RubeRad

Hey all,

Found (most of) a Rockhopper in the trash, workin on cleaning it up, getting it rolling again. It had no crankset or bottom bracket in the shell. I have a couple cartridge BB laying around (octalink, UN-55), and the standard threading seems ok, but there's a HUGE obstacle where the cable guide screw comes into the shell -- as well as extra metal there to hold the screw. Pic:




Got started filing it down, but it's gonna take a while. What kind of BB is supposed to go in there?

Here's a picture of the full bike:

Ross200

Traditional 3 piece BB slides right by-most likely what came out. One can remove the offending screw/bolt and cable guide, install cartridge BB and re install said cable guide and securing fastener. Power tools and threads can be a bad mix on this task.

Geepig

Ah, that brings back memories of a simpler time, when the plastic piece would crack and fall off the water bottle holder and we didn't bother to replace it

Retro Grouch 

A steel frame Rpckhopper. What a great find! Probably 25 years old.

I'm thinking that bike pre-dates cartridge bottom brackets so the separate spindle would miss that fastener. It's probably part of the under the bottom bracket cable guide. If It was my bike I'd see if I could pinch those two little ears together and push the BB guide out. Then I'd cut off the ears and hold the cable guide in place with a dab of 3M Badge and Trim cement (AutoZone has it). Now you can use a semi-modern bottom bracket. Oh - before you sbuy a bottom bracket, be sure to measure the shell width. It's probably 73mm but I wouldn't be surprised if it turned out to be only 68mm. I'd check the dropout spacing too.

Jeff Neese

I have a '93 and a '95 Rockhopper with the same BB, and I have UN55s in both of them. It's been a while but I don't remember either of them being a problem.

RubeRad

Even with the screw backed out (as pictured), those two 'ears' block the insertion of a cartridge BB.

Pinching the ears together, that's an idea, maybe flexing them back and forth enough will just break them off, and then as you say, just cement the cable guide in place, it's not that critical of a part.

Or should I look for an old 3-piece caged-bearing BB with a narrower spindle?

Crankycrank

Are you sure that the protrusion is steel? It kinda looks like a removable threaded plastic push pin. You'll find out when pinching the ears together.

ClydeClydeson

It is likely the plastic piece is a 'clip' part of the cable guide. It is possible it does not require a screw at all. If the plastic sticks through enough to interfere with the BB, you can break off or drill through the cable guide to remove the clip and just use a screw. NB, throw away that rusty MF'n screw someone found in grandpa's toolbox. The hole in the BB shell of the frame is very probably M5 threaded and a water bottle bolt will thread in and hold the cable guide tightly.
If the screw is sticking out so much it interferes with a BB, cut it, dear Liza, CUT IT. It's not rocket surgery.

RubeRad

Hmmm, it seems to be filing down like metal, but if it turns out to be just a clip part of the guide, that would be great!

cyccommute 

The UN-55 has a narrow middle so the screw shouldn’t be a problem once installed. You can pull the cable guide out, install the bottom bracket, and reinstall the cable guide. If the screw is too long, you can file off the end of the retaining screw. I’ve had to file many screws to make them fit on bottom brackets that are wider in the middle than the UN-55.

You could also clip off the ears of the cable guide and use a slightly larger sheet metal screw. The screw would screw into the metal of the bottom bracket shell. This is a common way to hold the cable guide on the shell. Again, you will probably have to file the screw down to fit.

Lubricate the screw, by the way.

cxwrench

Jesus, just remove the cable guide, install the bb and then put the cable guide back on. Maybe you shouldn't be trying to tackle something this complicated.

RubeRad

'just remove the cable guide' -- if I thought/realized those were just plastic clips sticking in, I would have done that already. It seemed like a metal collar to receive the screw.

cxwrench

It should be pretty dang obvious that they're plastic and part of the guide, and the the split is there so it can be installed/removed.

cyccommute 

Sorry I didn’t understand your concern. Your cable guide is similar to this one. This one isn’t exactly like yours and it is a design that isn’t very common but it’s around. Remove the screw all the way and you should be able to just pull the guide off. You might need to “persuade” the guide off with a screwdriver but it will pop off.


Once off, I’d proceed like I suggested above. Most newer designs don’t have the “ears” at all and just fit on the outside of the shell and are held in place with a screw.

RubeRad

awesome, thx. I'm sure that will get me where I need to go