Wheel size comparison, data based

[dilzy]

I am going to build a 100% rearward axle path bike. If only one person never says rearward axle path again, it will have been worth it.

You seem to build 29'ers, which do the same thing, reduce the angle of incidence on the oncoming obstacle, so I wouldn't be so hasty to bag the rear axle path crowd.

[rosenamedpoop]

Personal opinion after damaging many 26" wheels, f-29". It's just silly, so's 650b. The force vector difference when encountering an obstacle with these different size wheels is bugger all (as noted by the drawing on the op) and the whole thing smells of i-phone.

I like how my phone smells. It has a vibrator app.

[Sandwich]

Yeah, hitting a 4" obstacle doesn't make that huge of a difference, but nobody truly expects big wheels to flatten a 4" rock. I look to them for support in 1-2" roots and rocks, and use my suspension for larger impacts.

Could you repeat the drawring with a 2" rock?

[SuspectDevice]

My favorite part about the middle sized wheels is the increased directionality when drifting. They seem to hold a better line and almost feel like little "rails" (similar to skiing).

this- it's one of the mostest-funnest things. I had to start gluing the tubeless beads onto the rims for the xc racers because they started(wasting so much energy) slap-chopping and slashing stuff.

[General Lee]

My favorite part about the middle sized wheels is the increased directionality when drifting. They seem to hold a better line and almost feel like little "rails" (similar to skiing).

this- it's one of the mostest-funnest things. I had to start gluing the tubeless beads onto the rims for the xc racers because they started(wasting so much energy) slap-chopping and slashing stuff.

Show me a fancy graph with lots of vecterz or I don't believe you

[mtg]

Yeah, hitting a 4" obstacle doesn't make that huge of a difference, but nobody truly expects big wheels to flatten a 4" rock. I look to them for support in 1-2" roots and rocks, and use my suspension for larger impacts.

Could you repeat the drawring with a 2" rock?

Yes, that's no problem. I can tell you that the difference gets smaller on a 1"-2" step than 4", though. Before I posted the original graphic, I played around with differing step heights. I'll pull it up and post it when I get a chance.

[atrokz]

Results look pretty minimal. What's the % dif on a 2" rock?

[Sandwich]

Yes, that's no problem. I can tell you that the difference gets smaller on a 1"-2" step than 4", though. Before I posted the original graphic, I played around with differing step heights. I'll pull it up and post it when I get a chance.

sure, may as well have all the data out there.

[SuspectDevice]

Show me a fancy graph with lots of vecterz or I don't believe you

I know you're pulling my chain but:
Give me a $20k grant, wait until next spring and I'll give you a peer-reviewed scientific study on funnnnnn v. wheelsize.
I can think of a couple of sport psychologists that need thesis projects(publish or perish).

In regard to hard science:

It's not hard to design a study to evaluate things that are relatively irrelevant(parse that one) or marginally significant-
The current president of USAC got some fat grants from both ProFlex and Specialized in the '90s when he was at the University of Utah to publish somewhat dubious claims about suspension efficiency, for use in marketing materials, for example.

As far as the reality of science and 650b stuff-

The vaults of the French Cycling Federation contains a study they did in the run up to Atlanta(there was a huge arms race going on in cycling then) with Girard, Bossard, the Université de Lyon, Hutchinson,Mavic and Michelin over the winter 1995/spring of 1996(w/all the data they could collect(expired gas, power, blood lactate, kinematics telemetry) that identified 650b as the right tool for the job to win the XC race at the Atlanta Olympics. They were even spotted in Conyers over the winter poaching the course in February '96 on funny looking bikes covered with electronic crap and dudes with stopwatches and big noses.

Clearly, they never rolled that stuff into the public sphere, but it was common knowledge at the time that they were working on it and what the findings were. The speculation is that they were afraid of the IOC and the manufacturers wanted to make sure they could sell what they were winning on.

'96 inspired the Treaty of Lugano, and maybe we're all lucky that the French didn't race on custom wheels, otherwise we might be stuck with some of the same stupid technical rules that were implemented for road and track after Atlanta.

I'm quite sure that the testing that Scott did in the leadup to this year's Olympics was scientifically valid as well.

Science isn't hard and winning races is the most important thing in the whole darn world. I bet the DH testing Scott has done was also scientifically valid. It's Switzerland ferchrissakes!

At the most elite level of competition even the most marginal gains make a huge difference.

[Sandwich]

I get the sciencey ****, but I feel like preference is as much of an issue here. People may like or not like what big wheels do. I feel like 18" chainstays on a trail bike handle like ****, but turner freaking loves them, and there are plenty of homers to agree with them. The frontward axle pathed, 18.3" chainstayed 29er FS bike I had was one of the worst performing and handling bikes I've ridden, and that's saying a lot.

Just saying, even if lord Science tells us that 650b is only marginally better, or that 29ers can't corner as well in theory, if people go faster on them, isn't that telling enough? Even if the faster is because a rider does more better on them?

I need to pick up a second lefty hub and nevegal, then I can do my own comparisons with 650b and 26" back to back.

[mtg]

Here's some more graphs, with a 1" and 2" tall square edge:





The tangent lines are nearly indistinguishable on a 1" tall bump.

[HardtailHack]

If you make new standards that make bad riders faster in a straight line you would surely just end up with trails with blown out corners.

Big wheels should be in different race categories just like BMX.

Change is for hipsters

[Sandwich]

Come on dude, that's a pretty tired argument, especially in a thread that's supposed to cut to the facts.

Besides, the thing that really blows out corners is toolbag pinkbikers and their "skid into every berm" roost-throwing mentality. If you want to prevent the ruining of trails, I assure you limiting people out of wheels that provide more traction while allowing them to just skid constantly is not going to solve it.

[Sandwich]

Uh oh, wheel size just scientifically peed in your soda.

http://magazine.bikeradar.com/2012/1...t-the-results/



Pretty scientific, and you'll notice that even thought the 29" wheels automatically made the rider blow through every corner into a frustrated LBS filled only with 29" wheels, they were better than 26 in almost every aspect.

[Owennn]

Uh oh, wheel size just scientifically peed in your soda.
Pretty scientific

Apart from the lack of detail on effort put into each lap, the bike setup for each wheel size, wheel build etc. Also reads as if they used one rider for the whole test, do the same thing with many more people and they may have numbers more useful.