8-speed/9-speed question...
06-14-05 | 09:25 AM
#1
Thread Starter
Numbnuts
Joined: May 2005
Posts: 128
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From: Bozeman, MT
Bikes: KHS 555, Trek 820 converted to cruiser/winter bike, Trek 520 singlespeed conversion.
8-speed/9-speed question...
Is it possible to run a 9 speed chain/drivetrain with a crank designed for an 8-speed on temporary basis without mucking something up??
06-14-05 | 09:45 AM
#4
Gone, but not forgotten
Joined: Jul 2002
Posts: 2,301
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From: Newtonville, Massachusetts
Bikes: See: https://sheldonbrown.org/bicycles
Originally Posted by Brad01
Is it possible to run a 9 speed chain/drivetrain with a crank designed for an 8-speed on temporary basis without mucking something up??
Shimano is also concerned about clueless users. The worst-case scenario is that you will be riding along with the bike in its highest gear (large front, small rear) and then for some bizarre reason shift down in front before downshifting in the back. (There is no shift pattern in which it is reasonable to shift in this sequence.) If you [i]do[/] shift this way, there's a small chance that the chain might "skate" over the edges of the teeth for maybe half a turn.
In practice this "problem" almost never materializes. Many, many cyclists are using 9-speed chains with older cranksets and having no problems whatever.
My advice is to go ahead and upgrade your drivetrain, but leave the crankset alone until you've tried it out with the new chain. Most likely, you don't need to do anything to it.
Sheldon "Don't Believe The Marketeers" Brown
Code:
+----------------------------------------------+ | Always store beer in a dark place | | --Robert A. Heinlein | +----------------------------------------------+
06-14-05 | 09:56 AM
#5
Senior Member
Joined: Dec 2004
Posts: 1,509
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From: Quahog, RI
Bikes: Giant TCR Comps, Cdale R5000, Klein Q-Pro, Litespeed Siena, Piasano 105, Redline Conquest Pro, Voodoo Bizango, Fuji Aloha
On my beater, I replaced a 9 speed Tiagra triple crank with an older 8 speed 105 double, no problem many, many miles later.
Aw crap, forgive me Sheldon for answering the question after your expertise has already blessed his configuration.
Aw crap, forgive me Sheldon for answering the question after your expertise has already blessed his configuration.
06-14-05 | 09:57 AM
#6
Senior Member
Joined: Jan 2004
Posts: 9,428
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Originally Posted by Sheldon Brown
There is a lot of confusion about the compatibility of narrow 9-speed chains with older cranksets. Shimano says you should replace the inner chainring(s) with specially designated 9-speed ones, but then they're all too eager to sell you stuff, whether you need it or not.
Shimano is also concerned about clueless users. The worst-case scenario is that you will be riding along with the bike in its highest gear (large front, small rear) and then for some bizarre reason shift down in front before downshifting in the back. (There is no shift pattern in which it is reasonable to shift in this sequence.) If you [i]do[/] shift this way, there's a small chance that the chain might "skate" over the edges of the teeth for maybe half a turn.
In practice this "problem" almost never materializes. Many, many cyclists are using 9-speed chains with older cranksets and having no problems whatever.
My advice is to go ahead and upgrade your drivetrain, but leave the crankset alone until you've tried it out with the new chain. Most likely, you don't need to do anything to it.
Sheldon "Don't Believe The Marketeers" Brown
Shimano is also concerned about clueless users. The worst-case scenario is that you will be riding along with the bike in its highest gear (large front, small rear) and then for some bizarre reason shift down in front before downshifting in the back. (There is no shift pattern in which it is reasonable to shift in this sequence.) If you [i]do[/] shift this way, there's a small chance that the chain might "skate" over the edges of the teeth for maybe half a turn.
In practice this "problem" almost never materializes. Many, many cyclists are using 9-speed chains with older cranksets and having no problems whatever.
My advice is to go ahead and upgrade your drivetrain, but leave the crankset alone until you've tried it out with the new chain. Most likely, you don't need to do anything to it.
Sheldon "Don't Believe The Marketeers" Brown
Code:
+----------------------------------------------+ | Always store beer in a dark place | | --Robert A. Heinlein | +----------------------------------------------+
06-14-05 | 10:05 AM
#7
Thread Starter
Numbnuts
Joined: May 2005
Posts: 128
Likes: 0
From: Bozeman, MT
Bikes: KHS 555, Trek 820 converted to cruiser/winter bike, Trek 520 singlespeed conversion.
Wow, Thanks guys.
I'll still need to replace my crank eventually, the chainrings are not bolted, just rivited (Yuk) and it's flexy and sorta bent too...
Thanks again for your help.
I'll still need to replace my crank eventually, the chainrings are not bolted, just rivited (Yuk) and it's flexy and sorta bent too...
Thanks again for your help.
Last edited by Brad01; 06-14-05 at 10:11 AM.
