Hi
Have a small kids bike donated to me from a friend, on the service i was giving it before my niece gets it as a pressie i opened up the Bottom bracket area to re-grease the bearings, that was my first mistake.
The caged bearing race collapsed and guessing they'd be easy parts to replace i ditched the pair of them.
Now the problem, i cant find replacements, in the several LBs i've been in or online.
I can confirm that they're not BMX size cups but slightly smaller, crankset is a one piece with chainring attached.
Latest bearings i've tried are 1/4" caged races, these are too small. However the Bmx race's offered by the shops are too big to fit into the BB shell.
I need help, i need an online supplier of the bearing please or else i'll have one very upset Niece.
Can answer any questions in the pursuit of tracking the bearings down.
can you pack them with some free bearings and put enough in of a reasonable size to sort it?
tried that but the act of threading the one piece crank in, plus the difference in the cup and cone has made it a near impossible task. Although that is the last chance plan.
Enough grease in teh cup should hold them in, tricky to help remotely on this.
absolutely agree, exhausted the options locally so trying the hive mind.
for an ordinary bearing you need inner/outter dimension and width as three figues to search online for a replacement.
if you measure the outer dimension and work out the inner one by measuring the crank you maybe able to source a suitalbe replacement using the WWW. I find most of my bearing on E-Bay.
Good luck
I wonder if good ol' Sheldon can shed some light on this;
http://www.sheldonbrown.com/gloss_bo-z.html#bottom
http://www.sheldonbrown.com/opc.html
Might be worth a read as there are slightly different size systems used.
Totally agree it's virtually impossible to use loose bearings in a one piece crank - if ever there was a need for cages it's here.
coleman the first link shows the style of the bottom bracket it's a 'ashtabula' style, though i'm not sure if it's a standard size for kids bikes as well as adults.
The crazy thing is i believe that pretty much any kids bike that uses the one piece crank is the same as this bike, i just cant find the bearings.
grrrrrr
edit ... just looked at the second link and it could be a 5/16th bearing but the number of bearings within the cage are the important bit. Need to look through what i've already tried
Sorry can't offer any useful advice.
I've only come across different 24 & 28 tpi threads, both take 5/16 bearings, and as you correctly say the number of bearings, but the cages are diff. size and not interchangable. Have found these on a mixture of kids, bmx and cruisers.
Hope you get it sorted.