Coyote!

In an earlier message [https://www.bikeforums.net/showthread.php?t=201167], I asked about removing difficult cranks on my dear old beater, an early 90s TREK 930.

Well the cranks eventually came off OK, but it revealed the Bad News when I took apart the old cup-and-cone-with-a-tapered-square-spindle-and-retainer-ball-bearings setup. The bearing retainer ring had shattered and shot shrapnel into the beautiful old races which I appear then to have ground to dust. I have it back together, but it sounds like a John Deere tractor. . .not quite what you like in a bike.

Anyway, it’s decision time.

Questions:

1. Do I replace the old spindle-cones, cups, and bearings oooor do I upgrade to a nice cartridge? [I’d love to upgrade, but need to know the pitfalls/pratfalls.]

2. If I upgrade to cartridge, what do I need to consider? Shell width and spindle width, certainly. Threads with a 24 TPI pitch, certainly. Anything else?

3. What about square tapers? Are they standard. . .will my old spider and crank go on them?

Reading Zinn, it seems a pretty straightforward procedure but I’ve had my @ss in a crack in the past with “straightforward” things. [Marriage comes to mind.]

Anyway, Mercy Buckets [as Marie Antoinette said when the old Gilly-Teen made a quick job of her neck].

HillRider

Yes, certainly replace the old bb with a cartridge type. Shimano's BB-UN 53 is current or you might find an NOS UN-71 or UN-72. All are fine and very reasonably priced. You need an English threaded unit for 68 mm shell width and Shimano square tapers are all the same. As to spindle width, take the old axle with you and have the LBS match the length.

You will need a specific tool to install the cartridge but it is readily available from Park as the BBT-2.

Ya Tu Sabes

Just make sure you have the matching retaining bolts. Shimano cartridges have a hole into which a separate bolt threads; many older spindles have threads onto which a retaining nut is placed. The cartridges don't come with the bolts (I don't think), so get a pair from your LBS (should cost not more than a buck).

top506

1) I like cup and cone BB myself. I had bought a UN53 for my Atala, but replaced it with a 70mm cup and cone Dura-Ace when one came along.
2) The UN53 came with crank bolts, but I'd spring a couple of bucks for a pair of Sugino bolts with the 8mm hex socket head, just in case.
Top

Retro Grouch 

Easy decision. Go with a Shimano cartridge bottom bracket.

Coyote!

Thanks folks. . .wise counsel as usual. I'll get back when it's done. Watch this space.

Coyote!

Sucess! Went on slick as goose-grease. I laid out $20 bucks for the cartrige [Shimano BB-UN 53] and $3 for the tool. It took all of 1.5 hours to swap out between phone calls and talking back to the NPR news folks.

Thanks again for the advice and support.

cs1

Retro's right, they can be had at Nashbar for under $20 on sale. Very nice unit and worth way more than $20 bill. Good luck.

Tim

brokenrobot

Unlike marriage, you can't really go wrong with this one. A cup-and-cone replacement will be just fine, but a cartridge will be easier. I'm gradually moving toward the cartridge units on all my bikes.

HillRider

+1 and then some. After using cup-and-cone bb's for years, I've gone to cartridge bb's for everything. I've even got one on my wind trainer bike.