Know somewhat what I want, but need help guiding it in

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Know somewhat what I want, but need help guiding it in
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flag GrittyWhiskey
Posted: Sep 1, 2019 at 22:06 Quote
Hey all, first off, not at all new to the world of cycling, as I raced track bikes at the world level for a number of years. But after my departure of that, and not wanted to so much as look at a bike for years, my friends have been trying to get me on a mtb as a way relearn that pedaling a bike can, in fact, be fun. Second time out riding a borrowed bmc trailfox something, crashed hard, landed face first (had helmet on, but landed face first, and the helmet is just fine) broke 4 vertebra, as well as several brain bleeds. That was a year and a half ago, and 3 surgeries later, I'm almost ready (allowed) to throw a leg back over.

I live in at 8-9000' in the Colorado rockies. All I'm looking for for mtbs is a way to go hiking, that doesn't involve walking. That's what we invented the wheel for. I have no urge for my wheels to leave the ground unless they have to, and bombing downhill is not at all what I'm looking for, although, given the nature of where I live, it's pretty unavoidable.

I know I'm looking in the trail family of bikes. 140ish in the front and rear. I personally have always has a preference for smaller wheels (20in bmx over 24s, loved the 26in older mtb that tried to kill me, ect.) I know the 29er movement is strong, and while I'm not opposed, but I just know what I've always leaned towards.

I'd prefer aluminum over carbon, purely because I feel that the cost of the carbon, for me, is better spent on components on the bike. I also, and this is big for me, really want a real steep seat tube angle.

I've been looking at the RAAW Madonna (I know you cant get them in the US, but that wouldn't be an issue,) Guerrilla Gravity's Shred Dog, and Transitions's Sentinel. All those bikes have things I don't like, but short of having something custom built, my ideal bike probably doesn't exist. I just want it to be able to climb better than average, and not try and kill me coming downhill. I don't have a solid price range, as purchase is probably a year out anyways, as I'm still very much on the healing train.

Thanks in advanced everyone!
flag R-M-R
Posted: Sep 1, 2019 at 23:58 Quote
Congratulations on the recovery. Sounds like quite a journey and I hope the light at the end of the tunnel is getting close.

Be patient. You're looking at some of the most advanced bikes on the market (great choices, by the way) while still being new to mountain biking. These are seriously expensive bikes. You have a year to make your decision and you probably have plenty of demo events in your area. Dial in your preferences before dropping that kind of money. Ride as many bikes as you can, including ones that don't seem to be in your target "demographic". If you find a great deal on a used bike - even if it's not perfect - you can learn a lot about your preferences, then sell the bike for nearly zero loss. Repeat as necessary, with each one getting closer to ideal.

Some thoughts:

• Aluminum vs. carbon frame: I agree it's one of the lowest return-on-investment places to spend money. Suspension, contact points, and front tires are the places to spend your money.
• Bikes with less travel retain their geometry better on steep climbs and descents. You don't need quite as steep a seat-tube angle when there's less suspension to squat as your weight shifts rearward; similarly, you don't need quite as slack a head-tube angle when there's less front travel to compress on descents.
• Consider why you like small wheels. If it's the agility, maybe you can get that from shorter travel and / or a steeper head angle, while still having the rolling efficiency of larger wheels. For example, a Guerrilla Gravity Trail Pistol or Transition Smuggler may retain the positive aspects of the bikes you've mentioned with greater agility.
• The steepest seat-tube angle I've used is the Kona Satori - by a wide margin. The effective top-tube length felt short because Kona didn't lengthen the reach enough to balance the forward placement of the rider's hips, but I can almost overlook that after enjoying the climbing ergonomics so much. Best climbing bike I've tried due to the ergonomics and high anti-squat. Test one if you can.
• Size up. Slam the saddle forward and put on a shorter stem. Voilà: A steeper effective seat-tube angle and your weight is farther behind the front contact point. Better climbing and safer descending. Takes more effort to interact with the bike and the trail, but it can still be done and the stability may be favourable.
flag GrittyWhiskey
Posted: Sep 2, 2019 at 10:06 Quote
I'm very much the type to buy once, vs work your way up. Especially with demos being such a common thing in the mtb world. I will try to ride as much as I can before pulling the trigger, because if you can, then when not.

