[kennyo]

I want to upgrade my current rear deraler on my Barracuda. It is a Shimano Exage derailler. I want to upgrade to a SRAM X.7 derailler and shifters. Can I swap out my 7 speed cassette to a 9 speed cassette or will I need a narrrower hub in the back?

 

[Handlebarsfsr]

you'll need a new hub, 7 speed is different than 8/9 speed.

 

[RhinofromWA]

you'll need a new hub, 7 speed is different than 8/9 speed.

Requires a redish I beleive.

If I remember right....

7-8 spd required a redish of the wheel using same chain

8-9 required a narrow chain and new cassette with no dishing change.

To go 7-9 you need a redished wheel chain and gears along with a new derailer......

Someone correct me if I am wrong. But I am pretty sure that is right.

Buy a new rear wheel it is probably in need and you will be happier in the long run. Then a cassete and chain with your Shifter derailer. I am not sure about the front cranks I think they are OK.

 

[Wumpus]

Make sure the rear wheel spacing is 135mm. Some of the older bikes had 130.

 

[binary visions]

Rhino.. I can't exactly tell if you're agreeing with the statement of needing a new hub, but you do.

7spd actually has a different width cassette and freebody than 8spd. 8 and 9spd are the same widths. So you need either a new hub, or a new freebody - which is often available if you go to your LBS.

 

[BikeGeek]

7spd actually has a different width cassette and freebody than 8spd. 8 and 9spd are the same widths. So you need either a new hub, or a new freebody - which is often available if you go to your LBS.

Some of the more recent 7-speed offerings are using a spacer on an 8-speed hub to account for the different cassette size.

 

[kennyo]

Thanks for all the input. I might as well save my money for a new bike. What derailler would you recomend for a 7 speed?

 

[binary visions]

Thanks for all the input. I might as well save my money for a new bike. What derailler would you recomend for a 7 speed?

Derailleurs don't know how many speeds they're shifting for - the indexing is determined by the shifter, not the derailleur. So you can buy an XTR derailleur if you feel like flushing money down the toilet

If you really have the bug to buy something new, just stick with Deore.

 

[Handlebarsfsr]

Derailleurs don't know how many speeds they're shifting for - the indexing is determined by the shifter, not the derailleur. So you can buy an XTR derailleur if you feel like flushing money down the toilet

If you really have the bug to buy something new, just stick with Deore.

problem with that is, you'll have to use a 9 speed chain, which wont work well on 7 speed cassettes and rings. the chain width for 7, 8 and 9 speed is different, and you have to use the correct size chain or smaller or you'll run into problems with the chain jamming.

 

[DßR]

problem with that is, you'll have to use a 9 speed chain, which wont work well on 7 speed cassettes and rings. the chain width for 7, 8 and 9 speed is different, and you have to use the correct size chain or smaller or you'll run into problems with the chain jamming.

Not really. First off, a 9sp chain will work fine. 2nd, a 7/8sp chain works great with a 9sp rear derailleur - I've been running SRAM PC48s with 9sp Shimano rear derailluers since like 1999 and it works perfectly.

 

[binary visions]

problem with that is, you'll have to use a 9 speed chain, which wont work well on 7 speed cassettes and rings. the chain width for 7, 8 and 9 speed is different, and you have to use the correct size chain or smaller or you'll run into problems with the chain jamming.

Actually, I've used a 7spd chain on a 9spd rear derailleur and there were no problems - which is what he would have to do. The reverse is not true, though - a 9spd chain on an older rear derailleur does not fit properly (in my experience).

 

[Handlebarsfsr]

i built a bike for my girlfriend out of old parts, and i used a 9 speed derailleur with a 7 speed drivetrain, and the thing would constantly bind up, especially in the pulleys.. go figure.

 

[budgetrider]

Bikeroom.com has spacers to fit 7 speed cassettes onto 8-9speed freehub bodies. I just used a headset spacer, cut it in half then tapped each half in the middle a few times with a hammer to bend it outwards to fit the diameter of the 8 speed freehub. Then I stuck it in as a spacer before putting on the cassette. Works fine so far.

 

[kinghami3]

Requires a redish I beleive.

I always thought it required a bluish.