Can you identify this crankset?
01-06-24, 10:43 AM
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Can you identify this crankset?
Hi,
As a relative newb, I can't post photos, but there are three of the crankset in my gallery:
bikeforums.net/g/album/edit/page/1/?album_id=32210866
I'm trying to find a replacement for this crankset.
Doesn't have to be the same model, but just the right type and dimensions. I initially bought a Shimano FC-TY501 to replace it, which is fine except q-factor is much wider (further between pedals): 185.5mm. See them side by side in this photo:
bikeforums.net/g/picture/32273755
Only about half the gears can be reached with this new Shimano chainset, I assume because the chainline is out due to wider q-factor. Otherwise it's right:
- crank arm is 170mm
- BB type: square
Don't mind about the chainring teeth. Just want the gears to work. Is there a best way to measure the q-factor?
Many thanks
As a relative newb, I can't post photos, but there are three of the crankset in my gallery:
bikeforums.net/g/album/edit/page/1/?album_id=32210866
I'm trying to find a replacement for this crankset.
Doesn't have to be the same model, but just the right type and dimensions. I initially bought a Shimano FC-TY501 to replace it, which is fine except q-factor is much wider (further between pedals): 185.5mm. See them side by side in this photo:
bikeforums.net/g/picture/32273755
Only about half the gears can be reached with this new Shimano chainset, I assume because the chainline is out due to wider q-factor. Otherwise it's right:
- crank arm is 170mm
- BB type: square
Don't mind about the chainring teeth. Just want the gears to work. Is there a best way to measure the q-factor?
Many thanks
Last edited by cycle_plaza; 01-06-24 at 02:43 PM.
01-06-24, 10:54 AM
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Last edited by Iride01; 01-06-24 at 11:27 AM.
01-06-24, 11:04 AM
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q-factor is the width between the two planes the crank arms spin in where the pedals attach. Or something like that. It only affects how wide you have to put your feet. Not your chain line.
Unless you have physical limitations from a injury or something, then you should be able to handle a pretty good range of q-factor from narrow to wide. Your bicycle though will need a crank that gives it the proper chain line of the rings to the rear cassette. So unless you have a real need for q-factor, then ignore it.
Square tapers are a very old thing even long before the days of cartridge BB's. And there weren't any standards for what chain line all cranks should give with any particular length BB. So it's somewhat of a trial and error if you don't know what chain line that crank gives with any particular length BB. Though with cartridge BB's it's less so. But I happily left the mess and confusion of square tapers and put Shimano hollowtech II cranks in my old bikes with BSA threaded BB shells and the old cup, cone and spindle square tapers. It makes getting new cranks and BB's less of a hassle.
So hopefully some of the people that deal with square tapers will chime in to give you better help. If you are up for a entire crank change and BB change, then ISIS, Octalink II or Hollowtech II type cranks will make future stuff a little easier on you. And give you more selection of cranks to choose from. You have a BSA threaded shell. So a lot of choice is out there.
If you have the original crank on the bike, then the chain line can be measured from the centerline of the seat tube to the center plane between the stack of rings. On a 3x it'll be the middle ring. On a 2x the middle or the space between them. On a 1x... well obviously the only ring you can measure to. <grin>.
Chain line is actually determined by the gears on the rear wheel of your bike. So the number of gears on the rear, the drop out spacing and the wheel dish all work together to determine that. But since that is somewhat standardized, just knowing the number of gears and what type of bike it is will help get a really good guess of it so you'll know what chain line your front crank should be..
Unless you have physical limitations from a injury or something, then you should be able to handle a pretty good range of q-factor from narrow to wide. Your bicycle though will need a crank that gives it the proper chain line of the rings to the rear cassette. So unless you have a real need for q-factor, then ignore it.
Square tapers are a very old thing even long before the days of cartridge BB's. And there weren't any standards for what chain line all cranks should give with any particular length BB. So it's somewhat of a trial and error if you don't know what chain line that crank gives with any particular length BB. Though with cartridge BB's it's less so. But I happily left the mess and confusion of square tapers and put Shimano hollowtech II cranks in my old bikes with BSA threaded BB shells and the old cup, cone and spindle square tapers. It makes getting new cranks and BB's less of a hassle.