As far the the wheel size goes, I think it's a mix of liking how quickly I can change direction, but I'm realizing though studying all the geo talk that there might be better ways of going about doing that with bikes like these. For example, I feel when I'm riding a 24in bmx that I have to do everything in my power to get it to change directions, where as the 20in just does it as I think about it. That probably comes down to the bikes I'm used to riding. They change direction almost before I think about it, which I love, but it that might not be the best trait for baby's first mtb. I'm trying to keep that in mind, that because I come from years of only riding bikes that, in every sense of the word, couldn't be any different from these if they tried.

I like your post about sizing up. Again, completely counter-intuitive from what I'm used to, but that is the problem. Everything I'm used to couldn't be more different, so I'm really relying on the knowledge base of everyone here to guide me away from my old habits that very well could.

I'm still thinking 140 is the smallest I could really get away with up here. I've had people suggest that I just get a xc bike and call it, but if that's really what I wanted, I'd just but a gravel bike. Most folks I know riding around here are on 160 Tracers and the like. I want something I can grow into once my skills come up to snuff. But you won't ever see me hucking off some big downhill course. That's what the rally car is for.

I'll take a look at the Satori. Hadn't heard of that one, but that says nothing. Honestly, the Raaw looks like the ideal bike for what I want. Just wish it didn't weigh the size of a small boat anchor. I also have little problem buying used, as at least I have enough friends to bring with me that can loop
flag R-M-R
Posted: Sep 2, 2019 at 12:28 Quote
GrittyWhiskey wrote:
I'm very much the type to buy once, vs work your way up.

I get what you're saying, but you won't be the same rider with the same needs in a year as you are now. And again another year later. Rather than finding an inherently perfect bike that you just need to grow into, the perfect bike for you is changing with your abilities and experience.

Don't worry about weight. You seem like someone who appreciates the science, so here are some numbers:

Let's say two bikes differ by 2 lbs. The weight of your total system (you + bike + gear) is unlikely to be much less than 200 lbs, so 1% is the upper bound of how much difference it can make. That's only on climbs and assumes zero other sources of energy loss, such as air resistance, rolling resistance, etc.

Realistically, this 1% weight difference slows you down closer to 0.5% - 0.75% at most, and only on climbs. On flat terrain, the difference is essentially zero, with just the occasional small difference when accelerating after applying the brakes. On descents, the weight can actually help, though it's more realistic to call it approximately neutral.

Save your money and / or optimize for more important variables.

GrittyWhiskey wrote:
I'm still thinking 140 is the smallest I could really get away with up here. I've had people suggest that I just get a xc bike and call it, but if that's really what I wanted, I'd just but a gravel bike. Most folks I know riding around here are on 160 Tracers and the like. I want something I can grow into once my skills come up to snuff. But you won't ever see me hucking off some big downhill course. That's what the rally car is for.

Tires are an important part of the suspension picture. There's little overlap between the optimal parameters for each of the three systems: tires, frame & fork, body. "Plus" tires got a bad reputation a few years ago because many implementations had too-light tires on too-narrow rims. I'm a huge fan of large tires and large rims: currently using true 2.6" casings on 36 mm (inside) rims and I can see the value in 2.8" tires, especially on the front, especially for certain riders and certain terrain.

