Evolution of MTBs

Primoz
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9/8/2020 2:25pm
And to cap it off (I'd love to put all of this into one post, but Vital doesn't make that possible...), @digsafe, is that a TerraLogic in the background? Smile
brash
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9/8/2020 2:27pm
brash wrote:
That been said, I've still yet to find a rear suspension platform that worked as well as the old Devinci wilsons, I ride a lot of...
That been said, I've still yet to find a rear suspension platform that worked as well as the old Devinci wilsons, I ride a lot of bikes and that rear end is just on another planet, be it DH or Enduro nowdays.
Primoz wrote:
Old Wilson as in? Pre-Split Pivot? Or the smaller wheel versions of the Split Pivot bikes?
Mine was a 2014, so 26 inch split pivot. I'm getting emotional thinking about that bike!
Eoin
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Fantasy
9/9/2020 3:26am Edited Date/Time 9/9/2020 3:26am
Just a short rant that the roadies seriously need to re-evaluate their approach to sizing, i never realised how bad it was. Looking at a bike for my wife: the reach difference on a XXS vs XXL scott is 3cm, it seems bikes just get taller (seatube and stack) but dont grow in any meaningful way in length. Why even bother having 7 sizes, just compensate everything else with seatpost and stem?
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digsafe
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9/9/2020 4:42am
That’s the main reason why I went with a Mondraker. Those bikes are like choppers. I’m loving the long reach
Skerby
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9/9/2020 7:32am
How do you keep from nuking the exo tires? You could run DH casings and still have a really light bike, trust me they are worth the weight. Light tires are nonsense on anything but an xc bike, or I guess if your trails are perfectly smooth exo is fine, but the performance advantages of heavier casings are immense.
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digsafe
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9/9/2020 9:43am
? I run 25 lbs of air. I weigh 175. I hear the tires pinch off the rocks a lot But no problems yet, I’ve had them for a year now
Primoz
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9/9/2020 12:58pm
brash wrote:
Mine was a 2014, so 26 inch split pivot. I'm getting emotional thinking about that bike!
Could the performance of it be related to small wheel sizes giving you some rearward axle path compared to larger wheels?
Primoz
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9/9/2020 12:59pm
Skerby wrote:
How do you keep from nuking the exo tires? You could run DH casings and still have a really light bike, trust me they are worth...
How do you keep from nuking the exo tires? You could run DH casings and still have a really light bike, trust me they are worth the weight. Light tires are nonsense on anything but an xc bike, or I guess if your trails are perfectly smooth exo is fine, but the performance advantages of heavier casings are immense.
My logic is to run inserts on EXOs as opposed to DH casings as you still protect the rim that way. And the weight is similar.
Fred_Pop
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9/9/2020 11:43pm
Eoin wrote:
Just a short rant that the roadies seriously need to re-evaluate their approach to sizing, i never realised how bad it was. Looking at a bike...
Just a short rant that the roadies seriously need to re-evaluate their approach to sizing, i never realised how bad it was. Looking at a bike for my wife: the reach difference on a XXS vs XXL scott is 3cm, it seems bikes just get taller (seatube and stack) but dont grow in any meaningful way in length. Why even bother having 7 sizes, just compensate everything else with seatpost and stem?
Road bike geometry is governed by UCI rules since every single roadie on the planet races...lol
Someone should make a long and slack road bike!
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thejake
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9/11/2020 7:56pm
brash wrote:
Mine was a 2014, so 26 inch split pivot. I'm getting emotional thinking about that bike!
Primoz wrote:
Could the performance of it be related to small wheel sizes giving you some rearward axle path compared to larger wheels?
Axle path has nothing to do with wheel size. Pivot placement effects axle path.

I had one of those Wilsons, great bike. Before that I had a Rotec RL9 that had a Lawill design. That thing was amazing. Axle path was strait vertical and then went backward for the last few inches of travel. I had a short stroke shock which took it from 9” to about 8” and a -1 degree angles set. Looking back geometry was pretty dialed but I think I loved that bike so much because I owned it from 22-28 and rode the crap out of it with out a care in the world.
Primoz
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9/11/2020 11:39pm
Wheels size and axle path are of course not directly related. But if you want certain characteristics, certain anti squat, certain pedal kickback levels and so on, the pivot placement in relation to the BB has a huge role as you know. The catch is that a larger wheel moves the rear axle up relative to the BB and THAT fact connected to the position of the pivots effectively makes axle paths more forward without using an idler.

