Is the spacing on a 7 speed casette (or freewheel) the same as on an 8 speed casette?
I want to know if I can use my old 8 speed shifters on my wife's old 7 speed bike.
Thanks.
I'm sure it is.. I had a lovely set of 7 speed wheels to fit to an 8 speed set up and just dialled out the 8th click via rear mech 🙂
Don't know if this answers question though !!
yeah the spacing for the shifters is for shimano stuff at least.. Ive never had any issues running 8 speed shifters with 7 speed cassette.
for the change to 7 to 8 speed they just widened the freehub and popped an extra cog in..
everything since has just made everything thinner in the same space as an 8 speed cassette.
8sp spacing for shimano differs from 7sp.
that's why the usual trick to "upgrade" 7speed stuff is to take a 9sp cassette, bin 1 sprocket, and run it 8sp with 9sp shifters+mech.
8sp spacing for shimano differs from 7sp.that's why the usual trick to "upgrade" 7speed stuff is to take a 9sp cassette, bin 1 sprocket, and run it 8sp with 9sp shifters+mech.
No it really doesn't.
7 and 8 speed have the same spacing, just the 7 speed cassette is 1 cog& spacer narrower.
9 speed cassettes (and 10 for that matter) are the same width as 8 but with narrower spacing.
So TL:DR 8 speed shifters will work fine on a 7 speed cassette, you'll just have an unused click .
"that's why the usual trick to "upgrade" 7speed stuff is to take a 9sp cassette, bin 1 sprocket, and run it 8sp with 9sp shifters+mech."
so after buying everything else 9 speed you throw a sprocket away to save the cost of a hub.
certainly was never a normal trick where i worked.
shifter pull might be the same
some one better tell the late Sheldon Brown about 4.8mm spacing being equal to 5mm spacing then 😉
Have you ever actually tried this? In real life? With real parts?
EDIT - the 7/8 speed compatability, not the bodging a 9 speed cassette onto a 7 speed freehub.
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Hmmm. Some interesting discussion there.
I checked the good old Sheldon Brown website and it definitely suggests that I need an "alternate cable routing" to get the 8 speed shifters to work perfectly with the 7 speed freewheel.
http://sheldonbrown.com/derailer-adjustment.html#alternate
But I am guessing it will probably work ok (but not perfect) with just the normal routing. The spacing difference is only 0.2mm per shift. If I get the middle rear sprocket perfect, it will only be fractionally (0.6mm) out for the largest and smallest rear sprockets. And they won't get used much.
It'll work fine - I've done it many times with mismatched BSO's coming through the workshop. Shifting will be pretty much what you'd expect from a cheap 7 speed setup 😉
I used 8 speed Shimano bar cons for years on 7 speed cassettes thinking they were also 7 speed. Zero issues in real life. The 0.2mm per click must be taken up by the wobbly top jockey wheel on the der as there's no evidence it's even there.
Yep, it'll work fine. Still running 7 & 8 speed here on the mountain bikes.