8 speed cassette 7 speed hub advice needed

[sephscott13]

Hey all I'm putting my bike together now with x rays and a sram 9.0 woody derailleur both 8 speed. So I went out and picked up a sram 8 speed cassette without thinking that I needed to fit it to a 7 speed dx hub. It didn't fit, was to big for the freewheel so I tried removing the second cog and it is loose when fully tightened. I was going to exchange it for a 7 speed cassette but have been told the spacing is different and shifting will be affected is this true? My only other option I think is to get a spacer so I can fit the 7 gears from the 8 speed cassette and be able to tighten it down properly. Confused.

 

[FluffyChicken]

Your X-Rays are ESP and not SRT800 "X-rays" ? I hope. I don't know if they made the ESP's in the X-Ray style ?


You need the 8 speed cassette, 7 speed have a slightly wider cog to cog spacing so will not work well.
You can do as you say with the 8 and remove one and spacer it from behind a bit, the gaps exaggerated a bit as you have a DX freehub therefor not designed for the 11T cog I assume you have, but it's just more spacers.

or
You either need a new rear hub (be it wheel or not) or switch the freehub body to a newer version and alter your axle and true up the rear wheel to the correct centre spot (called dishing) a new wheel is often easier.

 

[sephscott13]

Right that makes sense but looks like you've just highlighted another problem I assumed the x rays would work fine with the woody what is the difference with the esp?

 

[sephscott13]

Never used sram before and starting to whish I hadn't bothered complicating things

 

[FluffyChicken]

Just checked and they did do the ESP900 in the XRay style.

The difference is the SRAM/ESP is designed with a different style of cable pull per cog position (mech/shifter only) to the Shimano (SRT) setup.
The cassette is the same though.

 

[sephscott13]

Cool I think I'm alright then will check shifter later. Thanks alot.

 

[FMJ]

Re:

Sram makes a specific X-Ray shifter for their 1-1 ratio derailleurs. I remember tossing a few back while looking for 800s in the Bin of Twist Shifters at my LBS.