So hopefully some of the people that deal with square tapers will chime in to give you better help. If you are up for a entire crank change and BB change, then ISIS, Octalink II or Hollowtech II type cranks will make future stuff a little easier on you. And give you more selection of cranks to choose from. You have a BSA threaded shell. So a lot of choice is out there.
If you have the original crank on the bike, then the chain line can be measured from the centerline of the seat tube to the center plane between the stack of rings. On a 3x it'll be the middle ring. On a 2x the middle or the space between them. On a 1x... well obviously the only ring you can measure to. <grin>.
Chain line is actually determined by the gears on the rear wheel of your bike. So the number of gears on the rear, the drop out spacing and the wheel dish all work together to determine that. But since that is somewhat standardized, just knowing the number of gears and what type of bike it is will help get a really good guess of it so you'll know what chain line your front crank should be..
Last edited by Iride01; 01-06-24 at 11:33 AM.
01-06-24, 11:09 AM
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Hi,
As a relative newb, I can't post photos, but they are the three of the crankset in my gallery:
bikeforums.net/g/album/edit/page/1/?album_id=32210866
I'm trying to find a replacement for this crankset.
Doesn't have to be the same model, but just the right type and dimensions. I initially bought a Shimano FC-TY501 to replace it, which is fine except q-factor is much wider (further between pedals): 185.5mm. See them side by side in this photo:
bikeforums.net/g/picture/32273755
Only about half the gears can be reached with this new Shimano chainset, I assume because the chainline is out due to wider q-factor. Otherwise it's right:
- crank arm is 170mm
- BB type: square
Don't mind about the chainring teeth. Just want the gears to work. Is there a best way to measure the q-factor?
Many thanks
As a relative newb, I can't post photos, but they are the three of the crankset in my gallery:
bikeforums.net/g/album/edit/page/1/?album_id=32210866
I'm trying to find a replacement for this crankset.
Doesn't have to be the same model, but just the right type and dimensions. I initially bought a Shimano FC-TY501 to replace it, which is fine except q-factor is much wider (further between pedals): 185.5mm. See them side by side in this photo:
bikeforums.net/g/picture/32273755
Only about half the gears can be reached with this new Shimano chainset, I assume because the chainline is out due to wider q-factor. Otherwise it's right:
- crank arm is 170mm
- BB type: square
Don't mind about the chainring teeth. Just want the gears to work. Is there a best way to measure the q-factor?
Many thanks
This site says it takes a 122.5. If you are using the 111 it won't work.
https://www.treefortbikes.com/Shiman...kset-28-38-48t
Last edited by curbtender; 01-06-24 at 11:15 AM.
01-07-24, 05:29 AM
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Super useful info. Indeed I should have gone with a more modern BB, would have allowed wider variety of cranksets and easier fitting. Curbtender, that pic is of old BB, new one (Shimano bb-UN101) is indeed 122.5 and the crankset fits fine.
New crankset (Shimano FC-TY501) is fine after all. Was a combination of the rear wheel being slightly misaligned due to skewer not being positioned correctly, and both derailleurs needed adjusting to accommodate the bigger crankset. Now all gears are being reached :-)
Completed my first ever complete drivetrain replacement. Crankset, cassette, chain, BB, and back wheel for good measure. Very satisfying. I did a 250 mile four day tour last year and my old rusty chain snapped climbing a hill in the middle of nowhere. Confident won't happen in this summer's tour. Thanks so much to everyone who's responded on this great forum.
New crankset (Shimano FC-TY501) is fine after all. Was a combination of the rear wheel being slightly misaligned due to skewer not being positioned correctly, and both derailleurs needed adjusting to accommodate the bigger crankset. Now all gears are being reached :-)
Completed my first ever complete drivetrain replacement. Crankset, cassette, chain, BB, and back wheel for good measure. Very satisfying. I did a 250 mile four day tour last year and my old rusty chain snapped climbing a hill in the middle of nowhere. Confident won't happen in this summer's tour. Thanks so much to everyone who's responded on this great forum.
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