Kevin23

I have a frame that I'm trying to build up into a fixed gear and I would need a bottom bracket. I know the bb has oily ball bearing in it. But could someone explain the bottom bracket for a newer bike I guess it would be. And my second question is, what is a cheap but good way to get a crankset for a fixie/ single speed bike. Thanks

TheBikeRollsOn 

Hmm, I'm not sure I understand what you're asking, but I think you mean you're looking for a cartridge BB. Probably will need a 68x107 or a 68x103, but it's hard to say at all considering you didn't say what kind of frame you're using. As far as cranksets go, you can use older Shimano 600 or 105 doubles take off a chainring or find a different chainring that fits, though you may have to play around with positioning to get a good chainline. Or you could get a Sugino RD for fairly cheap.

striknein

Most newer bikes use cartridge bottom brackets. If you're looking for a cheap crankset, these are good bang for the buck.

Kevin23

What bb would an older fuji valite frame use? Or a Raleigh grand prix? I read somewhere that 170mm cranksets were really good for fixed gears. Then I read somewhere else that they should be proportionate to your size or something. Any ideas? Does that size affect anything?

mashtofu

Shorter cranks reduce the likelihood of your pedals scraping the pavement. I use 165mm. I am hella short though.

elemental

These are pretty inexpensive, and come in a wide variety of colors if that's a plus. I thought I remembered that they were the same as the 1/8" or Andel or something, but I may be making that up.

A few factors impact crankarm length, and rider size is the main one. However, there are a few extra considerations for fixed gear riding. First, since you can't stop pedaling when you turn, a long crankarm, low bottom bracket (more likely if you're using a road and not a track frame), and bad timing/luck can cause pedal strike, which is your pedal hitting the ground. This is bad. Also, smaller cranks trace a smaller circle when pedaling, which is said to be easier on the knees. Since fixed gear riding can put you in high gear, low RPM situations that cause knee pain/inflammation for some, some riders choose shorter crankarms.

How tall are you? 165s are short and often used for fixed riding for the reasons I listed, 170 and 172.5 are the "standard" fit for many average size riders, and 175s are popular with taller riders.

striknein

The bottom bracket you'll need for those frames will most likely be 68mm. I say most likely because some older Raleigh frames have a 70mm bottom bracket shell. Spindle length would be determined by the crank you buy.

rustybrown

Bro, it sounds like you're looking at frames, bro. And bro, you're looking in the right direction, bro. But bro, just make sure it's worth it, bro. And bro, remember to haggle, bro.

Kevin23

I am 5'3". I will most likely use a fuji valite frame to make a fixed gear. How much does a new bottom bracket cost with a spindle and such? What size crank would be good for me. 165? Also for te crank there is different widths, like 1/8 and stuff. What would be the best size of that to make work on a fixed gear?

EssEllSee

1/8" refers to the width of the chain. There are generally two kinds - 1/8" and 3/32", with 1/8" being the thicker of the two. You must be careful because a 3/32" chain will only fit a 3/32" cog, whereas a 1/8" chain will fit both 1/8" and 3/32". As for the bottom bracket compatability with that frame, I'm sure other members can offer more advice there - but a BB can usually be had at 15-30$.

elemental

This sounds like a textbook case for 165s: Smaller rider, fixed road frame with presumably low bottom bracket. I'd start there.

yummygooey

I would go 165 or shorter if possible. I'm 5'8" and my recommended crank length is 165...

Sixty Fiver

Crank length and variances in that length don't have that much effect on riders as the difference between 165 and 175 is only 10mm / 1 cm / .5 inches.

You have to be really tall or really short to benefit from a shorter or longer crank.

Even with a fg that 10 mm difference is not much and you would do better to run narrower track pedals to increase clearance in cornering.

A road bike is going to have a lower bottom bracket than a track bike and a touring bike might have an even lower bottom bracket... knocking a few mm off a crank does not change much.