Bicycle Mechanics - Can I Upgrade?

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garrettbuckeye
10-15-07, 10:50 AM
I've got a new 27' wheel coming for my 1980 Motobecane Jubile Sport. I'm planning on switching the DT shifters to bar-ends soon. My question is... Can I upgrade the rear from a 6spd to 7spd? And how hard would it be if possible? Or is it worth having my LBS install the cassette?

Retro Grouch
10-15-07, 10:58 AM
The short answer is you can definitely upgrade to a 7-speed.

The more adequate answer can get pretty long. Potential issues include dropout spacing and repeated bent rear axles. At best, neither will crop up as a problem. Also at best, you won't be gaining much either.
Little Darwin
10-15-07, 11:31 AM
Also, you are probably confusing the term cassette with freewheel.

Freewheels are screw-on and are available in (typically) 5-7 speed and cassettes are locked on either with a lock ring, or the last cog acting as a lock ring, and are available with usually 7-10 speeds (with some 6 speeds)

More info here:

http://sheldonbrown.com/free-k7.html

I am having my LBS build a 27" wheel with a freehub so I can upgrade my bike to use up to 9 cogs... I would change to 700c, but my bike uses Cantilever brakes without the adjustment I would need to get to the 700c rims.

garrettbuckeye
10-15-07, 12:42 PM
Freewheel... very nice. Thank You!

Would I benefit in replacing the 6 spd freewheel with a newer one? w/ shift ramps?
HillRider
10-15-07, 08:02 PM
Freewheel... very nice. Thank You!

Would I benefit in replacing the 6 spd freewheel with a newer one? w/ shift ramps?
You are more likely to find a 7-speed freewheel with ramps and shaped teeth and they should be a direct replacement for your current 6-speed as the overall width is almost the same and they both were intended for 126 mm dropout spacing.

Shimano's 7-speed freewheels are index compatible so they have the improved tooth shape. Nashbar's housebrand freewheels (made by Sun Race) are also index compatible.