Bicycle Mechanics - Cranks don't spin straight after installation!

I'm installing my new crankset (road) on my frame. After tightening the bolt on the drive side the crankset doesn't seem to spin straight.

By this I mean the chainring seems to have some lateral movement when it is spun. Is this a BB alignment issue or do I have I tightened the crank on wrong (not tight enough?)

Are you sure the ring is true? Are the spider arms bent? Perhaps the BB spindle is bent. Did you use grease when installing the cranks? Unless there's a huge difference in taper between the crank and spindle, you shouldn't be able to mis-fit the cranks enough that it would result in visible misalignment.

There's an article on Sheldon Brown's site about that.

http://www.sheldonbrown.com/straighten_chw.html

I have a similar problem with some new Ritchey cranks on my road bike and hopefully will get to troubleshoot mine this weekend.

I just bought the crankset, I didn't grease the bb spindles (my LBS said not to) but I did grease the bolt. The BB I think is new?

I also installed the BB myself, could it be misaligned?

There's an article on Sheldon Brown's site about that.

http://www.sheldonbrown.com/straighten_chw.html

I have a similar problem with some new Ritchey cranks on my road bike and hopefully will get to troubleshoot mine this weekend.

Ooh thanks for that article, but it confused me even further, I went to the first step spun it, marked it out then I 180'ed the crank, but now there doesn't seem to be any error at all? Like I can still see a very small amount of lateral movement like.. <= 1mm.

:eek:

Ooh thanks for that article, but it confused me even further, I went to the first step spun it, marked it out then I 180'ed the crank, but now there doesn't seem to be any error at all? Like I can still see a very small amount of lateral movement like.. <= 1mm.

:eek:It's possible to have a worst case fit between the crank taper and spindle taper. Removing crank roating a different position can often cure it.

Ok now that this is.. roughly fixed.

1)I got some paint chips with exposed metal surface, is there somethign I should put on it or do besides repaint the frame to make it resistant to rust etc.?

2)I forgot to grease the BB cup threads when installing, should I take them back out and grease them? There seemed to be a bit of grease on it already (although not much).

1)I got some paint chips with exposed metal surface, is there somethign I should put on it or do besides repaint the frame to make it resistant to rust etc.?

Paint will do all that and make it look nice. If you're not too worried about perfection nail polish comes in lots of colors including one that's probably not too far off from your bike. Me, I use this weird translucent purple with sparkles that my wife gave me on EVERYTHING. It's amazing. At twilight that stuff just goes all flourescent and my mountain bike glows purple everywhere it's scratched.


2)I forgot to grease the BB cup threads when installing, should I take them back out and grease them? There seemed to be a bit of grease on it already (although not much).

Take them out and grease 'em up.