep track of the position, which is a little inconvenient. The low-speed compression knob on the bottom of the same leg does have countable clicks, though, 14 of them to be exact.

Intend Infinity fork review
Air pressure is adjusted on the left side, and rebound on the right.
Intend Infinity fork review
Low-speed compression is adjusted on the bottom of the right leg.

The damper uses a semi-open bath design – a smaller diameter tube that's inside the stanchion is filled with oil, and the bottom of that tube is submerged in oil. The compression damper is located in that oil bath, but if you feel like tinkering with the compression shim stack all you need to do is turn the fork upside down and it can easily be removed from the bottom of the leg without any oil loss.

On the topic of oil, the Infinity uses 2.5W Danico Biotech Race Shok oil, which is produced from German grown sunflowers. I feel like Intend should include a sticker that says, “This fork runs on sunflower oil.”

Intend Infinity fork review

Installation

I installed the Infinity on a Kona Operator 29 that was in for testing (look for that review soon). Without any steerer tube to cut, it was a simple procedure to get it installed and ready to go. The brake line routing is a little rudimentary, and it's important to make sure that it's done correctly, otherwise there's the risk of the brake line getting pushed into the wheel when the fork compresses. I'd say there's definitely room for refinement in this area – zip-ties and plastic cable guides seem out of place on a high-end fork.


On the Trail

All of my time on the Infinity was spent at the Whistler Bike Park, which is the ideal location to rack up a serious amount of vertical in a relatively short amount of time. Set-up was straightforward, and I ended up with 100 psi of air pressure for my 160 lb weight, with 7-clicks of low-speed compression and the rebound set according to my preference. The amount of range for the rebound and LSC isn't crazy – you can't make the fork return as slow as molasses, or feel like it's fully locked out – but it's reasonable, and I'd imagine that most riders would be able to find the sweet spot within the available settings.

The overall feel of the fork is one of controlled plushness – the travel feels bottomless, with just enough ramp-up at the end of the stroke to avoid any harshness. My hands welcomed the Infinity's trail-smoothing abilities, especially on high-speed, brake bumped filled straightaways. There was plenty of fore/aft stiffness on those straightaways as well, and the fork took whatever I plowed it through in stride, as long as I hit those obstacles head-on.

The downside to the Infinity's design, and the same issue that's plagued nearly every mountain bike fork that's gone down this route, is the lack of torsional stiffness. On sections of trail that required a lot of front end movement, that lack of stiffness became quite apparent. At times it felt as if there was a delay between when I turned the handlebar and when the front wheel moved, a sensation that was even more noticeable if there was a sequence of multiple quick turns. That's when it felt like I really had to use extra effort to get the front wheel to track where I wanted it to – it was like driving a car without power steering.

The flex felt detrimental when the trails were hardpacked and running fast, but there was one extra rainy day where the Infinity's potential shone through. The roots were slick and the mud was deep, but I found that if I relaxed and let the fork find its way there was much more traction available than I'd anticipated. I still had a few moments where it felt like the fork got hung up when I tried to force a direction change, but it was in those wet, slippery conditions, times where finesse is key, that the fork felt best.

Intend Infinity fork review
Kona Operator CR


How Does It Compare?

The last upside down DH fork that I tested was 5 years ago, on a bike with 26" wheels, so I can't draw any direct comparisons between the Intend and another USD fork. However, I can compare it to the RockShox Boxxer World Cup whose spot it temporarily took. The Infinity is a little lighter than the Boxxer, but I can't say that I noticed that out on the trail. What I did notice was how easy it was to initiate the travel on the Infinity - its beginning stroke was more supple than the Boxxer's, and overall it felt more linear and 'plush', for lack of a better term, while the Boxxer was more supportive in the mid-stroke. Of course, that trait can be tuned to some extent on both forks with volume spacers.

The Boxxer does have a wider range of adjustments, along with externally adjustable high-speed compression, which makes it easier to adapt the fork to suit a track or personal preference. And then there's the whole stiffness side of the equation, which the Boxxer wins handily - the difference between it and the Infinity was very noticeable.


Intend Infinity fork review
Intend Infinity fork review


Durability

The Infinity has seen a mix of dry and dusty days and some absolutely sloppy ones, and it's remained smooth throughout all of it. However, those muddy laps did begin to take a toll on some of the anodizing - the brake line rubbed through the blue in a few sections. Installing some clear protective tape ahead of time would be the best tactic to avoid this issue. How about those unprotected stanchions? They've survived without a scratch.



Pros

+ Plush and smooth travel
+ Light weight for a dual crown fork
+ You'll stand out from the crowd

Cons

- Lack of torsional stiffness
- No built-in cable guides
- Expensive, not available in North America



Pinkbike's Take
bigquotesWhile the Infinity isn't the way to go if stiffness is high on the priority list, the damper does work very well, and the overall ride feel is quite comfortable. Creating a suspension fork from scratch is no easy task, and this fork is a valiant effort from a very tiny company. It'll be interesting to see what Mr. Kapfinger comes up with next. Mike Kazimer







197 Comments

  • + 102
 Maybe it should include optional stanchion guards? Love to see the reviews of lesser known brands. Keep it coming!
  • + 1
 He doesnt built them as they are too expensive and not necessary to make.
  • + 18
 just in case if you need carbon stanchion guards

carverbikes.com/parts/accessories/carbon-stanchion-guards

i use same guards on my German:A carbon Flame forck
  • + 9
 Yeah second this. Really interested in the boutique stuff
  • + 3
 Check out a small British company called Gnartec

gnartec.com

They already have a range of stanchion guards that are pretty simply yet clever
  • - 3
 @NotNamed: They are great for adding stiffness which was one of the weak points of this fork. DVO did it on their Emerald fork, worked great and looked good.
  • + 6
 @hubsession: ... and did not work. A German magazine tested the fork in the lab with and without the guard and the difference was marginal. Definitely not worth the 200g extra unsprung mass.
  • + 4
 @hubsession: how exactly would it add stiffness ? Guards just protect from scratches and are fixed on one single point.
  • + 14
 His reply to this question his great:

(from website)
"No, my experience with that not covered lowers is: no problems at all. If you take "normal" care about your fork, there will not be more scratches on the lowers than on the uppers of a normal fork (there are no guards either and nobody gives a shit). If you are scared, there is a way: don't buy it Wink "
  • + 6
 @jmjr: well, it is still fixed only at the axle level right ? So it shouldn't change much, if at all, the stiffness. As I understand it the torsional flexibility comes from the stanchions themselves not from the axle level. Even if you guard was super solid, it would only block a minor part of the flex?
On a normal fork the contact points between left and right side are hub/axle, arch of the lowers, and the crown.
On an inverted fork you can not do better than hub/axle and crown. If you add the guard, it will look like you have an arch in the middle( like on a normal fork) , but as it is attached to the axle level, it will not do much.
  • + 2
 @zede: It essentially was designed to be the replacement for a typical arch of the lowers, but as I mentioned above, it didn't work according to magazine lab tests.
  • + 3
 USD forks look the business - always loved them, never had them. I just wonder what all the scratches on the legs of my 40s are going to look like on USD stanchions?
  • + 3
 @Ash-Ash: i could care less about my lowers getting scratched, these dont really help. its the stancions we are referring to
  • + 11
 @jjowens14: That is the dumbest response I have ever heard. Stanchions being lower exposes them far more to damage from kicked up rocks or during a wreck. Just take a look at the lower legs of the average downhill fork. I take "normal" care of my fork and my stanchions look flawless, my lowers however are thrashed from the normal wear and tear of shuttling and riding.
  • + 8
 @mixmastamikal: If every scratch on my Emerald guards was on the stanchions, the forks would be rooted. Try as the might, you can't advertise away the need for guards on a USD fork.
  • + 1
 @jjowens14: that seems wrong to me. I have a feeling lowers are more vulnerable to rock hits and damage from being dumped on the side of the trail. I've definitely got a few scratches on the lowers of my fork.

