Crankset/Schwinn Frontier
#1
Junior Member
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Crankset/Schwinn Frontier
I was given a 2000 Schwinn Frontier that I am trying to get back on the road. The middle and large gears on the crankset are damaged beyond straightening. My search so far leads me to think this is a Shimano Tourney crankset. I found two on Amazon with the same tooth count and part number but one is labeled 170mm and the other labeled 175mm. Can someone point me to what I need to measure (on the bike or on the old crank) to make sure I get the proper part? Thanks in advance!
#2
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The old crank should have a marking on the inside of the crankarm next to where the pedal would be attached . It should give the Shimano model number and then usually the length.
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Replacing the crankset sometimes leads to a problem with the chainline, the distance from the center axis of the bike to the middle chainring. You may need a different bottom bracket length to make a new crankset work correctly. If you can find the exact part number, you should be okay.
170 and 175 refer to crank length. There are charts available that show recommendations based on height and inseam.
170 and 175 refer to crank length. There are charts available that show recommendations based on height and inseam.
#4
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The crank arm says TY30. This is the one I hope will work. I can't post the link to Amazon but it is listed as TY501 28/38/48 tooth, 170mm
#5
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And now I may be able to post the link? Amazon.com : SHIMANO Shim CKST Tourney 170 28/38/48 FC TY501 6/7/8SPD W/C Guard : Sports & Outdoors
#6
Really Old Senior Member
I'm an old guy with bad knees. Anything beyond a 165mm length causes pain.
You'll be able to spin 170's a bit faster, but need a slightly lower gear, because of the slight decrease in leverage.
If you're young and tall, get the 175's. If not, go shorter. (shorter also gives that much more ground clearance)
You'll be able to spin 170's a bit faster, but need a slightly lower gear, because of the slight decrease in leverage.
If you're young and tall, get the 175's. If not, go shorter. (shorter also gives that much more ground clearance)
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Crank length is the distance from the center of the bottom bracket axle to the center of the pedal axle. It is often written on the back side of the crank arms (see example photo I was able to quickly google), you can also measure it yourself with a ruler.
Crank length is 170mm, it is written on the back side
Crank length is 170mm, it is written on the back side
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170 or 175 is the length of the crank arm from the center of the pedal spindle to the center of the BB spindle. It’s often labeled on the inside of the crank arm near the middle or near the pedal end.
If you’re off a bit the average infrequent cyclist won’t notice.
Chainline is a much greater concern, though I’ll let others who know those specific cranks chime in on that. I take it the old rings are riveted or one piece rather than replaceable?
If you’re off a bit the average infrequent cyclist won’t notice.
Chainline is a much greater concern, though I’ll let others who know those specific cranks chime in on that. I take it the old rings are riveted or one piece rather than replaceable?
#9
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Yes, riveted and looks to be pretty cheaply manufactured. Makes sense, I think this was the "entry level" MB offering at the time.
#10
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I'm still trying to understand if this TY501 will work in place of my TY30. crankset. I have disassembled the bottom bracket. It is not a sealed unit so, axle with caged bearings. The axle length is 124mm, BB is 68mm. I can look up the specs on the TY501 and TY301 but can't find specs on the TY30. Here's the link to the one I am looking at. Amazon.com : SHIMANO Shim CKST Tourney 170 28/38/48 FC TY501 6/7/8SPD W/C Guard : Sports & Outdoors
Last edited by louky; 08-29-22 at 02:11 PM. Reason: Forgot link
#11
Really Old Senior Member
This says it requires a 122.5mm BB.
https://www.treefortbikes.com/Shiman...kset-28-38-48t
If your existing BB is 124mm, there's a pretty good chance it will work with possible minor adjustments to the limit screws & barrel adjuster.
The offset on the DS may be identical with the difference on the NDS or not. It's a bit of a crap shoot.
Whats the actual "code" on the spindle?
It should be in the form of 3-? with ? being a letter.
https://www.treefortbikes.com/Shiman...kset-28-38-48t
If your existing BB is 124mm, there's a pretty good chance it will work with possible minor adjustments to the limit screws & barrel adjuster.
The offset on the DS may be identical with the difference on the NDS or not. It's a bit of a crap shoot.
Whats the actual "code" on the spindle?
It should be in the form of 3-? with ? being a letter.
#12
Junior Member
Thread Starter
The number on the spindle is 3NN, so it seems that the A and B sides are the same length?
BTW, some of the sealed units I've seen are available in the 122.5 length. Would installing one of these work with the new crankset in case I can't adjust the derailleur correctly?
BTW, some of the sealed units I've seen are available in the 122.5 length. Would installing one of these work with the new crankset in case I can't adjust the derailleur correctly?
#13
Really Old Senior Member
The website I linked to says what? Let them guarantee their words.
#14
Junior Member
Thread Starter
Thanks! I jumped to the chart and didn't look at the link at first. I am confident enough now to order the crankset. If I can't get the adjustments I need after I install the crankset, I will look into the sealed unit. I had no idea that there is so many iterations of these parts. I appreciate your time.