Drops_SxCx

Old 80's Schwinn(Parts said Suntour,and sugino crankset)
First Conversion
Surly flip/flop hub with 16 freewheel
I used the double chainring straight for a while.

So i wanted to convert it to a sealed BB,my local shop magically had one that fit.
[i was too excited to take length into consideration out $35 bux]
Thing is the old road bike chain ring(which i have alter to look like a single speed crank,nothing else can be done to this part to alter to fit!) hits the drive side on the chain stay. So my question is this. I do plan to buy a new crank set. but is what i have currently no good for either?

On the BB says :
BB-UN54 113 BC137 68

So does that mean i have 68 shell w/113 length?
Im looking at part and most single speed cranksets say "to use w/107-110 BB"

Thing is my sealled BB is 113 and the chainrings is hitting the chain stay already,so if i want a single crankset i need to go SHORTER?
Is the square taper fatter on these shorter spindles and dosent go in as deep into the arms as much? or am i SOL and have to go buy a longer BB,why do this part say to use w/107 length spindle? And if i do get a longer one so it wont hit my chain stay, what will happend w/my chainline? arent they shorter to have a straiter chainline?
Is this bike no good for my conversion dream?

Drops_SxCx

ok,all parts i have to use the 1/8 chain;but w/this one i can use the 3/32 but dosent specificy what length BB;can i use this?
https://www.amazon.com/Sugino-Single-...=1MNEKSBTOFWWG

And these are the other general parts that say 107-110
https://www.amazon.com/Origin8-Square...=1MNEKSBTOFWWG

https://www.amazon.com/Eighth-Inch-Cr...=1MNEKSBTOFWWG

which are a lot nicer

simonaway427

Perhaps its the way you altered your old crank. I used a 68 x 113 BB on my conversion and it fits perfectly with a SRAM s100 single speed crankset.

Rafussen

What is the spindle length of the original BB (if you still have it)? The bike shop should have measured that length before selling you a 113mm one. I assume you are using a square taper BB, right? If so, then the only issue should be going back to the bike shop, tell them they sold you a BB that is not long enough, and that you want to exchange it for a longer one. The shell width should not be that big of an issue, so if the BB is a 68 or 70, you should be able to get that to work, but you might want to measure the bottom bracket part of the frame (not the actual bottom bracket component) in order to get the accurate shell dimension for when you go exchange it. But, as I said, the issue should be resolved by getting a longer spindle BB, assuming you are using the original crank arms. If you are using different crank arms, then those might be also causing a problem, but probably not, and I would have to actually inspect them to give direction.

Go back to the shop and tell them they screwed up, especially if they had your bike in the shop when they sold it to you.

Trek400

I recommend reading Sheldon Brown's BB size, you get more detail answers to your questions. There is how to get a chainline measurement at the bottom. Your chainring hits the chain stay, you need longer than 113 or smaller chainring.
https://sheldonbrown.com/bbsize.html