Im sick of worring about this chainline issue, and i need a straight answer(no pun intended). So far, ive realized that my chainline will be off, not by much, and i can't really think of a mechanical reason why this would be that big of a problem. I think it will only be off by 1/8th of an inch. Any geared bike has big chainline "problems", but still works well. So what gives, and how much would i have to spend on fixing this issue? I was thinking of putting spacers between the spider and chainwheel, but i need to compensate for the 1/8th inch.

Chain may fall off more often.
*or*
Chain may be fine. Chain may obey trekkie820's wishes.

I'm pretty sure that it can handle being a little bit off with out many problems, but chain tension becomes more important to dial in. Unless you're way off, though, I wouldn't imagine that it would be a serious problem. And, if you do drop your chain, you'll know why, right?

The only real issue other than throwing the chain is the increased wear on the cog/chainwheel part of the drive system. You may not even notice it that much but it will be greater than that which is produced by a strait chain line.


fixedgearhead

Okay, sounds good. I just don't have the funds to make it perfect right now...but i will make it more and more close as i can put more cash into it. I think it will be close enough to where it won't be a major issue. The next thing is to make it fixed gear!!

If you have a little more room between the chainring and the chainstay, you may try to ad a washer between the chainring and the spiders of the crank. Or, depending on the size of chainring, sandwich another smaller ring (i.e 42 with a 39) between the drive ring and the crank.

Dave

What size BB do you have now? How far off is it? If you have 113mm, finding a 110mm for cheap should be easy. If you have 110mm, finding a 107mm should not be too hard either. If you need a 103mm like I did, the only thing I found was a $50 Dura-Ace that is getting hard to find.

Sorry for getting the chainline "stuck in your head".

Yeah, thanks !! Haha, just kidding, i do have a shorter BB but its off of a 99 Trek VW edition mountain bike, and its seen better days...useable, but not preferable. I think i might swap it anyway, it works, but not well. It would give me a good chainline...and after all, its a beater bike anyway. the crank is a standard MTB singlespeed conversion crank too, a Sugino Impel, so i think the junky, but useable BB might be a good idea for temporary use. I need to clean some rust off of it, and buy the cheap tool for the swap. All in all, i think it might just work.

And, WTF is up with Presta valves? How do you fill those damn things?

Unscrew the little nut on the end of the valve stem and put your Presta pump head all the way on the stem and pump to your hearts desire of poundage. Then pull the pump head off and screw the little nut all the way back down and install the valve cap and ride away.

fixedgearhead

do most pumps come with the presta valve head? is there adapters out there? Damn, this free bike is turning out to be anything but!

i noticed in your thread where you posted a photo of your new bike the chainring was on the outside of the drive crank spider. is this how you have it configured? on every fixed gear i have seen using road cranks, the chainring has always needed to be on the inside. that may give you that .125" that you need...

[ot]
hehe...
[/it]

fssb
sparky

Thats not the chainring that i have now...that crankset the guy kept for himself, and gave me the bike. The crankset i have now is a mountain bike crankset and bottom bracket. Im going to install the MTB bottom bracket(yes, it fits) and use washers on the chainring if needed. If this doesn't give me a straight line, im just not gonna fret over it. So far, my shopping list is this:

New tires, BB tool, Presta valve adapters, toe clips and straps.

With anyluck, this will total out to only about 50 bucks.

I love the saying that some body once said, "It's not the original price that will set you back, It's the accessories that will put you in the toilet"


fixedgearhead

Interesting. I just moved my chainring out to the outside of the crank to get the chainline straightened out. Seems to be better now than it was on the inside. In all honesty, though, I think the chain would be perfectly centered where the crank spider arms are.