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29 Inch wheels vs. 26 inch wheels
by: Lennard Zinn
Reprinted from Velonews, July 2005
29 inch wheels vs. 26 inch wheels
29er vs. 26er

I must ‘fess up to the selfish excitement I felt when I first heard about 29-inch wheels. Being a tall rider never completely comfortable with feeling a bit gangly riding with others, a tall bike with normal-sized wheels looks out of proportion and, well, gangly. 29-inch wheels seemed like the perfect way to avoid that “Are those normal wheels on your bike? They look so small…” question. For a tall rider, bigger wheels make sense; the bike is not only more normally proportioned, but the steering tube length on suspension forks is no longer such a limit on the maximum handlebar height, since the top of the fork is three inches higher due to the taller wheel. My own testing of big wheels head-to-head with 26-inch ones has put a grin on my face, but can the majority of people populating the earth benefit from taller, heavier wheels as well?

Well, given the results in endurance racing by normal-sized riders like Cameron Chambers, Nat Ross and Mike Curiak, it is certainly worth investigating. 29-inch wheels and tires are definitely heavier than equivalent 26-inch ones, and the frame rear end and fork legs must be longer, and hence heavier, in order to hold the big wheels. It would seem that a heavier bike with heavier rotating weight on the wheels would sap the energy of an endurance racer as the hours drag on. But Chambers’s recent 2005 National 24-Hour Solo championship in Spokane, Ross’s win in the 2004 solo 24 Hours of Moab, and Curiak’s victory over 16 days of racing from Canada to Mexico along the 2500-mile Great Divide Trail in 2004 all put that concept in question. Furthermore, experiences of small, novice riders on these big wheels, as well as that of Gary Fisher in making, riding and promoting 29ers, further push back the boundaries of who could benefit from them.

In winning the 24-hour solo national championship, Chambers rode a Fisher hardtail for the first 3-4 laps and a Fisher Sugar 292 suspension bike for most of the rest of the race. “I definitely feel that the big wheels are more efficient. I have my choice of what to ride, and I definitely choose a 29er to save energy over 24 hours,” the Gary Fisher rider emphatically states. “At Spokane , those first laps were incredibly fast, and I was constantly trying to catch a draft. The other guys (on 26-inch wheels) were pedaling like crazy, and I was just coasting while drafting them through loose and technical sections.”

The 5’10”, 155 lb. rider is aware of the arguments against a heavier bike but says, “While more rotating mass does have a negative side to it, I feel that it is far outweighed by other advantages. On a steep climb, I can get forward on the bike yet still have the tire hook up, rather than having to sit way back to get traction with too little weight on the front for good control, like with 26-inch wheels. I’ve never been dropped on a climb, and definitely the bike has not held me back there, even though it is heavier.Riding 158 miles a day on a Moots YBB 29er loaded with camping gear, Curiak climbed over 225,000 feet through Montana , Idaho , Wyoming , Colorado , and New Mexico to win the completely self-supported Great Divide Race and smash the old course record by more than two days. “For my racing purposes, 29-inch wheels shine because they not only are more efficient, but they make the ride so much smoother without having to complicate the bike and make it heavier with more suspension. They don’t fall into 27-inch holes!”

There is certainly a different style to riding the big wheels. Gary Fisher calls it “bigger rhythm.” When maneuvering, he says, “You literally take a bigger rhythm with it,” in moving the bigger wheels back and forth than you would flicking a smaller wheel around. Chambers remarks that, “You definitely ride them differently. You need to try it on different rides – how you get better traction on climbs and how you can lean over further in corners. I always lose the rear tire climbing and slide out in corners now on 26ers, since I am used to leaning over more in corners and climbing more up over the bike with the greater traction of a 29er.” And Curiak comments, “Going back and forth between them, it requires some adaptation. But going back to 26-inch I don’t like; they’re so sketchy, it’s like jumping on a BMX bike.”

That is not to say that it requires a higher degree of skill to ride a 29er; in fact, it may be quite the contrary. Curiak, who works as a mountain-bike guide much of the year in Crested Butte, Moab, and his hometown of Grand Junction , says, “Timid, technically inept women, for lack of a better way to say it, particularly benefit from them. The women I ride with around here call them “big girl wheels.” They love 29ers because they have so much traction, and they can ride lots of stuff they can’t on a 26er. They attribute it to having more stability and more confidence.” Chambers adds that, “Riding through sand is a huge benefit of 29-inch wheels – the bigger contact patch floats over sand incredibly well. In the 24 hours of Moab , I pedal right through sandy sections that good riders cannot make on their 26ers. Along the Arkansas River where I live in Kansas, it’s hilarious to see the difference between what guys do in the sand on their 26ers compared to what even beginners can do on the big wheels. My wife is an entry-level rider, and the guys I ride with are shocked when she rides through sand on her 29er better than they do.”

Testing the two wheel sizes head-to-head

I built two Zinn cross-country three-inch-travel suspension bikes identical in almost every way save for the different wheel sizes (a Zinn XC 26er and a Zinn Megabike 29er). With the riding position, components and suspension the same, I could isolate the differences in performance due to the wheel size.

I rode a lot in Boulder , Moab and Grand Junction on both bikes, and I would have to say that if I had to choose just one of the bikes, I would now pick the 29er over my beloved 26er, despite the fact that the 26er has a much nicer paint job. I expected the big-wheel bike to be slower on the climbs, but it was immediately apparent that this was not the case. As Gary Fisher says, “It seems faster because you’re pulling away from guys you usually go the same speed as,” and that was exactly my experience. On really steep trails, particularly with loose dirt or rocks that roll, I could stay on the bike and pedal up things that I could try numerous times on the 26er and still end up walking. Where the trail goes through narrow slots between rocks where I usually dab after clipping a pedal on one side or the other, I found that I could often just ride diagonally across the slots with the big wheels without dabbing, clipping pedals, or dropping into the gaps. As Fisher says, “Being able to stay on your bike and go straight through stuff is a great advantage.”

