Bottom bracket spindle lengths nomenclature

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rrarider

Veteran
Location
Liverpool
Having bought a wrong sized BB spindle length a while ago, I know how important it is to measure the one that currently fits and order the correct length for a replacement. I'm puzzled by the markings I see on a Shimano un55 packet, namely:
107 : ( M107)
110 : (M110)
113 : (LL113)
115 : (D-H)
118 : (XL 118)
122.5: (D-NL)
127: (D-EL)
The ones with digits in I could probably deduce myself but the alphabetic only codes seem most unintuitive. Is there some standard coding for BB spindle lengths that has somehow escaped me?
I ask because whilst looking on ebay for a spare one to have available, I'm surprised to see so many listings for used BBs that don't quote a spindle length. As a secondary question:

I know that the current 127.5mm BB fits my bike perfectly and I've just made a bid on a 127mm BB, assuming that the half millimetre difference can easily be accommodated by a bit of limit screw twiddling?

All answers will be gratefully received.
 

Cycleops

Legendary Member
Location
Accra, Ghana
Don't really see the problem, if you want 127 that's what you should order. Shops usually give that option on their sites so best to order there.
As far as I know 127 is the standard on UN55 bbs so likely the seller has made a mistake unless a different make but . 5 is not worth worrying about.
 
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