Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

9 speed rear, triple front, FSA claims only 10 speed cassette can be used?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

9 speed rear, triple front, FSA claims only 10 speed cassette can be used?

Old 01-05-14, 08:27 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Dec 2008
Posts: 90
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
9 speed rear, triple front, FSA claims only 10 speed cassette can be used?

Hello all... It's been a long time.

I'd like to swap out my current double chainring set-up, which is a FSA 46t/36t, with a FSA triple 42t/32t/24t. I have a Shimano XT M770 9-Speed Cassette and Shimano 9 speed bar end shifters. I use friction shifting in front and indexing in the rear. I'm aware of chainline and it's importance. I'm also aware I might have to swap out my front derailleur (it would remain friction).

I called FSA to get info about the swap; FSA claims their "42t/32t/24t SUPER TYPE CHAINRINGS FOR SL-K BCD 104/64MM triple" configuration will only work with a 10 speed rear cassette.

I'm skeptical... I don't see why it wouldn't work. Am I forgetting something?
alfred mcdougal is offline  
Old 01-05-14, 08:42 PM
  #2  
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times in 741 Posts
Originally Posted by alfred mcdougal
I use friction shifting in front and indexing in the rear. I'm aware of chainline and it's importance. I'm also aware I might have to swap out my front derailleur (it would remain friction).I called FSA to get info about the swap; FSA claims their "42t/32t/24t SUPER TYPE CHAINRINGS FOR SL-K BCD 104/64MM triple" configuration will only work with a 10 speed rear cassette.
If front shifting remains friction it is highly likely the current fd will work with a triple crank, particularly since the large chainring is only slightly smaller.

As to the "need" for a 10-speed cassette, that makes no sense to me either. Typically the crank has no idea what's going on in back and the overall widths of 9 and 10-speed cassettes are almost exactly the same.
HillRider is offline  
Old 01-05-14, 08:52 PM
  #3  
Senior Member
Thread Starter
 
Join Date: Dec 2008
Posts: 90
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
The only thought I have about the matter is 10 speed sprockets are slightly thinner than 9 speed sprockets. To the best of my knowledge, that's the case. I suppose that means it might be advantageous to machine your chainrings thinner in response to that spec. Also, maybe a 9 speed chain might not work the best with a chainring designed to be paired with a 10 speed chain. But, I can't confirm that... I have to look into it.

Any other thoughts on the matter would be appreciated. Thank you.
alfred mcdougal is offline  
Old 01-05-14, 10:50 PM
  #4  
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,003

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4172 Post(s)
Liked 3,793 Times in 2,272 Posts
I suspect the 10 speed only spec for the FSA triple crank is because of the chain width and possible lift pin catch when in the middle front and small rear combo. Andy.
Andrew R Stewart is offline  
Old 01-06-14, 01:19 AM
  #5  
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,533

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1520 Post(s)
Liked 716 Times in 508 Posts
Originally Posted by Andrew R Stewart
chain width and possible lift pin catch when in the middle front and small rear combo
This could be it, in which case you simply do what is general advice and use the chain appropriate for the highest-speed component in the drivetrain. IIRC 9s and 10s chains have nominally the same inner width; only the outer width significantly differs.

It's hard to say if the smallest cog will be in exactly same spot 9s vs 10s, but any difference would be tiny.
Kimmo is offline  
Old 01-06-14, 08:29 AM
  #6  
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times in 741 Posts
Originally Posted by alfred mcdougal
The only thought I have about the matter is 10 speed sprockets are slightly thinner than 9 speed sprockets. To the best of my knowledge, that's the case. I suppose that means it might be advantageous to machine your chainrings thinner in response to that spec. Also, maybe a 9 speed chain might not work the best with a chainring designed to be paired with a 10 speed chain. But, I can't confirm that... I have to look into it.

Any other thoughts on the matter would be appreciated. Thank you.
I can't say about FSA cranks but I have used 10-speed Shimano cassettes and 10-speed Shimano and Wippermann chains with a 9-speed Shimano crank for over 25,000 miles with absolutely no problems.
HillRider is offline  
Old 01-06-14, 10:23 AM
  #7  
Senior Member
 
Drew Eckhardt's Avatar
 
Join Date: Apr 2010
Location: Mountain View, CA USA and Golden, CO USA
Posts: 6,341

Bikes: 97 Litespeed, 50-39-30x13-26 10 cogs, Campagnolo Ultrashift, retroreflective rims on SON28/PowerTap hubs

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 550 Post(s)
Liked 325 Times in 226 Posts
Originally Posted by alfred mcdougal
I called FSA to get info about the swap; FSA claims their "42t/32t/24t SUPER TYPE CHAINRINGS FOR SL-K BCD 104/64MM triple" configuration will only work with a 10 speed rear cassette.

