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Discussion Starter · #1 ·
i recently bought an 1980s touring bike (trek 520) on ebay. it arrived and the crank (a triple) needs to be replaced (spider is damaged so the rings don't rotate in a single plane). i'm going to be using the bike principally as a commuter (35 minute rides each way) and some longer rides (two to four hours) on weekends.

i am fairly new to cycling and don't know enough about cranks to know at what price point i should be looking for new cranks - i wasn't expecting to have to replace them and was surprised to find them damaged, but that's another story. i don't have a fortune to spend and don't even know exactly what criteria i should be using to buy new cranks. i do have some questions (below) but am open to any unsolicited advice forum members might have.

questions:

1. should i be looking for new or used cranks?
2. the chain rings look to be in decent shape, so should i simply be looking for crank arms or buy arms with rings - seems like most online vendors sell the cranks with rings, so i'm guessing the savings would be marginal if i just bought new crank arms without rings.
3. which manufacturers are likely to be compatible with my bb? i know nothing about bottom brackets, but i do expect that, say, campy cranks (which are probably too expensive for me) would be incompatible with my bb since i have shimano cranks on them now.
4. i've looked at nashbar and seen that they have some of their house triple cranksets at a fairly low price, at least relative to the other cranks they sell. for my purposes, would their cranks be sufficient? is the difference between their product aesthetic, performance, or what? i should note that i do not have 9 or 10 speed casettes, which the top of the line cranks seem to be designed for.

anyway, here are links to the two nashbar triples:

http://www.nashbar.com/profile.cfm?...and=&sku=11462&storetype=&estoreid=&pagename=

and

http://www.nashbar.com/profile.cfm?...and=&sku=15121&storetype=&estoreid=&pagename=

5. i have seen on some other sites that the sugino xd is advertised as a great value (at about 110 dollars. what would be the difference between it and, say, one of the nashbar ones i've listed above.

i'm sure that some of these questions are silly or that they've already been dealt with on the site. but i've done several searches and haven't really been able to find answers to my questions. i'd be grateful for any and all help.

thanks,
jason
 

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navakahn said:
i recently bought an 1980s touring bike (trek 520) on ebay. it arrived and the crank (a triple) needs to be replaced (spider is damaged so the rings don't rotate in a single plane). i'm going to be using the bike principally as a commuter (35 minute rides each way) and some longer rides (two to four hours) on weekends.

i am fairly new to cycling and don't know enough about cranks to know at what price point i should be looking for new cranks - i wasn't expecting to have to replace them and was surprised to find them damaged, but that's another story. i don't have a fortune to spend and don't even know exactly what criteria i should be using to buy new cranks. i do have some questions (below) but am open to any unsolicited advice forum members might have.

questions:

1. should i be looking for new or used cranks?
2. the chain rings look to be in decent shape, so should i simply be looking for crank arms or buy arms with rings - seems like most online vendors sell the cranks with rings, so i'm guessing the savings would be marginal if i just bought new crank arms without rings.
3. which manufacturers are likely to be compatible with my bb? i know nothing about bottom brackets, but i do expect that, say, campy cranks (which are probably too expensive for me) would be incompatible with my bb since i have shimano cranks on them now.
4. i've looked at nashbar and seen that they have some of their house triple cranksets at a fairly low price, at least relative to the other cranks they sell. for my purposes, would their cranks be sufficient? is the difference between their product aesthetic, performance, or what? i should note that i do not have 9 or 10 speed casettes, which the top of the line cranks seem to be designed for.

anyway, here are links to the two nashbar triples:

http://www.nashbar.com/profile.cfm?...and=&sku=11462&storetype=&estoreid=&pagename=

and

http://www.nashbar.com/profile.cfm?...and=&sku=15121&storetype=&estoreid=&pagename=

5. i have seen on some other sites that the sugino xd is advertised as a great value (at about 110 dollars. what would be the difference between it and, say, one of the nashbar ones i've listed above.

i'm sure that some of these questions are silly or that they've already been dealt with on the site. but i've done several searches and haven't really been able to find answers to my questions. i'd be grateful for any and all help.

thanks,
jason

If it's an 80's bike, it probably has square bottom bracket spindles. If so, the ISIS trekking crankset would not fit onto your existing bottom bracket spindle. The Nashbar road crankset would. An ISIS crankset must be used with an ISIS bottom bracket,
For commuting, that crankset is fine. Somewhere on your old crankset should be stamped the length of the cranks, anywhere from 160-180mm. Whichever crankset you buy should be the same length as your old cranks.
In your case, you probably should get cranks with rings. If your spider is damaged, there's a good chance your rings are bent also.
 

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You'll probably just want to get a new bb--I'm guessing your older cranks came with a pretty wide spindle, which won't work with newer cranks. Get that second $24 Nashbar crankset with a cheap 115mm cartridge bb and you should be good to go. Of course you'll need tools to remove the old cup style bb (and the fixed cup could be a real pain if it's been in there for 20 years) and the tool to install a cartridge style bb, but you'll still probably get out for less than $100. Good luck.
 

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Agreed

Henry Chinaski said:
You'll probably just want to get a new bb--I'm guessing your older cranks came with a pretty wide spindle, which won't work with newer cranks. Get that second $24 Nashbar crankset with a cheap 115mm cartridge bb and you should be good to go. Of course you'll need tools to remove the old cup style bb (and the fixed cup could be a real pain if it's been in there for 20 years) and the tool to install a cartridge style bb, but you'll still probably get out for less than $100. Good luck.



