eyemkeith

Hi all.

I did something impulsive and stupid and won an auction on a crankset that, as it turns out, won’t fit my bottom bracket. It’s a Shimano Ultegra 6500 Crankset. I failed to see that it requires a Octalink V1 bottom bracket which, naturally, I do not have.

it’s not a total loss. I’m pretty sure my 30-year old bike has never changed the bb at all, so putting in a new one is probably a good idea anyway.

my question is: does anyone know what size I might need? Specifically a 73 or less?

I ride a 1992 Bridgestone XO-2. Sheldon’s site says Standard equipment is a 119mm spindle, but makes no mention of cup size.

also, the longest Octalink spindle I can find is 118.5, which seems damn close. That shouldn’t make huge difference, or am I wrong there too?

thanks in advance for any help.

Iride01 

If you have a BSA threaded BB shell, 1.37" x 24 tpi, then just figure out the width of the shell and put an appropriate sized two piece crankset with it's recommend BB that is also BSA threaded. Might be Shimano crank and bb with Hollowtech II, or maybe a FSA or Raceface crank. Not sure if Raceface still does road stuff, the one I put in my Raleigh worked really well.


If you haven't found one, pdf page 39 and 50 might be interesting for you. The rest of the catalog is interesting too, being that in 1992 catalogs were usually full color glossy paged things.

https://www.sheldonbrown.com/bridgestone/1992/1992.pdf

Russ Roth

You can't compare your current BB to the new one as they're two completely different cranks. Shimano offered only a couple sizes that were really meant to work with double, triple or a wider rear triangle. If you've got a double you'd use the one that's 113mm, 118mm for the triple and I think they did a wider for a triple with a 135 rear end. Other then that I think there were e-type versions but you want to match the width to the new crank, not the old BB.

HillRider

The Octalink V1 bottom bracket in 118.5 mm width was used with the FC-6503 Triple crank. For the FC-6500 double crank the length was 109.5 mm. Those particular bbs were only available in those two lengths.

Your bottom bracket shell is almost certainly English (aka BSA) threaded (1.37"x24tpi) and 68 mm wide. An English threaded Octalink BB-5500 or BB-6500 in the appropriate spindle length will work fine.

shelbyfv

Here they are, both double and triple https://www.universalcycles.com/shop...7&category=268

eyemkeith

Thanks, guys. Too cool of all of you. And thanks for taking it easy on someone who clearly has no clue what he’s doing. It all helps!

Crankycrank

I've lost a lot of money on my beginner mistakes over the years but saved a whole lot more from the lessons learned. I'll also add that with this type of bottom bracket be very certain when you install the cranks that they are perfectly positioned on the flutes before tightening the crank arm bolt. Push them on by hand as far as you can. If they are off slightly you can end up deforming the crank arm flutes and ruining the cranks. It's not a difficult task, just something to be a little more aware of than with other BB/crank types. Other than that these are solid cranks and the BB will last a long time.

eyemkeith

Good advice. Thank you!

Bill Kapaun

You provided helpful/needed details in your FIRST post that allowed someone to know what you needed to know.
It can make such a world of difference when one doesn't have to repeatedly try to "extract" needed info from the OP.
They make an early entrance to my ignore list.