Commuting - Building a commuter bike...have ???

Hi all,

I'm thinking of building up a relatively inexpensive commuter bike. I have a road frame that I'd like to throw some parts on it but don't know if they are compatible.

Can I use mountain bike parts - LX bottom bracket, crankset, front and rear derailleur and cassette on a road frame and road wheels with 105 hubs? Can I use LX brake levers with Sora brake calipers?

How about the other way around - all road parts except the shifters. Would MTB shifters work with a road drivetrain?


Thanks in advance.

Mountain bike bottom brackets are wider than road BBs. They will work but you will need spacers to make up the difference. Divide the spacers more or less equally between the 2 side of the BB shell.
Check www.sheldonbrown.com for compatibilty of Shimano road and mountain gear changers.
If this bike is just for commuting, my advice is simplify. I prefer double cranks, friction shifting, and 7s or even 6s freewheel. There is much less maintence, and you can use a wider chain, which is much easier and more reliable than a 9s chain. I can have one real low gear and several middle range gears even with a 5s. I don't need a 12 or 13, or even a 14 tooth cog for commuting.

A road bike has a narrower BB shell and closer rear dropouts compared to an MTB. You need to be careful with both dimensions to get the thing working. Be careful with MTB hubs on road frames, you need a shorter 130mm axle, and need to repace the hub. You are probably better off with a road hub.
Depending on your terrain, you could build a commuter up with a single, double, or triple chainset. The rear cog count is not too critical, 7/8/9 are all sufficient.
V brake levers and road calipers work but not too well. The cable pull is too much. Cantelever brake levers work better.

With front mechs, you need to match the radius to the chainring diameter. I have a road mech working with an MTB ring (46t). You may have problems working a 52T with an MTB small radius mech.


I use downtube mounted friction levers on my commuter. These minimise any shifting compatibility problems.

two words - single speed

An inexpensive commuter with 105 hubs? Hummmmmmm? If you intend to keep this bike outdoors, I hope bike theft isn't or those hubs could draw some attention. If bike theft is a problem, than lets hope the crooks don't know the difference between a 105 hub and a Magna.

Id agree with Steve. Low-end Shimano components can take the grind of commuting as well as the more expensive ones. My Altus hubs are pretty bomb-proof, but they are handbuilt into very strong wheels.
I have used SIS mechs with no problems, but have gradually upgraded to RSX/105 over the years. The place where you do need a little quality is in the bottom bracket and the headset.
Check out the parts bin of your LBS, you can usually find odd components that are very cheap and usable, ideal on a commuter that may get stolen.