Bicycle Mechanics - Upgrade to 8/9/10-speed
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
08-20-06, 08:53 PM
My road bike, Ironman Master, has a 7-speed cog and rear derailleur. The derailleur is Shimano 600. I'm thinking about upgrading it to more speeds, maybe 8/9/10-speed depending on budget and capability.
I'm not going to change the frame. May I just use the current one with a 8/9/10-speed cog? What should I measure to insure compatibility?
For the parts to be changed, I think that includes cog, rear derailleur and shifter. What else needed? Should I change front derailleur (2 chainring, I want to keep them intact) and shifter?
The cables for front and rear drailleurs look quite old. Does that mean I should change them?
I appreciate any of your suggestion. Thank you very much.
08-20-06, 08:55 PM
I'm not an expert, but it looks like everything you mentioned above.
Plus the rear hub if it's not a shimano-type freehub.
You would have to rebuild the rear wheel with a new hub or at least the hub shell if it can be replaced. The 8, 9, and 10-speed cassettes require a wider freehub. If the frame is steel it can be spread to accept the wider hub. If you want indexed shifting you would need shifters that match the number of cogs. And the chain also needs to be compatible with the number of cogs. Both old derailleurs and the crankset would probably work OK. Most compatibility issues are with the shifters, chain, and number of cogs. Non-indexed friction shifters would also work.
08-20-06, 11:39 PM
Thank you for the information. The frame is steel, and it's down tube indexed shifting. So I can basically keep the frame, and change other stuffs. But can I really keep the old rear derailleur (a Shimano 600, in good condition. I like it)? It's only been used for this 7-speed cog. Can this thing be moved to 8/9/10 positions for upgraded cog?
08-21-06, 12:26 AM
Visit Sheldon Brown's pages:
– Cassettes (http://sheldonbrown.com/k7.html) (which talks about the width of freehub bodies.
– 7, 8, 9 or 10 speeds? (http://sheldonbrown.com/speeds.html)
– Dura-Ace history (http://sheldonbrown.com/dura-ace.html) (which explains compatibility issues beyond the Dura Ace components.
In a nutshell, the freehub body of a 7-speed wheel is narrower than that of an 8, 9 or 10 speed wheel. So you'll either end up with "8 out of 9" speeds (explained towards the end of the cassette page), or you'll need a wider freehub body. You could achieve that by respacing the hub or by spreading the frame (widening the dropouts) and getting a new wider 8/9/10 hub. BTW, spreading the frame can only be done with steel.
Then you need to change the cassette, chain and right shifter. The rear derailleur doesn't care how many speeds you have. No need to change anything on the front end. However, I'm afraid you'll have to buy shifters in pairs and you may find that the new shifters look slightly differently than the old ones. In other words, you might change the front shifter simply because you have it in the box and for the looks.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.