Replacing Crankset, Can't Find Stock Version
#1
Senior Member
Thread Starter
Replacing Crankset, Can't Find Stock Version
Hi all,
I have a hybrid whose drive train has been neglected far long than it should have been. I'm replacing the chain and cassette, but the chainrings look to cost as much or more to replace than the entire crankset, so I'm just getting a whole new crankset. This is the original hybrid (https://2011.feltracing.com/USA/2011/...0City%203.aspx) which states that it has an SR Suntour XCT-T30848/38/28T crankset (https://www.srsuntour-cycling.com/ind...tail&tnid=1698). Now, I can't find anywhere that actually sells that crankset, so it looks like I need to learn about bottom bracket compatibility and cranksets.
I know that this crankset requires a square taper (the stock bottom bracket is a square-tapered cartridge) and that certain cranksets require certain bottom bracket lengths, but from there, I'm a bit of a newb. Could anyone look at the information that Suntour provides on their site and let me know how it translates into other brands' compatibility?
Example: The Suntour site shows "Compatible bottom bracket: HEXON (BB-XCT-HEXON) / SQUARE (MM110)". Does MM110 = 110mm length and thus allow for an Alivio crankset as per Sheldon Brown's site (https://sheldonbrown.com/bbsize.html)?
Thanks for any help you can provide.
I have a hybrid whose drive train has been neglected far long than it should have been. I'm replacing the chain and cassette, but the chainrings look to cost as much or more to replace than the entire crankset, so I'm just getting a whole new crankset. This is the original hybrid (https://2011.feltracing.com/USA/2011/...0City%203.aspx) which states that it has an SR Suntour XCT-T30848/38/28T crankset (https://www.srsuntour-cycling.com/ind...tail&tnid=1698). Now, I can't find anywhere that actually sells that crankset, so it looks like I need to learn about bottom bracket compatibility and cranksets.
I know that this crankset requires a square taper (the stock bottom bracket is a square-tapered cartridge) and that certain cranksets require certain bottom bracket lengths, but from there, I'm a bit of a newb. Could anyone look at the information that Suntour provides on their site and let me know how it translates into other brands' compatibility?
Example: The Suntour site shows "Compatible bottom bracket: HEXON (BB-XCT-HEXON) / SQUARE (MM110)". Does MM110 = 110mm length and thus allow for an Alivio crankset as per Sheldon Brown's site (https://sheldonbrown.com/bbsize.html)?
Thanks for any help you can provide.
#2
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If you are going to replace your crankset it would seem logical (to me) to replace the BB as well. It would then be a simple matter of following the manufacturer's recommendations for the correct BB for your crankset, rather than try to find a crankset which might or might not fit your old BB.
#3
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As long as you're staying with square taper, the crank will fit the spindle. Don't worry about your old cranks BB capability, just look up the suggested spindle length for the new crankset, measure yours and compare. As long as they match pretty closely, you're OK. Otherwise, worst case, you buy a new spindle (for loose cup BBs) or a new BB entirely.
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An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“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.
#4
Still learning
Newbies spend way too much time overthinking a crankset replacement. Your BB is 110mm wide, it is probably square tapered, so don't bother replacing it.
Any MTB triple crankset will do, you can find them used or new, and it doesn't have to be Suntour. Shimano, Coda, FSA should all be fine as long as it is square taper. If the number of teeth vary a little, it won't be the end of the world.
You should look for a crankset with alloy chainrings rather than steel. Much lighter, rust free, and they look a lot better. For a $549 MSRP bike, you shouldn't have to spend more than $60. I've found used Shimano Deore for $40 or so. You'll also need a crank puller ($15) and a pedal wrench too.
Any MTB triple crankset will do, you can find them used or new, and it doesn't have to be Suntour. Shimano, Coda, FSA should all be fine as long as it is square taper. If the number of teeth vary a little, it won't be the end of the world.
You should look for a crankset with alloy chainrings rather than steel. Much lighter, rust free, and they look a lot better. For a $549 MSRP bike, you shouldn't have to spend more than $60. I've found used Shimano Deore for $40 or so. You'll also need a crank puller ($15) and a pedal wrench too.
#5
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I've got a couple older used ones that would have the rings jammed against the chainstay if used with a 110MM spindle.
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+1 The offset of the rings is all over the place which is why crankset manufacturers make specific spindle (BB) length recommendations, and why they make so many different ones. In the OPs case the BB presumably has as many miles as the chainrings which are worn out. Replacing it with a new one which is assured to fit makes sense to me. Trying to find a crankset which fits the old BB instead is kind of like the tail wagging the dog.
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I agree that trying to but a crankset to match a specific BB is too limiting, if not impossible. But once having settled on a new crankset, it's simple enough to measure the existing spindle to see whether or not it's the right length. A measurement is quick and free, and can save you not only the cost of a new BB, but the time & tools involved in the changeover.
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An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“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.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“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.
#8
Senior Member
#9
Still learning
Davidad, doesn't a $150 new crankset on a bike originally priced at $549 seems excessive?
The Op's bike is one year old, as his link is to a 2011 model. There are no photos, but how bad can the drivetrain or bb cartridge be, unless it has been thru salt, sand, and crud?
I have pulled some triples off of 113mm bb's. A 3cm difference from 110cm is less than an 1/8 of an inch. It's worth trying the fit before spending $25+ on a new bb cartridge.
The Op's bike is one year old, as his link is to a 2011 model. There are no photos, but how bad can the drivetrain or bb cartridge be, unless it has been thru salt, sand, and crud?
I have pulled some triples off of 113mm bb's. A 3cm difference from 110cm is less than an 1/8 of an inch. It's worth trying the fit before spending $25+ on a new bb cartridge.
Last edited by oddjob2; 10-06-12 at 08:55 PM.
#10
Senior Member
Thread Starter
Hey all. Thanks for the fantastic input. With a currently blown knee, my significant other isn't letting me hobble downstairs to the garage to check all the measurements just yet, but I've committed everything to memory. I believe the bottom bracket is in good condition. There are no knocks, crunches, bends, or anything else. A new crankset may show a weakness there, but since I'm already replacing the cassette, chain, and crankset, I'm going to lead with a bit of hope that I will not need to replace that too. If I do, well, that's the way the dice roll.
Davidad - that's a very pretty crankset, but as others have noted, this is my workhorse hybrid and I'm more likely to pull another crankset from a junked bike than spend over $40 for a new one. Thank you for the link, regardless.
Davidad - that's a very pretty crankset, but as others have noted, this is my workhorse hybrid and I'm more likely to pull another crankset from a junked bike than spend over $40 for a new one. Thank you for the link, regardless.