Conditions that favour larger tires:

• Loose dirt
• Rough terrain
• Dry climate
• Priority on traction / safety margin
• Lower descending speed and/or less aggressive rider

The last point may change over time. If this describes you and your west-of-Boulder conditions, you may enjoy a little more tire with a little less travel. An ideal set-up could be:

Front
Tire: 2.8"
Rim: 35 mm - 45 mm inside

Rear
Tire: 2.6"
Rim: 30 mm - 40 mm inside

You would probably need to build your wheels from scratch to hit such precise numbers. I'm not necessarily recommending you do that, though it's easy and cheap with the current variety of rims available, including outstanding carbon options from Asia at reasonable prices.
flag GrittyWhiskey
Posted: Sep 2, 2019 at 21:48 Quote
I can't thank you enough of the info on the tires. I've always known there's a relationship between them and the actual suspension, but how you laid it out is pretty beautiful. My question then still becomes, why not still go with a 140, and a larger tire like you have laid out of eloquently. I guess the real question is why not have the extra 10-20mm and not need it, vs needing it and not having it.

Weight wise, I really couldn't care less, and the points you laid out are perfect. I've always thought as weight being helpful on the way down, and my engine can drag a couple extra pounds up the the hill. I've long said that the best weight reduction you can do before a ride is take a dump.

Wheel wise, I have enough builder friends that would probably be stoaked just for the fact their building me a wheelset, which means I'm riding again. Granted, the mtb wheels don't need to be tied and soldered, but still.

I do see what you mean about finding the perfect bike. Once again, I have to remind myself this isn't my normal world where once you have your unicorn bike, your riding isn't really going to change. Not so much the case here. A lot depends on what's used out there, and when I decide to buy, because why I can buy new, that first bike should probably be used.

Am really digging on that kona satori you mentioned. Especially if it looks like people are kind of shitting on it because of it fitting in a nitch that doesn't exist (except for folks exactly like me,) I'm in


I've learned a ton from this, and a I truly cannot thank you enough. There should be an easier way to send one a 6 pack online as a thank you.
flag R-M-R
Posted: Sep 2, 2019 at 23:02 Quote
GrittyWhiskey wrote:
I can't thank you enough of the info on the tires. I've always known there's a relationship between them and the actual suspension, but how you laid it out is pretty beautiful. My question then still becomes, why not still go with a 140, and a larger tire like you have laid out of eloquently. I guess the real question is why not have the extra 10-20mm and not need it, vs needing it and not having it.

Weight wise, I really couldn't care less, and the points you laid out are perfect. I've always thought as weight being helpful on the way down, and my engine can drag a couple extra pounds up the the hill. I've long said that the best weight reduction you can do before a ride is take a dump.

Wheel wise, I have enough builder friends that would probably be stoaked just for the fact their building me a wheelset, which means I'm riding again. Granted, the mtb wheels don't need to be tied and soldered, but still.

I do see what you mean about finding the perfect bike. Once again, I have to remind myself this isn't my normal world where once you have your unicorn bike, your riding isn't really going to change. Not so much the case here. A lot depends on what's used out there, and when I decide to buy, because why I can buy new, that first bike should probably be used.

Am really digging on that kona satori you mentioned. Especially if it looks like people are kind of shitting on it because of it fitting in a nitch that doesn't exist (except for folks exactly like me,) I'm in


I've learned a ton from this, and a I truly cannot thank you enough. There should be an easier way to send one a 6 pack online as a thank you.

Always happy to help! I actually work in the industry as a product manager and engineer, so we're barely getting warmed up here! Wink

Your observation on weight reduction is correct. Marketing department isn't going to like it, though ... lol

The question of why a person would want less travel is interesting. Let's start with a thought experiment: what would happen with essentially infinite travel? A meter, for example. The suspension would be incredibly compliant and you'd have about a foot of sag (negative travel). The upside is being glued to the ground and a super smooth ride. The downside is that the bike would be unresponsive: you couldn't "hop and pop" around on the terrain, pumping through rollers would accomplish nothing, turn initiation would be delayed, and the bike would pitch fore and aft like a dinghy at sea when you climb and descend. You would just sit on the saddle and be a passenger.

Now let's flip that and imagine a trials bike: responsive, agile, able to get up and down the wildest terrain, and maximum reward for your efforts to interact with the terrain, but terrifying at high speed and unbearably jarring.

