Changing the chainring

[benb]

Hi all

I need to replace the chainring on my bike. I've done the cassette with no issues, so I'm happy that I can do it without recourse to the LBS.

I just want to know whether I need a special tool. Do I need a crank extractor?

Thanks.

 

[MacB]

Depends on what cranks/BB you have

 

[benb]

According to the specs it's a Shimano FC-M443

 

[MacB]

is that square taper or octalink? I haven't dealt with the latter so don't know exactly what's needed but I thought it was still a square taper fitting. If so then either would require a crank puller unless you happen to have self extracting crank bolts(unlikely).

Epsom isn't that far from here, if you want to pootle over some time then I'll show you how to do this.

 

[ianrauk]

Here are the tech docs.
You will need a crank puller such as this one for a tenner from Merlin Cycles.

And there are plenty of You Tube tutorials.

 

[guitarpete247]

Are you just changing 1 of your chainrings if so check the BCD to find the size you need. Sheldon has the measurements you need to work this out. Then check that your front derailleur will accept the new range of rings if you are going for something different to the original. If fitting the same size as your old ring is worn then apart from the correct allen key usually 5mm and either a large flat screwdriver (stubby is best) or the correct chainring nut tool. Either of these for your size chainring nut.

or

.
You may not even have to remove the crank arm or the pedal so crank extractor might not be necessary (though is a usefull tool to have) . I didn't last time I replaced the outer chainring.

Looking up your crank set it does look like you will need the crank extractor.

 

[byegad]

If it's a big ring then you can leave the crank arm alone and undo the chain ring bolts with Allen keys.

 

[benb]

I'm not changing the size - just need to replace as they're worn.

I might as well grab a crank extractor so I can do it properly.

Can anyone advise which of the chainrings I should be getting:
http://www.wiggle.co.uk/shimano/chainrings/

The specs are Shimano FC-M443, 48/36/26

Thanks all, the hivemind is indeed knowledgeable!

 

[benb]

Or would it be cheaper/easier to just get this:
http://www.wiggle.co.uk/shimano-deore-m590-9-speed-chainset/

 

[PpPete]

This will work fine for the inner: http://www.wiggle.co.uk/shimano-64-pcd-deore-m510-4-arm-inner-chainring/
middle: http://www.wiggle.co.uk/shimano-104-pcd-deore-m510-4-arm-middle-chainring/
Cant find a cheap outer 104 BCD at Wiggle....
CRC have thme though: http://www.chainreactioncycles.com/...le&utm_medium=Shopping&utm_name=UnitedKingdom

 

[benb]

This will work fine for the inner: http://www.wiggle.co.uk/shimano-64-pcd-deore-m510-4-arm-inner-chainring/
middle: http://www.wiggle.co.uk/shimano-104-pcd-deore-m510-4-arm-middle-chainring/
Cant find a cheap outer 104 BCD at Wiggle....
CRC have thme though: http://www.chainreactioncycles.com/...le&utm_medium=Shopping&utm_name=UnitedKingdom

Thanks. Might as well get the whole lot from CRC in that case. Better luck next time Wiggle.

 

[RecordAceFromNew]

Worth checking if it is economical to change rings. Sjs sells an octalink one e.g. for £30.

The other thing is to check if it is square tapered or octalink (if the bb is ok). For the former you should be able to see the bb spindle having square sides when it enters the chainset. No crank extractor tool is required to remove octalink chainset.

 

[benb]

Worth checking if it is economical to change rings. Sjs sells an octalink one e.g. for £30.

The other thing is to check if it is square tapered or octalink (if the bb is ok). For the former you should be able to see the bb spindle having square sides when it enters the chainset. No crank extractor tool is required to remove octalink chainset.

Thanks. It's definitely Octalink. So I should be OK without a crank extractor?

 

[benb]

Here's my shopping list. Anything else I need? (I already have the lockring tool and chain whip for the cassette)
Shimano Deore Chainring Outer M510 4-Bolt 104mm 48t Silver 9sp
Shimano Deore Chainring Middle M510 4-Bolt 104mm 36t Silver 9sp
Shimano Deore Chainring Inner M510 4-Bolt 64mm 26t Silver 9sp
Park Tool Chainring Nut Wrench
Cyclo Cotterless Crank Extractor With Handle, Splined (will remove on confirmation that Octalink does not need a tool)
Shimano HG73 Chain 9 Speed
Shimano HG50 9 Speed Deore Cassette 11-34

 

[PpPete]

Most crank extractors have a magnetic button that can be used to turn a square taper extractor into one for Octalink styles. They are sometimes needed.
Oh - and make sure you remove that button BEFORE using one to remove a square taper crank. DO NOT ASK ME HOW I KNOW THIS !