07 June 2010

Bert Has Issues (LGRAB Summer Games post 2)

Today I'm blogging about performing a maintenance task as part of the Learning Experiences section of the LGRAB Summer Games.



Sometimes fixing a small problem makes you realize you have a larger one.

Remember this little issue with Bert, the 1976 Canadian-built Raleigh 3-speed?


Well, it turned out that what you see there is a Sturmey-Archer cable attachment that leads to the Sturmey-Archer 3-speed trigger shifter, and a Shimano bit (actually called a bell crank) that attaches to the 3-speed hub. Previously, I took Bert to my local bike kitchen (EBC's Bikeworks) in search of answers, and with the help of Alex we figured out how to solve it, and Alex helpfully macgyvered a Shimano attachment onto the end of the Sturmey shifter cable. So far, so good, but we couldn't adjust the 3-speed once attached because the bottom bracket was way too stiff. Come back another day and we'll repack it, he said. It should only take 30 minutes. (Cue rueful chuckles.)

So yesterday we returned to EBC, and Coreen was a goddess of grace and good humour as she walked me through the 10-step process of repacking the bottom bracket:

1. Carefully remove the R nuts and washers from the cotter pins.

2. Use a press to remove the crank-side cotter pin: or in my case, bend it at a strange angle then snap the threaded end off. Then, use a chisel and a mallet to, instead of firmly and in a single stroke removing the broken cotter pin, flatten the end that used to have threads on it so that nobody will ever be able to remove it. Yes, it's still there. Suggestions for fixing it will be welcomed in the comments. Lesson learned: cotter pins are definitely made of softer metal than steel, and the press absolutely must be aligned correctly at the start, or you're boned.


3. Having utterly shattered your confidence, get the goddess of grace and good humour to remove the second cotter pin. Huzzah! It came out unscathed and can even be reused! Pull the pedal off, and marvel at how much grit is in the place where it attached. Clean with a rag and some Simple Green degreaser.

4. Carefully disassemble the next two parts, which are called the lockring and the cup. This part is complicated by the 16mm bottom bracket wrench being a fraction of a millimetre too big. Try not to drop all the ball bearings on the floor when the cup comes out of the bottom bracket. Pick up the ball bearings and count them. Wonder whether any of the ball bearings you picked up were there before you started work.

5. Take a look at the cup, and the bottom bracket. In my case, what I saw were matching rings of white. waxy, almost plastic, goop on both the cup and the bottom bracket - that must be what the original factory grease turns into after nearly 40 years without being cleaned or changed. I wish I had taken a photo of it. It chipped off easily using a combination of an old spoke, an old tootbrush, and my fingernail. There was also some brown debris (a mixture of rust flakes and dirt, I think) inside the bottom bracket, but there was surprisingly little of it.

6. Carefully clean out the cup and the bottom bracket. A rag, a toothbrush, a single spray of WD40, and some more Simple Green did the trick. Since we couldn't remove the cup and bearings on the other side, we just did the best we could to flush it out then dry it off. Have your helpful god or goddess of maintenance work check to make sure that your cup isn't too pitted to reuse.

7. Add new grease. Coreen handed me a tub of greenish goop from Park Tools, and I glommed it into the bottom bracket a fingerful at a time, then used an old spoke to push it to the other end in hopes that it would work its way into the bearings I couldn't get at (thanks to the busted cotter pin from step 2). Once I was satisfied that I had filled the bottom bracket, I totally filled the cup with the green stuff, then carefully added new quarter-inch ball bearings in a circle around the edge. Only 11 fit. 11? Check with goddess that it's not supposed to be 12 (the number picked up from the floor). OK, you're good to go.

8. At this point, if you have been as generous as I was with the green stuff, your god or goddess of maintenance work will deftly swipe some out of the bottom bracket and some more out of the middle of the cup, set the cup in place, and hand you the wrench for reassembly.

9. Screw the cup back into place. Try not to strip it in the process since, as noted in step 4, the wrench doesn't fit quite right. Do not, as I did, tighten it all the way, forcing the god or goddess of maintenance work to use a well-placed mallet strike to help with untightening. (If it's tightened all the way the movement of the pedals will be too stiff, the ball bearings will get malformed, and you'll have re-repack the bottom bracket.)

