I just got a great deal on a lightly used set of 75's and plan on throwing them on this weekend. Right now my BB is 103mm and I read that the 75's take a 109mm. I don't think I can get away with just slapping them on, so I'm gonna need a new BB.
So what are you using besides the 75 BB? Any sealed options? Any cheap options?
Use the 75 BB. Its made to work with that crank. Everything else is a compromise. I've tried other BBs, but it just isn't the same. I've been using the same 75 BB for three years now, and I have only overhauled it once. The grease inside was still as fresh as the day I installed it. People have been riding around with unsealed BBs for more than a century...you have nothing to worry about.
Well he'll need an ISO taper spindle to work with the 75's. I will agree that 103mm is a bit more ideal than 109. Never quite understood why Sugino made them around a 109, which is typically a pretty wide chainline.
Well, it just creates an opportunity for the crank arm to walk, which will in turn ruin the square hole and render the crank arm useless. Using an ISO taper crank on a JIS spindle will make the crank arms sit out an additional 4.5mm. It's not ideal, but dudes do it all day long without problem. I have never tried because I like my expensive SG75's and want them to last a long time.
That protype is a new bb, first time I've seen it. Definitely the cheapest option.
All this fussing and worrying can be avoided by simply using the correct BB. If you want to ride in the mud and slop and don't want to overhaul the BB, chose a different crankset. The OP asked for a low-cost option. Whats the point of buying a really expensive crankset and then getting some cheap-ass BB that only works half-assed with that crankset? If you really insist on combining a SG75 crankset with a sealed BB go with the WI BB, its not much cheaper than the SG75BB but is sealed and may have the right tapir but its still not the same length as the SG75 spindle. Whats a mm difference?...not much, but having the matching components with matching taper and correct chainline is still better than close but not perfect.
Mihlbach, WI and Phil are anything but "cheap-ass BB that only works half-assed with that crankset". I know this because I used both of them on SG75s. If you haven't used it, how are you able to comfortably tell the OP not to?
For the record, the Phil bb is the only one I've had that gets close to a perfect chainline, and only when I move it outboard to NDS by 2.5mm. A 109mm spindle is really a bit wide for track bike based around a 42mm chainline.
Presto NJS build, Specialized Allez Pro w/ full Dura Ace and Ksyrium SLs, 1990something Specialized Sirrus
Read sheldon. The whole JIS vs. ISO thing isn't as big of a deal as people make it out to be. Using an ISO crank arm on a JIS spindle just moves the crank arm 4.5mm outboard, which brings me to 107.5mm, which is pretty close to 109. I've been running Sugino 75 cranks on a 103mm JIS BB for a while now and have had 0 problems.
They played a show here in Dallas at the Club DaDa. The line was around the block, and because the people managing that club at that time (dada is now, regrettably, defunct) got booking and capacity and ticket sales assbackwards, nearly half of them didn't get in.
So what did BRMC do? They finished their set and saved the club organizer's faces by actually going outside and playing an acoustic set for the fans that got left in the cold.
Mihlbach, WI and Phil are anything but "cheap-ass BB that only works half-assed with that crankset". I know this because I used both of them on SG75s.
Yeah, I know, but still nothing better than using the BB that was intended to go with the crankset. I've used a Phil BB with my 75s along with a cheaper shimano BB, but neither were as compatible with my SG75 crankset as my SG75BB.