Also, my dirtbike has an inverted fork... And guards. Seems like an easy thing to design with a low weight penalty, why wouldn't you add them?
  • + 3
 @jjowens14: his attitude towards the topic almost makes him seem like he’s defensive about it. The proof is in the pudding. The lowers are way more prone to rock chips and damage when setting the bike down. If his point was true then no USD forks would have guards on the stanchions and my lowers would have less or the same wear as my uppers... and they don’t. Way more nicks and scratches on them. No way I’d buy one of these forks. My summary on this article is, if you want a fork that’s not near as good as a Fox 40, not near as stiff and you want to pay almost twice as much then this fork is for you.
  • + 1
 @jjowens14: unless you crash , and scratch them. Got those on my , guards .
  • + 1
 @jmjr: oh no, not 200g unsprung mass !
  • + 6
 I have the single crown version on my bike for a few month now:
1) I have no scratches on my stanchions. If you crash into a pile of rocks damage can always happen no matter if stanchions are further up or down on the fork and for the rest of that days when you don't try to get a part in the next episode of the Fridayfails just take care of your stuff and everything will be fine.
2) measured stiffness values are an absolutely irrelevant number German Bike magazines cam up with so they can be German and compare something. Matter of fact everything needs to flex. An absolute stiff fork would be an nightmare to ride.
An upside down fork flexes different than a conventional mountain bike fork and this is what people notice when they use a fork like this for the first time. better or worse? try t out!
By reversing the fork flex in certain directions like back and forth becomes much better where as torsion becomes a bit softer. Its a trade off. A certain amount Torsional flex is actually nice for a smooth controlled ride.
Back in the day I had a dorado and people who never rode the fork or anything similar had the same complaints which honestly is ridicules. Don't judge stuff you have never experienced.

finally, cause I know its going to come up, no I am not I dentist, I wholeheartedly hate going to the dentist...
  • + 73
 Nice to read a neutral review of Intend products. The german press, especially mtb-news, is virtually jerking him and his products off on every review. Yes, they are very nice and performance is good, but for the german press its like Jesus came back as a Mountainbike-Fork.
  • + 70
 Lets be honest here, our german press jerk off anything german. Car and motorcycle magazines and websites are a joke...we dont make decent cars since the early 90s but magazines and ppl still talk about german cars as if there was nothing else out there...same thing for motorcycles. As an ex-engineer-test-driver (cars) and current development R&D engineer (motorbikes) i am completely disgusted by how these 2 markets are dealt with over here. The companies are as corrupt as it gets and the media treats them like Gods...if only ppl knew how these markets ACTUALLY work...and now the same thing is starting to hit the bike market, the way our press talk about Canyon, YT etc. is just simply disgusting...
  • + 10
 @pperini: compleytely agree , I used to work indirectly for VW. I vowed never to buy a German car after my T4, most surprisingly is that the French seem to have turned quite a big corner in regards to quality and technology
  • + 5
 @sewer-rat: funny you should say that, cuz my bike-carrier/campervan is a renault kangoo and its way better than my previous overrated vw caddy...the kangoo is rock solid, love it, never had a single issue with it
  • + 4
 @pperini: media in
1st World country: our stuff is best.
2nd world country: other's stuff is best.
  • + 2
 @pperini: recently had one of these, my 3rd Peugeot. They have even converted my dad who always told me to never touch a French car and always go Japanese lol . I've been driving Peugeots nearly 5 years now and had zero issues which is more than I can say for my VW's and Honda's

www.peugeot.co.uk/about-us/awards/cars-awards

www.pinkbike.com/photo/17255346
  • + 1
 @pperini: so what cars are good now, in your opinion? I’m really curious about a German’s perspective. Toyota has gotten my money the last few times for trucks, but a Bimmer always peaks my interest for a smaller car.
  • + 2
 @sewer-rat: omg thats even funnier, because i also used to be the "go jap, dont touch french" car opinion lol am loving the renault though

BUT! (just to bust your balls a bit if i may lol) you pug is not a pug, its based on a Mitsubishi ASX, which is a great car btw..
  • + 22
 @whambat: well, being german or not, one thing i can tell you for sure: after you work as a test-driver/engineer your perspective about vehicles changes drastically.

If you ask me now "what is just simply the best car in the world hands down", there is really only one answer: Lexus if you have money, Mazda if you dont (not that they are cheap though lol). I used to put Toyota and Honda in that list, but there is one simple reason why i dont anymore (at least for the time being): both brands are switching their models policy from local to global, and they are running over bumps because of this. Now, toyota is handling the situation better than Honda (as expected, since they have more experience with world-market platforms through Lexus) so they dont have quality issues, they have other issues that dont affect customers really. Honda though, did one major mistake imo, they went both feet in at the same time with new technologies (mainly mass produced turbo engines) AND a world-market-platform policy. Thats why more than ever you hear about ppl having trouble with their Hondas lately, something that used to be a tabu in the near past. Honorable and well deserved mentions def go to Suzuki, Dacia/Renault. These guys have been putting out some SERIOUSLY good vehicles lately, their improvements on quality, attention to detail, production plants and customer service have been nothing short of amazing in the past 5-10years..

Two things need to be added ti the equation though: 1. every brand has good and bad cars, nothing is perfect, not even a Lexus. Even though thats the brand imo that comes darn close near perfection...and 2. Time has shown me that this "list" changes all the time. New techs, production and trends shift things around more drastically then ppl realize. And thats my main problem with german brands: they used to concentrate on building cars, now they are concentrating on building trends. Thats why there is a new german model almost on a daily basis and new "gimmicks" from them every day. Thats why my friend that works for AMG works 12hrs a day fixing them, but at the same time a Smart is a Twingo as much as a Citan is a Kangoo. And guess what, both of the "renaulcedez" are (again, at the moment) the ones with the least amount of warranty issues...but trust bro, i could go on with this for days...but i'll shut up now and get back to work LOL
  • + 1
 (and an X is a Nissan Navara! Lol)
  • + 5
 @pperini: wow, that was a thorough response for pinkbike. Much appreciated. Don’t have much of an option for French cars in the States, and I wouldn’t have considered Suzuki. Not sure how it is in Germany, but BMW buyers in the states mostly lease, so the used market is crazy cheap here for them, especially after 60-80k miles, you can get them cheaper with AWD than Subaru. And Subaru isn’t as reliable as they used to be after 120k miles. Lexus, like Toyota trucks, tend to hold their value more on the used market and don’t have the performance feel of BMW, tuned for comfort like Mercedes. I’ll look more into Mazda. I just want a small awd car to keep my Tundra parked as much as possible for fuel savings and keeping the mileage off the family camping rig, trucks get really expensive to replace these days.

Thanks for the sidetracked discussion, I appreciate it.
  • + 0
 Who said he got refused?
  • + 5
 @pperini: What do you mean by "starting to hit the bike market"? The German mags have been praising Canyon and co. to high heavens for more then a decade.

