Bicycle TutorBicycle Tutor

Show off your bike!

Related video tutorials:
Crankset Question
#1
Hi, I'm trying to replace chainwheel, chain and freewheel. They all are very worn. I can't use the Bolt Circle Diameter method for my 4-arm crankset because it has 2 rivets on one arm and 1 rivet on the next arm. It's a Suntour SR. I read that on that kind of crankset I can't replace a single chainring--that the whole crankset has to be replaced. As for the chain, I guess I can just use a 3/32" 7-speed chain since the freewheel is a 7 speed. And I guess I can just get another 7 speed freewheel. Am I correct about what chain and freewheel to buy? And how do I know what crankset will fit? Will the ones at these urls work? http://www.amazon.com/Shimano-FC-M131-Tourney-Crankset-48-38-28/dp/B003ZMDJW6/

http://www.amazon.com/Shimano-FC-M171-Altus-Crankset-170-mm/dp/B003ZMFNX4/

http://www.amazon.com/Shimano-M361-Hybrid-Crankset-Black/dp/B004V2996E/

Thank you.
Reply
#2
Hard to answer because we don't know anything about the bike you are trying to put these on. Can you supply more complete information?
Reply
#3
Hi Mark;

Any of the cranksets will work okay; the cheapest will last as long or longer than the others.

I would replace the BB at the same time.

http://www.amazon.com/Shimano-Square-Bottom-Bracket-68x110mm/dp/B005DTIG9U/

For the M131; Shimano recommends 123mm BB; but I found on my GT http://forums.bicycletutor.com/thread-3167.html that 113mm would suit me much better. The 123 put the chainwheels in a position such that the 28-11 combination works with no chain rub, but the 48-30 and even the 38-30 have too extreme a chain angle. I don't care if the 28 at the front can't be used with have the cogs at the back, but I want to be able to use the larger cogs at the back with the larger rings at the front.

Freewheels: I have had two bad Shimano freewheels, and have switched to Sunrace 13-25 on both of my bikes with freewheels. I plan to try an IRD http://www.amazon.com/FREEWHEEL-7SP-DEFIANT-13-24T-NICKEL/dp/B003PXYV1S/ next time, but the cost is holding me back. The IRD's ratio are better balanced: 13/14/15/17/19/21/24 compared to Sunrace's: 13/15/17/19/21/23/25 which results in too big a jumps at the high end, and too little a jumps at the low end.
Nigel
Reply
#4
(03-20-2013, 08:08 PM)nfmisso Wrote:  Hi Mark;

Any of the cranksets will work okay; the cheapest will last as long or longer than the others.

I would replace the BB at the same time.

http://www.amazon.com/Shimano-Square-Bottom-Bracket-68x110mm/dp/B005DTIG9U/

For the M131; Shimano recommends 123mm BB; but I found on my GT http://forums.bicycletutor.com/thread-3167.html that 113mm would suit me much better. The 123 put the chainwheels in a position such that the 28-11 combination works with no chain rub, but the 48-30 and even the 38-30 have too extreme a chain angle. I don't care if the 28 at the front can't be used with have the cogs at the back, but I want to be able to use the larger cogs at the back with the larger rings at the front.

Freewheels: I have had two bad Shimano freewheels, and have switched to Sunrace 13-25 on both of my bikes with freewheels. I plan to try an IRD http://www.amazon.com/FREEWHEEL-7SP-DEFIANT-13-24T-NICKEL/dp/B003PXYV1S/ next time, but the cost is holding me back. The IRD's ratio are better balanced: 13/14/15/17/19/21/24 compared to Sunrace's: 13/15/17/19/21/23/25 which results in too big a jumps at the high end, and too little a jumps at the low end.
Thank you for your help.
Also, as for the chain, the 3/32" for a 7-speed freewheel will work?
Mark
Reply
#5
Hi Mark

Any 7 or 8 speed chain will work. The Bell brand chain at Wal-Mart is fine. I have a couple of those on my bikes, as well as SRAM, Shimano and KMC.
Nigel
Reply
#6
(03-23-2013, 11:04 PM)nfmisso Wrote:  Hi Mark

Any 7 or 8 speed chain will work. The Bell brand chain at Wal-Mart is fine. I have a couple of those on my bikes, as well as SRAM, Shimano and KMC.

Thank you Nigel,
Mark
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Triple crankset to Single crankset blbaszis 5 4,129 09-25-2014, 01:37 AM
Last Post: blbaszis

Forum Jump:



ISSN 1918-3445 © Copyright 2007-2010 Bicycle Tutor / Privacy Policy / Created by Alex Ramon

feed