13/08/2019 - Is Mixed Wheel Size The Future?

Is Mixed Wheel Size The Future?

Cy Writes.....

You might have heard much talk on the race scene and beyond this year about mixed wheel sizes; so-called mullet bikes. Business up front, party out back? 29" front wheels, 27.5" rear wheels. As usual, there has been a lot of hot air, a lot informed and not-so-informed chatter, hand waving and general pontificating.

As it's my job to get involved with new trends and see if they might result in better bikes, I ran a 27.5 x 2.6" tyre on the back of my RocketMAX earlier in the year for a few weeks. I didn't really notice much difference. It wasn't some big break through, but it wasn't awful either. Actually, I tell a lie: When I just put a 27.5" rear wheel in the bike, it was fairly awful, but nothing to do with smaller rear wheels being a bad idea in general, just for my bike. The 27.5" rear wheel dropped the BB about 10mm from an already low position and slackened the already very slack (63.5 deg as standard) RocketMAX head angle into the 62's. As I have mentioned before, we got to where we are with Longshot geometry because I went even slacker than we currently offer on our bikes, and found it was making the handling worse again. I talk about this in the first Downtime Podcast I did all about the Longshot Geometry development. The short story is, we went too far, too slack, too low, then came back to an optimum for production. The smaller rear wheel pushed the geometry back into 'too far' again. After a bit of geometry tweaking to get the angles and BB height back where I wanted them, the bike worked great, but as I said, it wasn't some massive difference or revelation.

Rocket with different sized front wheels

After this testing I got talking to Chris at Downtime Podcast about what I had found, and he put forward a point about it possibly suiting shorter riders better than me. I like 29" wheels, and at 6ft 3in there are pretty much no drawbacks to running them. Chris at 5ft 8in on his FlareMAX 132 found he sometimes caught his rear wheel on his shorts in steep terrain and it was certainly something he considered when moving around on the bike, and maybe a 27.5" rear wheel would suit better? As I had a rear wheel all ready to go thanks to our friends at HUNT giving me an Enduro Wide 27.5 to use, along with a big WTB 27.5 x 2.6 Trail Boss, I sent it over. As the FlareMAX isn't quite as the extremes of angles as the RocketMAX (it has a 65 deg head angle), Chris found he could quite happily drop the 27.5" rear wheel into his bike with no adverse effects or need for hardware changes to make it work right. In the end I think it was just a slightly tweak to shock and fork pressures and that was it.

We then got together with a stop watch and a couple of different bikes to get some data, and then we had a chat about it. Grab a coffee and see what we thought. Are they the future? Listen and find out.....


Listen to Cy's Longshot podcast here…