I would argue that the manufactureres know very well what the magazines (and their readers) want and value, so they make product that caters to the market.
Example: For many years German riders didn't care much for geometry but would buy the bike with the best components for the price. And Canyon/Radon/etc. excel at that metric and therefore won every comparison test.
  • + 7
 @whambat: Though I don't do it for a living anymore, I spent many years as an ASE Master Auto tech and have owned dozens of cars over the years. I got my first BMW about a year ago (440i) and I cannot say enough good about this car, I get bored of vehicles quickly but have yet to NOT be excited to drive to work in this thing (the stick-shift helps). Toyotas are, in my opinion, one of the best values in cars out there but if the Bimmer piques your interest, you will not be disappointed. It's a helluva machine.
  • + 12
 @pperini: Haha (priceless)

I have worked in the motor industry for 29 years and currently I'm an electrical engineer for a manufacturer (previously BMW 13 years - master technician)

I think you should become a tabloid commentator in the motoring section with your in-depth knowledge of the motor industry (No offence intended pperini)

Personally....I could tell you about the department I work in and what they do quite confidently, I could also tell you how to diagnose and fix BMW's (past models that I worked on, up to 2015) .....what I couldn't do confidently is tell you the facts about what is the best car on the road, which ones to avoid and why to avoid them and crucially which country makes the best cars (I could read a lot of the stuff in the press from industry analysts BUT I wouldn't know anything of actual substance)

So really guys when somebody offers an opinion, it's just that...an opinion. My opinion is that German motor manufacturers make damn good cars and motorcycles compared with what I have owned and worked on in the past 29 years

Cracking looking fork by the way (wonder how much mileage accumulation / durability testing a one man band could do though compared with the big players)

Tschuss Smile
  • + 2
 @pperini: It seems to me that the only metric you use for the automotive industry is reliability, am I right? If so, I don't really get the point of the argument, especially on pinkbike. Single-speed belt-driven rigid commuter is way more reliable than downcoutry and broduro bikes, yet still, for some bizarre reason, people buy full-suspension bikes. Even a basic 320d is miles ahead of majority of the world market in terms of driving dynamics/seating position/interior quality in my personal opinion. Is there a more reliable way to get from A to B than a M140i? Yes. Will it be safer and more fun? Most probably not.
  • + 2
 @pperini: Well BMW is known for reliability issues and others are meh compared to Japanese but to say that French cars are better, even if only in reliability is quite foolish. Their commercial vehicles are solid but normal cars were often terrible and yes they are getting better (especially Peugeot). But in the end when you've grown in German cars driving others doesn't feel right, everithing is too soft and sluggish. I'm not saying that German cars are perfect or always good but in they are usually the best in class. Yet I would probably buy a Volvo if I could afford it Smile
  • + 0
 @pperini: fun fact you say mazda is the best but at least in europe mazda uses psa (peugeot) diesel engines
  • + 1
 @winko: Different reason, EU emission standards, Mazda decided not to develop a diesel engine because they already had difficulties with previous standard (EU3 or 4).
  • + 3
 @pperini: I dunno man. Benz and BMW are pretty sick cars and BMW makes some of the best motorbikes in the world now (S1000RR and GS series). I think the germans are doing ok.
  • + 5
 Ok just to clear some things up. Some people here took my words as of i was trying to make some sort of "definitive argument on how good cars really are". I was not, i was just stating that things are just simply not always the way they seem. Of COURSE there are many, many great german cars as well as there are shitty Lexus out there. As our friend up there mentioned: its just MY opinion/experience. Being from the industry i also (obviously) know personally and even work together with ppl (on a daily basis) that have extrem opposite opinions/experiences to mine. That why i started my argument by saying that "this job changes your perspective drastically". I didnt mean it necessarily to the worse (though that was mainly MY experience). I was just sharing MY opinion and it should be taken as such. This is not a war, you dont have to take sides. Something that 650b and 29ers have proven that people love to do, take sides. Pointless arguments like "mazda uses pug engines"........so?....did you know that BMW uses Toyota, Pug and some no name British engines in their cars? .....so?.....thats not the point!! Aaaaand thats why i finished my argument by saying "everybody makes good AND shitty cars"...period. Stop taking other ppl opinion so personally. Stop taking sides. And above all, stop being a butt hurt fanboy...and dont forget to ride 29ers ONLY! Of course until 32s come out..
  • + 1
 @pperini: >> we dont make decent cars since the early 90s
>> Of COURSE there are many, many great german cars

What does it even mean?

It is obvious that there are unreasonable politics in many, if not all, corporations. It is also obvious that every car is a different project with different constraints and requirements and different people working on them. So I still have no idea what your point was, since usually if one blames media for jerking someone off, reasonable arguments are expected. In this particular case, I find it impressive that one man made a product that is on par with competition on multiple parameters.
  • + 0
 @Skinnyman: again, my opinion. It doesnt "mean" anything, its an OPINION! Take it as it is! And the second sentence (that there are great ones out there) is NOT an opinion, its a fact. You know the difference between both or do i need to spell it out in german for you? You want a resonable argument for blaming the media for some massive jerkoff?! Well buddy just ready any car magazine really! Its not that hard! And, wtf do you even mean with you last sentence?! Seems like all of the sudden you jumped from cars to the Fork in this article?! Get your ideas straight before posting...
  • + 2
 @pperini: * it's been since 80's to make a decent car
  • + 1
 @pperini: Your OPINIONs contradict each other, which is weird. Good for you for having an OPINION, but the question arises whether it is worth sharing, since no valid arguments can be shared to back it up. I have read tons of comments already about this "media-jerkoff", but never a concrete criticism of a particular magazine article or whatever, just "hurr durr I know things you don't know and it's my opinion". Other people have opinions too, just saying. And a secret tip: media is rarely independent and unbiased, and it's the consumer who drives this state of things forward.
  • - 1
 @Skinnyman: my opinions dont contradict each other, show me where. Second, "whether its worth sharing"??? Wft do you mean??! Someone ASKED for it!!! Trust me i have to deal with a bunch of f*cking morons that THINK they know anything about cars and motorcycles because they read waaay too many magazines EVERY f*ckING DAY! So trust me when i say that i dont usually have these type of conversations for no reason, specially on the internet on a website that isnt even about the subject! And right now it just so happens that someone asked for my opinion! Now you wanna tell me "trust me media is rarely unbiased"?! Are you even serious???!! Im out of this conversation, i have to deal with "know it better people" every day, but at least i get paid for it. Now if a bunch of ppl take someomes opinions too personal on the freaking internet, now thats not my problem. Live happily with your creeds and leave me alone with mine. If my opinions "insult" you in any way, then stop reading, its that simple.
  • + 4
 @pperini: >> my opinions dont contradict each other, show me where

I already did it:

>> we dont make decent cars since the early 90s
>> Of COURSE there are many, many great german cars

Who precisely asked for this opinion? www.pinkbike.com/news/review-intend-infinity-dual-crown-usd-fork.html#cid2323689

I was the one who has asked for your opinion when I asked whether I understood correctly that you use reliability as the only characteristic to define whether a car is "good" or "bad", but never got an answer. Nothing on internet "insults" me, I was just hoping that this time maybe I will read constructive arguments instead of "it's bad and it's my opinion". Can you please share a link to some sort of a material where a car magazine article is constructively criticized? I would really love to read it.
  • + 0
 Tldr train wreck
  • + 3
 @Skinnyman: Ok, last try.

"we dont make decent cars since the early 90s". Now, this is my opinion. This is me, expressing a personal opinion, that cars since that era arent up to my personal standards anymore.

"of course there are great german cars". This, now this is NOT an opinion, this is a fact. Regardless of how i feel about newer german cars. Some of them are very reliable, comfortable, fast, spacious, etc. Some of those (and more) attributes is what contributes for what we call a "good car". And again! Thats a FACT! Regadless of how i feel about it.

Why isnt this a contradiction? Simple, its called being an adult and being able to admit to the world that facts OVERRULE your personal opinions. In other words, not only because i THINK all cars are no good anymore, doesnt mean that they actually arent, and i RECOGNIZE and admit that FACT. Thats why it is NOT contradictory.

Who precisely asked for my opinion? Mr. "whambat", when he said: "in your opinion".

To address your point about reliability: yes, i highly (but not exclusively) rate vehicles high or low judged on reliability. Why? Two main reasons. First, a vehicle is first and foremost a transportation mean, and if the vehicle cannot function its primary purpose because it constantly breaks down all the time, then its value start to decrease in relation to its primary function. Not to mention unnecessary costs etc. Second: because i worked for a very long time as a quality manager when i was an engineer/test-driver, and as i mentioned, such a job can really change your perspective on things.

Now, do i judge a Lotus Elise the same way i judge a Corolla? Of course not. You dont buy an Elise for reliability, comfort, space, luxury, even speed (cuz really they arent even that fast). You buy an Elise because it is FUN. In my opinion.

