Replacing the old BB with sealed unit.
 

Im replacing the BB on my Nishiki and I cannot seem to locate the same width anywhere. the axel is 116mm wide with an English thread. Most sites seem to have 115mm & 118mm wide axels not 116mm.

Is it OK to purchase the 115 or 118mm? Would I experience any issue come installing the unit?


Cheers
B:thumb:

It depends. If the smalles chainring is extremely close to the chainstay, getting a spindle that is shorter "could" cause it to rub, so look at that.

Some spindles are asymmetrical- longer on the drive side & shorter on the non drive side. Modern ones are symmetrical. Have you measured each side of your current spindle?

It also depends on the taper of your existing spindle versus the new cartridge one. Kind of a black art, really.

I've shimmed the drive side of a sealed BB when replacing a an older BB to pick up a little chainstay clearance and improve the chain line. I'd try the 115 and pick up a two or three .5mm shims.

If it's a Nishiki, then it's probably a JIS spindle, unless it was a Sugino Mighty crank (old Campagnolo taper). Most standard cartridge BBs are JIS taper. A crank with any other taper is going to sit farther out when fitted to a JIS spindle; they're the "stubbiest". It's considered (by Phil Wood) to be OK to install an "old Campagnolo" (pre-1994, when Campagnolo changed to ISO) taper crank on a JIS spindle; I believe that's what PW supplies for such cranks.

I agree with Murray Missle's advice above. The chainline shouldn't be that critical unless the bike is singlespeed/fixed or an internal geared hub. Crank arm and chainwheel frame clearance is an issue, of course.

What crank set do you have most older Nishiki's had Sugino cranks which had longer spindles than 116mm and were asymmetrical? If it is a 116 I would go with the 115mm BB with a 1mm spacer on the drive side.

It's probably JIS as stated above. Look for a number/letter code stamped into the spindle and go to the Sheldon Brown website to cross it over to a symmetrical cartridge bb equivalent.

116mm BBs were usually symmetrical, weren't they? Shimano's loose-ball BBs were, and their 115mm cartridge BB measures more like 115.5mm, so just get that. I have my doubts that you'll need any spacers. :thumb:

Sugino Mighty did not come 116 mm, only 114 (road double) and 120 (triple). Marked MW-68 for English thread (Nishiki). Other Sugino cranks should be JIS. If OP could provide how the old spindle is marked, that would help identify.

Thanks for the response. Here is a photo of the crank. I measured it and it appears symetrical. The axel has a D-3L stamped on it if that means anything. The cups have 1.37 x 24T stamped.

If I placed a 115mm width crank in would the cups still fit snug in the BB? I was concerned I may not be able to tighten them up fully.

This is the old unit and the one I was looking at buying. Im assuming Wiggle have forgotten to include the thread for the oppposite side and that it is included with the unit....

3L is a 32-52-32 (116mm) spindle. Haven't heard of a cartridge BB being sold without both cups -- I assume they just left it out of the picture for whatever reason.

As long as you get the right BB for your frame's shell (most often 68mm English or 70mm Italian), the NDS cup will thread in far enough to lock everything in place correctly, regardless of the spindle length. I don't recommend using spacers unless the NDS cup looks like this one (no ledge on the outer side to prevent it from threading all the way into the BB shell):

https://www.universalcycles.com/imag...dium/37183.jpg

Unless you've been cutting it way too close when it comes to clearance between your crank arm and chainring and your frame, a 115 mm Shimano UN55 should do you just fine. Compared to a 116 mm spindle, it's only a difference of half a millimeter on each side of the bike.

If you're really concerned about that millimeter, FSA sells a 116 mm bottom bracket:
FSA Power Pro Bottom Bracket | Chain Reaction Cycles

I just checked eBay. There's a bunch of 68x116 bottom brackets on there.

Great thanku. I was in the process of trying to put a batch order thru Wiggle :) and they only had 115 or 118mm. At 21 bucks I could try the 15mm if you think thats the best option.
I dont recall the crank arms being that close that 1mm would hurt.

Thanks for the feedback everyone much appreciated .
:)

Since it is JIS standard 116 BB I would say just go with one of the Tange 115 BB which is about the closest match to the original for $20.
Tange Seiki Cartridge BB, CroMo Bottom Bracket LN-3922, 68mm; Sizes: 127mm 115mm