was going to get some RD2's.....
02-10-09, 08:56 PM
#1
Senior Member
Thread Starter
Join Date: Jan 2009
Posts: 347
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
was going to get some RD2's.....
What the hell.....Who makes a track crank setup that has a 45 mm chainline
I've already got a 130bcd ring that I intend to use, and I really want to go down from my 172.5mm shimano 105's to something with a 165mm arm length. There aren't really many 105's in that size to be found, so I was going to just get some sugino RD2's.....But they have a 45mm chainline, and I need to run 42mm because that is what my cog is, and my 105's right now are 42.5-43mm (close enough), and it would just make life easier if I could find something with a 42mm line.
Suggestions on something in that price range that is good?
I really don't want to drop as much cash as it would take for truvativ omniums or Sug 75's.
Thanks for any help
I've already got a 130bcd ring that I intend to use, and I really want to go down from my 172.5mm shimano 105's to something with a 165mm arm length. There aren't really many 105's in that size to be found, so I was going to just get some sugino RD2's.....But they have a 45mm chainline, and I need to run 42mm because that is what my cog is, and my 105's right now are 42.5-43mm (close enough), and it would just make life easier if I could find something with a 42mm line.
Suggestions on something in that price range that is good?
I really don't want to drop as much cash as it would take for truvativ omniums or Sug 75's.
Thanks for any help
02-10-09, 09:33 PM
#2
Junior Member
Join Date: Dec 2008
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I feel that the issue of chain line (when we're talking about 1-2mm) is pretty much a non-issue.
Here's a list of the chain line generated by certain combinations of components: https://www.sheldonbrown.com/chainline.html (scroll down about halfway).
The RD has a 45mm chain line because it's not really a "track crank," it's a re-purposed road double. There's really nothing wrong with this, I use one on my Austro-Daimler conversion with a Miche hub and Dura-Ace cog and have no problems. I think when you get this close--1-2mm over a distance of say, 70cm from chain ring to cog--you're not talking about a whole lot.
The advantages to having a perfectly straight chain line might include reduced wear and reduced noise. If your chain line is reasonable, and you have your chain tensioned appropriately (read: there is some slack, but not too much), then you're not going to have the chain jump, nor will you see any real-world performance gains by moving the crank 1mm closer to the frame.
My LBS installed two really thin spacers between the cog and hub flange for me, totalling maybe .5mm. With this configuration my bike is quiet and smooth.
I'd advise against spending money when you think you need (want) to, and unless you're riding competitively, then pot-holes, taxi-cabs, and broken glass are probably more important things to worry about.
Cheers.
Here's a list of the chain line generated by certain combinations of components: https://www.sheldonbrown.com/chainline.html (scroll down about halfway).
The RD has a 45mm chain line because it's not really a "track crank," it's a re-purposed road double. There's really nothing wrong with this, I use one on my Austro-Daimler conversion with a Miche hub and Dura-Ace cog and have no problems. I think when you get this close--1-2mm over a distance of say, 70cm from chain ring to cog--you're not talking about a whole lot.
The advantages to having a perfectly straight chain line might include reduced wear and reduced noise. If your chain line is reasonable, and you have your chain tensioned appropriately (read: there is some slack, but not too much), then you're not going to have the chain jump, nor will you see any real-world performance gains by moving the crank 1mm closer to the frame.
My LBS installed two really thin spacers between the cog and hub flange for me, totalling maybe .5mm. With this configuration my bike is quiet and smooth.
I'd advise against spending money when you think you need (want) to, and unless you're riding competitively, then pot-holes, taxi-cabs, and broken glass are probably more important things to worry about.
Cheers.
02-10-09, 09:48 PM
#3
Senior Member
Join Date: Mar 2005
Location: Richmond, VA
Posts: 286
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
guy up there is right
though i got a 42mm chainline with the rd2's by running the chainring on the inside of the spider
though i got a 42mm chainline with the rd2's by running the chainring on the inside of the spider
02-10-09, 10:00 PM
#4
Senior Member
Join Date: Jul 2007
Posts: 842
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
this has been discussed alot, and after all i read, i upgraded and ride rd's. they're great (with sugino 103mm bb) dont worry about. im using them now, and glad i got them
