TBH I listen to what NASA say, they’re one of the few publicly funded American organizations that are right about whatever topic/research area they decide to have a nosey around. They make a nice change from all the governmental organizations associated mostly with defense.

Brilliant organization.

Stoner….bit tall aren’t you. 8O

Should have taken up basketball!

wat da **** are those lol

Do they work?

I must have them for the sheer lolz but they look very pedal strikey.

All other things being comparable, aye. I think people are confusing the BB-drop effect with COG (taller wheels meaning that for the same BB height you’re dropped further below the axles)

If you run flats you can also go some of the way to having this effect by running silly thin pedals such as Point ones or crampons.

But yes the actual CoG of a 29er is higher – however being lower relative to the axles makes them harder to tip from side to side I think.

Also, as the CoG of a 29er is higher isn’t this going to negate some of the extra grip from the larger tyres at high lean angles. Let’s say for the same weight a 2.3 29er running 21mm internal diameter rims…. you could run 2.4 or larger diameter tyre….and you run that with a rim with a 33mm diameter internal width…..which is going to have more grip/stability and when?

I’d argue on high speed flat (non bermed turns) turns the latter is going to have more grip as the bike would have a lower centre of gravity, the increased diameter of the tire would negate some of the grip advantages, the increased rim width would add more stability by decreasing tire deformation which would in turn allow you to run lower pressures.

Gwinn is faster in the first (rougher) section

Gwinn must have been hanging at the end pedalling his DH bike

Buowharhar buowhahahahaharrrrrrrrrrrrrrrrrrrrrrrrrrr

Apparently Steve Jones and all the writers in Dirt Magazine because they draw ridiculous conclusions from data that partially argues against their actual conclusion.

Oh man the comments section in that Dirt Mag article prove what gullible idiots people can be.

It’s not really a huge gap when you consider Mitch was also much much faster than James when riding a 26er as well.

I just love the fact that I got to use my biology degree for critically appraising and destroying a dirt mag article. Heh

The comments are the important part. Steve Jones is also faster on the 29″.

Yeah it proves Steve Jones doesn’t know shit about how to setup a non-biased study and I would quite happily tell that to him personally. Feeling faster does not always mean you are actually faster and the clock only tells the truth when the design of the testing is correct to begin with.

Question everything and believe in nothing my friends, I’m off to get breakfast. :mrgreen:

What’s even more hilarious is a quick glance at the data makes me think even more bias was introduced into the data by swapping the riders onto different opposing wheel sizes half way through. The general picture of the runs is of decreasing run times right to the very end (Which means a potential variable was the run number itself…eg warming up)…. if that isn’t a study designed with a certain outcome in mind I don’t know what is.

Overall rich’s time decreased by about 4 seconds despite moving to a 26er half way through and Box’s time decreased by about 6 seconds whilst moving to a 29er half way through. LOLZ that’s statistically significant proofs right there! :mrgreen:

The comments are the important part. Steve Jones is also faster on the 29″

No they arn’t if you look at the data James Richards was faster on his 26er whilst Box was faster than James on both 26 and 29 inch bikes and put his best times in with the 29er.

Which means that one rider was faster on his 26er, one rider was faster on his 29er and one rider was faster than the other.

Proves **** all.

Strava can introduce bias as it’s not a great timing system.

The fact that you would be doing it alone would introduce selection bias. A 29er might be faster for you, due to your build or riding style or whatever? Or it might be faster because subconsciously you decide to ride faster on the 29er to prove your point.

No, the only time you will convince me is if someone does properly timed runs with a selection of at least 60 randomly chosen riders from a pool of amateurs and professional riders. Bikes with equal setups would be distributed, a range of courses would have to be ridden to take into account different types of terrain.

Then other people would have to do the same in other countries (Seeing as how individual RCT’s are often biased anyway despite the best intentions) and then I could finally carry out a meta-analysis of the results.

