8 speed chain on a 9/10 speed crank?

[RS]

I want to put a newer compact crank on an older down-tube shifter
roadbike and was looking at the Shimano R700 compact, which should
work fine with 9/10 speed chains. But I've got an older 8 speed system
on the bike and its fine for me. Will the 8 speed chain be too wide?

If too wide fixes would be space the inner ring out (not as desireable
because of more chain rub on cross gears) or go to a 9 speed system
(different DT shifters and cassette)??

 

[Qui si parla Campagnolo]

On Jan 26, 12:57 pm, RS <[email protected]> wrote:
> I want to put a newer compact crank on an older down-tube shifter
> roadbike and was looking at the Shimano R700 compact, which should
> work fine with 9/10 speed chains. But I've got an older 8 speed system
> on the bike and its fine for me. Will the 8 speed chain be too wide?

No, it will work fine. The chainring didn't get fatter, the small ring
is a weebit closer is all but nobigdeal.
>
> If too wide fixes would be space the inner ring out (not as desireable
> because of more chain rub on cross gears) or go to a 9 speed system
> (different DT shifters and cassette)??

No need..I have put so called '10s' cranks on many 8s systems..

 

[D'ohBoy]

My Frankenbike has FSA compact "Campy 10" crankset, Campy 10 shifters,
LX hubs/rear der, 8s cassette (Campy 10 shifts a shimano 8 perfectly).

Nice, but I think I will seek out a closer ratio rear cassette (have 12
- 28 and the jumps are too large and the low end with the compact is
not needed). Also, the 135mm rear hub makes for a reduction of one
gear on the rear due to chain rub on the inside of the large ring in 6
- 8. Probably would gain a noiseless cog with a 130 mm rear hub.

The 10 speed crankset is not necessary either. I also ran a Campy 8s
crank with a 10s drivetrain for a long time. Worked fine.

D'ohBoy

 

[A Muzi]

RS wrote:
> I want to put a newer compact crank on an older down-tube shifter
> roadbike and was looking at the Shimano R700 compact, which should
> work fine with 9/10 speed chains. But I've got an older 8 speed system
> on the bike and its fine for me. Will the 8 speed chain be too wide?
>
> If too wide fixes would be space the inner ring out (not as desireable
> because of more chain rub on cross gears) or go to a 9 speed system
> (different DT shifters and cassette)??
>
Should be fine. This is not a critical dimension. If you notice the
chain rubbing in your high rear/low front gear, don't ride there.

Your standard front changer will usually shift well. If you're
dissatisfied, use a compact front changer.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971