Need help finding a certain size bottom bracket.

[HypnoToad]

I need a square taper bb with a 127mm spindle and 73mm wide shell.

Does anyone know of one?

I'm trying to get a 55mm chainline and the cranks I'm using say that a 44mm chainline is achieved with a 118mm spindle

 

[FluffyChicken]

55's very wide and I don't think that will do it, might get you to 50mm.
What's it for out of curiosity.


Edit to answer the question.
Phil wood do length to something silly in the 140/150 region.
Paying for it though

 

[Elysarian]

You might be able to get a Shimano UN55 in that width but that is a pretty long axle length you're looking for.

 

[FluffyChicken]

The 73 in the un55 seem to stop at 122.
68 in 127 are fine.

It's not that long, it's the 50mm chain line for pretty much all pre '92 shimano triple chainsets as well as many other companies.

 

[HypnoToad]

55's very wide and I don't think that will do it, might get you to 50mm.
What's it for out of curiosity.


Edit to answer the question.
Phil wood do length to something silly in the 140/150 region.
Paying for it though

:shock: That Phil Wood BB is a little too expensive I'm afraid.

I've got a 2005 p1 frame that I'm running single speed.

Up until recently I've been using BMX cranks which allow me to space out the chainring using washers. However the bearings on these have bit the dust and I was looking to change the crankset for something a little lighter.

My rear wheel uses a DMR revolver, and the centre of the freewheel cog is around 12.5mm from the inside of my dropout, so I hope I got my calculations current when I landed on the 55mm chain line figure.

New the cranks I've ordered may have the 44mm chain line with the chainring in the inner position, so maybe moving the chainring to the outside would give a 50mm chain line?

Even so, a 122mm spindle would give another few mm, maybe 52mm, and maybe I could add in a BB spacer also, along with chainring spacers, but ideally I'd like to avoid using spacers if possible.

It's a shame the un55 comes in 127mm if you get the 68mm version and not the 73mm version, otherwise I could just fit and forget.

Would it be worth looking out for some different cranks?

 

[dan28]

if I remember correct cooks brothers use a 122 / 125 axle i had some when I was around 16 didn't use internet back them an I couldn't find a bottom bracket anywhere
then I went to recycle in headingley an they had one

hang on
73mm an 68mm bottom brackets are the same apart from the cups aren't they?
so pop the cup off the un55

 

[FluffyChicken]

if I remember correct cooks brothers use a 122 / 125 axle i had some when I was around 16 didn't use internet back them an I couldn't find a bottom bracket anywhere
then I went to recycle in headingley an they had one

hang on
73mm an 68mm bottom brackets are the same apart from the cups aren't they?
so pop the cup off the un55

No, there is no cup on the drive side and modern UN's.

If you can find a super low profile crank like ,m900, m737 etc, raceface turbine LP that use 107 bottom brackets you have a lot more choice.
I don't know enough about dmrs and s/s to add anything useful.

But make sure your using the rings chainline and not a quoted double ring measurement.

 

[HypnoToad]

if I remember correct cooks brothers use a 122 / 125 axle i had some when I was around 16 didn't use internet back them an I couldn't find a bottom bracket anywhere
then I went to recycle in headingley an they had one

hang on
73mm an 68mm bottom brackets are the same apart from the cups aren't they?
so pop the cup off the un55

Well, if the cup is the only difference then that's good news. I managed to pick up a 68mm shell 127mm UN55, and ground the lip off the non drive side cup.

I then installed the BB and all seems good, chainline is bang on and my crank arms clear the chainstays.

I know it's a bit of a bodge, but it works, feels solid, and once I get everything back together I'll see how it rides.

Thanks.