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Old 04-02-12, 07:53 PM   #1
macphisto23
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Change crank on Surly LHT

My bike: 2011 Surly LHT - 26" wheels - 56cm
I have to be honest, I am a novice when it comes to bicycle mechanics and lingo. I am looking to switch out my stock surly lht crankset with a new crankset that gears lower. I know that the stock comes with: "Andel RSC6 , 26/36/48t" crankset. I would like to get a crankset of 44/32/22. I have a few questions:

- If I switch out the crankset with a new one would I need to get another bike fitting with the new crankset? Or is it possible to find a crankset that has the same measurements as the stock crankset? If it is not possible how do I determine which crankset will fit my bike?

- Other than the crankset what else would I need to change out?

- Any recommendations as to model?

Thanks in advance
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Old 04-02-12, 07:57 PM   #2
kycycler
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I do not feel that you have to change the crank set to get the results you desire. You just get new chain rings in the combination you specify. There are a lot of good crank set on the market.
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Old 04-02-12, 09:24 PM   #3
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I think the 56cm LHT comes with 175mm cranks. It should be printed on the back of the crank arms. If you choose replacement cranks of the same length, your fit should be unaltered (but your q-factor will change). I'd look at a Shimano Deore 44/32/22 crankset. Higher zoot cranks are nicer but this is the value sweetspot IMO. In addition you will need a Shimano mountain front derailleur to match the larger chainline of Shimano mountain cranks. This setup will make the front and rear halves of your drivetrain line up better than the stock configuration too.
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Old 04-02-12, 09:39 PM   #4
Bill Kapaun
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You won't need another bike fitting with new cranks.
If you go to shorter or longer crank "arms", you'll need to raise or lower you seat the same amount.
We're only talking 0,5 or 10MM.

You MIGHT have to change the BB cartridge to match the new cranks.
You probably should lower the FDER to match the smaller rings, but I have a hunch you might not even notice the difference if you don't.
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Old 04-03-12, 12:58 AM   #5
macphisto23
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I have been looking at these:

Shimano Deore M590 $91.95

Shimano Deore M591 $99.99

Shimano Deore XT $219

Not sure which one I should get? Is the more expensive one worth the money? I am not sure what a "2 piece crankset means"?

Aside from the front derailleur would I also need a new cassette?

Thanks
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Old 04-03-12, 02:00 AM   #6
Bill Kapaun
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According to the Surly website, that bike has a 34 tooth largest cog.
Are you sure you need lower gearing? You should be able to climb walls with a 26/34!

Are you sure you really don't want "more useful" gearing, where you get rid of the 11 tooth cog and space the other cogs a little closer together?
Maybe a cassette change to something like a 12-25 or 12-27 from your 11-34??????
12-13-14-15-17-19-21-23-25
or
12-13-14-15-17-19-21-24-27

I think any Deore crank should be quite serviceable.
I'd personally go for the $99 one WITH the correct bottom bracket.
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Old 04-03-12, 11:40 PM   #7
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Thanks for the help! I just have one last question....

So I purchased the following:

Shimano Deore M591 Crankset

Shimano SLX CS-HG-61 29er Cassette

Will I have any fitting problems with those?

And finally, I am looking for a front derailleur; would this work:

Shimano Deore 9 Speed Mountain Bicycle Front Derailleur - FD-M591

So I won't need a rear derailleur, correct? Or anything else.

Cheers

Last edited by macphisto23; 04-04-12 at 02:12 AM.
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