Go and watch Mr Hill etc at a DH race dragging their chain guides through ground… They seem to think CoG is pretty important.

Funnily, a lot of riders have gone back to 14 inch BB’s.

There’s a theoretical argument against everything, what I want is more fun from 29ers and to see timed runs with proper controls, over several different tracks. Then, I’ll make up my mind.

Till then the benefits (beyond giving n00bs more confidence and rolling over objects more easily….unfortunately the latter isn’t a golden bullet) have yet to be proven.

That test proves one rider was faster than the other, not whether 29 wheels are faster. The controls are fundamentally flawed.

I love the fact I studied science.

I’ve never heard a higher CoG called a benefit before… I still think you can load the suspension just fine. It’s a bike after all. If a Supercross rider can have an effect on the suspension of a 200lb dirt bike, a mountain biker can have more than enough effect on a 30lb bike.

I have, they redesigned the Honda GP bike with a higher CoG to get it to tip over quicker. Not really a problem with MTB’s but I feel that it does contribute to some of what I feel is the lazyness in handling that I’ve gotten from all the 29ers I’ve ridden.

Ask any motorsport driver what car is fastest and he’ll say the safest, most predictable and confidence inspiring.

Yes….race superbikes bikes are safer and easier to ride than GP bikes….softer suspension setups, smoother power delivery, heavier and more stable cornering, often feel as if your perched in the bike as opposed to on top of it. They’re definitely faster round the track. For sure.

I think the whole CoG benefit is a low of horse pooh imo and part of the fundamental problem for me in the way 29ers ride. I don’t want a lazy bike.

You have so much more confidence

Boom see above, is it the psychology or the physics of the bike making you go faster. Most people would be slower round a track on a Moto GP bike than they would on a CBR1000.

from the CoG stability that you can chuck the bikes around without worrying about grip loss on transitions into corners. The longer chainstays give you more front weight bias so I find it much easier to weigh the front.

The longer chainstay also makes it harder to get the front end up, lazier in corners, lazier in jumps. Etc ad nauseum…short chain stays are generally accepted as a good thing.

CoG stability is not always a good thing, it ends up meaning that you have to fight the bike to lay it over. And give me a break at any decent level of riding you need to be able weight up either wheel and feel the grip easily. Loading the suspension and supporting it with compression is entirely different to making loading it harder by lowering the CoG.

Maybe if you ride around the trails hitting jumps and having a laugh they’re not for you, but if you want to go A-B as quick as possible

1) Is that speed because A) The bikes faster or B) You feel safer and thus more confident being sandwiched between massive wheels (a bit like back braces in horse riding)

2) What happen’s if those trails include tight steep sections leading into large gap jumps with directional transitions? Like on a reasonably hard downhill course?

Or do we redesign tracks to be more suitable for 29ers?

3) Also this whole thing about not having to use body english to ride a 29er smacks me of missing the point of riding altogether….or for me anyway…..riding is like dancing….there’s great joy in throwing your body around in tune to the trail. Loads and loads of it.

The debate is starting to remind me of the debate that revolves around traction control in motor racing.

P.S. Sorry the scientist in me has to over-analyze and disbelieve everything until it is utterly proven beyond reasonable doubt…. personal experience counts for nothing as other variables other than the experimental arm (29er wheels) such as the placebo effect or increased confidence could effect the outcome.

well…..780mm low rise (10mm) bars are fads in certain applications. Eg steep as **** courses or 150mm trail bikes that have short head tubes married to tall riders.

For that matter lock ons are **** shite as well, I’ve gone back to good old slips on’s. There’s a reason MXers don’t use them.

Plenty of people who have ridden them agree they are boring to ride on our favorite trails, not all of us are bowled over by them JCL….

I really find it hilarious that people claim they are faster but that all timed reviews so far have indicated the opposite on timed downhill sections.

We need EBC, evidence based cycling.

