Dumb drivetrain questions

RonSonic wrote:
Is there any reason to not use a Shimano road cassette on an off-road
drivetrain? Either 8 speed or 9 speed?

The cassettes I see offered for mountain bikes have cogs I will never use on
both ends. Seems that getting more choices of useful gears would be better than
having a 30, 32, 34 I never use never mind the 11 or 12 I don't have enough
torque or large enough hills for. Something like a 13-28 would be great, but
isn't sold as a "mountain" cassette.

The only issue I've ever had is that MTB derailleurs are designed with
a steeper swing angle than road ones, so the distance from the cog
tends to be a bit unpredictable. My Galaxy currently has a long-arm
mech and I swap between a 11-32 and 12-23 depending on commuting or
touring - the 12-23 has noticeably worse shifting despite the closer
cogs.

13-28 replacing a 11-34 ought to be no problem though.

So any reason to not use the road parts? I've got an 8 speed setup now, but
might convert to 9 when I start replacing this stuff.

Will a 9 speed crankset work well with 8 speed chain and front der? In case I
get a deal and want to start the conversion there.

Thanks all.

Ron

On 26 Jul 2005 08:28:34 -0700, wrote:

ah no the cassettee's are not the same and it's possible that the
application needs a ring shim allowing the cassette lock ring to thread
down tight.

http://sheldonbrown.com/k7.html
| Any Shimano Hyperglide cassette will fit any Shimano Hyperglide hub with the following exceptions:

| * 7-speed hubs only accept 7-speed cassettes.*
(and 7 speed cassettes need a 4.5 mm spacer on 8/9/10s hubs. This is not a
subtle difference.)
| * 2004-2005 Dura-Ace 7800 10 speed hubs only accept Dura-Ace 10 speed cassettes.
| * Many older hubs have a problem with 11 tooth sprockets.

take one road and one ATB in each hand( you got two hands right?) and
gander at the cassette's inboard big cluster side.
the LBS may have a shim selection. get the spectrum and try getting the
cassette on mit shim if the lock ring doesn't screw down tight or
doesn't enter the thread when tried without shims.
i run atb on the road ( no chrome-14 bottom plus 34 custom top)-the
thread entry finesses with opening the standard spacer's (this is the
custom cog spacer plus .5mm shim) holes to accept the ATB's inboard
spacer bumps-and this goes on correctly in one position only!

Shimano cassette bodies, ever since Hyperglide came on, have had identical
spline patterns on road and MTB. For that matter, pre-HG, the UG cassettes
had identical spline patterns as well, just slightly different ones (In
that UG cassettes will fit on HG bodies, but not the other way around).

I suppose it's remotely possible that random cassettes with random hubs
(especially non-Shimano-brand 'compatible' ones) might occasionally need a
subtle extra spacer, but it's not due to Road/ATB differences. If the
cassette is a custom one, I'd wonder if one of the internal spacers wasn't
the wrong one by accident.

Jasper

On 26 Jul 2005 05:46:49 -0700, "Qui si parla Campagnolo"
wrote:



RonSonic wrote:
Is there any reason to not use a Shimano road cassette on an off-road
drivetrain? Either 8 speed or 9 speed?

Nope

The cassettes I see offered for mountain bikes have cogs I will never use on
both ends. Seems that getting more choices of useful gears would be better than
having a 30, 32, 34 I never use never mind the 11 or 12 I don't have enough
torque or large enough hills for. Something like a 13-28 would be great, but
isn't sold as a "mountain" cassette.

So any reason to not use the road parts? I've got an 8 speed setup now, but
might convert to 9 when I start replacing this stuff.

Nope again...the cogsets, regardless of size, are essentially the same
and cross compatible w/o any issue other than PERHAPS needing to
shorten the chain a wee bit.

Will a 9 speed crankset work well with 8 speed chain and front der? In case I
get a deal and want to start the conversion there.


Yep, w/o problem.

Remember, no dumb questions.

Especially if it saves fussing and fixing.

Thanks for the confirmation and everyone else. I had pretty well suspected all
this would work but wanted to verify before accumulating parts.

Thanks everyone else as well.

Ron

On Tue, 26 Jul 2005 23:51:58 +0000, Jasper Janssen wrote:

Shimano cassette bodies, ever since Hyperglide came on, have had identical
spline patterns on road and MTB. For that matter, pre-HG, the UG cassettes
had identical spline patterns as well, just slightly different ones (In
that UG cassettes will fit on HG bodies, but not the other way around).

yup,

My utility bike is an 87 Rockhopper with the short lived UG cassette. the
gears were, much like the OP's, rather inappropriate for city use. I broke
apart a slightly worn Sram HG 8 speed cassette, and used the old spacers
from the original UG to make a city appropriate stack (12-25) Shifts just
fabulously, better than the original, despite the fact (?) that the new
sprockets are slightly thinner than the originals.


I had to grind down on of the spline "teeth" on each of the HG sprockets
to make it work.

the old UG sprockets make awesome single speed cogs and fit great on new
cassettes. They only have twisted teeth, no ramps, so don't cause your SS
to derail.

On Thu, 04 Aug 2005 05:22:44 GMT, maxo wrote:

the old UG sprockets make awesome single speed cogs and fit great on new
cassettes. They only have twisted teeth, no ramps, so don't cause your SS
to derail.

If the teeth are causing your SS to derail, check your chainline and
tension. Also, no derailer cog will ever be as good as a true singlespeed
cog.

Jasper