Plus the fact that a smaller wheel with the same BB height will have a higher geometric (disregarding the effects of the chain pull) antisquat component than a larger wheel, again because of the pivot placement and the swingarm orientation.

The differences are small and not catastrophic, clearly, but are present.
9/13/2020 2:46pm
I think that geometry still has room for improvement when it comes to the front-/ rear center ratio, especially when it comes to bikes in larger sizes. Having a long front end and a short chainstay forces you to really weight your front wheel when cornering which sometimes feel unnatural In my opinion. I'm mainly thinking about dh bikes, but a longer rear center would also be beneficial when climbing in steep terrain.
Primoz
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9/14/2020 4:59am
That implies that the position of the BB relative to the rear axle plays a significant part in pedalling performance, but not where the rider is sitting. If you move the BB and the rear wheel in relation to the seat (i.e. steeper seat tube angle), you still move the rear axle rearwards compared to the CoG, but the chainstay still stays short.
9/14/2020 11:49am
Yes, steep seat tube angles are great for seated climbing, but you arent always seated going up. My point was that a longer rear center would benefit the weight distribution of the bike when going down.
Primoz
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9/14/2020 9:50pm
Yeah, you're not, only what... 99 % of the time? Plus on an average ride you're climbing ~80 to 90 % of the time with the descending taking up maybe 10 % of the time, if not less? Seated climbing should take the biggest possible priority when designing MTB geometries and fit. The time and energy usage simply dictates that.
9/14/2020 10:58pm
I disagree with your opinion there, thats like saying that randonee skis should be designes with climbing being the priority because you're going up the mountain 99,9% of the total time spent skiing. Your percentage of time spent going up/down doesn't really hold water as some of us live near a lift. If you ride four times a week; two times pedalling to the top and two days in the bike park, your descending to ascending ratio will be way off from what you said.
I was trying to say that a byproduct of a longer rear center would be better climbing. Also theres no reason why you cant have both steep sta's and long cs'.
Primoz
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9/15/2020 11:30am
I think most people don't ride lifts or have park bikes for that, which is a different story.

As for skis, as far as I'm informed, DIN bindings perform better for skiing and are safer for the knees/legs (skis popping off the boots), yet everybody now skis with Dynafit style bindings. Because they are much lighter and give a better walking geometry. So yeah, skis are optimized for going up. And you also have split boards, which also suffer in torsional rigidity, but outperform a standard snowboard going up by miles.
9/15/2020 1:09pm
DIN is the mechanism that keeps your heel in place. Dynafit is a binding where you can have your heel loose from the ski itself for walking uphill and then you snap your heel into them at the top. Of course randonee skiers aren’t walking up with their heel stuck to the ski. The randonee ski itself (not the binding) is optimized for going downhill in loose powder -thats why they are so wide.

As for people in bike parks and their bike of choice: The majority of people (at least here) bring their enduro bikes, which I assume they also pedal up when not in the park. I’d say that the percentage of dh bikes the last few years in my local park is around 25 if not less.
Primoz
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9/15/2020 2:39pm
https://cdn.shopify.com/s/files/1/0906/3946/products/276569-114303_AMBI…
This is what I meant.

Looked up the terminology (I'm not into ski touring yet and not as well versed as in mountainbiking, so please excuse my ignorance), I'm talking about frame bindings vs. tech bindings for touring. So the frame binding went the way of the dodo. Because weight (and if I'm not mistaken geometry as well, as the pivot point is further forward). Therefore it's an uphill optimisation. That's my point.

I still say if a bike is designed to be pedalled around, it should work well in that scenario. Park laps are an extension of the intention of a bike like that and most people still use them to pedal around. And in that case the time spent going up is still the majority.

