drewfio

I've been rebuilding a 1985 Nishiki Prestige. After servicing the bottom bracket, The cranks (Sugino GP) and chainrings appear to be crooked/angled. Not sure if they were this way beforehand.

There was a lot of resistance/binding when spinning the cranks, so decided to overhaul the bearings. I took the cranks off and could barely spin the spindle with my hand. I was also surprised to see it was a triple being used as a double. The next thing I noticed was that the DS fixed cup was not tight at all. In fact I could unscrew it with my hand. I then removed the bottom bracket altogether. The spindle had minor pitting on one side. The cups looked well used, and worn, but no pitting. I decided to go head and put in new loose bearings (11 on each side) and see how it went. One thing I did not do, which I wish I had, was make a note of the spindle orientation. I took a guess at which way it went. I then reassembled and was able to adjust it so it spun pretty smoothly with no play, albeit with a little of roughness I attributed to the pitting in the spindle.

But now that everything is back together with the cranks on, I noticed the crank arm on the drive side is closer to the chain stays than on the NDS. And the reverse is true when measured from the down tube (although slight less extreme since that position is less horizontal. Also the chainrings look like they might not be parallel to the frame. There is no wobble at all though; it spins true but at a slight angle.

So my question is, what is causing this, and is it fixable?

My hypotheses include:
- Cups damaged enough to cause crooked spindle angle
- Incorrect installation somehow. (I'm quite sure there was no cross-threading during installation, so.. reversed spindle? Something else?)
- Twisted/bent bottom bracket shell

Any other ideas and help would be really appreciated! Pics attached.

SpedFast

It is possible that you put the spindle in backwards. But you're right, that looks more like it's off at an angle. Good luck and keep us posted.

drewfio

Another hypothesis is that with the loose drive side cup, the play allowed for wear and damage to the shell/threads causing or allowing it to be off center.

rccardr 

Did you roll the spindle across a flat surface to check for straightness?

ClydeClydeson

Re angular misalignment...

The chainrings appear parallel with the bottom bracket cup, and the cup appears straight and fully seated in the BB shell, so unless the frame is massively tweaked, I'd say it's just an optical illusion caused by the angle between the chainstay and chainrings.

drewfio

I did not. So perhaps it is not straight. But wouldn't this cause a wobble in the crank/chainrings as they spun, not just and angle?

merziac

I would string test the back end for alignment and RDO's distance from the ST.

Then check and compare RDO's distance from each end of the spindle with arms removed and with bolts for the string to wrap around as far outboard as you can.

And you can turn the spindle around as well as check it on a flat surface.

repechage

caged bearings installed inverted?
with the excess resistance, that popped to mind right off.
individual cup bottom brackets are quite tolerant of misaligned bottom brackets actually.
a Nishiki with a big organic problem is not expected.

if the bearing cages were installed backwards on one or both sides, migrate to loose balls, add a bearing to the number on the originals each side
If installed inverted, the metal cages are to be considered distorted, suspect.

Greg R

Lay a straight edge, or a string line, across the chain ring to the rear. See how that lines up with the frame's centerline. Try it on different points of the chain ring as sometimes they'll have a bit of run out. Keep a string taught being careful not to move it beyond touching 2 points on the chain ring.

drewfio

Ah, good call. I should string test. Pardon my ignorance, but what does RDO stand for?

merziac

Sorry, rear dropouts.

And this will only show a discrepancy on the horizontal plane, maybe string the spindle up to the top tube as well.

drewfio

There were originally cages with 9 bearings on each side when I opened it up, but I replaced those with 11 new loose bearings on each side. That's one more than you suggested adding. I went off Sheldon Brown's recommendation for number of loose bearings to use. 11 seemed to fit all right. Is this potentially wrong in this case, and could that cause the issue?

drewfio

By the way, I really appreciate all the replies!

noobinsf 

Is the bike stock, or was it modified at some point? If you're not the original owner, it may be impossible to know for sure. The reason I ask is that you indicated the crank is drilled for triple but being used as a double, and it's not unheard of to flip the spindle if you decide to remove your smallest chainring on a triple and reinstall the crank as a double. If the previous owner got a workable chainline of 43.5mm or thereabouts, they may have decided the extra space on the non-drive side was acceptable and just pedaled ahead.

https://www.sheldonbrown.com/chainline.html

By all means, the alignment measurements that are being suggested above are good ideas to ensure the frame is straight, regardless.

drewfio

That was my first thought when I saw that it was a triple—that it had been changed from stock setup. I can't find the catalogs for this year/bike, but I have tracked down a bunch of photos (mostly here on Bike Forums) of the same exact bike other people have. They all appear to have the same two chainrings and same Sugino GP cranks as mine (as well as other parts as far as I can tell), unless they had been upgraded in obvious ways. I can't tell from those photos if the others are also triples set up as a doubles and they all came that way, or if there was a double version of the crank others may have shipped with. Because my bike looks the same in most or all ways as many photos I've seen, I lean towards them all having shipped with triples set up as doubles. But who knows.

jdawginsc 

If it is an asymmetric spindle, that could be an issue with the distance not the alignment. Use velobase to be sure you have the right length spindle for that crankset. You may wish to replace out the triple or add the chainring.

When you spin the crank on DS do the chain rings wobble or spin straight? After you check for alignment in the horizontal plane, you might want to check the vertical alignment as well.

If straight, then the spindle is straight and it could be a twisted Bb shell, or misaligned bottom bracket threads.

Personally, I think you should flip the spindle and see if it looks better!

repechage

If it is overstuffed, yes, but cheaper caged bearings short-changed to 9.

the only other clue would be roughness on the spindle.

Pitting for me advises it is time to toss it.

overstuffed bearings Would have the cranks walk, (wander) but that would move around and dimensions between the stays and arms would vary from experience in fixing customer repair attempts.


I would take it apart. cranks off, drive side down. remove the spindle and adjustable cup as a sub assembly. document the spindle carefully in mm and markings for sourcing a replacement.

test run the adjustable cup with bearings in your hands, watching the bearings roll. Satisfy yourself with the bearing qty, Match both sides.

reassemble and adjust.

with a decaying spindle, there will be roughness or small play at some point in the rotation.

merziac

The pitting roughness can be somewhat diminished by using regular thick automotive bearing grease, I use it on most bearings now days as many of the C+V bikes have succumbed to plenty of wear if not actually excessive by this point in time.

You can always change it out again after you get it sorted but I know for a fact it can extend the life substantially while we decide what to do for the long term.

The drag is of little consequence for the prolonging quality IMO.

garryg

I have a Prestige in the shop.The distance from crank to chainstay on drive side is much larger than non driveside. Thinking you may have spindle backwards.

drewfio

Nice—someone with the same bike. Will try flipping it. Thanks!

garryg

I know from experience that this can be the problem

Narhay

A $15 cartridge BB would fix a lot of this.

Moe Zhoost

I can't see any alignment issues in your pictures. If the spindle turned smoothly when you rebuilt the BB, I'd say that your only problem is that you reversed it. Sugino spindles were asymmetric with the longer side on the drive side. Flip it and you'll be happy.

Greg R

I highly doubt it. Going on my Sutherland's, 11 is good. 9 ball caged is easier maintenance but higher ball contact pressures. 11 balls distribute loads better.

SpedFast

Yes, it would wobble. So we're back to the spindle being backwards. Hope it works out.