chainring replacement help
#1
Full Member
Thread Starter
Join Date: Oct 2012
Location: Santa Barbara
Posts: 317
Bikes: 2011 Surly Cross Check
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 6 Times
in
4 Posts
chainring replacement help
I recently changed out my worn chain and rear cassette on my year 2000 Trek 7000 mountain bike. I am find that I still have drive train issues, my 32 tooth (center) chain ring needs replacement also, as I am getting chain skipping only on this chain ring. I am looking around for replacements and having a bit of trouble identifying exactly what I have. An online Trek manual for the bike identifies the cranks/chain rings as Icon Onyx, 4 arm 44/32/22. My chain ring appears to be 104mm BCD.
My question is this. I can find lots of chain rings, but some of them have the following statement or something similar -
•ChainRings: from Shimano HollowtechII & Octalink MTB cranksets have different length tabs & are not interchangable
My crank set is neither, but I don't know which of these my Onyx cranks are compatible with. Can someone provide some insight on this? I tried searching the shimamo website but could not ever pull up any documents, and they are not accepting email.
I pulled the chain rings off today, and the middle one is marked with Shimano M9 N-32, then opposite this marking is "EB". The large chain ring is similarly marked Shimano M9 N-44, and not too far away is "AE". The smallest chain ring is marked with just "22". The crank is marked with AOB21L 175
I know I have previously replaced at least the outside and middle chain ring previously. The inner one looks pretty clean, so I suspect it is a replacement also.
My question is this. I can find lots of chain rings, but some of them have the following statement or something similar -
•ChainRings: from Shimano HollowtechII & Octalink MTB cranksets have different length tabs & are not interchangable
My crank set is neither, but I don't know which of these my Onyx cranks are compatible with. Can someone provide some insight on this? I tried searching the shimamo website but could not ever pull up any documents, and they are not accepting email.
I pulled the chain rings off today, and the middle one is marked with Shimano M9 N-32, then opposite this marking is "EB". The large chain ring is similarly marked Shimano M9 N-44, and not too far away is "AE". The smallest chain ring is marked with just "22". The crank is marked with AOB21L 175
I know I have previously replaced at least the outside and middle chain ring previously. The inner one looks pretty clean, so I suspect it is a replacement also.
Last edited by sbslider; 08-17-14 at 11:33 AM.
#2
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,656
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5762 Post(s)
Liked 2,534 Times
in
1,401 Posts
Despite no picture, I suspect that your crank arms have supporting shoulders for the middle ring. That means the mounting tab has to be machined in a circle to fit. Many rings are made to fit arms that don't have locating shoulders and therefore won't fit.
Tab with machined circle
wrong tabs
Tab with machined circle
wrong tabs
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Last edited by FBinNY; 08-17-14 at 11:37 AM.
#3
Banned
Hollow tech desire I'm supposing is a whole crankset BB replacement
stick to flat chainrings , when in doubt visit a Bike sdhop where they can see what your kit is
Shimano Chainring guide
octalink has been superseded by the external bearing .. tube fixed into the right crank arm
https://www.google.com/search?q=Shim...ml%3B615%3B461
there are aftermarket suppliers of the 4 bolt chainring ( I'm not recommend any on line sellers, thats up to you)
stick to flat chainrings , when in doubt visit a Bike sdhop where they can see what your kit is
Shimano Chainring guide
octalink has been superseded by the external bearing .. tube fixed into the right crank arm
https://www.google.com/search?q=Shim...ml%3B615%3B461
there are aftermarket suppliers of the 4 bolt chainring ( I'm not recommend any on line sellers, thats up to you)
#4
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,626
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3870 Post(s)
Liked 2,563 Times
in
1,577 Posts
#5
Full Member
Thread Starter
Join Date: Oct 2012
Location: Santa Barbara
Posts: 317
Bikes: 2011 Surly Cross Check
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 6 Times
in
4 Posts
Here are a couple of pictures
Based on these and the advice from FB I think I am looking for a chain ring as he posted with tabs with machined circle.
thank you all for the feedback.
Matt
Based on these and the advice from FB I think I am looking for a chain ring as he posted with tabs with machined circle.
thank you all for the feedback.
Matt
#6
Banned
the tab is so the shift pins & ramps of all 3 are in the right places , relative to the power stroke..
you align them up.. ..
you align them up.. ..
#7
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,656
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5762 Post(s)
Liked 2,534 Times
in
1,401 Posts
If you cannot find the right rings at a reasonable price, you can buy standard ones and file enough off the tabs to clear the shoulders. You'll lose the benefits of the shoulders, which help keep rings concentric and prevent the bolts from working loose, but many cranks these days don't have the shoulders and they work reasonably OK.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#9
Newbie
Join Date: Sep 2014
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
How did it work out? I have the same problem; I have a 2000 trek 7000 but can't find spares advice anywhere.
Which chain ring did you find to replace the worn original that came on the icon onyx crank?
Which chain ring did you find to replace the worn original that came on the icon onyx crank?
#10
Full Member
Thread Starter
Join Date: Oct 2012
Location: Santa Barbara
Posts: 317
Bikes: 2011 Surly Cross Check
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 6 Times
in
4 Posts
It could have been better. The middle chainring worked fine, it was a Shimano Deore M532 32t 104mm 9-Speed Chainring
The outer chainring was a Shimano Deore LX M580 44t 104mm 9-Speed Outer Chainring
I had to dremmel a few places to get it to fit onto the crank properly. Not the end of the world, but I basically wasted the hour or so doing research trying to find one I would not have to modify. The actual work took maybe 10 minutes.
I could not provide advice to you as to how to pick the right outer one without having to modify it. But if you have the tools (file would work, dremel type tool is much easier IMO) it is not a big deal.
The outer chainring was a Shimano Deore LX M580 44t 104mm 9-Speed Outer Chainring
I had to dremmel a few places to get it to fit onto the crank properly. Not the end of the world, but I basically wasted the hour or so doing research trying to find one I would not have to modify. The actual work took maybe 10 minutes.
I could not provide advice to you as to how to pick the right outer one without having to modify it. But if you have the tools (file would work, dremel type tool is much easier IMO) it is not a big deal.
Thread
Thread Starter
Forum
Replies
Last Post
ColonelSanders
Bicycle Mechanics
3
06-04-15 06:28 PM