[omgBikes]

So, I've always been a Campy guy, but I'm pretty familiar with Shimano stuff, as it's on almost every bike in the shop where I work. I got a little confused with some of the compatibility issues when the 7900 and 6700 stuff came out, but I thought I got it all figured out. However, I ran into an issue tonight. I have a cross bike set up with SRAM Force, but with a 6600 cassette and a 7800 chain. I'm building a new road bike and borrowing some of the components from my cross bike, namely, the wheels. I went to put on my new cassette, which is an 11-25 6700 cassette. The old one is a 12-27 6600 cassette. I'm sliding the cogs of the new cassette on to the freehub body, and I have like 3 left to go, and I think to myself, 'there's going to be space left over.' Sure enough, I slide the 11t cog on, and there's space for a whole other cog. We're not talking slack that would be taken up by the 1mm space that Shimano provides, we're talking major gap here. What's the deal? Am I overlooking something?

 

[estone2]

So, I've always been a Campy guy, but I'm pretty familiar with Shimano stuff, as it's on almost every bike in the shop where I work. I got a little confused with some of the compatibility issues when the 7900 and 6700 stuff came out, but I thought I got it all figured out. However, I ran into an issue tonight. I have a cross bike set up with SRAM Force, but with a 6600 cassette and a 7800 chain. I'm building a new road bike and borrowing some of the components from my cross bike, namely, the wheels. I went to put on my new cassette, which is an 11-25 6700 cassette. The old one is a 12-27 6600 cassette. I'm sliding the cogs of the new cassette on to the freehub body, and I have like 3 left to go, and I think to myself, 'there's going to be space left over.' Sure enough, I slide the 11t cog on, and there's space for a whole other cog. We're not talking slack that would be taken up by the 1mm space that Shimano provides, we're talking major gap here. What's the deal? Am I overlooking something?

Forgot the spacer that goes against the freehub body? Got 9 speeds on there?

 

[frdfandc]

+2 on the forgotten spacer. Shimano 10 speed cassettes require a 1mm (might be 1.5mm) spacer that goes onto the freehub body first, then the cassette. This is due to the narrower overall width of the 10 speed cassette as compared to an 8 or 9 speed cassette.

 

[omgBikes]

Right after I wrote my question, I did decide to go try it with the spacer. The thing is, I'm using Campy wheels, and I therefore have the Shimano freehub body that is made by Campy. For whatever reason, the new cassette sat very low without the spacer (more than 1mm too low). I added the spacer and the 3-4mm of emptiness was gone. I guess it just had to do with how Campy cut the splines in the freehub body. The new cassette is able to sit lower than it is supposed to.