26 vs 29er – a racer test


Might be a bit flawed (comments below but this from the mtbr site …)

I know this story is going to open a Pandora’s Box, but in the name of mountain bike journalism I’m going to do it anyway because people need to hear the truth, not a bunch of marketing hype – which bike turned faster lap times at this year’s 24 Hours in the Old Pueblo, a 26er or a 29er? I brought both this year to the high desert outside Tucson, Arizona to find out which bike could better handle the 16-mile lap with roughly 1,000 feet of climbing per lap. The bikes of choice were the 26-inch Ibis Tranny and a 29-inch hardtail from Bailey Bikes, a custom builder based in San Diego.

I was racing for the defending champion four-man singlespeed team, Single Minded, and set both bikes up with the exact same gear ratio of 55 gear inches (38:18 on the 26” and 34:18 on the 29”). Both bikes also had the exact same tires (Maxxis Crossmark), the same carbon Niner fork (the length of the carbon fork on the Tranny was the exact same length as a 100mm Fox 26” fork) and both weighed in at a scant 17.5 pounds. So for all intents and purposes, the only difference was wheel size.

By looking at the Old Pueblo course profile, it seems the 29er would have a distinct advantage. The opening section called “The Bitches” is an undulating fire road that favors momentum and the big wheels of a 29er, as do numerous section of slightly downhill singletrack that really can get the big wagon wheels rolling and a final, somewhat rocky descent that is much smoother to ride on a rigid 29er.

However, the 26er I was riding is no ordinary 26er, it’s the Ibis Tranny; far and away the most impressive hard tail mountain bike I’ve ever ridden in my life. It should be known that I’ve been racing on the Ibis for three years, so there is definitely a predisposition to the Tranny, but I had already ridden the Bailey enough times to get comfortable and confident on it, as the Bailey rides exceptionally well. In fact, it’s perhaps the most comfortable 29er I’ve ever ridden.

The plan was to swap laps with each bike and let the lap times tell the story. Each lap ended up being just over an hour, so if the difference in lap times was under a minute, I would consider it negligible, but if the difference in lap times was a minute or more, it was telling me something.

Celebrating its 14th running with nearly 2,000 total participants and an equal number of spectators and supporters, the 24 Hours in the Old Pueblo has become the premier 24 Hour race in the United States and the perfect venue with which to conduct my 26er vs. 29er test. I elected to start the race by running the quarter-mile LeMans start, trying not to get trampled by nearly 600 crazed, lycra-clad lunatics in the process. Because of my history with the Ibis Tranny, I elected to ride it first.

 

Lap #1 – Ibis Tranny – 1:05.39

This lap was a modified lap, because it included a two minute run and we went down an opening fire road that bypassed the first section of trail that everyone would ride from lap two onward. But the difference in time between this modified lap and the standard lap was negligible. The start was as insane as I expected. I had a good run and was 10th man on the bike but quickly got spun out in the mad dash of geared riders. In the very first corner turning onto The Bitches, some guy with more fitness than skill ran out of talent in front of me. I had nowhere to go but right into his bike. Fortunately, bike and body were unscathed, but unfortunately my front tire had burped about 10 psi, leaving me with barely 20 psi in my front tire for the entire first lap. Not a good start! I quickly got back on the Tranny and settled into a solid pace. There was a wicked headwind on the backside of the course for a good 20 minutes, which meant finding a wheel was crucial. Because of my partially deflated front tire, I had to back off a bit on the downhill sections, a place where I typically make up lost ground. Definitely would have been in the 1:04s with a fully-inflated front tire.

Lap #2 – Bailey 29er – 1:07.20

The first lap on the Bailey went very well. No issues at all. The bike was extremely comfortable, and compared to the darty, zippy, somewhat unstable riding nature of the Tranny, the Bailey was smooth and composed over all rocky and technical sections. It was clearly an easier bike to ride with control. But there was a variable emerging I hadn’t factored in before the start of the race – lapped traffic. By the time I was on my second lap it was nearly 5PM and we were passing A LOT of people. I stopped counting how many people I passed at 50.

Passing on the Old Pueblo course is a dangerous proposition due to the sea of cactus covering every square inch of the race course. If you clip a corner by even six inches, you’re getting a face full of cholla. Although there were numerous sections of fire road, most of the course was single track no wider than two feet. The 20 mph headwinds on the backside of the course made passing even more difficult at times.

The big wheels of the Bailey were noticeably harder to accelerate when passing, and when you had to do it more than 50 times in a lap, the exerted effort started to add up. The big wheels also tended to understeer in corners, forcing me to use much more body English to get the Bailey through turns quickly and smoothly.

Lap #3 – Ibis Tranny – 1:08.42

It should be noted that this was the first nighttime lap, so times are naturally a little bit slower. On this lap I had eaten a sandwich a little too close to my lap time, resulting in some stomach issues. My legs felt good, but I felt as if I was riding slower than I should have. Headwinds had died down, but there was still a ton of traffic to pass. I noticed immediately once getting into the singletrack that the Tranny was far easier to accelerate and shoot past people with.

Set up as a rigid bike, the Tranny felt like a tight and dialed cruiser BMX bike on the downhills; a little twitchy, but undeniably fast with razor-sharp precision through the turns, rewarding a rider willing to push it into corners with fast exit speeds. When I came in and looked at my lap time, I was pleasantly surprised. I thought it was going to be slower than the time showed.

Lap #4 – Bailey 29er – 1:10.03

Although I was on my fourth lap, thanks to all the GU Energy and endurance racing wisdom my teammate Yuri Hauswald was hooking me up with, my legs felt amazing. Having eaten hours before this lap, I had no stomach issues and was ready to uncork a faster lap than lap #3. I went out of the gate charging at 1:30AM and found a race course more empty than it had been all day long. I was setting my sights on a 1:07 lap. The Bailey rolled effortlessly through The Bitches and along the flat fire road sections. The winds had completely died to nothing more than a gentle breeze and most of the slower riders had gone to bed. Things were looking good.