Now, "fun" became the main function of the vehicle. You did not buy an Elise to go from A to B. So if this vehicle starts to give you trouble, it is up to YOU to decide if this trouble is worth its VALUE. And that is something that everyone has to decide for themselves. Thats why i keep on banging the argument that everything i said is purely based on opinions and experiences. Values differs from people to people. So ones opinions might not match others values.

Obviously i cannot share any documents or links with you because i used to work with highly secret prototype vehicles, and ive probably signed more papers then i can remember on "confidentiality terms". So the internet is most definitely the LAST place i would publish the things that i know.

But then again, do the things that i know have to affect anyones life? Of course not. As i already said, everything is relative to your values. Just as much as i saw many BMW fans (for example; co-workers) that would crawl under their cars on the hoist every single weekend to fix something that was broke and still praise BMW to be the best brand out there. Again, its a VALUE thing. They value other things beside reliability. And thats fine, unless one is extremly stubborn and obtuse. Would i buy a new German car today and if yes what would it be? Well, i wouldnt buy one out of the blue because for me personally their prices outweights their value, BUT, if i "had" to buy one, funny enough it would be a BMW M2. Why? because that car IMO gathers the essence of everything that i like so much about old BMWs. Regardless of how "good or bad" it is, my personal value to this particular vehicle is based on a subjective sentimental fundament, Therefore overruling any other downside that the vehicle might present when judged by other terms.
  • + 0
 @Skinnyman:
Yeah I agree with you totally reliability isn’t the only standard. The UK hasn’t made a reliable car since the horse but it’s made plenty of great ones!
  • + 2
 @pperini: Holy crap, too many things in common. I too am a Quality Manager and have been for many years in the automotive sector
  • + 2
 @kipvr: Nissan Sunderland will beg to differ as will Vauxhall now its owned by PSA, their reliability has climbed significantly in recent times
  • + 3
 @pperini: funny you would say nothing decent was built since the 90ies. in my opinion that's the sweeet spot Cornelius's fork hits. its built like in the 90ies. Simple, no plastic internals, lots of oil, nothing that could cause you trouble. no stupid CTD or stuff like that that never works anyways.
Honestly, I have one of his forks, its just a good working no BS product which is really unique these days on any product.
Its unfair to compare him it to "Auto Motor und Sport" making the Audi or VW win every shoot out even though the lack handling or safety features or whatever, by simply giving them maximum pointing for glove box ergonomics...
  • + 1
 JFK who the hell is going to read your book in the comments bud? keep it short @pperini:
  • + 0
 @pperini: Why did you type this wall of text just to repeat what I said? Last try in what? Facts are indistinguishable from opinions in your posts.

>> Obviously i cannot share any documents or links with you because i used to work with highly secret prototype vehicles, and ive probably signed more papers then i can remember on "confidentiality terms".

1) you tested prototype vehicles, but you voice opinions on mass-produced vehicles, which makes no sense. There is a reason for a big red button in a prototype car;

2) you have probably not read those papers, since they are not that restrictive. Quality engineer usually has no idea about intellectual property behind the product and you can easily say something like "once upon a time I found a critical problem in a suspension linkage and the product went into production without a fix", since this information does not link you to a particular company/product. If you really "worked very long time as a quality manager", most of the NDAs have probably expired either way, since the concepts behind the product have been made publicly available until today;

3) do you have any information about the work of quality engineers in the companies that, as you have stated, make "good" cars?

4) I asked for links to any material that, for example, takes an allegedly biased magazine article and picks it apart with constructive criticism, not necessarily written by you personally.
  • + 1
 @Skinnyman: holy crap you go on!
1) no pro types usually derive from existing platforms in group, therefore some flaws which designers feel aren’t flaws carry over

2)spot on, quality engineers look at process control, not fit and functional performance this is down to engineering. They don’t fix components they look at cause and effect

3) see above- I worked at Bentley, the perfect mix of VW strategies mixed with blokes that smile roll ups and love a hammer

4)there are plenty of consumer reviews that disagree with mass German brand arse licking, look at any decent shootout in the comments

There not war and peace but facts
  • + 2
 @sewer-rat: I go on because I never received a sensible answer that an engineer or a manager would have to trouble giving and I would really like to learn literally anything that supports pperini's point of view besides anecdotes.

1) Designers work under constraints and have a set of requirements. What quality department might treat as a flaw is oftentimes just an expected behavior. Do you have any examples of carryover flaws of any platforms?

2) If it's spot on, please feel free to share any info, I'd love to learn more on the topic.

3) pperini did not name Bentley as a "good" car, what is that all about?

4) Do you care to share any links? I never saw drastic differences between german and non-german press, we're not talking about consumer reviews here, since it's a whole different story.
  • + 1
 @sewer-rat: yeah I was only joking really bud. My wife has a Nissan and loves it, it did break down yesterday though- whilst on holiday in France, which serves me right for my earlier post!
  • + 2
 @Skinnyman:
1) absolutely , I work in braking. The amount of flaws I see in rotor development alone that OEM’s carry over because “it’s the way they’ve always done it” is shocking. Coating on Lotus discs is sacrificial and applied at 3 microns, we them receive complaints that the discs rust!
2) Quality engineers are there to provide assurance that the product meets the customer and engineering specifications in the most economical manner, they do not question really the performance of the product. They may in advanced performance quality planning meetings when the process / design failure mode effect analysis is carried out (google APQP and FMEA) bit as a large they are there to assure product performance against engineering specifics / customer specific requirements
3) Bentley are basically VW carry over , I could mention other OEM’s I’ve worked with , Mitsubishi, Audi, BMW, Jaguar etc, they ALL use the same core tools and have to as it’s a requirement of the automotive task force specification IATF16949 which is the benchmark for automotive standards

4)I’ve seen various on Auto Express shootouts, I’ll have a dig
  • + 0
 @sewer-rat: Thanks for the reply! The original point however was german media bias and not the state of automotive industry in general. We all know what the current condition of Lotus is and how aggressively every company out there is chasing the bottom line. The reasons might be different — for Lotus it was an extremely small enthusiast market, for germans — absolute morons in management positions, for whom short-term goals in the form of bonuses are way more important than company's existence in 10-20 years and any kind of social responsibility (I manly refer to them giving out free 100k€+ cars to football players every year and lobbying against taxation of US tech giants). It's just not okay when senior management has lower brand loyalty than the market they are targeting. And it's not just automotive too — the shitty practices are everywhere, just take a look at Boeing.

Since all the manufacturers use +/- the same tools and processes, I do not see an argument for german cars being inherently worse and german media being overly biased. Besides that, if reliability is the primary metric of how good a car is, how is a journalist supposed to estimate it if he/she has access to a car only for a few hours/days? I have read the used market guides in those same german magazines and they explicitly mention most of the problems the consumers report on forums etc.

Coming back to this article, we (I at least) have no idea what the QM process at RockShox looks like, maybe their engineers roll their eyes when they read PB reviews too, I have all the reasons to believe that's the way it is after owning RS. The only way forward for me is supporting small engineering efforts like Intend, which have a decent product and extremely good customer service. I was also curious why so many germans are professionally unhappy with anything german (I am not german and my location on PB was picked randomly :-) ).
  • + 1
 @johnbalz: thanks for the input!
  • + 0
 @Skinnyman: ok now you are just floating out on the blue and seem not to even know anymore what is it that you are searching for, since you keep jumping back and forth between two subjects that have absolutely nothing to do with each other...you are more than welcome to send me a personal message should you have any concrete questions, cuz what your doing here on this thread now is what i consider "trolling"...telling me i "didnt read those papers" and second guessing what my job actually involves? Give me a break...you clearly have no clue what an engineer test-driver does nor do you have a clue on how confidentiality terms work...they apply for a lifetime just so you know. Even after you leave the company they are still effective...expiration dates?! God you gotta be kiddin me...a test-driver has no idea about "intellectual property" of what he is testing?! LOOOL yeah right because we just test stuff for fun right?! Its not like we have to write a huge report about the parts in question! Its not like we have to know what the hell we are doing right?! Jeeeeesus...sorry but that must have been the most obtuse reply ive ever seen...again, got any concrete questions? Please write me PM...
  • + 47
 back in the days my shiver had about 900 ms steeringping
  • + 3
 this gave me the shivers.... but for real, the shiver was the tits.
  • + 17
 Cornelius Kapfinger sounds like an awesome Bond villain.
  • + 14
 Can we get a Review of the CRC-conception fork and maybe their Tuning open bath catridges?

