9spd wheelset 7 spd cassette need to make work

[Kritter]

How can I make this work? I have an old bike im rebuilding and have a set of XT wheels I want to put on it but the 7sp cassette isnt large enough. Is there a spacer available to take up the gap? Can I just machine a spacer and not worry about the extra gap so long as I dial in my der stops? Am I going to have der. problems?

Can I use a 9spd cassette and just have 7 of the gears?

The project is about $15 from its $100 budget to get it going again. I was just gonna say screw it and go single speed but the bike will be mostly for people who dont have a bike and want to try out mtb'in so I dont want them getting turned off by a single speed.

Anybody got anything lying around to get me going on this? Need an old 7 spd trigger shift that attaches to the brake lever assembly as it is trick to get it to go through all 7 gears. Something in the ratchet assembly.

[bikeadict]

You can use some PVC pipe (I forget what diameter) just cut it to the size you need. I think this will be the cheapest solution. A slightly more expensive solution would be a SS spacer kit such as Endless Fibonacci spacer kit.
http://www.endlessbikes.com/products...s/spacers.html

Also concerning the using a 9speed cassette with a 7speed shifter.. I'm pretty sure it won't work well, because:
9speed cassettes have a center to center spacing of 4.35mm and 7 speed cassettes have a center to center spacing of 5.0mm... I think then the shifts will be off.

[Pho'dUp]

Nice project!

Bikeadict is right you need a spacer. Most bike shops should have something for you. Or you could just ditch the rear cassette. Run a BMX Cog ($5), spacers, the existing rear derailleur, and use the Front derr. only for a 3 speed bike.

[carbonman]

I think it is something like 4.5mm that goes behind the 7spd cassette. Check Jenson I think they have something listed on their site.

[autoduel]

Originally Posted by bikeadict

You can use some PVC pipe (I forget what diameter) just cut it to the size you need. I think this will be the cheapest solution.

I'd advise against making your own. If it's not cut square, you'll get runout in the cogs. I tried sanding an aluminum spacer down and the cogs ended up wobbling. Any SS spacer will work, or if you have an old cassette, drill out the pins and you'll have 6-8 spacers. Spacers go on the hub first.

[boludo]

Just go to the local LBS and buy some spacers. They look just like headset spacers, just thinner with a bigger diameter. My two 7 speed wheelsets for the old beast are on 9 speed hubs. 2 spacer on each did the job.