Bayliss Wiley BB playing up

destry

Dirt Disciple
Hi there, I am fitting a set of Bayliss Wiley bb cups and axle. Brand new 1/4 inch bearings and all the races are pretty good, but...

Once assembled, the axle keeps "catching" - turns smoothly for a few revolutions, then there's resistance and you have to turn a little harder to get over the "hump". Usually happens when you turn one way for a few revs, then reverse. At first I thought a stray beairng was fouling something, but no. There's a complete set of bearings in both cups, and they look nice and snug.

I can't figure it out - these things are so basic it's hard to see what can go wrong. Ideas welcome!
 
By complete set do you mean you have completely filled the race.......or left one out to give them room to spin?

Shaun
 
Well, there wouldn't be room for another one in there, but there seems to be plenty of space for everything to move around in. You think I should try whipping one out?
 
Sounds like you have the right number :) It's possible with loose bearings to slip an extra one in and not notice and the race and bearings don't line up........

I'll have a think but apart from that there's not a lot to go wrong if the surfaces are OK and not brinelle'd etc...

Shaun
 
How are the threads on the cups and BB shell? Are they a tight fit or is there a bit of play between the threads? If there is play in the thread, and the faces of the BB shell are not totally true, the cups could be slightly out of alignment with eachother. If this was the problem though, you'd expect the bearings to 'catch' once on each revolution.

Perhaps you could try installing the bracket on another frame and see if you get the same problem?

If it's installed clean and right, and still doing this, there's obviously a 'tolerance' issue somewhere--bent axle, distorted cup, or rogue ball-bearing. You can either hunt it down and correct it, or just back off the adjustable cup a tad and accept a bit more play in the bearing/cup interface than you would prefer.
 
Thanks for the input!

I took everything out, cleaned off all the grease and inspected the cups with a strong light and a magnifying glass... Turns out the adjustable cup had a small amount of tracking in a short arc covering about twenty per cent of the race. Must have missed it first time -- or more likely I convinced myself it would be fine, as it was some time ago I set aside these cups for this bike.

Amazing how little it takes to let one of these chaps pop up and refuse to play ball! I have a new cup in there now and all is sweet.
 
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