Cheers
  • + 2
 Maybe even big USD forks comparison, even if some most known brands are not really new products (Dorado, Emerald,...)
  • + 2
 @winko: I really would like to test the single crown USD from them- but 1300€ Just for Testing?
I bet it rides extremely good
  • + 1
 Would love that! I have a CRConception open bath cartridge........and its been amazing!
  • + 11
 Absolutely beautiful fork. I'd love to own some of Intend's products. Crankset and stems also look excellent
  • + 4
 Same! Love Intend stuff.
  • + 7
 I wonder: if problems with torsional stiffness are inherent to the upside down layout, how come that motorcycles have no problem using it?
  • + 3
 they have exactly the same . but for motorcycle (and for a lot of mtb people by the way) , less sttifness is a good thing. Because you have lot more weight that goes a lot faster than a bicycle , and cause everyone is not someone who pass enough time on a bike to be strong for not suffer from a 40 stiffness. yeah , that wrist and arm pump you have , comme from stiffness too.

so , this "smouthness" help keep control of the motorcycle , absorb heavy side impact , and keep traction. that's why they use steering damper and USD fork , stiffer is not always better , especially when going fast with big side forces on the front wheel.
  • + 2
 Not even MX motobikes have problems with USD. So there apparently is a solution. X-Fusion Revel fork uses some key-in pins or something to improve torsional stiffness. I'm sure Cornelius is able by himself to design a working solution but it would add another cost to the product. He must find an affordable way for cheaper production process that would allow him to further improve overall performance.
  • + 4
 @Megazzz: Motorcycles dont use steering dampers to help with stiffness of the fork, steering dampers are used to reduce / control lateral movement.
  • + 3
 @fluider: As @Megazzz said its not so much of a problem with motorcycles where in road racing (track) they often engineer a reduction in torsional stiffness, so nobody is looking for a solution in MX or Moto racing as its not really a 'problem' more designed solution.

An MTB is a completely different thing to a moto though, for a start its about 400lbs heavier so they can build a fork in a mich more substantial manner so a desired stiffness is probably not so hard to achieve there.
  • + 7
 It's not a problem in Moto etc due to the size of everything and the weight isn't an issue. If you put an Ohlins DH fork next to a Moto fork the DH fork looks like a baby in comparison, and the DH forks a lot less too. If the weight wasn't an issue they could easily make a USD MTB fork that's as stiff as a Fox 40.
  • + 5
 it the 20mm axle, if they go to 30mm, it would probably be fine.... Which I've brought up with multiple people who make upside down forks... they all think no one will buy a new hub, meanwhile Sram whips up a new standard every week.
  • + 3
 @Freakyjon: You pretty much summed up what I was saying.

I know the fox 40 is a conventional fork so no direct comparison but it has a staction diameter about the same size as a modern yamaha R1....
  • + 1
 @mark4444: SRAM dictate the market, DH forks sales are tiny and the big two seem perfectly happy with the 'conventiona'l fork arrangement.
  • + 1
 @mark4444: Remember when Fox tried an inverted fork?

www.pinkbike.com/news/fox-dh-fork-inverted-prototype-2012.html

They tried many different axle sizes and arrangements, but still couldn't get it torsionally stiff enough.

The old Curnutt inverted fork that came on the Foes Mono had a 30mm thru-axle, and was stiff enough that no one complained, but it also weighed over 10 pounds.

www.bikeradar.com/reviews/components/bike-frames/mountain-bike-frames/foes-racing-21-dhs-mono-review
  • + 1
 @wowbagger moto inverted forks don't have offset axles, axle is located in the middle of the stanctions thus only side loading is transmited to the stanction this minimalizes the twisting. Rake or offset is adjusted by the tripple trees length, or crowns as we say in mtb. This though creates a space issue with mtb forks as most of them have the rebound knob on the bottom of the stanctions and makes offset axles a must. They can put everything on top but this creates a crwoded damper/rebound shaft etc.
  • + 1
 @adespotoskyli: I've never seen a MX fork with the axle located on the center line of the fork tubes. You have either your compression or rebound adjustment on the bottom of the fork leg, just like on a MTB, and the axle is offset forward by an inch or so. True, nobody sells MX lowers with different offsets, you're just stuck with whatever offset KYB/Showa/WP gives you so you have to go buy an aftermarket triple clamp if you want to change the geometry.
  • + 1
 @ryetoast: mx don't see that hard cornering due to traction, weight and speed compared to street racers. Was not refering specifically to mx forks, as you know hard braking and cornering in high speeds on tarmac puts a lot of stress on the stanctions, this is the reason motos don't use offset lowers. The triple clamp can be a given choice as mtb did not set yet at what we like!
  • + 5
 Isn't the Cannondale Lefty an inverted fork design? Its always got great reviews for stiffness so certainly there is bicycle compatible solution for the (lack of) torsional stiffness without being excessively heavy...at least until you add on the missing leg to make it dual crown that is...
  • + 10
 the leftys internals are square and run on needle bearings. That creates a ton of stiffnes and makes it super supple. However, it is a lot heavier, so even if you only use spuare internals on the damper side, the weight would still go up quite a bit.
  • + 1
 @jaybobo: I've actually been thinking about this a lot, and I bet it could be done without adding too much weight. It wouldn't need to be nearly as robust as the Lefty since there are two fork legs on a traditional fork. XFusion did it with brass keys that slid along linear races on their Revel, but word on the street says that the brass keys break easily when you wreck, so they don't sell it outside of Asia.
  • + 0
 @hamncheez: any front fork would feel great on that outdated rear suspension design!
  • + 1
 @truehipster: nothing wrong with a linkage driven single pivot,... go ride a decent one and come back
  • + 2
 @truehipster: Cannondales ride great, what are you talking about?

The main flaw of the leftys were their garbage damping. They had 0 high speed compression and the low speed compression always felt funny, like it was super supple off the top but then would hit this wall of peanut butter, as if it had only two inches of travel, and then once you passed that threshold it just blew through all its travel, and had way bad brake dive. Their rebound was rubbish too. The chasis, however, was perfect. If they resurrected a 150 or 160mm 29er with their new, updated damper and a modern offset, it would be at the top of my wish list!
  • + 6
 How is it that most enduro/mx motos have USD forks but apparently do not suffer from stiffness issues? Or do they but its not seen as an issue?
  • + 7
 Armchair engineering here but I'm guessing in MX, riders care about traction more than weight, so slightly increasing overall weight to reduce unsprung weight is worth it. On a MTB the unsprung weight is comparatively low anyway and from what I've heard from other internet geniuses, not substantially reduced by turning the fork upside down because MTB fork tubes are so light. Also, you can't really go out and buy a fork for your dirt bike. The forks are spec'd by the manufacturer and tuned for the chassis, so the engineers don't have to worry that they won't sell any forks if they make them slightly heavier. They can just take the weight out of somewhere else on the bike. Dirt bike forks are heavy as hell, and I've seen enduro riders take bolts out of their fork claps to give them MORE flex... It's a strange world...
  • + 4
 @ryetoast @headshot @wowbagger


My 2cents on this subject:

I have limited MX experience, but, in general, when riding MX you should either be on the gas or on the brakes. An MX track is always flat (as in starts and finishes at the same height) and the whole track is 'important'. When you are on the brakes and/or hitting bumps in a straight line, the USD design offers a much stiffer chassis and much less binding/stiction under these loads.

