142mm MTB is back!

Ronen and I were discussing some details for a few of his upcoming frame building projects. He is fresh off a success in building (almost) 100% of his new Raven Caw in his own workshop. Like the Sith (see: Rule of Two), he has the twin to my Cyberdyne frame fixture. He’s just got a few small tools that are on back order, once he has those he can to do everything on his own without my help.

We were discussing bikes for small people, MTB and AR bike differences, and transmission drivetrains. We were discussing knock on effects of various choices. We both want the narrowest cranks we can. We want to be able to use transmission drivetrains as an option. I’ve been testing transmission drivetrain with a 148mm rear and a 51mm chainline as I use a Q150 crank. It works ok but I would prefer to be a little farther from the edge of what functions for most setups.

142mm hubs just kept coming up. This is inspiring me to move forward with a change that I’ve been thinking I’d need to make. A 142mm rear hub would balance things out considerably.

I prefer my chainlines being slightly toward the lower side of the cassette in normal use, I may be too far for the transmission to work best at 51mm. I knew this when I built the Millennium Falcon. I needed to do a test to find out. It works but I imagine that it should work better.

Further, mountain bikes for very smaller riders would do well with a Q145 crank and that is too far for a 148mm rear to work well. A 142mm rear end would make that possible. A major upgrade for shorter folk.

I’m also having a slight issue on the Falcon with my heels rubbing the rear end of the chain stays when riding in flat pedals. I’m going to do some reshaping and a bend location change for my new builds to help with that but 3mm on each side would really help open that space.

There’s another advantage, with both MTB and AR bikes using 142mm hub spacing, most part models for the frame become very consistent. This makes more elaborate modeling possible without breaking in the computer. I really like that.

So there it is. It’s a new era with a shift of building 142mm rear ends on the mountain bikes. Time to order up some hubs!