7 speed to 8 speed can it be done?

Sir Neil d'Menture

Devout Dirtbag
I have a seven speed wheel. Not a cassette but a freewheel.
Can I simply put an 8 speed freewheel on the wheel and use 8 speed index (Shimano) shifters, or do I have to make some modifications?
 

jimo746

Gold Trader
MacRetro Rider
Feedback
View
Re:

Is it a freewheel? Or a cassette/freehub?

I don't think you can with a freewheel??

If it's the latter then you can put a 8 speed cassette body on there,may need to swap axle spacers around, or red-dish the wheel slightly, I've done it a couple of times and not needed to adjust the wheel though, used an 8 speed STX cassette body and axle the last time.
 

mdvineng

Senior Retro Guru
Feedback
View
It depends on the OLN and frame stay geometry. If your 7 speed looks like it has plenty of spare space between the last sprocket and frame, then it might fit an 8.
 

legrandefromage

Bin Monkey
BoTM Winner
PoTM Winner
GT Fan
Feedback
View
can always play around with the axle spacing to get it to fit, then redish the wheel over

just remember it puts a lot of pressure on the axle and they can snap as the bearing is almost in the middle whereas cassette hubs the bearing is outboard
 

Peachy!

Retrobike Rider
BoTM Winner
rBotM Winner
Claud Butler Fan
Feedback
View
Fit the 8sp, pop it along to your LBS... Bob’s your mothers brother
 
Top