https://cgi.ebay.com/TRUVATIV-ISOFLOW...item35b2fb4c9e

i want to get the single speed crankset in the link above, but what bottom bracket do i get? i cant find anything on Amazon.


it's going on the bike below by the way

You have a standard bottom bracket shell on the frame, with (I'm fairly sure) are ISO 1.370x24tpi threads. (you can confirm this easily enough by looking at the right side threads. If they're left handed (tighten to the left) it's ISO, if they're RH, sale as on the left side it' a 36x24 Italian.

You should check the width with a metric ruler. It's either 68mm or 73mm. Once you confirm the thread and width, shop for any BB compatible with your crankset.

thanks for the reply sir!

i measured 68mm, but can not tell whether or not it is left or right hand thread on the right side of the bike.

my other concern is whether i should go with the truvativ 68mm/108mm, or 68mm/113mm

which size do you think is best for that truvativ isoflow single speed crankset i posted in the first link?

If it's 68mm it's definitely ISO since Italian BBs are 70mm. as to which width spindle, you have to look up, or measure the rear sprocket chain-line (distance from centerline of hub/bike) then check the specs for your crank to see which spindle gives you the nearest chainline.

thanks again!

so this means i need to get a wheelset first right?

i plan on using a regular tire that had a cassette and then getting a surly spacer kit to line it up. fit a freewheel cog, and then lockring. think that will work?

No, if you're using a standard road or mtn spaced hub tou can assume the chainline will be between 44 and 50mm, and buy accordingly. Then use the spacers to fine tune from the hub end.