You wouldn't take a trophy truck to an auto slalom and you wouldn't go WFO through the desert in a go-kart. Everyone has their own ideal balance of comfort & speed vs. responsiveness & interactivity. I feel most people ride more travel than necessary because it's easier than riding with more skill - and I can't fault people for buying a little extra speed and control.

The recent trend is toward "overforking", i.e more travel on the front than the rear, as this allows a better balance of terrain interaction and comfort.

Here are a couple of great videos from Steve at Vorsprung:

How Much Travel Do You Really Want?
How Much Travel Do You Really Need?

The Freehub review of the Satori is in line with my own impressions. It's an incredible climber, very agile, responsive, and lots of fun on not-too-scary terrain, but gets out of its depth on steep terrain or when going all-out on descents. Ideal for riders who value climbing as much as descending and either aren't very aggressive on descents or really value agility. For my taste, I'd like to see a lot more reach and maybe a slacker head angle because I like the feeling of a long saddle-to-bar and I carry a good bit of speed on descents. These changes would alter the character of the bike, though, and not everyone shares my preferences.

When someone says they want an off-road BMX with a super steep seat-tube angle, no other bike fits that description better - the question is whether you'll still want that after some demo rides!
flag R-M-R
Posted: Sep 3, 2019 at 11:49 Quote
Two more bike ideas:

• 2020 Devinci Django
• Fezzari La Sal
flag GrittyWhiskey
Posted: Sep 5, 2019 at 0:09 Quote
How those Vorsprung videos don't have more views is beyond me. But then again, I think I watch wayyy more videos of dudes standing in front of white boards than most people do/would want to admit to.

I guess my big problem with knowing how much travel I need is just not knowing all the trails I want to be riding. Again, I want to hike with wheels, more than something like enduro. Not to say I'm not gonna bomb down some flowy stuff, but my definition of "bomb" is going to be drastically different than most. While I'm stoked I still have the ability to ride, breaking my back again is pretty much a guarantee to paralyze me.

Very much understand the overbuying of suspension, and even feel a little penis envy of "my bike has 170 while your's only has 150." That being said, I very much disagree with not wanting to bring a trophy truck to an auto salon, but that's because I'm a bit messed up in the head Wink Also, stadium super trucks looks to be about as much fun as one could have in a vehicle, but all your points of why it's a bad idea from an idealistic standpoint hold up wonderfully

That review of the kona sounds pretty damn ideal for what I'm looking for. The rear end kinda makes me a bit uneasy, but I have to remember wtih a lot, if not all of this, I'll be learning how to ride trails on whatever bike I end up getting. My bike handling is pretty excellent, but my handlebars were also 330mm, not 800, so again, the skills I do have are going to need some adjusting at best

I'll check out those other two rides
flag R-M-R
Posted: Sep 5, 2019 at 4:23 Quote
We're getting to the point where the theory is well explored, so it's time to start demoing. Not a bad position to be in!

The more you describe your (expected) riding style, the more I think you'll like big tires. A couple years ago, I rode with someone who's taken a liking to hiking / riding up hiking trails high in the alpine, then descending on the loose, scree-covered hiking trails. He switched from bringing his summer bike (typical enduro fare) to his winter hardtail fatbike. The speeds and lateral forces aren't enough to expose the downsides of the fat tires, so it's all upside as he enjoys the traction - while trying to avoid sidewall tears!

You probably wouldn't want to go full fatbike, but a chunky 3" front tire (ex. Maxxis Minion, Bontrager XR4 / SE4) on a 45 mm - 50 mm rim could give you that margin of safety you need on loose trails without too much compromise on low-angle hardpack trails. Could be a tight squeeze in most forks, but at least you don't live in an area that requires clearance for mud build-up.
flag GrittyWhiskey
Posted: Sep 5, 2019 at 8:51 Quote
I have ridden a fatbike, and it was easily the worst pedaling experience I've ever had. I'll quantify that with saying the hardest part about mountain bike riding for me is the lack of efficiency. Not that bikes can't be efficient, but when every fiber of my being is used to pushing in X watts, and getting say, 35mph out of those watts, and now those same watts might get me 10mph. Numbers are kinda irreverent here, but I came from arguably the most efficient use of human power production (silk tires at 220psi, on wood, with bikes that flat out dont flex,) it's taken me a long time to accept that putting in 500 watts just doesn't give me nearly the same return.