My 29″ wheels are lighter than my DH wheels and under a pound heavier than my old 26″ AM wheels. Sure there is a little more rotational inertia but that also gives you momentum in stuttery stuff so it’s a wash.

Lighter and weaker than your DH wheels and almost a full LB heavier than your 26 inch wheels! Great! I went from 2200 gram god awful old wheels to 1800 gram Flows and noticed a huge difference!

Haven’t had a problem personally and I’m only 5’8″. With the centre of gravity being so low I find I can stay much more centralised on the bike without worrying about overweighting the front on steeps.

And it’s this precise reason that I find the bikes harder and slower to lean into corners and harder to weight up the front wheel in flat faster corners.

gives you momentum in stuttery stuff

Won’t this kind of become negated when braking bumps and trail wear are predominantly caused by 29ers? Bigger braking bumps! WHOOOOOOOOOOOOO

Again the CoG being so low means the front to back roll centre is much more stabilized than a 26″ with an upto 40mm higher relative BB height. This means your weight isn’t effecting the suspension to the same degree a a 26″ when you brake or are on a steep up/downs and is ultimately why they feel like they have more travel than they have.

Again, see above. Weighting suspension is good….. good suspension tunes are there to remove brake dive. What your saying is effectively “I can’t control my bike properly and need wheels that compromise handling to make me feel safe”

Loss of acceleration? Maybe (I doubt it) an issue or XC racing but for gravity racing I’d say that the lower rolling resistance easily makes up for accelerative losses.

Rolling resistance helps you use less energy once you’ve got going and perhaps let’s you accelerate a bit faster but the predominant factor that effects acceleration for me is rotating weight.

The hilarious thing though is that what really REALLY reduces rolling restance is rim width….Syntace have just brought out a 40mm wide 1800 gram 26 inch wheel. I’d like to see you do that on a 29er and keep the weights within reason.

“the key to reducing rolling resistance is minimizing the energy lost to casing deformation, not minimizing how much tread is in contact with the ground. All other factors being equal, wider casings exhibit less ‘bulge’ as a percentage of their cross-section and also have a shorter section of deflected sidewall.”

Also if it’s going to be wet (most likely) and you’re a rookie rider I would perhaps invest in as tackier tire as possible for the front without compromising your ability to ride the bike all day. Not a mud tyre, CYB is mostly rock and roots but definitely something soft. Continental Black Chilli compound or a Maxxis Super Tacky of some sort.

If your a rookie or unused to rooty rocky trails it will make your day a lot more relaxed. If you cant afford it though, no worries just ride safe.

1. Keep your riding within 90 percent of your limits, give someone ETA’s and give them a printed map of your route.

2. Take a first aid kit with you.

3. Take your phone with you, although it may not get reception.

4. Take spare clothing in your bag in case you get stuck somewhere, people throughout the world have been known to die a few hundred meters from cafes due to exposure. A lightweight bivy if you have one is a bonus.

5. Take plenty of water and energy food.

6. Wear a jacket that is high viz if you can so that people can spot you lying in bushes.

7. If you come off and hurt yourself badly, damage your helmet or bonk due to a lack of sugar do not attempt to use an escape route than involves riding technical trails….use a fireroad, blue trail or specific escape routes where possible. Only use technical routes if you really really feel that it is necessary or if you can get back home quicker by walking down them. Riding a techy trail after any of these three events is a recipe for disaster.

Keep those things in mind and have a fun time!

650b/24 inch SS downhill fatbikes

Jcl the 29er crowd is the clueless cult. All the time we here how amazing they ate from the converted…for others they arnt great for what we like to do. Wheelbase doesnt matter so much, rotating weight does as does the physical size of the wheels themselves in relation to body language (complaints about rubbing your arse on the rear wheel on steeps etc) as does the loss of travel, as does the loss of acceleration, loss of turn in, increased aero drag. There are plenty of reasons to dislike 29ers other than wheelbase length.

