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Discussion Starter · #1 ·
The time has come replace the chainrings on my old (circa 2001) Deore chainset, which is equipped to a GT XCR 3000.

I'll be running an 8 speed chain so I was looking at these Alivio outer and Alivio middle rings.

For less money I could get myself an 8 speed Truvativ Isoflow chainset.

The bike will not be used a great deal as my single speed has taken over mountain biking duties.
The only use the old bike is likely to get is the odd bit of light downhilling a few times a year.

Should I just go for the new chainset? The Truvativ on my GT Peace has been good so far.
 

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Old man on a bike
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Depends. Cost of a set of chainrings can often exceed a whole new crank crazy as that seems. Then there's the possible additional cost of a bottom bracket you might need. You might look at a new external type crank that comes with a bottom bracket for cost effectiveness. Do you even know if both those square taper cranks use the same length spindle on the bottom bracket? They're not all the same, didn't look it up myself...
 

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Discussion Starter · #3 ·
Thanks for the reply.

Bikinfoolferlife said:
Depends. Cost of a set of chainrings can often exceed a whole new crank crazy as that seems.
In this case it does, quite dramatically considering the chainrings are only Alivio ones.

Do you even know if both those square taper cranks use the same length spindle on the bottom bracket? They're not all the same, didn't look it up myself...
I wasn't aware there were different spindle sizes on square taper bbs, never had to replace one.
Will some chainsets only be compatible with certain bb spindle sizes?
 

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RichyX said:
Thanks for the reply.

In this case it does, quite dramatically considering the chainrings are only Alivio ones.

I wasn't aware there were different spindle sizes on square taper bbs, never had to replace one.
Will some chainsets only be compatible with certain bb spindle sizes?
Yes, they're specific; some consistency with some but depends on specific model number (look on the back of your crank arm near the pedal threads). Here's Sheldon Brown's list of bb compatiblility with cranks up to a point (since he's passed on) which is pretty decent for square tapers in any case http://sheldonbrown.com/bbsize.html, plus filled with links to relevant subjects.
 

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If you like your current crank arms, just keep them. You could buy the *chainset, strip the rings off, and use them to replace the ones on your current crank arms. It's cheaper than buying the individual rings. Sorted.

*chainset - that's a crankset for us Yanks. I had to use an English to English converter to work it out. :thumbsup:
 

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RichyX said:
Which heading on Sheldon Brown's list refers to the length of the spindle?

It doesn't list that specific Truvativ model but the ones it does include seem very similar in spec to the Deore I currently own.
Uh, the heading is the third one, the one that says "length" and has numbers ranging in the low 100's (millimeters). The Truvativs you're looking at are too new for that list. Maybe SRAM's site has specs for the Isoflow but I think they kept to the same lengths as the ones that are on Sheldon's list, not sure.

Which Deore model do you have?
 

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Discussion Starter · #8 ·
Bikinfoolferlife said:
Uh, the heading is the third one, the one that says "length" and has numbers ranging in the low 100's (millimeters). The Truvativs you're looking at are too new for that list. Maybe SRAM's site has specs for the Isoflow but I think they kept to the same lengths as the ones that are on Sheldon's list, not sure.

Which Deore model do you have?
It's the basic Deore model from the year it was launched (2000 maybe).
The length is listed as 110-113 on Brown's site.

Truvativ's spec pdf doesn't have a comparable heading. The crank length and BCD are the only things listed really.

The Truvativ's listed on Brown's site are 113.
 

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RichyX said:
It's the basic Deore model from the year it was launched (2000 maybe).
The length is listed as 110-113 on Brown's site.

Truvativ's spec pdf doesn't have a comparable heading. The crank length and BCD are the only things listed really.

The Truvativ's listed on Brown's site are 113.
Duh, only one plain ol' Deore on there (was thinking of all the listings literally starting with "Deore"). I'm thinking you more likely have the 110 installed now (but best for you to check it), which still might yield a decent chainline with the Truvativ crank, possibly you could tweak it with just a spacer on the drive cup if needed.
 
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