With fatbikes, it felt like no matter how many watts I threw at it, they damn thing just didn't want to move. I loathed that feeling.

Now, I understand you're not saying proper fatbikes here, but I'm worried with the real wide stuff, that it'll rob so much power, I wont want it. Granted, the answer here very well might be "suck it up, buttercup, and learn the new way of life," which I can, albeit slowly, accept. Still the idea of a think 3 inch tire on a 29 inch wheel just sets off alarm bells that makes me want to retreat back to my 20in bmx bike, where I'm guaranteed to break myself again, and then I'll be stuck designing my own wheelchair, not playing with designing my own bike.

The main person I'd be riding with is on a hardtail, and has the same mentality of going down quickly as I have. Which is good, because in not wanting to drop her, she'll keep me safe from wanted to see that speed climb on the downhills. I just know myself well enough that S=d/t is tattooed on me, right next to the adrenaline molecule. The both things I'm addicted to.

Demoing bikes, unfortunately, still wont be able to happen until next spring. I'm not even allowed to throw my leg over one until February at the absolute earliest. So in the mean time, I'll keep researching tires, rear suspension setups, and all that other jazz. You are right in thinking I'm the type of brain that needs to be fed info, especially in light of not being able to just go ride some damn bikes
flag R-M-R
Posted: Sep 5, 2019 at 17:25 Quote
Fatter tires roll faster. Lots of studies have shown that, recently. (Calm down, I'm supporting your observation, in a roundabout way. Patience. Wink ). The micro-suspension effect is more beneficial than the increased contact area is detrimental. There's probably an inflection point, but it's beyond what we're looking at. So ... where are fatbikes dissipating all that energy? Because I agree, they are.

Rolling efficiency. That's what everyone has been testing. Few are testing driving efficiency - power transfer. That's where the loss happens. Most tests are seeing only half the picture.

My empirical observations are that driving efficiency is pretty good, until it's suddenly not. I believe it has to do with shear deformation in the casing, like when a dragster's rear tires deform during launch. A fatbike actually climbs pretty efficiently if you inflate the tires to a point that eliminates this shearing, but produces too much undamped rebound for safe riding over mixed terrain.

If a tire doesn't reach this point of shear collapse in the casing, the efficiency is fine. It may even be faster because the micro-suspension benefits are still outpacing the power transfer losses. Cyclocross tires are slow in proper mountain bike terrain because they hang up on everything - not to mention having to back off for difficult terrain. At the other extreme, fatbikes are slow. Medium-width tires are fast. There's a point of maximum efficiency somewhere between those extremes.

Front tires aren't subject to shearing loads when pedaling, so you just get the rolling efficiency benefits (to a point, of course). Thus, you can get closer to fatbike territory on the front than the rear. Also, more traction on the front is nice: you can recover from a rear wheel slip, but rarely from a front slip, so having less traction on the rear is like having an early warning system for impending doom.

Seb Stott is probably the brightest mountain bike journalist out there. Here are some of his explorations of this topic:

2016 video.
2018 article.
2018 video.


