Ritchey compact crank problem (chain rubbing)

I bought a Ritchey compact crank (110bcd & 50/34 chainrings) to help my
riding in the hills.

It's a great crank, but the problem I'm having is that while on the small
chainring and two smallest cogs, I get the chain rubbing laterally on the
large chainring.

Could this be because I'm still using an 8-speed system, and thus wider
chain (i.e. the chainrings are spaced closer together for 9 and 10 speed
systems?)

Yes, I know I shouldn't use the small/small combo, and I don't. I'd just
like to have it setup so that it doesn't rub in the 2nd smallest cog/small
chainring combo.

Thanks for any advice

"Jason Galarneau" wrote in message
54.202...
| I bought a Ritchey compact crank (110bcd & 50/34 chainrings) to help
my
| riding in the hills.
|
| It's a great crank, but the problem I'm having is that while on the
small
| chainring and two smallest cogs, I get the chain rubbing laterally on
the
| large chainring.
|
| Could this be because I'm still using an 8-speed system, and thus
wider
| chain (i.e. the chainrings are spaced closer together for 9 and 10
speed
| systems?)
|
| Yes, I know I shouldn't use the small/small combo, and I don't. I'd
just
| like to have it setup so that it doesn't rub in the 2nd smallest
cog/small
| chainring combo.

Maybe, but it's as much due to your bike probably having really short
chainstays and there is a measurable larger 50t outer that the chain has
to clear.

Your choices seem to be:
- Don't run the 30 x 12 or 13 combo, you admit you shouldn't be :-)

- Add a bottom bracket space to tweak the chainline. Start with 1mm and
go out. But remember, the farther out you go, you begin to affect the
chainline for your larger cogs in back.

- Use a longer bb. If you have a 108, try an 110. But remember, that
is only moving the crank out by half of the total length, so maybe a
113. Spacers would be a quicker way of determining the chainline.
See Sheldon Browns wise words on chainline he
http://www.sheldonbrown.com/gloss_ca-m.html#chainline

John Rees

I bought a Ritchey compact crank (110bcd & 50/34 chainrings) to help my

riding in the hills.

It's a great crank, but the problem I'm having is that while on the small

chainring and two smallest cogs, I get the chain rubbing laterally on the

large chainring.

This is not un-normal today and you may get some relief by moving the cranks a
bit to the right with spacers. Unless the chain is being picked up by the big
ring it's just annoying. I have a 7 speed/triple CR that did it-I just moved
the crank a bit.
Phil Brown

On Tue, 24 Aug 2004 16:21:02 GMT, Jason Galarneau
wrote:

It's a great crank, but the problem I'm having is that while on the small
chainring and two smallest cogs, I get the chain rubbing laterally on the
large chainring.

Could this be because I'm still using an 8-speed system, and thus wider
chain (i.e. the chainrings are spaced closer together for 9 and 10 speed
systems?)

Yes, I know I shouldn't use the small/small combo, and I don't. I'd just
like to have it setup so that it doesn't rub in the 2nd smallest cog/small
chainring comb

The chain likely ticks the pin shift assist on the big chainring. The
pin sits away from the inner face of the chainring. You might get
enough room to clear the 2nd smallest cog by using a 9sp chain. The
Shimano 9sp chain would give you the best shot.

"Jason Galarneau" wrote in message
54.202...
I bought a Ritchey compact crank (110bcd & 50/34 chainrings) to help my
riding in the hills.

It's a great crank, but the problem I'm having is that while on the small
chainring and two smallest cogs, I get the chain rubbing laterally on the
large chainring.

You should not be using those extreme crossover gears anyway. It has always
been a no-no to use the big/big and little/little gears as the chain is at
an extreme angle causing more wear. With compact chainsets it is even more
of an issue. I have never used the outside 2 or three cogs anyway as things
just start to get too noisy, time to shift up front when that happens.

Tim McTeague

gala- It's a great crank, but the problem I'm having is that while on the
small
chainring and two smallest cogs, I get the chain rubbing laterally on the
large chainring. BRBR

COMMON with this and most anyother crank particularly when the chainring
difference is 16t.

Cogsets are a traveling outward and rings have all sorts of doo-dads that stick
out to make shifting more automatic.

