Sugino 75 and BB alternatives
 

I have a Sugino 75 crank with Surly Hub and EAI cog. Currently I'm using a Shimano UN73 110mm BB. I'm disatisfied with this BB. The spindle is asymmetrical and moreover, I can't achieve a perfect chainline with it. Theoretically, a 110 mm spindle should only throw the chainline off 0.5mm or so, which would be perfectly acceptable to me, but it looks to me like the square tapers on some of these BBs are minutely different, thus throwing the chainline off about 2mm more, apparently because I cannot get the crank arm to slide all the way onto the spindle.

Although I know it would solve the chainline issue, I'm hesitant to go with a matching 109 mm Sugino 75 BB because I'd rather have something sealed that requires less maintenance.

For all you Sugino 75 cranks users out there, what BBs are you using and hows your chainline? I'm thinking the best option is to go with a Phil Wood 108mm BB. The chainline of Phil Wood BBs are adustable 2.5mm either way, so it should do the trick. Does anybody have this setup or know of any other good options?

i have read in older threads that a un73/53 with a 107 spindle will at least solve the problem of it being asymmetrical

If you're going with the Phil, go with the larger one (110? 111?). I had roughly 2mm of clearance on the non-drive side of my Steamroller when I was rolling SG75 crank and BB. If I had gone with the shorter spindle, there was a significant possibility of the crank touching the BB shell. I went with the slightly longer option, which only moves the NDS out a few mm and everything is hunky-dory.

running a 107mm un73 and perfectly happy.

Yeah I wondered about that...with the 110 spindle the asymmetry is achieved by a slightly longer non-drive side of the spindle, which throws the left crank arm out a few mm more than the right (drive) side crank arm. My understanding of the un73/53 107 mm BB spindle is that the non-drive side part of the spindle is the same length as the drive side, thus resulting in a symmetrical spindle, but that the drive side part of the spindle is the same length as the 110 BB, and would have no effect on chainline. Is that correct?

I used to worry about the unsealed BB thing, but I've been running SG75 bottom brackets (the regular and the slightly cheaper version) on both of my rides for a perfect chainline. Every time I decide to do a little maintenance, I find the bearings in virtually new condition and coated in clean grease (phil wood waterproof), even after riding in rain and snow. As long as you have plenty of grease, the cheap plastic sleeve and a drain hole in your BB shell, the thing should stay pretty clean. Maintenance is not as great a problem as it would seem.

disclaimer: I actually like doing things like repacking loose ball bearings.

The 107mm and 110mm shimano bbs have the same length on the driveside. I'm running the 107 with my 75s and the chainline is perfect.

a sugino 75 bb would match pretty well. 109mm i think.

Are you sure?? Have you actually measured with a calipers or did you just eyeball it? I would be very interested in a more precise assessment of your chainline if you don't mind. I've measured mine (110mm UN73 BB with 75s) several times and its off by 2-2.5 mm.
Heres my method.
1. Distance from the outside of the chainring (at the base of the teeth) to the left side of the seat tube.
2. Subtract half of the diameter of the seattube.
3. Subtract half of the width of the chainring.



Maybe I'm being nitpicky here, but that 2 mm is really buggin me and I think it might be responsible for my slight chain buzz.

yeah but he wants a sealed bb.

I wouldn't mind either...but I lack a garage and my apt. already has enough black grease/dirt stains on its floors and walls from bike maintenance. So sealed is best for me.....

This is correct.

i found myself in a similar predicament to yours with my new cranks, mihlbach... i wanted a sealed bb for my 75's, but don't have the scratch right now for a phil... i have a un73 with a 107mm spindle, but haven't installed everything yet. i will be getting on that in the next few days, and if you are interested, i will report back on the chainline.

Yes...please do.
I actually have an 111 mm Phil BB that I'm going to try to install with my 75s..its from another bike I once had. But I had to order new cups and I'm still waiting on that. The Phil 111 may be too wide, depending on how far the cranks will slide onto the spindle, but I'll report the results of that back as well..as soon as I get the cups.

^That's the perfect size. You end up with just a smidge more spindle on the non-drive side but the drive side works out perfectly.

110 works fine, that is what is on my bike right now.

does anyone know if the IRD bottom brackets 107 or 110 work as well. my friends at the shop said they're a little nicer for the money.

I've got the 108mm phil with my 75's. Perfect chainline, no problems. If you can tweak them as much as 2.5mm, then the 108 or the 111 should work.

109mm sealed dura ace 7600 series bottom bracket. end of story.

75s with a 75 bottom bracket end of story...the bottom line!

**** your hatta :P

haha. not mine, i just like em. i am a phil wood and campagnolo man. currently running on a suntour superbe pro, which works fine (and would also work for the OP. it has some seals, but is servicable.)

TA Axix