V73

Hello everybody.

I went to remove the bottom bracket on my Diamondback Sorrento today, as it had been clicking and needed to be serviced. I had thought from the lockring that it was an adjustable BB but the cranks are too big to see behind so it wasn't until I removed it that I saw it also has splines.



I went ahead and removed the lockring because I could and I don't have a tool to remove the bits with splines. Lockring is on non-drive side. On removing the lockring, the bearings for that side came with it:







The drive side doesn't have anything other than the splined ring. I used a light to make it easier to see.



The non drive side after I removed the lockring/bearing:





So what is this? Is it a sealed bottom bracket or an adjustable cup/cone style one? I thought that with cartridge style sealed bearings, both the left and right bearings were contained and inaccessible by the user. In this case, the left side bearings came out with the lockring. This is my first time going at the BB on a bike, so I might just be making a beginners mistake.

As I said, I don't have a tool for removing splined BBs, so one way or another I'll probably need that. Also, most of the stock components on this bike were Shimano, so chances are so is the BB. But should I buy a new cartridge style BB, and is so what kind, or is it an adjustable BB that I can clean, repack and reinstall?

Thanks for your help.
-V73

Bill Kapaun

It's a cup & cone.
It takes the cartridge type removal tool however + the lock ring tool.

This might be what they call a semi-cartridge type???

Many of these have the splines cast poorly and I seriously recommend attaching the removal tool to the fixed cup like in the pic.
You need it tightly engaging the splines, else you might ruin the tool AND screw up the cup.
Trying to "chisel it off" or similar tactics will leave you in a bigger pickle.


Apply some "real" penetrating oil now. Extra soak time is GOOD! Reapply a few times as it wicks in over the course of a few hours/days.

V73

Thanks a ton for the quick help! I'll see if I can get one of those removal tools somewhere local for a price that's not obscene, but If I have to wait for one in the mail that's that. In that case I might just throw my Trek back together, just so I have something that works to get me back and forth for the week.

I'll hit it with some penetrating oil, most of it thus far has come apart pretty easy but better safe than sorry. Thanks for the tip with the bolt & washers too, that should come in handy.

I'll post back when I've gotten the tool to get it all out, with some pictures of whatever I find.

Thanks again!
-V73

Bill Kapaun

Pull out the spindle and clean whatever grease you can, within reason.
Lay the bike on its side, with the fixed cup down.
You can now squirt the PO onto the shell threads and have it run into exactly where it needs to go.

BTW-
The crank bolts are 8X1.0MM, not the more common 8X1.25MM.
when I bought mine, I drove the guy at the auto parts store nuts until we figured out what was wrong.

Also-
Are you going to service this or just install a cartridge BB?
If the latter, look for a code on the spindle such as 3-P, 3-S etc.
That tells the length and we can suggest a "symmetric equivalent" cartridge BB.

If the races and spindle are good, buy 22 1/4" bearing balls and a tub of grease.

techsensei

If you're going to buy the tool to remove the bottom bracket, IMO you may as well replace the bottom bracket itself. The one you have is low quality; it is not Shimano, but a generic unit. It wouldn't surprise me if the bearing surfaces are damaged. A new sealed bearing cartridge is very cheap and will run much smoother; a Shimano UN26 is only $15 or so.

Homebrew01

Remember the drive side cup is left hand thread, so "clockwise" to remove.

dsbrantjr

A BB-UN55 is only a few dollars more and has a metal (as opposed to plastic) NDS cup which many folks prefer. Shimano UN55 Bottom Bracket > Components > Drivetrain > Threaded | Jenson USA

Use antisieze and torque the cups per spec.