Bicycle Mechanics - Asymmetrical BB Spindle Sugino RT

I didn't pay close enough attention on the dismantle of my 1984 Lotus, with a Sugino RT bottom bracket and crankset. The spindle is asymmetrical, longer on one side than the other. I am thinking the shorter side is the driven, chainring side. Can someone verify?

Next time, I will pay closer attention...

Usually, if there is any text on the spindle it goes so you could read it from the top looking toward the front of the bike. Worst case put it together and it'll be obvious quickly. You have a 50% chance of getting it right the first try.

On the older cranks I have taken apart the long end is the drive side. I remember this because a quick way to improve chainline in a single speed conversion is to flip the spindle.

There is writing on the spindle, so I will check it and see if the drive side is the long side.

thanks!

bill

Every one I've ever dealt with has the longer side on the right - the drive side. If you think about this logically, you'll see why this should be.

On the older cranks I have taken apart the long end is the drive side. I remember this because a quick way to improve chainline in a single speed conversion is to flip the spindle.

I just pulled apart a Siguno BB on my 1983 stumpjumper. I agree the long side should be on the drive side in all cases.

I am thinking the shorter side is the driven, chainring side.
...


How can you possibly come to that conclusion?

Its the way I had the pieces laying on the work bench. When I take something apart, I usually place them in reverse order on the bench, as I remove them. So they were in the order that would dictate that position if you follow me. But I did not mark it in any way, and did not carefully lay it out. So I wanted to check, rather than put it back together twice. Check twice, install once kind of thing.

Reassembly is tomorrow (framesaver went in today). So the timeliness of the replies is very appreciated.

thanks!

I know most cup-and-cone bottom brackets install with the longer end of the spindle toward the drive-side but I have come across one exception.

I have a '93 Trek 7000 MTB with a bonded Al frame and LX components. When I first overhauled it and took out the bottom bracket I was surprised to find the bb spindle had been installed "backwards", i.e. longer end to the nds. After grousing about factory incompetence, I reinstalled it the "correct" way.

Wrong. Installed with the long end of the spindle toward the drive side, the chainrings were way too far outboard and the nds crank arm hit the chainstay. Apparently the super fat stays on this frame required a long spindle and reverse installation to clear everything and keep the proper chainline.

I've since replaced the cup-and-cone bb with a Shimano cartridge but it required a 127.5 mm spindle and the nds crankarm now clears the chainstay only by about 3mm.

Folks;

I did a repair job on a Sugino AP BB on my '86 C-dale and the asymetrical spindle was longer on the drive side.

JF