Ask Pinkbike - Fork Lengths, New Frames and DH Chainring Size
Here at Pinkbike we get inundated with all kinds of questions, ranging from the basic "Can I have stickers" to more in-depth, soul searching types of queries like if you should pop the question or what to name your first child. Ask Pinkbike is an occasional column where we'll be hand picking and answering questions that have been keeping readers up at night, although we'll likely steer clear of those last two and keep it more tech oriented.
Fork Length Concerns
Question: Pinkbike user goldhecklerswag asked this question in the Downhill Forum: So I'm looking to upgrade my BoXXer to a Marzocchi 888 RC3 Evo, and my only concern is the longer axle to crown height of the 888. I personally like a low handlebar so I'm wondering if the added 13mm of height will be noticeable?
 | A change in bar height of 13mm is a fair bit that most will take note of, but less perceptive riders might not feel a difference. That said, you mentioned that you prefer a relatively low handlebar so I'm guessing that you would pick it up right away. The taller bar might not be a terrible thing, though, as the average downhiller would be quite surprised at just how high a professional World Cup racer prefers their grips. That doesn't mean that everyone should go that route, of course, but it doesn't hurt to try a different setup every now and then. Want to keep your bar at the same height regardless of what others are doing? Start by measuring its height - make sure your bike is standing straight up and not leaning over, then measure from the ground to the top of the end of the handlebar. If you want to also preserve your bike's handling so it is close to being the same as with the BoXXer, you can use an angle finder app on a smartphone to match it after you install the new fork by sliding the 888's stanchions up and down in its crowns (be sure not to exceed the lowest recommended position). It's true that those angle finder apps might not be the most exact, but that doesn't matter as you're only aiming to match the numbers taken with the old and new forks. Once you've got the new fork installed, start by using the angle finder and by sliding the stanchions in the crowns to match the head angle of your bike with the old fork. Now, take a ground up measurement to the top the the handlebar to see how much, if any, further adjustment you need to make by adding or removing headset spacers under the top crown, buying a handlebar with a different rise to it, or going with a different stem. If you actually discover that you need to go slightly higher, a number of companies offer spacer kits that fit between the direct mount stem and the fork's top crown. All of the above might sound a bit like OCD to someone who prefers to just jump on their bike and ride, but those who are picky about their bike will understand. - Mike Levy |
There are all sorts of tricks to employ if you want to tinker with your bar height, which comes in handy when you want to swap to a different fork but keep the same handlebar position.
New frame or a New Bike?
Question: Jayandgt asks in the All-Mountain, Enduro & Cross-Country forum:I recently cracked my Voodoo hardtail frame. It's been round Welsh rocky trails for the last four years and a recent stint around Swinley forest led to a cracked dropout and snapped saddle rails. So, now I need a new frame, and I want to upgrade to a full suspension. I'm not the richest person in the world, with rent and my car and other financial drains, so I reckon I got a budget of around £1000 for a 140mm trailbike. Do I buy a full bike and then transfer my bits that are better over, or do a direct swap on my frame? I'm currently running 26 inch wheels. Is it worth going to 650b?
| The perfect storm for your budget is to find a close-out deal on a 26-inch dual-suspension frame that fits the components of your Voodoo hardtail, but that may not be possible. Your Voodoo probably has quick release rear dropouts, while modern suspension bikes have 12 by 142 millimeter through-axles, I'd guess that the Voodoo doesn't have a tapered head tube either, which creates a compatibility issue for your existing headset and fork steerer and may force you to buy a headset to adapt the fork to the new frame. Seatpost diameters tend to be smaller on hardtails, so you'll need to measure and match it, or be prepared to buy a new one, and many rear suspensions require specific front derailleurs - top or bottom pull, or direct mount - to clear the swingarm bits. The good news is that it should be easy to find a frame with a threaded bottom bracket shell to fit your existing crankset, and that your fork is already compatible with your front wheel. Switching over your components to a new frame is only advisable if you are well versed in component compatibility and have a comprehensive tool kit. Forget about upgrading to mid-size wheels, because the frame upgrade will also force you to purchase an expensive new fork and wheels. Your best bet, although it will bust your budget, is to search for a close-out 26-inch trailbike that an on-line store or LBS is trying to unload at or below their cost. The overnight success of 27.5-inch-wheel mountain bikes has made new and slightly used 26-inch models almost worthless, so this is your shining opportunity to buy a great 140-millimeter trailbike bike for very little cash. - RC |
We doubt that jayandgt will find a new 2014 Specialized S-Works Stumpjumper Evo to fit his budget, but with 26-inch-wheel stock crashing like Wall Street during the Great Depression, he should be able to score a top-performing, 140-millimeter small-wheel trailbike from a respectable bike brand for 25 pence on the pound.
