Wheel size

The Rookie

Great article in MBUK this month with extra info at http://magazine.bikeradar.com/2012/11/1 ... e-results/

Looks like when they picked 26 as the MTB standard it was 'just too small'.....

So which would I pick, well money no object 650B, but that is never the case, and on my budget I'll stick with 26, why? Because the above test was very much made with an effort to get all else equal, but on any sort of normal budget (so sub £4K) you'll get a lighter tighetr bike as a 26er......

Discuss!

Chunkers1980

I say what moron created those graphs

The Rookie

Graphs could have been done better, data is the important part though, not what they look like!

supersonic

Discussed here:

viewtopic.php?f=10002&t=12890409&start=20

The Rookie

Thanks SS, looked but didn't find, perhaps as the OP wasn't addressing the review!

The Northern Monkey

But what tyres were used?

A high volume 26" tyre can make a wheel bigger than a 650B with a skinny XC tyre etc etc.

The Rookie

Control tyre of 2.35 Hans dampfs on all 3 wheel sizes.

mrmonkfinger

None of that is matched up to rider's power output.

I'm out.

njee20

Yes it is. Matt had PowerTaps on all bikes, and power output varied by 1-2 watts throughout the test (ie sod all).

The Rookie

Read the thread SS linked to.......more details.

jimothy78

The Beginner wrote:

So which would I pick, well money no object 650B, but that is never the case, and on my budget I'll stick with 26, why? Because the above test was very much made with an effort to get all else equal, but on any sort of normal budget (so sub £4K) you'll get a lighter tighetr bike as a 26er......

Even more so as, if a lot of people do switch to a larger wheel size, there'll hopefully be lots of nice 26" components coming onto the secondhand market

Woodmonkey

They were all hard tails too, doesn't account for when it gets lumpy with the compromises in geometry to gain more travel.

mrmonkfinger

njee20 wrote:

Yes it is. Matt had PowerTaps on all bikes, and power output varied by 1-2 watts throughout the test (ie sod all).

although not mentioned in the article linked to

anyway, a (human) rider + powertap with average power display, does not make for an impartial power source.

The Rookie

Got a better idea, you complained it wasn't equated to power, it was, now you complain it is.......my only criticism is that the bikes shouldn't have been ballasted to the same weight but to a weight allowing for the lighter 26er wheel and fork.

njee20

anyway, a (human) rider + powertap with average power display, does not make for an impartial power source.

No, but it's about as accurate as you're gonna get!

scarbs85

Power variations could have assisted the 26inch bikes, meaning the margin turned out smaller than it should be. Its ppotentially a flaw, but not one to specifically aid one bike or another. Plus multiple runs will help to negate any random spikes or differences.
Would be nice to see this repeated with different riders and on different trails. The more repititions the more statistically significant the data will become.

paulneenan76

scarbs85 wrote:

Power variations could have assisted the 26inch bikes, meaning the margin turned out smaller than it should be. Its ppotentially a flaw, but not one to specifically aid one bike or another. Plus multiple runs will help to negate any random spikes or differences.
Would be nice to see this repeated with different riders and on different trails. The more repititions the more statistically significant the data will become.

I agree. Whilst you don't need 100's of similar tests, you do need more than one to get a stronger indication. I'm not an expert on this but I've recently worked on something similar and you need a higher representation of the riding demographic for greater accuracy. But that's only if you want to understand the effect on the riding population and terrain/conditions the population ride.

I guess this is why demo'ing a bike to see if it suits you personally is all important.

mrmonkfinger

The Beginner wrote:

Got a better idea, you complained it wasn't equated to power, it was, now you complain it is.......

Not particularly. I just wanted to point out there are a huge number of uncontrollable variables in this test.

However I do say full marks to BR and the rider for giving it an honest shot.


How are automotive suspension systems & wheels tested, presumably in a lab on dynos?

The Rookie

Rig test or on road test, the only dyno test would be on a flat floor dyno for preliminary roling resistance and grip profile against slip angles for the tyre, but most testing is on 'road'.

The reason 29ers roll faster than a 26er is due to the lower ramp angle when hitting imperfections, so a rig test would have to involve imperfections.

JayKay3000

Although I'd say for most real world examples wheel size does not matter as most real world riders will be on a similar skill level so it ends up like apple vs microsoft vs google....

scarbs85

Proving it beyond all doubt may be difficult, and designing a perfect test near impossible. The results from this experiment backs up what is showing from race results across the country though, and the evidence is growing to support 29ers.

The Rookie

Eh? If the bike rolls faster, it rolls faster regardless of who's riding!