Shift into the big ring and up a couple 'o cogs, same ratio.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

junk- - Use a longer bb. If you have a 108, try an 110. BRBR

Ritchey compacts are octalink only at this point. 109.5 shimano BB...Should NOT
go to a 118mm triple one.

Like I said, I think spacers or anything else is just NOT necessary. It's like
starting your car from a stop sign in 3rd instead of 1st gear...just don't DO
that.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Peter Chisholm wrote:

gala- It's a great crank, but the problem I'm having is that
while on the small chainring and two smallest cogs, I get the chain
rubbing laterally on the large chainring. BRBR

COMMON with this and most anyother crank particularly when the
chainring difference is 16t.

Cogsets are a traveling outward and rings have all sorts of doo-dads
that stick out to make shifting more automatic.

Right. Cross-chaining small/small combinations is a Bad Thing, and the
smaller the chainring, the worse it is.

Shift into the big ring and up a couple 'o cogs, same ratio.

Oops, he means shift _down_ a couple o' cogs! Peter's not alone in this
confusion, but it's a bit surprising in somebody of his general competence.

Shifting the rear to a bigger sprocket is shifting _down_, to a lower
gear. If you have trouble remembering this, think about the direction
the derailer moves.

junk- - Use a longer bb. If you have a 108, try an 110. BRBR

Ritchey compacts are octalink only at this point. 109.5 shimano BB...Should NOT
go to a 118mm triple one.

Like I said, I think spacers or anything else is just NOT necessary. It's like
starting your car from a stop sign in 3rd instead of 1st gear...just don't DO
that.

That's a _very_ good analogy. I may steal it...

Sheldon "Chainline" Brown
+-----------------------------------------------+
| I must have a prodigious quantity of mind; |
| it takes me as much as a week sometimes |
| to make it up. -- Mark Twain |
+-----------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

"Qui si parla Campagnolo " wrote in message
...
| gala- It's a great crank, but the problem I'm having is that while
on the
| small
| chainring and two smallest cogs, I get the chain rubbing laterally on
the
| large chainring. BRBR
|
| COMMON with this and most anyother crank particularly when the
chainring
| difference is 16t.
|
| Cogsets are a traveling outward and rings have all sorts of doo-dads
that stick
| out to make shifting more automatic.
|
| Shift into the big ring and up a couple 'o cogs, same ratio.
|
| Peter Chisholm
| Vecchio's Bicicletteria

Lest you not believe us, look at the numbers from Sheldon's gear inches
calculator
34x12 or 13 is also obtainable with 50x17 or 19. Also, look at how
50x25 (bad idea on the other side) is IDENTICAL to the more acceptable
34 x 17

Gear chart using Gear Inches (courtesy Sheldon 'gear man' Brown)
For 700 X 23 / 23-622 tire with 172.5 mm cranks
With 9-speed 12-13-14-15-17-19-21-23-25 Cassette
34 50
12 74.5 109.5
13 68.7 101.1

14 63.8 93.9
15 59.6 87.6

17 52.6 77.3
19 47.0 69.2
21 42.5 62.6

23 38.8 57.1
25 35.7 52.6

John '18 combos don't mean you really have 18 gears' Rees

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In article ,
Sheldon Brown wrote:
Peter Chisholm wrote:

gala- It's a great crank, but the problem I'm having is that
while on the small chainring and two smallest cogs, I get the chain
rubbing laterally on the large chainring. BRBR

COMMON with this and most anyother crank particularly when the
chainring difference is 16t.

Cogsets are a traveling outward and rings have all sorts of doo-dads
that stick out to make shifting more automatic.

Right. Cross-chaining small/small combinations is a Bad Thing, and the
smaller the chainring, the worse it is.


_ What little actual research I've found suggests that it's not
cross-chaining that's "BAD", but small rear spockets in
general. I.e. it's just as "BAD" to use the Big/small as
the small/small.

_ Personally, I set up my wide range double so I could use these
gears when I want and my chain doesn't seem to be wearing any
faster than average. However, my smallest rear cog is a 14.
I try not to ride in them for long stretches, but I find these
gears useful enough to make them available.

_ If you do buck the wisdom of the experts and add chainring
spacers be very careful to make sure that the chain can't
slip down between the chainrings. If it can, eventually a
shift under load will wedge it there semi-permenantly,
with potentially disasterous results.

_ Booker C. Bense


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