Bicycle Mechanics - Inner chain ring removal help please

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I have a busted inner chain ring on my mountain bike...I am assuming I need a crank removal wrench to get to it, right?
There are several types I have seen...which one do I need to get?
Attached are some pictures. Also while I am down there should I repack the bottom bracket?
194981194982
thanks
BikeWise1
03-25-11, 08:48 AM
Well, I would certainly pull the crank. The BB is probably sealed, so no repacking possible. If is it loose, or doesn't spin smoothly, replace it.
Remove the 8MM allen bolt, and if you see a square axle in there, insert standard threaded crank extractor, remove crank. If the BB axle is not square, you will need a different extractor for Octalink. I have heard of folks using a penny along with a standard extractor for Octalink, but have never had to do that. For the BB, you need the tool appropriate to the brand of BB- probably Shimano- and a big wrench.
I am almost positive that is going to be a square taper bottom bracket. Should be able to remove the allen headed fastener and used a standard square taper crank puller.
http://www.nashbar.com/bikes/Product_10053_10052_501866_-1_201538_10000_202573
fietsbob
03-25-11, 09:24 AM
I'm guessing Octalink. the right arm appears to be of the spline connected spider 3 piece type.
arm-spider-lockring.. I have a version from US maker AC, that is what they sought to be compatible with.
Shimagnolo
03-25-11, 09:27 AM
I have that exact crankset on my mtn bike.
You need a standard crank extractor.
The BB is the standard square taper cartridge.
ok...just to understand it all, what is Octalink and how is that different than a standard square taper.
I am pretty adept at figuring things out, but I like to understand it all before I proceed...so how exactly then does onee use the crank extractor?
thanks
Shimagnolo
03-25-11, 09:48 AM
Back out that hex bolt you see in the center of the crank.
Thread in the extractor.
Crank the handle of the extractor to push it's center post into the spindle, and the crank arm comes off.
Forget about Octalink; You don't have it.
blamp28
03-25-11, 09:52 AM
Take a look at these but yours is most likely square taper. as noted above, you can tell for sure by removing the 8mm crank bolt. This was at Sheldon's web site. Bookmark it as a great source if information. http://www.sheldonbrown.com/gloss_n-o.html
http://i27.photobucket.com/albums/c154/blamp28/bbsx4-labeled.jpg
davidad
03-25-11, 10:12 AM
http://www.parktool.com/product/universal-crank-puller-for-square-taper-and-splined-cranks-CWP-7
http://www.parktool.com/product/bottom-bracket-tool-BBT-22
There is a tool to change out the chain ring spider, but I don't remember which one does it. I doubt that you could get the other spider anyway.
blamp28
03-25-11, 11:45 AM
That one is called a Chainring Nut Wrench park CNW-2 http://www.jensonusa.com/store/product/TL406B01-Park+Tool+Cnw-2+Chainring+Nut+Wrench.aspx?sc=FRGL
davidad
03-25-11, 12:04 PM
That one is called a Chainring Nut Wrench park CNW-2 http://www.jensonusa.com/store/product/TL406B01-Park+Tool+Cnw-2+Chainring+Nut+Wrench.aspx?sc=FRGL
The spider that holds the chainrings is removable on that crank. You can use either the 4 bolt shown or a 5 arm spider with the 94 and 58mm bolt circle diameter rings.
This tool fits the spider lock ring: The http://www.parktool.com/product/bottom-bracket-tool-BBT-18 It is used with this piece to hold it in place: http://store.icyclesusa.com/shimano-tl-un75-bike-crank-tool-p1199.aspx
so I thought that the inner chainring would just unbolt...do I need that spider removal tool to remove the inner chainring?
Shimagnolo
03-25-11, 01:43 PM
so I thought that the inner chainring would just unbolt...do I need that spider removal tool to remove the inner chainring?
No
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