32 Tooth Chainring for DH?
Question: PB user griz23 asked this question in the Downhill forum: Any thoughts on running a 32t chainring on a downhill bike and if so would I need to change the chain length?"
| You can certainly run a 32t chainring on a downhill bike, although you won't have quite the same top speed before you spin out as you would with a 36 or 38 tooth ring using the same cassette. The terrain you typically ride on will determine whether or not you'll miss those extra teeth - on really steep, technical tracks it will hardly be noticeable, but on wide open, fire road or ski slope type sections you may find yourself wishing you could throw in a few pedal strokes to gain additional speed. The question about shortening your chain will depend on the size of the ring you're currently running. To figure it out, once you have the new ring installed, shift down to your hardest gear in the rear and look at the rear derailleur cage. If the chain is sagging, or if the chain on the upper pulley is touching the chain on the cassette then you'll need to take out a link or two. If you're running a chainguide, you'll also want to lower the upper guide, and raise the lower roller as well. Many chainguides be adjusted down to accommodate a 32 tooth ring, but it is possible that you may need to purchase a different guide if this isn't the case. - Mike Kazimer |
Going to a smaller front ring means that any chain retention device that's in place will need to be adjusted.
Have some unresolved tech questions? Jump in the Pinkbike Forum and we'll look to answer it for next time.
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This is sad and true. I can't sell any used 26"-bikes for a fair price. The bike is brand new? Noone cares... i was recommended to sell my bike for 20% of the original retail price. I'd rather keep it and ride it till the frame dies!
My "old" bike is great and i hate to sell it, but I'll have to stick to another brand due to sponsoring and work. I worked hard and long for it, but two bikes of the same kind is too much for me. All I want to say is that I don't understand how two years ago, I could have sold the bike for a decent price and now, with 26" wheels, you don't even get a third of the retail price back...
I don't have much influence on the price. I added a brand new Havoc wheelset, new pair of brakes, free tires of choice and maybe this will get me 50 bucks more...
Don't sell.
It doesn't - neg prop me all you like, lesson below.
It's still second hand and you want to sell it, along with your second hand 'upgrades'
I wanted a new carbon wilson last year, I sold my WC spec Orange for 1300 when others were asking more than 2k, why? Well I wanted a new bike and in order to get it At the bargain price I needed to sell my used race bike, I bet the people asking 700 more still had it for sale 6 months later while I had 6 months on my new bike.
Did the same with a reign this year, wanted a stumpy evo so let a reign go for 500 when the market was saying 8-900. Painful but I won't be looking for bikes for 3 years, my bikes won't be worth much so I'll hunt for bargains at the start of new product releases (I.e a 2016 model as 2017 hit the shelves) and I'll let mine go for cheap, why? Come on...... You're not really asking now, are you.........
Your comments make sense - market will pay what market thinks its worth, not what seller assumes its worth
I've sold dozens of frames over the years including fs MTB, ht MTB, road, bmx and hybrid
Always sold with aggressive discount and drop 10% to secure sale
Its just a numbers game - customer with hard currency wanting that size at the time you are selling, always compromise on price to secure 'that' sale then its done, dusted and you are moving onto your goal of a new bike / frame, even if you have to find a little more cash
Best advice: "better to have some pounds in the bank, than a bike in the basement"
Seen too many friends get too precious on price and still have that frame for sale a year later...
Bring back the Mobster 2.7 Maxxis !
The way i see it is simple
I ride twice a week on average, across 3 years that's around 300 rides, bikes cost around 3k, that's ten quid for each ride that may be between 1 and 9 hours, each ride keeps me out of trouble, makes me a bit more healthy, perhaps helps me live a better life and have more memories and stories than just spending every weekend f*cked up on booze and other material and hating my bank balance and work every Monday.
It's a bargain :-)
Saturation of everything = Smaller interest
I shat myself with the amount of options for my XC ride, I settled on the stumpy after riding around on 6 other bikes, that's a small pot of the available options but choice is a good thing right? Hahahaaaa yes to a degree. Well it seems another bike comes out very other week sometimes, most I'll never get to ride so I fear I may just miss the best bike I never had.
You can have a 5k bike that's never ridden and guess what, its used, no warranty and it's worth a lot less.
Why would anyone take on the risk of an un-warrantied bike to save a few hundred bucks?
I see so many bike where people say one ride, or only ridden a few months and still want to get 80% or more of MRSP- that's ridiculous.
First, no one pays MSRP
Second, if I wait til the end of the year, the used bike without a warranty you're trying to sell me for 80% MRSP will be on closeout out new with warranty for that much.
