View this post on Instagram
27.5” rear wheel / 29” front wheel / 200mm travel. I haven’t built a Frankenstein bike in a while, and Ben and I talked about trying this for a while. I started with my prototype 29er Tues and swapped to a 27.5” rear wheel. This dropped the BB about 20mm and slackened the head angle, so to bring it back up I got a longer shock. The bike takes a metric 250x75mm shock, so I got a 10.5x3.5” (267x88mm) and reduced the stroke 10mm making it a 257x78mm shock. 7mm at the shock moved the rear axle enough to put the BB back up to stock height. My theory was that the bike would do everything that you can argue is better on a 27.5” bike or 29er in one bike. The 27.5” rear wheel would give you more clearance to get over the back of the bike without getting buzzed by the tire, turn quicker, accelerate faster, and have more brake power. The larger front wheel would roll over square edges better and get more grip with a larger contact patch. I’ve made homemade modifications like this in the past that were a good idea in theory, but the execution was pretty janky, and you could feel that when you rode it. This set up was solid. After two days of riding, I felt that all the advantages I mentioned above were hardly noticeable. The one thing that stood out was that it was much easier to scrub/stay low on jumps and hitting jumps in general felt much more natural. Whenever I thought that the 27.5” rear wheel would turn quicker, I’d switch back to the 29er and feel like I could ride it just the same. Normally when testing wheel size, you are on 2 different bikes, so there are a lot of variables, but with this set up I could change the shock/rear wheel in about 5 min between runs. Riding the same bike both ways brought me to the conclusion that the wheel size didn’t make as much of a difference as I thought it would. I’m tall and have long legs so I don’t really have a problem riding the 29er. For shorter riders or women, I could see this set up working well with the clearance advantage. It’s fun trying this stuff. Whether it works or not you always learn something. Next time I ride I’ll do some timed runs to see if there is an advantage one way or the other. Thanks for reading!
View this post on Instagram
I put a stopwatch to the 27.5” vs 29” rear wheel this week and ended up with very similar results. My fastest times on each wheel size were 0.4 sec apart on a 2 min track, with the full 29er set up fastest. Conditions were wet, and I did the best I could to ride fast enough to test it at speed and be consistent, but it was tough. My feeling was pretty standard to most wheel size debates- the 29er felt smooth and easy to ride and the 27.5 felt super fast, but in the end the times were roughly the same. My first run on the 29er I did get my ass chewed by a fresh mud tire about 10 sec into the run, a good reminder of the lack of clearance. I adapted to both within a few corners and felt comfortable from there. For me, that’s the feeling I get with many things I try. Changing the bike will make it handle differently, but a good rider can adapt to that quickly. Glad I got to put some data behind this!
Cool FeaturesSubmit a Story to Pinkbike
RSSPinkbike RSS Feed