JoeDaddio said:Don't own a fixie yet, but I've got a lot ov BMX experience... hopefully it applies here. If not, disregard!
When I raced we'd put our bikes in the stand and spin the wheel to see when the chain tightened up. Because chainrings aren't perfect circles, it'll be tighter in one position than it is anywhere else. Anyhow, when it got to the tightest point, we'd stop it there and adjust the back wheel accordingly. I found the easiest way to do this and keep everything square was to loosen the bolts on the axles and adjust the tire with the chain tensioner, pulling out till there was enough slack to let the cranks spin smoothly, but not so much slack that the chain is hopping around. If you don't have a tensioner, you can just pull back on the drive side axle till you get it to the proper tension. When you get it all tensioned up be sure to give her a few spins to make sure that the chain is not tightening up too much that it actually slows down.
Hope I helped. And if things work differently for a fixie, lemme know!
I do pretty much the same thing, but I also use a partially used roll of electrical tape in between the back wheel and frame. The roll is squished into a deformed C shape and I just rotate the wheel to apply pressure on the tape roll. I find having that roll as a wedge makes keeping the tire centered very easy. Kinda acts as a third hand to hold the wheel in place.rusa1586 said:I put the bike in a stand at set the cranks so the chain is at its tightest point. I then loosen both track nuts, pull both sides back so the wheel stays centered between the seat stays, and simultaneously hand tighten both sides. Next I use a ratcheting box wrench to sock down the track nuts. I alternate sides, tightening 1/2 turn at a time and use the wrench so that every tightening motion is pulling toward the back of the back. My guide for chain tension is 1/2 inch of up and down movement.
I tried the loosening of the chain ring bolts for adjusting the crank rotation, but I don't think it worked out to well. I still have that really tight spot in the chain rotation and then it gets loose again. Maybe about 1/2" - 1" ot play when I hit the loose spots, do I need to worry about this? or keep trying with the chain ring bolt adjustment. First time I've tried this and its a bit different...........
fixintogo said:I found that the chainring bolt adjustments that Sheldon Brown advocates had little effect, or I lacked the patience/skill to do it right. Tighten them up and try one of the other suggestions for getting the chain tension right. An inch of play is excessive.
CioccLA said:I thought it was just my technique or lack of technique, because I did not see that much of an improvement. I will try the ol' roll of tape move suggested by "Magic" in a previous post............Thanks fixintogo , I see I'm not alone in this!!!!
Some cranks are just too far out of wack to get right. If you've given it your best shot, give up an except a slightly tight spot and a slightly loose spot. If tight spot does not bind and the loose spot does not drop the chain you'll be fine.
imetis: I think we have a conflict of terminology.imetis said:I've only had 2 rides on my fixed gear, and am running into tension issues as well. The first ride I had pulled the chain way tight, and there was little play in the chain, but if you spun the wheel it quickly stopped (chain was binding coming off the chainring teeth). After reading this thread, I loosened it a bit, and now it spins freely, and the chain doesn't seem anywhere near falling off, but as the cranks change direction there is noticable slack before the chain tightens on the top or bottom before engaging.
fixintogo said:imetis: I think we have a conflict of terminology.
Typically, "binding" is when a chain is stretched so tight it stops the chainwheel and cog from spinning. Please clarify what you mean by "chain was binding coming off the chainring teeth."
Also, please explain what you mean by "the cranks change direction" and "noticable slack before the chain tightens on the top or bottom before engaging."
I'm trying to visualize what's happening here and why it's annoying. Thanks!
imetis said:Sorry for the confusion. Yes, the chain was stopping the chainwheel and cog from spinning. Looking closely, I could see and hear it catching on the teeth of the chainring, specificly the last tooth on the chainring before making it's way to the cog. It was not so tight that it wouldn't move at all, but it did slow things down significantly.
Regarding the slack, it was noticable when track standing, when making that minor motion from forward pressure to backward pressure. Also, in the instant when begining to slow down. Forward pedalling kept the chain tight, but if I let off, and the wheel/cog rotated faster than the crank, there was a bit of slop while the chain tightened in the other direction. As I try to turn the crank by hand, I can see the chain stretching and compressing. When pedaling forward the section of chain above the cog and chainring is tight, and there is slack in the section below. When back pedaling the opposite is true.