When you are on the gas, acceleration makes the front wheel is light (watch pro-riders and their front wheel is barely on the ground) and the torsional flex helps the lightly-weighted front wheel track well especially in ruts and when trying to keep the front wheel carving a nice turn while on the gas – if the fork was super stiff torsionally it would track badly and bounce off the terrain easily.




On a mountain bike, you ride in different ways, but descending is the main bulk of 'important' riding, we often start and finish at the same point, but going uphill doesn't matter much to the type of fork. Riding on flat ground starts to create some problems, but going downhill is where it gets complicated. Descending performance is the most noticeable/important to riders, which takes in many factors like braking/cornering/difficult terrain/pumping etc, doing anything you can to keep your front wheel where you want it and heading down the trail.

I rode the Intend Edge last year, and riding straight into square-edged bumps on or off the brakes shows a completely different level of stiction-free and smooth performance from the USD design than any other conventional fork available. Also if you are off the brakes, and going through rocks/roots/off-camber it also offers a different level of tracking and performance - especially in the wet.

Like I said above, the problems start when descending/braking/difficult terrain are all happening at once, all of your mass is moving forward on to the front wheel, this is also when your brain starts to get the most scared and you have the hardest time gauging what is going on. The USD has a much more vague feeling when all this is happening, but the torsional flex isn't the only issue. I was told by a certain engineer who worked on the USD forks for a major company (they probably don't want to be named), and it makes sense when thinking about it on the trail – the issue comes from the lower legs moving at a different rate to each other – this means the wheel does not go through its travel vertically but in more of an 'S' or wavy line. If there was a way to fix both lower legs so that they travel at the same rate (like the DVO solution) then the USD fork would be more suitable for MTB riding overall*


*I think
  • + 2
 @ryetoast: I think you are on point, excellent armchair engineering :p.

I service my fork myself and when I have those lowers in my hands I'm always impessed by the lightness. The weight is very close to the stanchions'.

I'd be curious to do the math but I don't think there is a substantial unsprung weight reduction on inverted (mtb) forks. Most of the unsprung weight comes from the wheel anyway, shaving a few grams on the unsprung part of the fork probably doesn't do much.

I think.
  • + 3
 @paulaston: A more apt comparison would be moto enduro/hard enduro. The enduro tracks I ride are chunkier than much of the mtb stuff I ride.
  • + 1
 @paulaston @ryetoast

Nah, it's not as easy as that. Riding MXs bikes quick is way more than that. You need to balance between beeing on the gas and braking it in for stability. Also tracks really vary in height, and due to the nature of the sport you put much more stress on the suspension components (eg. heat etc.) That's why you will feel a bad suspension-setup way quicker on a motobike than on the mtb.

But the weight doesnt matter that much on the bike, sure there is air-forks like the Showas or AER WP's but it's a small difference and many people opt for A-Kit or 3rd party suspension when racing anyway.

As you said, you really need the flex in the front end to keep it tracking in ruts, while beeing beefy enough to hold up 100ft hucks to flat on full throttle.
  • + 3
 Cool to see something else reviewed. That said, I do wish Pinkbike would take more time to really weigh the differences between USD and non-USD forks. While there is no question they are less torsionally stiff, I'm not sold that this is ultimately a bad thing. It takes some time to get used to, but if the engineering is done right, I could actually see it being a positive for a bike's handling if the entire package is taken into account.

Moto forks are not torsionally stiff, either, yet nobody in moto is looking to flip the fork "right side" up because we've all decided in that sport the flex is exactly what we need. These are machines that weigh far more than a mountain bike, often traveling at higher speeds and doing crazier things.

We need to open our minds, and we need to be more objective when testing product like this. Spend more time on it, put some laps in where you are comparing it to a baseline like the 49 - and let the times (and arm fatigue) speak for themselves.

...plus, wheel selection, wheel size etc all has to be a part of this!
  • + 7
 The main reason why motos flipped their forks over 30 years ago wasn't for increased performance, it was for ground clearance. As travel increased, the axle to crown lengths were getting too long because moto forks need more bushing overlap than a bike fork. The bottoms of the fork sides were getting way below the axle so there was room for the stanchions to telescope into them. Motocross racing develops deep ruts that you use as berms, so they had to flip the forks upside down to get ground clearance in the ruts.
  • + 4
 You can't compare moto fork with mtb forks. Not the same size, weight, task.

Differences between USD and non-USD (for dual crown forks)are:
- longer bushing overlap on USD forks, so less frictions. Between 30% more and twice as much bushing overlap.
- No arch so more flex, and it can be more than twice "flexy", and it has some "degressive stiffness" so more difference on tight corners. It can be a real issue depending on your riding style and your favourite tracks.
-higher diameter at the clamp, so if designed well, you can partially offset the flex issue.

There is a smaller difference:
oil has to go over the stanchion to access the seals, so lubrification has to be managed properly.

And there is no real difference in "unsprung weight", and if it has a marginal one, non-usd forks does have lighters lowers than usd have.
  • + 3
 @hamncheez: incorrect and it certainly wouldn't explain why all street / sport bikes have gone to USD as well. USD forks are stiffer and perform better which is why they are used. There may be a benefit due to less overhang, but it's certainly not the main driver.
  • + 5
 @hamncheez: @RadBartTaylor nailed it. This isn't why moto forks are USD.

People keep saying I can't compare mountain bike and moto, bla bla bla.

Fact is, if we would have followed the path moto laid out way back when, we would have had modern geo, correct trail numbers, and every suspension layout would have been rising rate. My Transition Sentinel has more in common with respect to handling and suspension with my KTM 300 XC than it does any bike I owned over a decade prior.

So yeah, keep "believing" USD c an't work for mountain bike. I think its a perception problem, not a performance problem.

Try something...

Take your front wheel and brace it against a wall or similar. Cycle the fork. Feels good huh? Now apply a little bit of torsional load to the bar. Tell me how good that fork feels now...

Sure, its pretty dang stiff! But this stiffness comes at a cost, not only will it be more prone to deflect but the bushings will bind on the stanctions.

With more overlap, and an USD design, you'll get more flex, but you'll also allow the suspension to work in these lateral load events.

I'd 100% go to an USD fork that was flexy, and I think the market will one day see the light - too.

This isn't even debated in moto. And for good reason...
  • + 4
 @JeffreyJim @RadBartTaylor I said that moto forks were INITIALLY inverted to get better ground clearance.

If an inverted design is superior, then why didn't the Dorado sell better? Why won't x fusion sell their Revel outside of Asia? Why did Gee, Gwin, and Fox give up on their inverted prototype?

www.pinkbike.com/news/fox-dh-fork-inverted-prototype-2012.html
  • + 4
 @hamncheez: X-Fusion won't sell their Revel because its God-Awful. Lol. It was one of the scariest products I've ever used. It literally rides like its locked out under any load due to their keyed bushing configuration. Its terrible.

The reason inverted hasn't caught on is the same reason DH bikes "couldn't turn" with 64 degree head tube angles back in 2002, or "29" wheels sucked at cornering" in 2009 or "51mm offset cornered better in 2011 (for 29)". ***PERCEPTION***

We all have far more cognitive bias than you want to admit. Its not just the consumers that buy into all this, pro riders, too, have biases. If something feels different they may say "no" even if it is indeed better.

Sometimes you have to reframe 'right' before you can determine if it is in fact better. Sometimes you have to change your riding style, something pros may not be willing to do. Sometimes you have to reframe the problem - such as "what kind of flex is good, what kind is bad".

Finally, the Dorado didn't sell because Answer has been in the shitter for over a decade. They don't support racers. They don't support races. They are just off the back when it comes to overall product experience compared to Fox/RS.

I'm not saying all forks will be USD, but I am saying for enduro I'd 100% expect a dual crown USD fork to come to fruition in the next few years...and it will be better.
  • + 1
 @JeffreyJim: Suppose that user bias mostly explains why traditional forks sell better. They why did fox abandon the idea for DH racing? Why did Giant use DVO's traditional fork when they ran their suspension last season?

