[head1st]

I acquired a free low end Trek MTB thats about 10 years old. The components on the bike function pretty well but the chainrings and cassette have worn or missing teeth on several of the gears. Now I am using this bike as a self taught wrenching 101 bike and I am converting it to a commuter/errand bike. I know that the bike may not be worth saving I some eyes but it serves as an educational experience and it gets me on the bike that much more.

With that said, here is what I need to know. What is the biggest chainring I can put on the bike if I change the front derailer? It currently has a 38 tooth big ring and Altus components. I would really like to get a road double for it if at all possible but I am not sure about the compatibilty. I am also going to change out the rear cassette, possibly upgrading it to an 8 or 9 speed from the existing 7 speed but again I dont know if the frame can accept the new hub.

Any insight into gearing options would be great but I do not want a single speed and I will be upgrading overtime but the chainring has got to go now.

 

[DM-SC]

You can and you can't

Installing a road crank is fairly easy to do as long as you match the derailuer/crank/bottom bracket. You need to make sure there's room (no water bottle cage mounts in the way) to mount the deraileur higher on the seat tube.

The BIG problem is with your wanting to upgrade from 7 speed to 8 or 9 speed. I don't think you will be able to do this due to the spacing of the rear drop outs. The bikes I've seen that have 7 speed are too narrow to fit an 8 or 9sp rear hub. It's possible to spread a steel frame enough to fit the 8/9spd hub. An alloy frame...it's a risky thing to try.

 

[head1st]

thanks

Thanks, the important thing for me is the front, I needed more speed on my morning commute and the 38 tooth just wasn't getting it done. I can live with the 7 speed as soon as i replace the worn components.