On descents, the 29er gave the impression of having more suspension than the 26er, because it rolled over things the other bike dropped into or bounced back from. When you hit a big four-inch-high square edge, for instance, it hits high enough against a 26-inch tire to push it back pretty hard, not just upward. If you hit that same square edge with a 29-inch wheel, however, it hits lower on the tire, more under it than against the front of it, and the wheels rolls up on it with less of a jolt and less loss of momentum. I found myself pedaling down rough sections where I normally coast and hang on. As Chambers mentioned, riding in sand is far preferable on a 29er. I rode Poison Spider Mesa above Moab on my 29er, a ride well known for copious amounts of sand requiring lots of pushing and much dumping out of shoes. I thought that I had maybe not remembered it right, because I just rode right through almost all of the sand on a hot, dry day. I had gotten so used to the 29er that it had not seemed strange how easily I had ridden up the steep lower sections of the road that are covered with small rock flakes that slip out under the rear wheel. However, once I saw guys on 26ers failing to come even close to riding through the sandy sections I was riding, I recognized the flotation advantage my bigger contact patches were giving me. The downside, I discovered, was that I could carry speed through the sand up to super-steep slickrock coming out of it and would try to ride right up things I otherwise would have been hike-a-biking before even reaching. However, once grasping for a handhold on a near-vertical slickrock face covered with black oil and tire marks from jeeps as I slid back down it was enough to remind me that the sand the tires carry with them makes for a slippery surface on oily rock.

Tall riders benefit from 29-inch wheels, and there is ample evidence to suggest that, at least in endurance events, low-traction conditions, descending, or rough trail riding, so do average-sized riders. Small riders can run into pedal-overlap problems with a short top tube, but Curiak thinks that anyone over five feet tall can be accommodated. “My wife rides a small Lenz Leviathan with a 22-inch top tube, and her foot doesn’t hit the front tire.”

SIDEBAR

The nitty-gritty details of the two bikesI made both bikes 3-inch-travel rear/4-inch-travel front and equipped them with RockShox Reba forks, FoxRP3 rear shocks, SRAM X.0 rear derailleurs, X-Gen front derailleurs and 9.0 trigger shifters , Bontrager Race Lite Disc wheels and Bontrager Jones XR tires, Selle San Marco MT RaceGel saddles and Crank Bros. Candy pedals. The seatposts, stems, handlebars, headsets and hydraulic disc brakes varied in brand but were all nearly identical in position, weight, and performance. My riding position the same, I cut the bars to the same length used the same grips, and I set up the positions of the brake levers and trigger shifters the same. Because of the requirements of the suspension system we use on Zinn bikes, I used different cranks, however. In order to approximate a vertical rear wheel path with the main pivot centered around the bottom bracket shell, the bottom bracket height must be about the same height as the rear hub. Since a 29” tire is about 30mm larger in radius than a 26” tire of the same diameter, I made the cranks close to 30mm longer. I used 175mm Truvativ GXP cranks on the 26”-wheel bike and 200mm Zinn custom cranks on the 29”-wheel bike. (Don’t worry; for a rider with a 38-inch inseam like me, 200mm cranks are still shorter for me than are 175s for a rider with a 33.5-inch inseam.) Despite the difference in bottom bracket height (and much higher chainring clearance of the 29er), this made the ground clearance of the pedals, and the seat height above the ground (and hence the height of the center of gravity of the rider), the same for both bikes. The 29er weighed 1.1 pounds (one half kilogram) more than the 26-inch-wheel bike. The fork, wheel and tire weights are listed in the accompanying What We’re Riding. The 29er fork is 48 grams heavier, the 29-inch wheelset is 162 grams heavier, and the 29-inch tires add 84 grams; inner tube weight is the same. The total weight difference for forks, tires and wheels: 294 grams = 0.65 pounds The additional 0.45-pound weight difference is in the frames and the cranks.

SIDEBAR

The downsides of big wheelsNot everyone is a fan of big wheels, and the current state of development of available forks, tires and wheels is a drawback. But Fisher says that the volume of 29-inch-wheel bike sales is doubling every year, which will fuel future development. “It was really small when we started. Dealers would order in two bikes and wouldn’t even stock the inner tubes.” But the company’s 30-percent growth projections for 2005 were so much lower than the 100-percent increase that occurred, that even he can’t get one right now! Campbell thinks that, “Soon, you’ll see a lot more riders on them, because development will bring the weight down. Trent Lowe rode a Fisher 29er in Moab and raved in the car to me about it all the way back to Lafayette , CO . But for now, the weight is too much for him to race on them.” Even Curiak says, “If I were a downhiller, I would use 26-inch because they have beefier tires available. The tough tire casings are the only drawback at this point, although I posted a photo I took (http://forums.mtbr.com/showthread.php?t=107647) of Red Bull rider Lance Canfield doing a 30-foot huck on my Lenz Behemoth!” 1990 world downhill champion Greg Herbold admits to being “old school when it comes to mountain bike geometry.” “The wagon wheels are really great in rolling terrain when you keep momentum going,” he says, “And the longer banana-shaped contact patch is good in loose traction and rolling terrain. But for stunts and tricks, littler wheels offer more mobility.”

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