P.S. Although I didn't hit your level of racing, I managed to partially put myself through university as an NCAA road racer - not exactly "ball" scholarship dollars on offer - and raced alongside a reigning U23 national champ and someone who went on to win a couple Giri d'Italia Femminile. On dirt, I prefer to beat my ride buds both uphill and down, leaving no room for "Yeah, but I was faster in the other direction" excuses. I'm competitive, I know what "proper" speed looks like, and I know how hard it is to give up the tiniest bit of it. I get you. Don't worry, I won't recommend lame gear that takes away your brand of fun. Wink
flag GrittyWhiskey
Posted: Sep 6, 2019 at 18:13 Quote
A lot of that makes complete sense. I've always wondered how much the suspension effect of the tires is calculated or looked at in overall suspension talk. It's the first thing to hit the object, and thus the first thing to offer any kind of suspension. Larger in the front, and smaller in the back makes complete sense as it's where you need the most grip. And unless you've gone so skinny in the back that you don't have the contact patch to grip anything, you're fine. Understeer on a bike, like you eluded to, is kinda a no go. But oversteer can usually (hopefully) be recoverable

I'm read a bunch on the movement in the sinnyy tire movement to wider tires and rims while running less pressure, but that'l purely for lower rolling resistance. My world is kinda starting to listen, but not in terms of psi. I used to run a 19mm on the front, and a 22 in the rear, both a 220psi. Now folks are starting to run wider tires, but the psi I dont see changing. Like said, flex is a killer.

The problem with my brand of fun is my forcing myself to have to patience to learn it. Speed is easy when it's just 4 turns and some banking. But right now, I'll settle with beating someone up crazy techy climb, and watch them ride away as my soul screams to go faster. But faster is what almost paralyzed me the first time. As much as I love all my para friends, I don't want to become one of them. Not fully anyway.

Hasn't stopped me from playing in cad and the linkage bike simulator.
flag R-M-R
Posted: Sep 6, 2019 at 21:53 Quote
The micro-suspension advantage of tire flex is related to the amount of roughness in your terrain. It doesn't take much: even slightly pebbled pavement is enough to favour wider tires at lower pressure, such as 28 mm or more, as low as 60 psi front and maybe 90 psi rear. Nasty chip-and-seal favours even wider tires and lower pressure. Rough off-road terrain ... a lot wider and softer!

Track is as extreme as it gets. Obviously. It's the one environment so controlled that a silk casing inflated to near its breaking point and painted with just enough rubber to soak the threads is the way to go. Anywhere outside of a track, though, everything you've known about tires for your whole racing career no longer applies. The dominant variables on track become nearly trivial and variables that were nearly zero on the track utterly dominate the efficiency and performance equations. But that's to be expected: 60 km/h on varnished wood vs. 15 km/h across a rock garden - totally different situations require totally different solutions.

Embrace the benefits of fat(ish) tires and low pressure. It will be foreign at first, but you'll learn to love it.
flag GrittyWhiskey
Posted: Sep 7, 2019 at 16:36 Quote
That's been the hardest thing for me is trying to unlearn everything that I had perfected during track. Tires are the easy one, it's just a matter or learning what is a safe low psi, or what psi I good for what conditions. All stuff I'll learn from riding with forks more experienced than myself. The harder one is body position. I move the bike on the track with my hips, and slight flicks with my knees. Hands are just there for something to hold on to. And the center of gravity is such a small, small envelope to stay in as to keep the rear tire on the ground, or not picking up the front tire is tricky. With mountain bikes, you have so, so much more room to move on the bike, that that'll take me a while to feel ok with. But again, that'll come with riding with people that know more than me, and allowing myself to experiment on the bike.

There's a lot to be learned, both with the bikes, and on the bikes, and all I want to be is a sponge. Also feel like I live in the right area to teach me what I need to learn on the bike.

My main problem now, especially with so much time on my hands, is not getting too caught up in all the tech terms an numbers. Again, I've been playing in cad, building what I think might be my idea bike, without having any real world experience to back any of it up. It's fun, and a good way of keeping my brain active, but still.
flag R-M-R
Posted: Sep 8, 2019 at 0:21 Quote
It's great to put so much thought into the project! The limitation is that you probably don't have the familiarity to know how every parameter feels, let alone how they feel together.

I'm not discouraging you from the research and design, just encouraging you to calibrate your ideas against actual models that have as many parameters as possible in common with your ideas. Try to employ "fail fast" principles by testing the most unconventional features and combinations as soon as possible.
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