And to cross over to the ski area again, you can do laps on your touring gear. But anyone serious about freeriding inbounds will use skis with full on bindings, not tech bindings (park bike analogy). How many people still buy frame bindings to cover both areas?
9/16/2020 5:52am
Yes, I think we both agree that a bike that is designed to be pedaled should climb well. My point was that gravity oriented bikes like dh and "enduro" bikes should be designed with descending in mind. However theres no reason why enduro bikes shouldn't be good climbers, but in my opinion their climbing ability should not be prioritized. When it comes to bikes other than enduro and dh, then yes I agree that climbing should be prioritzed more. I dont believe that a longer rear end would impact climbing negatively anyway. Though most climbing is relatively easy, some steep and technical trails require you to stand up more.
Anyways, I hope more brands follow suit to norco and forbidden with size specific chainstay lenghts.
Verbl Kint
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9/16/2020 9:11am Edited Date/Time 9/16/2020 9:12am
Those who are thinking that the current "modern" geo is good enough as it is now and will only get "minor updates" in the coming years are probably the reason why the mtb industry is hesitant to roll out the 61° head angle, 80° seat angle Enduro mullet mtb of the future, with a dual crown fork, of course.
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Zero Cool
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9/16/2020 11:55am
I think that Enduro bikes will gradually become like the Grim Donut and Paul Aston’s Nicolas G1 while trail bikes will stretch out and become more like short travel enduro bikes (and we’ll all buy them because Enduro bikes will have become too specialist like DH bikes.

I think it will take a few brave individuals like Chris Porter, Paul Aston, Isaac Levisson(sic) and the Grim Donut guys to prove that the more extreme geometry works for racing and going fast.
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Primoz
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9/16/2020 1:08pm
I still say if you pedal, it should be the priority. Saving 1 W climbing (pedalling) will be more beneficial energy wise (due to the time difference) than saving 5 or maybe even 10 W descending. Saving energy going up will enable you to more than compensate for any potential shortcomings going down through saved energy.

As for 61° head angles... I'm not entirely sure it will be doable with current PTFE bushings in forks. Plus it might work fine for racing, but I'm also not entirely sure it's the best thing for all terrains and people, kinda going against what Paul said in his bike check.
9/23/2020 1:44pm
brash wrote:
I got a classic. Took this a few years back. 2014 Devinci Wilson (Ex Dean Lucas worlds bike) 2015 Spec Enduro Evo 1997 Barracuda XXXC I...
I got a classic. Took this a few years back.

2014 Devinci Wilson (Ex Dean Lucas worlds bike)
2015 Spec Enduro Evo
1997 Barracuda XXXC

I bought the Barracuda new in 1998 with money I made mowing lawns (I was 14) and it was a shitload of money for a kid. It was a cutting edge bike at the time. Attached is the Geo Chart lol.

I raced XC, FourCross and Downhill on that bad boy! Sadly I sold it as finances were not too hot. I wish I kept it as it's an awesome reminder of some great times on a bike.






That Barracuda is totally retro.. I kinda dig it haha
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Sesame Seed
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9/23/2020 3:10pm
Primoz wrote:
I still say if you pedal, it should be the priority. Saving 1 W climbing (pedalling) will be more beneficial energy wise (due to the time...
I still say if you pedal, it should be the priority. Saving 1 W climbing (pedalling) will be more beneficial energy wise (due to the time difference) than saving 5 or maybe even 10 W descending. Saving energy going up will enable you to more than compensate for any potential shortcomings going down through saved energy.

As for 61° head angles... I'm not entirely sure it will be doable with current PTFE bushings in forks. Plus it might work fine for racing, but I'm also not entirely sure it's the best thing for all terrains and people, kinda going against what Paul said in his bike check.
I think the having psuedo intellectual internet banter just because some internet hacks worked a deal inside of whatever to-scale supplier because, noone says not to is ridiculous.

Where are the standards upon the places these bikes would be ridden?
Since there are no rules as in that sacred-arguement that pins DH, or XC, or even Road, as two-wheeled heir-apparent to FiA FormulaOne glory, the standardization of terrain would be the 'need' for such the 'want'.

Of which there's none and, eroding soil is not anything to base a complete dumping of convention. Instead, it's just going to be left to the good 'ol Internet and 'Dash Riprock' w/ his 14000 posts in 1 3/4 years vs. 'Kitchner Leslie' and his 47 posts in 6 months as to what is the urgent need. No Professionals, Race Organizers or Sanctioning Bodies saying enuff's enuff.

Say little Billy Boinger wanders into city traffic on his Grom Unit Sparkler version and endos into the path of a 3 ton City Bus at 40mph because the bike would not steer, we're all fucked by an Ham Sandwich served an Indictment over careless/negligent product.

If such a bumblefuck contraption is all that's going to appease and get tham clicks... take up skiing. It's all downhill, and a Potty at the end.
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