USD forks is actually something I've put a ton of thought into. In order to torsionally stiffen them up, you need either keyways like the Revel (that doesn't sound like it worked) or some sort of bearings like the Lefty on at least one leg (which requires twin crowns, now too heavy for anything but DH) or a scissor linkage like what airplanes use (too ugly for fickle cyclists).
  • + 4
 @hamncheez: I just think we are trying to stiffen something up in the wrong way.

Nico ran an USD fork, and often detensioned his front wheel a bit, too, for more grip. He was looking for a balance between flex and stiffness. Go ride a Fox 40 with some old school enves and tell me how awesome it really works. Precise? Yes. Faster? No way.

This "engineered flex" is common in a number of other off road sports, where engineers are trying to get something to give in a certain way for the best possible handling. Hell, even Yeti went through pretty crazy lengths to try and get their new SBs to flex more than their old bikes.

Dirt bikes do not have keyways or roller bearings. They run on bushings, just like mountain bike fork.

Here is how I think you make it work...

1) Go back to the drawing board with respect to crown design. We are going to need crowns that have more clamping surface area than most being used or that have been tested.

2) Make sure you have extensive bushing overlap. This is key.

3) Accept that there will be a weight penalty (this is likely the reason we haven't seen it yet). I'd guess it will be around 300grams in a best case scenerio.

4) Stop confusing steering with cornering. They are different. An USD fork will corner awesome when done right, but it will be more flex prone when "steering".

5) In a shorter travel application (170-180mm) it'll be easier to achieve acceptable overlap without undue weight.

6) You could use the fork slider protectors to make some kind of an arch to give a tiny bit more stiffness (this could be part of the engineering)
  • + 1
 @JeffreyJim: So my friend still has his old Maverick DUC 32 USD fork from back in the day. it had a custom 25mm axle, and the lower crown was literally welded to the tubes; you can't get a stiffer crown interface than that. It was also dual crown, with tapered tubes to reduce flex as much as possible. Even at only 150mm of travel, it was still pretty flexy. It rode great on small 26" wheels, as long as you understood that it was a trail fork, not an enduro/freeride-lite fork. This was also back when HTA were 68-70 degrees. At that same 150mm of travel, on a 29 inch, 65 degree HTA bike it would be too flexy torsionally, or rather imprecise in its steering. Of course, this was comparing it to my bike at that time (i rode them back to back often) which had a lefty on it...


forums.mtbr.com/attachments/maverick/34722d1097682539-29-maverick-duc-32-fork-ml7-frame-duc32_600.jpg
  • + 1
 @JeffreyJim: So you're truly just saying moto with no engine
  • + 3
 @JeffreyJim: Answer hasn't owned Manitou in over a decade, and the Dorado has been through multiple upgrade cycles since then. customer support is one of the best in the industry. The chief engineer came over from Showa and the products are legit, as everyone will find out with the Mezzer.
  • + 2
 @JeffreyJim: Agree with everything you have said regarding "Perception". Flip flopping of people supposedly "in the know" on those topics has irritated me for some time.

That is an interesting tidbit you shared about the Revel. Real world ride reports are scarce for that thing, and I had always wondered about how the keyways avoid stiction (and wear). From what you're saying, it sounds like they don't.

And as Mullen also said, Manitou has been owned by Hayes for many years.
  • + 1
 @hamncheez: Your point about Giant not using the Emerald and using the traditional fight side up fork instead is an interesting one.

Anyone have any inside intel on why the Giant team, who presumably had their pick of the litter, chose to go that route? Weight? Torsional stiffness? Habit?

Any one @DVO care to comment? We think your forks, both USD and right side up are great, so please give an unvarnished perspective rather than a marketing spun one. ;-)
  • + 1
 @thekaiser: I remember Marcello said it was about weight, but I can't find the source.
  • + 1
 @thekaiser: I'm sure its about oem spec numbers/ costs. one of the reasons the Shiver was tossed was manufacturing costs. Also, a better axle bolt on the original axle yielded much improved torsional stifness. the hub spacers and bearings can't 'shift' around if there is enough tension through the centre line. they become a rigid tube. also using longer threaded pinch bolts and greasing threads and bolt seating area, pinched the axle down tighter and stiffer too.
  • + 3
 The real question is has anyone done a USD any better then the Dorado or White Bros USD? Those two have been around forever and are awesome.

Still don’t understand where the whole stiffness obsession thing came from either. I came to mtb from an off-road moto background and still prefer the chassis feel of some of the older non super huge stantioned forks. (The new dampers are the tits though).
  • + 2
 DVO Emerald
  • + 4
 @krashDH85: I’ve never heard of anyone going from a dorado or emerald to anything else because of performance issues either. My point is USD flex is way overplayed.
  • + 1
 @cougar797: No I get that, but for me personally I think the Emerald is superior to the 2 listed. Feels better, the engineering is well thought for those of us that do our own work (no special tools), customer service, etc. Yeah You can feel the stiffness difference between USD and a standard fork, but I agree it's not anything that would push a rider away from it. It's noticeable, but doesn't make me want to go back to a non inverted fork
  • + 3
 @krashDH85: I have an emerald and love it. I have noticed not issues with any additional flex. But I will add that I am just a recreation rider and I likely don't exert the same forces on my bike as a pro or high level rider.
  • + 1
 don't know man.....I had a Maverick Duc 32. Never again on the USD fork idea. Thing would twist at the worst time causing some hellacious crashes.
  • + 3
 Doesn't seem like its a whole lot better than the most recent Manitou Dorado, I got my girlfriend a 27.5 Devinci Wilson and the owner had put one on at some point and I was actually really impressed with it especially for a lighter rider I don't think the stiffness is an issue.
  • + 2
 Less stiffness is most often a good thing- it adds compliance.. same for steel frames.
  • + 5
 I though “USD” meant “US Dollars” as in “this will take all of them
  • + 5
 I totally get the analogy, but driving a car without power steering feels awesome (until you slow down).
  • + 2
 I suspect that the reason MX upside down forks are known for their stiffness compared to earlier right side up forks is because motocross front axles are not only thick, heavy, and strong, but are clamped on either side usually by two 8mm studded bolts to something like 13 ft lbs. Not an expert here, but I assume that the MX way ties the fork legs together firmly making them operate as a single unit whereas a typical mtb front axle leaves a lot to be desired in terms of firmly attaching the two telescoping fork legs to each other at the axle, lots of room for flex and independent movement.
  • + 5
 Wrong.

Moto axles aren't that much crazier than a 20mm mountain bike variant, especially considering the machine in question.

Mountain biking has long tried the moto axle attachment method. It works. And it should be further utilized for perfectly straight forks, but it won't solve the stiffness "problem".

GO up to a moto. Put the wheel between your legs and twist. Guess what? They are "flexy"! But nobody cares, because its a problem that exists in a vacuum in that world.
  • + 1
 The main reason is because the wheel axle is not offset to the centre of the stactions aplying twisting force to the stanctions, it's placed directly in the middle thus side loading only and a thick stanction with a 20mm thick through axle clamped at both ends wond budge a thou of an inch when side loaded. The issue is when you offset the axle more than an inch outwards the centre of the staction, when side loading the wheel and twisting force aplyied the round stanctions tend to twist in the uppers. To counteract this you need to set the axle directly in the middle and use the tripple trees to set the offset or rack.
  • + 2
 @adespotoskyli: That is a very interesting point. I hadn't thought about how dropout offset would impact USD fork torsional stiffness. I had a Mr. Dirt USD DH fork back in the day, and now that you mention it, it had the dropouts inline with the leg. img.photobucket.com/albums/v520/boostedte37/foes1.jpg

I had assumed it was for ease of manufacture, but perhaps it was for structural reasons.
  • + 2
 @thekaiser:
Offset doesn't change stiffness. And wheel contact point is never in the alignement of fork's legs, so even "in line" dropouts have an "offset" regarding forces.

