BB change

[Thomas Lynn Skean]

I have used a 113mm bottom bracket for my Hillbornes. I knew there was ample clearance for my XD2 triple. And I was okay with the chain line and its general behavior.

But I was inspired by recent group posts to see if a 110mm would work on my frame with my crank. It does! And it does improve my chain line and allows my front derailer to operate more vertically throughout its range of motion. This means less trimming. It was not something that bothered me significantly before... I'd only even think about it on the few occasions I'd be severely cross-chained. But now it's even easier to find a spot where I can span the range of my IRD 7-speed freewheel in my middle chain ring without raking against my IRD alpina-d front derailer's cage.

Bear in mind the specifics. Many of them might matter:

Shimano UN55 bottom brackets
Waterford 60cm Hillborne
Sugino XD2 triple 24-36-46
crank torqued roughly to spec
IRD Defiant 7-speed freewheel
Phil "IRD" freewheel hub
IRD alpina-d "braze-on" front derailer
separate derailer clamp from RBW

YMMV!

Yours,
Thomas Lynn Skean

[charlie]

You might consider a 106 to 107 also.......I know its only 3-4mm
difference but that is what I have on mine with a seven speed cassette
and spacer and it works nicely with even better alignment and shifting
IMHO.

On May 19, 11:22 am, Thomas Lynn Skean <thomaslynnsk...@comcast.net>
wrote:

[Thomas Lynn Skean]

I tried a 107 once and couldn't even get good torque on the crank against the taper without interference from the bottom
bracket itself. In short, my crank didn't work with that 107 bottom bracket, completely independent of the frame. Just weird.

Assuming that was a fluke (say, incorrectly labelled length or taper or just a bad BB) and none of that applies, though, I look at the clearance in my 110's installation and believe I'd lack confidence with a 107's clearance. There are a couple millimeters, surely. But with the 107... well, these parts would have to move *very* little relative to each other for me not to worry about my chain stay and inner ring meeting.

It's so close that I think a 108 might work but a 107 wouldn't.

Of course, that could just be my rationalization of Phil products kicking in... :)

Yours,
Thomas Lynn Skean
who thinks 110 is his limit

[charlie]

Right on Thomas......every bicycle/bicycle part can be a little
different.

On May 19, 12:16 pm, Thomas Lynn Skean <thomaslynnsk...@comcast.net>
wrote: