mbtigger

The rear part of my tandem has a Bottom Bracket with a locking ring and what appears to be a rubber washer. I was looking at putting on a stoker kit for my 6 year old, but I found some more fundamental problems

attached should be a pic of the Bottom bracket. Do I need a tool to deal with the lock rings? I expect there is a cassette behind the rubber area but I am not sure. How to get the hub out and what can I expect?

Thanks in advance for your help

MudPie

A week ago or so, there was a post about a Gary Fisher bottom bracket, which sounds similar to your set up. Basically I recall someone mentioning the need for a c-clip plier to remove the retaining clip. These are pretty available at hardware stores or Sears. You might want to search on "Fisher bottom bracket".

ultraman6970

I saw one of this ones years ago... I believe u need something like a SNAP RING PLIER to take that seal ring thing. Do you have one on each side maybe?... well at least u know how to take the ring out

https://www.sjdiscounttools.com/otc7125k.html

MudPie

Title of the aforementioned post is "Weird Bottom Bracket".

rhenning

If that is a Burley just remove the snap rings and push the whole thing out. The bearings are standard sealed ball bearings and can be bought at most bearing supply stores. Take the bearing with you so the store can match the numbers on your bearing to a new bearing. There are two bearings in the BB. Roger

kycycler

Snap ring pliers to remove the lock ring and just pull the axle and bearing out. As was stated by rhenning a bearing supply house should be able to fix you up. Good luck

2372ighost

What rhenning says^ +1

mbtigger

Thanks Rhenning, it is a Burley. I suppose I will getting a C-clip plier/snap ring pliers to take the rings off.

mbtigger

Update:

I have removed the locking rings, but the unit does not move out of the housing. Should it push? Do I need to unscrew it? is there some way to get a grip on it since it is inside the housing?

This is rather frustrating. I have not come across a bottom bracket like this before...

Thumpic

Can you see threads on the inside of the bb?? If not, run the crank nut back on the shaft to protect the treads, and give it a few taps to see if you can push the bearing out on the opposite side......gently......they probably aren't pressed it, but it should be a very good fit at the least....

mbtigger

I'm pretty sure what has happened is that it is rusted in there. I had a bit of trouble getting the seat post out of the tandem. I have tried tapping it. I was able to remove the gasket and clean out the bearings and grease the heck out them. I think it moves slightly better now, but I don't think it will ever be as good as it should be. (The front BB still works great!)

For future reference, does this type of bracket have a name? can I get a replacement? I fear getting the bracket out now might involve having to destroy it.

Perhaps at some future time if I have a replacement I might be willing to put some harsher acidic treatment down the seat tube and remove the rust and get the whole thing out...

MudPie

Correct, if you apply too much force on the spindle, the force will be transmitted to the inner race. However, the outer race is probably stuck to the shell. Hence, you might end up destroying the cartridge bearing completely if you whack it with a hammer to get it out. There is not much holding the inner to outer race together with a force in that direction.

I would guess those are standard industrial bearings, and the good news is they are readily available, see www.mcmaster.com, for example or any industrial supply house, or maybe a descent LHS (local hardware store) can get them for you. Can you see a number on the black cover? Industrial bearing are coded to ABEC standard and you may see a number like "6006 2RS". If forget what it all means, but Wikipedia has an article on Annular Bearing Engineering Committee. The basics are inner diameter, outer diameter, type of rolling element, type of seal...it's all in that code. Again, if yours has a number, most likely you'll be able to find its equivalent.

This guy sells all sorts of bicylce bearings, including bottom bracket bearings (not sure if yours are included): https://www.enduroforkseals.com/id180.html

I've never seen a bottom bracket with cartridge bearings (although I know they exist), but it seems like they need to press-fit into the shell to remove potential play of putting the bearing into a slightly larger hole.

EDIT: I can almost see the number on the photo of the bearing, but even placing my eyes 2 cm from the screen, no luck.

MudPie

You might try to loosen the joint with a penetrant, like Liquid Wrench or WD40 or PB Blaster. Howerver, these products are likely to seep into the bearing and dissolve the grease in the bearings. But if you are planning to get new bearings, then no big deal.

mbtigger

I already tried to loosen the unit with PD blaster, and after doing so, I removed the gasket, cleaned out the bearing and added as much grease in there as I possibly could.

Thanks for the link Mud! The number on the gasket is a very legible 62030 KBC. Looking at the bearings it seems that the standard is 5 numbers. There is a standard 6203 bearing housing, so I think it very likely that that bearing housing should fit the tandem. McMaster has them available. Silly of me not to think of McMaster or Granger, but it has been so many years since I needed to get something from them...

Do the original bearings tend to be normal or stainless steel. the difference in cost is a factor of 6! I suppose what I COULD do is order the steel bearing and make sure they work, and then, should I feel the need, order the stainless.

Now I have to search the threads for the best way to remove rusted in bearings...

Thanks again!