B45er if your not being sarky there wont be imo….champery is to steep and techy in a way that increased roll over wont make up for…it requires a more chuckable bike…have you felt how little room there is for body language on a 29er

Ive ridden a few 29ers….they are no where near as nice for jumping….not even close tazzy. They give up so much of the fun in return for stability.

Plus isnt the solaris a hardtail? Try adding 140mm of travel, sail like wheels and slower acceleration to jump handling….it really isnt as fun.

No wheel size is better they are just more suited for different preferences and uses.

Still suggests it was a course for trail bikes even if third was a 650b trail bike. 29ers might be faster for that kind of track which is close to what most middle aged audi driving mtbers ride…the majority of mtbers….I doubt they will be for places like champery and they will never be better for youngsters that like air time.

Looking at videos of that track, short travel light bikes have a huge advantage even disregarding 29ers. In a way it shows how damn good gwin was to place that high on a demo 8.

Nice thing about 26 all mountain bikes is that they can do everything quite literally…reasonably well…my brother was whipping out a nomad the other day on the biggest doubles at sherwood pines…i dont think he could have hit the rhythms perfectly on a 29er or got as much style off them.

650b DH bike came third, 26 inch DH bike came second. The wheels had nothing to do with it….the weight and travel of the bike did.

As others have mentioned…. that course can barely be called a downhill track.

Hitting shortish rock gardens at speed on a trail bike is not the problem…this would cause little loss of time and little fatigue to someone on a trail bike….hitting rock gardens at speed for lengths of time is a problem. That’s when milliseconds start to add up and fatigue starts to set in. Trail bikes have won downhill events before,…. sea otter, Lopse at US nationals etc.

I’ll accept 29ers are better when we see results like this on multiple tracks and tracks where one would not expect them to win – eg Champery.

By dwell time I’m assuming you mean how long the g-forces were applied for. I’m also assuming that if G-forces remained the same for each impact then the helmet with the lower g rating would see the energy of the impact spread out over a longer period of time.

Not a physicist, so I wouldn’t mind knowing why dwell time is so important in a controlled test.

Good way to kill yourself whilst looking like a tit…… at least skiers, downhillers, base jumpers and motorcyclists kill themselves with some panache.

Wasting so much good potential riding there using one wheel when they coud be going faster and hooning off things with two wheels,

Not very useful for those of us that swap between regular and goofy footed

40mm lower BB to axle centreline compared to 26″. That is a fundamental advantage in stability descending and cornering, increased climbing ability from lower effect of weight distribution on suspension. That’s without getting into the lower rolling resistance of the wheels

what about the higher centre of gravity caused by wheels that are significantly taller….or the shite airborne handling….or the lack of wins at DH, Enduro and even plenty of XC events.

BOOOOOOOM……and I’ve killed this thread.

Imagine a Mega 29er

The horror!

omg my eyes

If there was one person the Blur TRC was made for then judging by the OP it was him

If you rode at places like coed-y-brenin then you wouldn’t last two minutes on a hardtail! I’ve started riding the black routes and tbh I don’t think you’d get around it on a hardtail without pushing sections.

lol my brother rode the red bull run at CYB on a fully rigid Marin when he was 7 and I used to ride the place all the time as a teenager on a Santa Cruz Chameleon.

That or great troll!

Ummmm. No. It doesn’t. The mega is on its own in terms of ugly.

Ugly? Pfft. It’s a butter face…..29ers are ugly. Like severe untreated craniosynostosis mixed with a bit of hydrocephalus ugly

BTW I swear to god I’ve seen an exact Chinese carbon copy of that Rocky Mountain going for about 400 dollars.

looks like an lt

So agricultural then. :mrgreen:

I’ll get my coat.

TBH it’s a pretty bike in an understated way but as others have mentioned….the top tube length….ewwwwwwwww

Snore.

The Norco Range Killer and Sight Killer are by far the nicest 650b bike’s I’ve seen so far. Better geo, more travel, prettier etc etc

This looks as agricultural as my Mega.