10. Next the lockring goes back on, then the pedal, then the cotter pin. Take care to make sure the pedals make a straight line. Oh, bugger, they don't make a perfectly straight line; it's off by a couple of degrees. Confer with Coreen before making the cotter pin permanent; decide that the broken cotter pin on the other side is to blame for the misalignment, and we can live with it for now. Use press to reinstall cotter pin, and cap with washer and R nut.

See the green stuff oozing out around the crank? That's evidence of a job well done.

OK, so the bottom bracket is repacked, and as I turn the pedals the movement gets looser and faster. Yay! It worked! And it really wasn't all that hard to do. Especially with expert help. I even think I could do it without help next time - or with just Sheldon Brown's guidance.

Next we turn our attention to the chain, which seems a little loose. Well, is it too loose? Let's install the chainguard I bought online and see if the chain rubs...


Oh, it rubs, alright. Furthermore, the notes from the seller indicate that this Z-bracket is supposed to attach to a braze-on that isn't on this bike, so we'll probably have to macgyver something for that so it doesn't rattle or rub.

Well, Coreen suggests that maybe it rubs because the rear wheel is too far forward in the drop-outs. Let's take it out of the drop-outs. Oh, isn't this interesting! This wheel is too narrow for the dropouts! (Well, of course it is. It has a Shimano hub instead of the Sturmey it should have.) We need to find a couple of washers to add on either side of the axle to make it fit better.

Once correct washers have been found in the big-bin-of-miscellaneous-washers, and new nuts too to replace the ones that are rounded off,  reassemble the parts in the right order on the axle, then try it for size. It fits! Now have the god or goddess of maintenance work help you figure out how to put it on the correct way, with the chain attached - you might need that chain to make the bike move. 

Aaaand... the chain is still too long. And you've been at it for hours, and it's time to go home and have supper. Sigh.

So here's what's still to do on my next visit to EBC:
- Shorten the chain. On a previous visit to EBC, Molly taught me how to break a chain, so I should be able to do this without help.
- Reattach and adjust the 3-speed, assuming the Sturmey shifter will play nice with the Shimano hub. In the likely event that they won't cooperate with each other, replace either the stupid back wheel with the wrong hub in it (the proper restoration and probably what would actually fix all the fit issues) or the shifter (a less expensive option that may or may not work correctly).
- Drill a hole and wire the chainguard into place at the top; epoxy the Z-bracket onto the bottom; manhandle to get it to stop scraping against the chain. If this doesn't work, give up and remove chainguard, and resume looking for suitable replacement chainguard.
- Remove nuts on front fork and attach stays to half-installed Wald front basket.
- Lemon-and-aluminum treatment of all rusty spots, then wax or clearcoat them, plus the bottom of the bottom bracket where I noticed the paint has chipped off the steel when I was cleaning it.
- Oh, and do something about that cursed cotter pin.

So why is this old bike worth so much effort? Well, first of all, there's having a bombproof bike at the end of the process that will serve me and my family well, and likely survive another 40 years or more. These old three-speed steel bikes were built to last with minimal maintenance. There's also the satisfaction and self-confidence that comes with making or fixing something with your own hands, and the practical skills your learn in the process. However, I also have more philosophical reasons to fix up my bikes myself: knowing how my bike works will make me enjoy riding it even more, and I'm teaching my kids by example that it is better to repair and reuse things than replace them. That's surely worth the trouble!

3 comments:

  1. Excellent! I do believe you may have set the bar!

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  2. The Sturmey Archer shifter will not play with the Shimano hub because of different actuation rates and if you happen to see Bicycle Repairman (he will be at the repair-a-thon) he has never been defeated by a stuck cotter pin.

    Cotter pins also need to be replaced in pairs to get the cranks to align properly.

    He probably has a Shimano shifter too.

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  3. @M&G: =D
    @Sixty Fiver: Thanks! That makes sense. I was planning to go to the repairathon tomorrow night. I'm pretty sure I'll be able to find a Shimano shifter at EBC for the replacement - and I'll save the Sturmey shifter for the Eaton's Glider (we're planning to get a Sturmey 3-speed hub for the wheel rebuild on that).

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