Some forks does have "inline dropouts" because there uppers are so big, they can effect the steering angle. So you have two ways of solving the issue:
- wider crown
- more offset at the crown, thus less offset at the dropouts.
  • + 1
 @faul: if you side load a single stanction leg at the offset it will twist around it self quite freely, if you side load the leg at the centre line it will go nowhere, if extreme force applied it will tend to bend so it makes a big structural difference regarding load transfer while riding. Offset is a matter of crown dimensions, not hard to accomodate that in the design.
  • + 1
 @thekaiser: if you look closely street racers and heavy motorcycles, like the ktm 1190 use centreline attachet through axles, and sturdy triple trees or crowns as we call them.
  • + 1
 @thekaiser: you still own/ride that beast? Looks nice by the way!
  • + 2
 Seeing how long the cable/brake housing lines are gives me an anxiety attack. I get it's a test mule and doesn't have to be dialled but seeing it gives me the "here let me fix that for you please" thoughts!
  • + 2
 BTW - you "can" buy it in North America, at least in the USA. I contacted him and he said no problem. Shipping cost will be tremendous though. Overall, poor people need not apply :/
  • + 5
 MRP Bartlett review???????
  • + 0
 The tortional stiffness thing still perplexes me. On moto bikes it's the complete opposite, upside down forks like this are substantially stiffer than the conventional forks, I don't know why it wouldn't be the same on mountain bikes.
  • + 2
 Moto forks are stiff enough because they weigh a ton compared to a bike fork.
  • - 2
 @hamncheez: moto bikes weigh a ton compared to a MTB too....
  • + 3
 It's still a weight thing. With a motor driven bike, adding extra material for stiffness is fairly reasonable because the motor can easily handle the extra weight. With human powered bikes, weight makes a bigger difference.
  • + 2
 Two things jump to mind. First, do the moto bikes with right side up forks that you are referring to have arches, joining the sliders/lowers, as we do on right side up MTBs? I have seen some motos with right side up forks that have no arch, and the arch, is what confers the torsional stiffness advantage. With no arch, USD would actually probably be more torsionally stiff due to having the larger diameter legs where forces were greatest.

Second, the term "stiffness" is very broad, and there are different sorts of it. USD forks for MTB indeed ARE stiffer than traditional right side up forks...in a fore-aft direction. On the other hand, torsionally (like if you held the wheel between your knees and twist the bars), they are less stiff, and similarly they are less resistant to independent leg compression, again due to a lack of an arch joining the lowers.

Is it possible that when you have heard references to USD being stiffer in moto, they were talking about fore/aft stiffness, and not the other sorts?
  • + 1
 Scroll down (up?) To find Paul Astons comment. Its VERY insightful.
  • + 0
 No arch on moto conventional forks, this is all placebo anyway. Most flex happens at the crown, and an inverted design flexes less dispute to larger tubes and more clamping surface. Geometry changes less as the inverted forks don’t flex as much fore and aft. The steering precision is why the moto world switched to inverted. Roger Decoster kept conventional alive, and the size of the tubes needed to get the same steering precision as inverted resulted in excess friction in the massive seals and bushings, so even he has to switch his team. The real reason is inverted designs are more expensive, as tolerances are tighter. It’s cheaper to keep selling conventional designs, and therefore, more profit,
  • + 4
 The idea of a central bolt vs a tube holding the crowns together is cool.
  • + 1
 Would be interested in how much of a difference the USD makes to the fork stiffness in most situations (given a rotating wheel with a small rubber contact patch)? Or is it a placebo effect?
  • + 0
 Looks familiar. Anyone ever own these?

www.mtbr.com/product/older-categories-bikes/2005-front-shocks/maverick/duc-32.html

Loved them at the time but had to own 2 of them since I was sending them back to the factory every 2-3 mos.
  • + 2
 You should see the shock he's made! It's beautiful too! His products are outstanding in look and performance plus he is a super nice guy too! Service is great too!
  • + 1
 Super cool, but sounds like it needs 40mm stanchions and a proprietary hub 25/30mm axle set up if they wanna hit a decent torsional stiffness, based on what im hearing from a 160lb test rider.
  • + 1
 ''The Infinity's air pressure is adjusted via a Shrader valve on the top of the right leg, which is the case with nearly every air-sprung fork on the market.'' Next photo caption states it's on the left side.
  • + 1
 You’re right, it’s on the left. That’s been corrected.
  • + 3
 I don't really care if this fork works or not. I want it. gimme gimme gimme
  • + 3
 Kudos for reviewing something non-Fox or Rockshox!
  • + 2
 We-ll, Ill be a Cornelius Kapfinger soaking in in German sunflower oil, if that aint a purty fork!!!
  • + 2
 I feel like there would be axle flex if the stanchions can move independently of one another
  • + 3
 Intend forks use a steel axle, which is stiffer than the normal aluminium one
  • - 3
 @jmjr: I'm not sure the steel axle is stiffer to be honest. Steel has inherent flex/give which is one of the benefits of steel hardtails vs aluminium, which is very harsh in comparison, and when you're talking about a piece of metal as small as an axle I'd be inclined to think aluminium would be stiffer....I might be wrong...
  • + 7
 @nicklesterrides: steel is stiffer than alloy. A steel mtb frame has some give because the tubes are often smaller diameter and have a thinner wall thickness.
  • + 10
 @nicklesterrides: An aluminium frame is harsher as the stifness is generated by the oversized tubing compared to a steel frame. Young's modulus for Aluminium is only about a 1/3 of the one for steel.
  • + 9
 @jmjr: @jamieridesbikes you learn something new everyday...cheers
  • + 2
 SIngle crown but check out the CRConception Fore

www.crconception.com/FORE-SC
  • + 1
 Oh look. Another usd that handles like a noodle. Who could have guessed?

Oh yeah. Everyone...
  • + 2
 Foes F1 had 30mm axle with a custom hub.
  • + 2
 The WANT is strong in this one O'Gee-Want-Can't-Own-Thee!
  • - 1
 Ultimate Dentist fork!
A DH fork that rides like a noodle.
Moreover reading how arrogant this company is "we made the best of this and that"....
It looks like a "just out of school" project to me.
  • + 0
 no stanchion guards? he is crazy. what if i drop my bike onto some shit sideways and scratch or dent a stanchion i should buy a new one?

no stanchion diameter? wtf?
  • + 2
 Lefty is more stiff than USD downhill forks..
  • + 1
 Thanks for showing me Forks I can not own in the US. Nice fork though, 5.5lbs is very light for a dual crown.
  • + 1
 Fap fap fap fap fap fap fap fap Fap!
  • + 1
 Nothing but respect for people who go out and do it on their own.
  • + 0
 so if you want to steer your bike, you should look elsewhere. Nice piece of wall art though...priced like it too.
  • + 2
 Don't get it twisted
  • + 1
 So not as stiff as a dvo emerald.. I wonder why..
  • + 1
 One day there will be a 5lb DH fork! somehow.
  • + 0
 These actually look gorgeous with the black stanchions. Not sure about extra expensive parts as a strategy though...
  • + 2
 Whare did zzyzx go
  • + 1
 in the garbage bin, where they belong
  • + 1
 It's stored right next to the front derailleur and tubes.@theberminator
  • + 1
 @Civicowner: the forks were great until you got them in the mud and then they turned into a boat anchor
  • + 1
 @pinnityafairy: they were ok until they got any dirt in them. and they were enourmous
  • + 0
 No any legs protection???
  • + 1
 It's too heavy.
  • + 0
 Or hainbrink
  • - 1
 Looks like a white bros...
  • - 2
 in black pls
  • + 2
 They already have it in black
  • - 1
 No
Below threshold threads are hidden

Post a Comment



Copyright © 2000 - 2019. Pinkbike.com. All rights reserved.
dv56 0.058291
Mobile Version of Website