Mid 90's mtb
- Thread starter coopey
- Start date
Re:
The OLD (over locknut distance - basically the width between the rear dropouts) is likely to be 130mm (or even 126) if you have 6 speed bolted and the 8 speed will need 135.
If you're really keen to do it and it's a steel frame there's a guide on sheldon brown website for 'cold setting' the frame - basically pulling the rear dropouts apart in a controlled manner. Potentially that will break the frame.
It's sometimes possible to wedge a wider wheel in but it can mess with the indexing, which is gonna be messed with anyway.
Probably best getting a frame that's designed for 8 speed together with the shifters and mech. Often cheaper to get a complete bike too and then switch out the wheels if yours are better
What's your current bike?
The OLD (over locknut distance - basically the width between the rear dropouts) is likely to be 130mm (or even 126) if you have 6 speed bolted and the 8 speed will need 135.
If you're really keen to do it and it's a steel frame there's a guide on sheldon brown website for 'cold setting' the frame - basically pulling the rear dropouts apart in a controlled manner. Potentially that will break the frame.
It's sometimes possible to wedge a wider wheel in but it can mess with the indexing, which is gonna be messed with anyway.
Probably best getting a frame that's designed for 8 speed together with the shifters and mech. Often cheaper to get a complete bike too and then switch out the wheels if yours are better
What's your current bike?
In addition to the above: probably your rear mech will work, as Shimano didn't change any of the fundamental mechanics between 6 and 9 speed MTB derailleurs. An 8 speed shifter should be compatible. However, the mech was never designed for the wider cassette and you may encounter problems, particularly if your frame has thick dropouts.
Usually you will get it to index fine regardless of re-spreading the frame - the critical dimension is the dropout to cassette distance. One issue is that later (7+) speed run with the smallest cog much closer to the frame. Older frames lack the flattened area to give chain clearance which can be problematic with the chain jamming in top gear.
Unless your frame is very special, consider swapping as jaypee says.
Usually you will get it to index fine regardless of re-spreading the frame - the critical dimension is the dropout to cassette distance. One issue is that later (7+) speed run with the smallest cog much closer to the frame. Older frames lack the flattened area to give chain clearance which can be problematic with the chain jamming in top gear.
Unless your frame is very special, consider swapping as jaypee says.
- Feedback
- View
The 6spd mechs will do 9 quite happily but as above not in that frame if you start stretching stays too far.
It is feasible but with work.
if the existing hub is Uniglide, the freehub body can be replaced with an 8spd but you'd have to some surgery to make room or as mentioned, the chain will rub on the stays or the final sprocket will foul the frame.
The back end may need widening a few mm to 130 spacing at minimum, the hub will need redishing to move the rim over and centralise it. but will make for a weaker wheel too.
Lots of tea, biscuits, 3in1 and time should see something emerge.
It is feasible but with work.
if the existing hub is Uniglide, the freehub body can be replaced with an 8spd but you'd have to some surgery to make room or as mentioned, the chain will rub on the stays or the final sprocket will foul the frame.
The back end may need widening a few mm to 130 spacing at minimum, the hub will need redishing to move the rim over and centralise it. but will make for a weaker wheel too.
Lots of tea, biscuits, 3in1 and time should see something emerge.
Similar threads