Although I ripped the downhills on the Bailey, I had to be very careful, as its low bottom bracket had me clipping a few rocks when trying to gently pedal through corners. I also found myself dragging a bit on the power pole climb, getting out of the saddle numerous times to try and keep the big wheels of the Bailey rolling fast. I crested the power poles climb and careened downhill to the transition zone all smiles…until I saw my lap time at a 1:10. I guess I was just getting more tired and didn’t realize it. I hadn’t yet made my decision on which bike I thought was faster, but the last lap for me was the clincher.

Lap #5 – Ibis Tranny – 1:07:04

It should be noted that this was the ‘sunrise’ lap. I started in the dark at 6AM and by about halfway through the lap I turned off my lights. But regardless, the half-lap of light was not the reason why I was three minutes faster. Additionally, this lap saw more traffic and passing than lap #4. I also did not feel as good mentally or physically at the start of this lap as I did on Lap #4, where I went out of the gates charged up and ready to uncork one.

Lap #5 started with less mental motivation. I was slower through The Bitches, but once I got on the single track and descended past the whiskey tree, things started to click. The Tranny was talking to me. It just felt right. When I got to my split point two-thirds through the lap and saw I was two minutes ahead of my last lap split, I charged as hard as I could up the power line single track and bombed the downhill back to the transition zone. I couldn’t believe I had just turned a three-minute faster lap. I don’t think my teammates believed it either.

Lap Summary

Lap #1 – Ibis Tranny – 1:05.39
Lap #2 – Bailey 29er – 1:07.20
Lap #3 – Ibis Tranny – 1:08.42
Lap #4 – Bailey 29er – 1:10.03
Lap #5 – Ibis Tranny – 1:07:04

Conclusion

Let me start by saying both bikes are exceptional machines. They’re both insanely light, they both handle extremely well and they’re both super comfortable and easy to get accustomed to. You can call me biased, you can say my analysis is flawed, but at least for me, the Ibis Tranny was clearly the faster bike on the 24 Hours course. What it really came down to was the exerted effort of having to pass dozens of people per lap. The Bailey clearly required more energy to do this, and because both bikes were set up with the exact same gearing, there was no masking the acceleration deficiencies of a 29er. You can hide these deficiencies with gears and derailleurs, but when you got only one gear, immediate acceleration will always bend in favor of the 26er.

Does a 29er roll in a straight downhill line faster? Sure. Of course it does. But how many mountain bike races do you do where the downhill is perfectly straight? Although the Tranny doesn’t roll as fast as the Bailey, the Tranny accelerates so fast that within three pedal strokes you’re completely back up to the speed of a 29er.

People have told me I’m faster on the Tranny because I’m used to it, and that if I just ride a 29er for a month or two and get accustomed to it, I’ll go faster. What logic is that? If the 29er was truly a better bike, I should have seen immediate improvements in lap times, not gradual improvement over the course of a month or two. I’m not saying that the 29er is a bunch of marketing hype. The sub-1000 gram Bailey 29er is an incredible machine, and at a $1500 retail price (You can buy it for $1250 on their website), it’s among the best performance values on the market today with the best OEM warranty in the industry (features a two-year, no-fault 100% repair or replacement).

But what I am saying is that a well designed bike is fast regardless of what size wheels it has. I understand why people like 29ers; they’re comfortable, they’re smooth, they’re easier to ride fast, especially over rocky terrain. But if you’re looking for an all-out speed machine that absolutely shreds downhills and accelerates like an arrow from a crossbow uphill, I’ve yet to find a bike that’s better than the Ibis Tranny. The 26er is not dead, it just smells funny.

NOW SOME COMMENTS I LIKED

March 1, 2013 at 2:22 pm

Great write up. I just did a little statistical analysis where I compared the three Ibis 26″ times to the two Bailey 29″ times. Statistically there is no difference between the two bikes. You would need many more runs to actually tell if they were different with times this close. The best thing you can say at this point is they are not different, at least with that data. This in itself is interesting…you are saying that the 29 does not give a clear advantage. Warning: the test has very low statistical ‘power’ with this sample size, and no ‘pairing’ of laps was done.

I would say energy used on previous laps, and amount of rest between laps as well as day and night time laps had more to do with time differences than wheel size.

Take lap 4 and 5 for instance. Lap 4 started at 1:30am in the dark verses 6:00am on the 5th lap. Everyone is slower in the dark, and given your lap time, you would have finished your lap at 2:40am, giving yourself 3:20 of rest and refuel before you started your next lap.

These difference alone can skew your results.

Poorly run studies are not helping anyone make the right choice.

Ride what makes you happy regardless of wheel size.

Interesting read. The only two things I would point out is that the improvement you experienced with the 26 is not quite as clear as the conclusion states. The second lap was faster than the third. And the second point is that one problem with a “scientific study” in any case that involves humans is the the human involvement. The human variable is one of the most difficult to account for in any scientific study. We tend to screw everything up. Also, were temperatures, wind conditions, light, other riders, tire, pressure, energy use, etc all identical in every lap? The variables that can get involved can boggle the mind. This is one big reason why environmentally controlled rooms and robotics are used so much in data collection. However, I don’t think it’s wrong at all to say that for you the 26 worked better for you in this case. Emotional conclusions can have a big effect on performance in humans (Placebo’s sometimes work for a reason). Ride whatever you feel most awesome with and you will probably perform the best. Hard to really go wrong with either bike choice you had handy that weekend.