7/8 speed compatibility

Overview Chat Bike Members News Women

This topic has 5 replies, 5 voices, and was last updated 6 years ago by theotherjonv.

Viewing 6 posts - 1 through 6 (of 6 total)

7/8 speed compatibility
theotherjonv
Full Member

Picked up a bike for my daughter which is 3×7 equipped. I want to convert to trigger shifters, she finds the gripshift difficult and looking at kit I can get 3×8 shifters and a cassette for not much more than the cost of the 3×7 triggers

I am right in recalling that 7 and 8 speed are the same chain width, aren’t they? Am I missing anything?

Posted 6 years ago

maccruiskeen
Full Member

3×8 shifters and a cassette

The wheel might not be compatible – weren’t 7sp and 8/9sp hubs different? Look and see if theres a spacer in there. The chain was the same width so the cassette (and therefore the free hub) had to be wider for 8sp

Posted 6 years ago

Junkyard
Free Member

what they said cassette on 8 is wider and 8/9 was same with spacer needed for 8 speed

& works with 7 speed only

Posted 6 years ago

hols2
Free Member

As above, the 7 speed cassette is narrower than the 8 speed. You can fit a 7 speed onto an 8 speed hub with a spacer, but not vice-versa.

Posted 6 years ago

thecaptain
Free Member

You can just use the 8 speed shifters on 7 speed cassette. It’s not perfect but works well enough (4.8 vs 5mm gaps on cassette IIRC). We swap regularly on our tandem – touring and race wheel are 8 and 7 speed respectively.

Posted 6 years ago

theotherjonv
Full Member

The chain was the same width so the cassette (and therefore the free hub) had to be wider for 8sp

good spot – will have a look in a bit

Posted 6 years ago