If it's that old, I would replace the whole bottombracket and crankset...If you only replace the crankset and the BB wears out in the next year, you'll be kicking yourself.
 

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Fix it yourself

navakahn said:
i recently bought an 1980s touring bike (trek 520) on ebay. it arrived and the crank (a triple) needs to be replaced (spider is damaged so the rings don't rotate in a single plane).
You might be better off to try to fix this yourself before you dump a bunch of $$ into a bike that is not worth much. Auuming your wobble is a slightly off spider arm, it is a very common thing (I won't say problem, because in most cases, it has no effect on performance).

Assuming that your BB is OK (i.e. not loose - it's extremely unlikely that it's bent), just hold a small screwdriver or other short, pointed object against the seat tube so that the tip just grazes the crank spiders as they pass. If the spiders are bent (most likely problem), you can even them out as follows:

Place the bike on its side with the crank supported on a block of wood at the axle. With another block of wood or a stout dowel placed at the end of the offending spider(s) give it a whack with a hammer. Check for change in alignment. If you got no change, hit it harder next time. Repeat until all the spiders are even. You may need to bend them away from the frame (brace the right crank on the block of wood) or toward the frame (brace the left crank).

Once the spiders are even, check the chain rings with the same technique except put the point of your screwdriver at the teeth of the rings (most likely the big ring only if the spiders are even). Straighten the chain ring by placing a large adjustable wrench over the ring with the jaws adjusted for a slip fit over the ring. Bend gently, and check alignment. Repeat until you've got it right.

Even with the chain rings dead straight, you still will get some deflection due to pedaling forces, but that should greatly improve your situation.
 

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Sugino XD Triple, $110 from Rivendell

Might be the XD-2 now--they changed the finish or something and I think it got a new designation. I have 8,000 miles on one on my Atlantis and about 2,000 on a Rambouillet I bought used. Works great, looks fine, stands up under 240 pounds and it's cheap:
http://www.rivbike.com/webalog/cranks_bbs_c-rings/12067.html. Should work with your BB spindle, too, or if not they'll sell you one.
 

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That Nashbar Trekking crank should be fine if you like it. I have read favorable things about it.

I would recommend getting a Sugino XD300 or XD600. I am using a Sugino XD300 on my Surly LHT and it has been working well for me.

You would need to get a new BB for the Nashbar Trekking. It needs an ISIS spindle. You would probably want to get a new BB of the correct length for the Sugino XD. I use a 68x113 BB and it gives me a great chain line. IMO, you should pick the crank you want then buy a new BB to match it not try to find a crank to match your BB. Decent quality cartridge BBs can be had fairly inexpensively.
 

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Kerry Irons said:
You might be better off to try to fix this yourself before you dump a bunch of $$ into a bike that is not worth much. Auuming your wobble is a slightly off spider arm, it is a very common thing (I won't say problem, because in most cases, it has no effect on performance).

Assuming that your BB is OK (i.e. not loose - it's extremely unlikely that it's bent), just hold a small screwdriver or other short, pointed object against the seat tube so that the tip just grazes the crank spiders as they pass. If the spiders are bent (most likely problem), you can even them out as follows:

Place the bike on its side with the crank supported on a block of wood at the axle. With another block of wood or a stout dowel placed at the end of the offending spider(s) give it a whack with a hammer. Check for change in alignment. If you got no change, hit it harder next time. Repeat until all the spiders are even. You may need to bend them away from the frame (brace the right crank on the block of wood) or toward the frame (brace the left crank).

Once the spiders are even, check the chain rings with the same technique except put the point of your screwdriver at the teeth of the rings (most likely the big ring only if the spiders are even). Straighten the chain ring by placing a large adjustable wrench over the ring with the jaws adjusted for a slip fit over the ring. Bend gently, and check alignment. Repeat until you've got it right.

Even with the chain rings dead straight, you still will get some deflection due to pedaling forces, but that should greatly improve your situation.
Good call. Doesn't hurt to try anyway.
 

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Discussion Starter · #9 ·
thanks, everyone, for all of the helpful comments and suggestions. it's pretty clear that one of the spiders on the crank is pretty bent out of true. i'll give it some whacks and see what happens. because the bike arrived with the two outer rings off the spider, only the inner ring was damaged, so if i can bang the crank into shape, i should be okay, at least until i've got a better sense for what i want out of this bike. and, i suppose, if i can't get the spider true (or close) or if i damage the bb, i can always move to plan b, which is to look for a new crank.

otherwise, does anyone have any experience dealing with fedex insurance claims? the bike seems to have been damaged in shipping and i'm curious to know if i have any shot at getting reimbursed. along those same lines, what do you think a fair estimate of the damage would be if i need to replace the crank with a comparable product? are the sugino cranks a good barometer?

thanks again,
jason
 

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Assuming you want to stick with the triple, another good option would be to hit up the Ebay. There are tons of take-off triples with bottom brackets to be had on there for cheap as lots of people like to switch out to doubles as they start to race or ride harder (just a generalization). Lots to pick through on there from Bontragers to Specialized house brand, etc...
 
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