I'm skeptical... I don't see why it wouldn't work. Am I forgetting something?
The "9 and 10 speed compatible" chain rings on my FSA 50-34 Carbon Pro Compact crank were very close together and the small ring was unusable on the last three small cogs with a 9 speed Campagnolo chain due to rub on the big ring. While I eschew small x small, with a tight cassette that meant no usable overlap between rings which was unacceptable.

OTOH, shimming the big chain ring out to 9 speed spacing (LeTour makes 0.6mm spacers specifically for this purpose, and Wheels Manufacturing also has thin chainring spacers) allowed using all the small cogs and got me some overlap between rings.
Drew Eckhardt is offline  
Old 01-06-14, 11:02 AM
  #8  
Senior Member
 
Join Date: Nov 2009
Posts: 555
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Likes: 0
Liked 10 Times in 8 Posts
Originally Posted by alfred mcdougal
Hello all... It's been a long time.

I'd like to swap out my current double chainring set-up, which is a FSA 46t/36t, with a FSA triple 42t/32t/24t. I have a Shimano XT M770 9-Speed Cassette and Shimano 9 speed bar end shifters. I use friction shifting in front and indexing in the rear. I'm aware of chainline and it's importance. I'm also aware I might have to swap out my front derailleur (it would remain friction).

I called FSA to get info about the swap; FSA claims their "42t/32t/24t SUPER TYPE CHAINRINGS FOR SL-K BCD 104/64MM triple" configuration will only work with a 10 speed rear cassette.

I'm skeptical... I don't see why it wouldn't work. Am I forgetting something?
Nobody who designs components has the time or money to see that they will work with every possible combination. The best that can be hoped is that the components will work for the limited number of combinations that the manufacturer states. Here are some possible considerations behind FSA's disclaimer.

1. Your current setup uses a crankset and chainwheels that are 110 mm BCD. The setup you want uses 104/64 mm BCD.

1a. This means you must change the crankset to one that will accommodate the new chainwheels.

1b. FSA's website states for all their triple cranksets "Compatible with 10 speed systems MTB."

They will not go further than that statement.

Here are some possible reasons for their reluctance.

2. There are different widths for 9 and 10 speed chains (6.4 vs. 5.88 mm)

2a. The spacing between chainwheels on FSA cranks reflects this difference. Therefore a 9 speed chain may not easily fit between two chainwheels on an FSA crankset designed for 10 speeds. N.B. this is different than using a narrower chain on a crankset and/or cassette designed for a wider chain.

3. If you use your 9 speed chain, you may have to place shims on the chainwheel mounting bolts to move the large chainwheel further out and the inner chainwheel further in. You may also have to move drive side bearing further out (with another shim), if the small chainwheel does not clear the frame.

3b. At this point you are definitely not using FSA's crankset and chainwheels as designed. Whether it works depends on your skill not their design.

4. If you change to a 10 speed chain, you will be able to use FSA's crankset and chainwheels as designed.

4a. It's most likely that you will have to change your cassette because of wear.

4b. It's most likely that your new 9 speed cassette will work with your new 9 speed chain. However, the new chain's narrower width will mean that your trim setting will have to be dead on.

There are other considerations regardless of which width chain you choose.

5. The new chainwheel set has an 18 tooth difference rather than a 10 tooth difference.

5a. You may need a new front derailleur with a longer cage because of this bigger difference.

5b. Your rear derailleur may not have an additional 8 tooth wrap capacity. It too might have to be changed.

Given all the components that might have to be changed, you should check the costs and decide whether it's worth it to you.
SBinNYC is offline  
Old 01-06-14, 01:48 PM
  #9  
Senior Member
 
Join Date: Aug 2005
Posts: 1,743
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 329 Post(s)
Liked 209 Times in 133 Posts
People are way over complicating things. It will work fine with a 9 speed cassette and chain.
Canker is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
JWK
Bicycle Mechanics
21
02-26-16 09:33 AM
zjrog
Bicycle Mechanics
25
09-25-15 08:38 PM
williamskg6
General Cycling Discussion
7
09-13-15 12:23 PM
accuracy
Bicycle Mechanics
5
02-21-12 10:45 PM
canobeano
Bicycle Mechanics
6
05-13-10 02:17 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.