Chesterton

My road bike (1990 Schwinn World Sport) has developed a clicking in the cranks, generally once per pedal stroke, although it comes and goes to some extent. I noticed there was tangible play in both pedals, so I disassembled the pedals and discovered that there is pitting on the cones (and some, although less severe, on the spindle cups too). For now, I switched to a new pair of MKS Touring pedals that I had available, but I am wondering whether these pedals are beyond repair, or if that pitting won't be a problem with new balls and grease.

Unfortunately, the clicking has not gone away completely, so it appears the bottom bracket bearing also has issues. When moving the cranks by hand there is a definite and fairly substantial "catch" in the rotation, at the same place each time round. There is no side to side play in the cranks, however. I have not overhauled a bottom bracket before, so my question is, as with the pedals, at what point do you simply replace the whole thing rather than just replace the balls and repack the grease?

Aubergine 

Iride01 

If the pitting isn't really bothering you, then there is nothing to require it that I know of. It's not like your life is going to be endangered, unless you routinely ride in high motor vehicle traffic and cannot risk any component failure. And remember, this thing is only spinning a very low rpm. So there won't be any parts flying out like shrapnel as does parts on a turbine engine that spins 10,000 to 20,000 rpms

Also, if you do decide you want to fix it, then you might also consider replacing the entire crankset and bottom bracket. Your chainwheels might be getting worn anyway if you put a lot of miles on it.

I get confused about some of the old Schwinn's with World and Sport in their name. Is this one of the <24 pound bikes?

Oh... the last time I had anything clicking that sounded like it was the BB, it turned out to be one of the pedals.

Chesterton

So is the worst thing that will happen just the clicking and knocking? As long as there is sufficient grease in there, it won't rapidly degrade further, right? I don't actually think there's *that* many miles on it, maybe a few thousand over three years. Possibly the grease got washed out by too many times getting caught in the drenching rain.

I doubt the bike is under 24 pounds. It's Taiwan-made (by Giant), chro-moly main tubes and basic steel fork and stays.

andrewclaus

Grease gets washed out, dirt gets washed in, and bearing surfaces fail. It's cumulative, and you can arrest the process temporarily by cleaning and regreasing. Pitted bearings of course will never feel like new, but I agree it's not dangerous. Replace as you can afford it, bit by bit or entire bike.

Definitely inspect the BB.You will need special tools and skills. Cartridge BBs are not too expensive at the lower end.

Iride01 

Assuming you correctly assemble and adjust them, then the worst I'd expect is that they'll wear quicker and you'll have to deal with them sooner than you felt like dealing with them this time. At the worst, they might just get harder and harder to turn, but that's more unlikely I'd think.

I think one or two model years of the World Sport were actually pretty light bikes compared to others that were built of cheaper tube for the mass market. Chome molly tube might get it down to where the true light weights start (IMO). I only asked that as for me and me alone, that is the point at which I consider if a road bike is worth it to me to spend money on. Your desires and situation are not mine so I won't make fun or deride you if you think spending money on it is well spent.

Chesterton

It has been a pretty decent bike for me. I did a 200K brevet on it, as well as many informal metric centuries, etc. I think this was the last year of the World Sport. I am building up a new randonneuring bike soon and I think I will turn the Schwinn into a fixed gear once that's ready, just for something different. I don't want to spent much money on it since my focus is on the new bike, but since I do intend to keep it in one form or another I'll probably eventually have to replace the BB.

okane

IN my area World Sports are commonplace and step thru models with low mileage are often available for $20 or less. If you have the crank puller parts swap is easy and takes less than an hour. I have 4 World Sports, and the last one I got in like new condition for $7.00.

This one is too nice to part out.




Original wrap and saddle, pedals in the bag

Koyote

There's a little pitting on the cups of my SS commuter's wheel hubs. With new bearings and fresh grease, they run as smoothly as any wheels I've used. So you might be surprised what can be accomplished with a proper overhaul.

Otherwise, as others have explained, you can replace or just keep riding. No biggie, if it doesn't bother you.

Chesterton

I guess as long as it's not going to seize up or something, I will just continue riding it and live with the clicking until I get my new bike built up. Then I'll deal with it when I do the fixie conversion.

davidad

Open up the BB and inspect it. If the cup and cone surfaces are not pitted and the ball have their shine, clean it up regrease it and go ffor a quiet ride.

cpach

I like overhauling cup and cone bbs, but also keep in mind that a replacement sealed unit costs like $15. Still, all you need to overhaul the bb are crank pullers, a lockring wrench, and pin spanners some grease, and some new bearings. Honestly you can cheat the pin spanners carefully using a drift on the adjustable cone.

Chesterton

Update: I opened up the bottom bracket and discovered that the spindle races are pitted. The cups look OK. The balls on the drive side all readily fell out of the retainer cage when I plucked it out of the shell, and they are dull and "burnt out" looking. The balls on the non-drive side are much shinier and tight in their cage.

Since the spindle is pitted, I was thinking of just installing a cartridge unit. However, there is a protruding bit on the bottom of the bracket shell that is threaded for the cable guide screw. It protrudes into the space by maybe 4 or 5 mm and the screw tip a few more mm above that. I can get a shorter screw easily enough, but will I have to saw off the metal bit? Will the screw still hold the guide on without it? How much room does a cartridge bearing unit allow for in the center?

Am I better off at this point just getting new retainers and balls and putting the original bearing back together?

Kovkov

You don't even need retainers. That way you can use 2-3 more balls per side for better load distribution. But I would get a new spindle.

Chesterton

Yes, that's true, I could just buy loose balls. I might rummage through the community bike workshop's parts drawers for a spindle in good condition. It's 137mm if I measured correctly, is that an unusual length? When you measure the spindle, do you include the threaded part where the nut goes, or just the square taper part?

Kovkov

Can't really help there, mine are cottered, never worked on a square tapered one.

cpach

Just measure the square taper part. 136 would be uncommonly long but not impossible. If it's that long on the taper, I would not bother trying to find a spindle. If it is that long: https://www.ebay.com/itm/132377175081

Chesterton

Some further research suggests that the "3L" printed on the spindle indicates 116 mm. I'll verify that tonight, but it sounds reasonable, with about a centimeter of threaded post at each end beyond the square taper.

andrewclaus

That cable guide screw looks unusual, a sheet metal screw in a plastic anchor? Even the anchor looks like it'll interfere with a cartridge. If you change to a cartridge, you may need to drill out and tap that hole, or more likely a new hole, for a machine screw.

If you change to a cartridge, you'll also need the width of the shell, 68 or 73 mm usually, and may need a spacer which may affect your chainline.

116 sounds like a more reasonable length, and no, you don't include the threaded studs in the measurement. Your new spindle may have threaded holes and you'll get crank arm bolts with it, instead of nuts.

Chesterton

All's well that end's well! I picked up a replacement (lightly used) spindle from the local community bike workshop for $1. Had to dig through the junk bins to find one with the correct length code and taper type and then hope it was less pitted than the one I had, but I finally found a decent one. Replaced the retainer cages holding 9 balls per side with 11 loose balls per side. Rode the bike to work today as a shakedown ride and it is buttery smooth now.