Do a search for 650B and you get a whopping 45.
The same for 27.5 and you get 51.
Even assuming equal demand, supply suggests 26 will be a lot more difficult to move without discounts.
Whilst I feel a bit sorry for you young 'uns, it makes great reading for some of us oldies who can see ourselves pedalling out our days on 26.
In fact, no edit that, it makes great sense to pick up a heavily discounted 26er for anyone any age; you could get a new bike with geometry and componentry that many could only dream of a few yers ago for next to nothing and have a great time on it for years and since you bought it at a ridiculous discount you are hardly going to miss any loss of resale value. In fact, you may well lose more on resale if you buy a new 650B.... so, go on, follow PB's advice and search out a kicking 26 inch trail bike at a ridiculous discount and have some serious fun!
Try this for 1200 GBP www.jensonusa.com/Mountain-Bikes/Jamis-Dakar-XCT-Pro-Mountain-Bike-2012?cu=GBP
Right now on ebay.com, in the cycling section there is a total of 890,647 listings, of which 2252 come up if you search for 650B, and 2625 if you search for 27.5 but only 1757 if you search for both together (showing you that not every seller is smart enough to list both terms in the title).
Put simply, this really isn't the place to shop for bargains or specific things, you're far better off using ebay.
What is noticeable though is the sleeker more compact look, better ground clearance, ease of cleaning after a muddy ride, slightly lower weight (smaller ring, cassette and shorter chain), and generally less to get in the way of your ankles when peddling. Plus if you go narrow-wide you can get away with a smaller lighter chain guide. Recommended !
I too found there was more bob with 32 t compared to 36 t ! (very noticeable)
Yes you can maybe possibly do 30mph plus with 32/11 if your legs are doing 2000 rpm...
All I know is that I run exactly the same set up on my work commute bike and can keep up with 30mph traffic.
Maybe if you are an aspiring pro riding in different countries then you would want a 34t but I think for the majority of privateer riders 32t is sufficient. Let's be honest, how often do most of us actually use the smallest cog? I'm not sure if I ever used it on my previous cassette. Personally I would say to the average rider that the benefits of a smaller ring outweigh the disadvantages.
Cassettes are now available with up to a 42t ring at the larger end, and this combined with a 32 up front will pretty much allow you to ride up a vertical wall, which I believe to be far more unlikely than the, admittedly infrequent, spinning out of the highest gear. I think also most people will be happier to get off and push if they do find themselves faced with a slope that they really can not pedal up, than run out of gearing coming down the other side (especially if late for work). Yes there is a slight weight advantage to smaller rings all round, but this is very small, and at least in my opinion offset by the reduced efficiency and faster wear rates on the entire drivetrain that smaller rings cause. I run a 54t front ring on my 700c commuter. Combined with an 11/28 cassette at the rear, I can not only keep up with 30mph traffic on the flat for short periods at least, I can also happily overtake them when things are sloping downhill.
I did list the advantages in my initial post. I agree with the uphill argument - I would rather push too. Ultimately it comes down to personal preference I suppose (and what you ride/where you live).
For dh I am happy to stick with 32t. My friends all run 34t for dh now and race regularly. There isn't a massive amount in it.
@goldhecklerswag there are a few things to bear in mind if you buy forks with an increased axle-to-crown height. The axle to crown height quoted is the minimum height which the LOWER crown can be run at. Therefore with the lower crown at its lowest setting, the bottom of your headset will be 13mm higher (from the floor) with the 888 than with the Boxxer.
The distance from your BB and your saddle to your handlebars will REMAIN IDENTICAL to when you had your boxxers (as long as the thickness of the top crown is the same). Even though the distance from the floor to your handlebars will increase by 13mm.
The head angle of your bike will be slacker with the new forks, and your bottom bracket will be slightly higher. So although you may be able to lower your bar height with a different bar/stem/spacer set up, the handling of your bike will still change.
I think that most riders would notice this 13mm change, but some may see the extra slackness as a positive. However most manufacturers try to provide a low axle-to-crown height on DH forks as this gives you the option of going steeper and lower if riders want, but they can slide the fork legs through the crowns to give a higher axle-to-crown height if needs be.
Hope this helps!
Will
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as far as selling 26", 27.5", 29ers... big squish bikes... lots of interest in the 27.5 stuff but I would not say the 26" or 29ers are going to see their value decrease because of 27.5"... they're just different. still plenty of 20" wheels being sold out there too.
couple of you commented about you can't sell your used 26" at a good price --- that's bikes for ya --- they're just as bad as driving a new car off the lot --- value drops soon as ya pay for it.. think about it, there's very few products out there that really hold their values.. cameras, computers, boats, lawn equipment, the list goes on and on...