harpdog

I commute to work on my bike 3 or 4 days per week, and ride additionally on other days. Generally my ride duration is 40 to 50 minutes. Fitness is one of my major goals. I tend to keep in a lower gear and spin fast to keep my heart rate up. I also tend to power up hills in the same gear. I'm pretty strong and on the heavy side.

Riding home from work, my bottom bracket started skwauking badly - so I assume it's the bearings.

So am I doing damage by powering up the hills?

Cyclist0383

Most likely it's just a rubbish BB. Do you know what kind it is? Or, what bike do you have?

stapfam

So how many miles on the BB? Then what quality?

I normally use "XT" shimano bottom brackets and only ever change them on the Tandem- where they do take a lot of Punishment. But I have had XT BB's fail on me after what I think is a relatively short time- and then I have a Mountain bike that has had the same BB in it for about 20,000 miles.

I doubt that it is your riding style- Unless you are a clyde mashing up steep hills and then you would knock them out relatively quickly. Just go for LX or XT quality in the Shimano range and you should be OK.

Velo Dog

Probably it's a combination of a junk BB and cheap assembly, without sufficient grease. You don't mention the type of bike or bottom bracket, but that's a common place for manufacturers to cut costs because nobody sees it--they'll use a brand-name stem or seatpost, something that shows, and cheap out the BB. Skimp a little on grease, too, and there you are. I doubt your size or riding style are factors--I'm 6'4 and 250 pounds, and I've never worn out a bottom bracket. I don't track mileage carefully, but one of them has at least 15,000 on it.
Chances are you haven't trashed it, though. I've repacked (cleaned and greased) several BBs, and they've run smoothly. Pull the bearings and take them to a bike shop to get new ones, then reassemble and adjust (www.parktool.com for details; click on REPAIR HELP). If the LBS can't supply replacements, try reusing the old ones. I've done that several times with good results.

harpdog

I do mash up the hills pretty heavily - and I suppose at 235 lbs I qualify for Clydeness.
Can't say what brand the bb is, (until the suggestion of brand, I assumed that the bracket was just the hole all the bearings and spindle are housed in)only that it's a 25 year old US made Ross mountain bike. I've replaced a number of components, starting with wheels that flexed and seemed beyond rational repair.
I obtained it used and started heavy use last year, going maybe 50 to 100 miles per week in commuting (15 miles round trip) and fitness rides up to 15 miles.

I need to learn more about repair - I can handle obvious simple stuff, but taking apart bearings would make me nervous...

geo8rge

My guess is you have loose packed bearings not a cartridge BB. Loose packed bearing require 'repacking' every 6m to 1yr. If you didn't do that, that is the problem.

assuming parts are not fused together by rust, your LBS should have no problem replacing with a cartridge BB.

You probably can do it yourself but tools are expensive and will clutter up your life. LBS is best solution.

duffer1960

It may be a one-piece crank. They're easiest to service and you may not need any special tools. May still need a pedal wrench. If the balls are bad, just get new balls. The cups & cones may be a little chewed up but they'll work unless they're really beat. For more info on one-piece cranks, see https://www.sheldonbrown.com/opc.html .
If you have to replace everything, then parts are available. Something like this: https://www.bikepartsusa.com/bikepart...ackets-1-piece . Have to press the cups into the frame.

If it's a three-piece crank, special tools and more finesse are required. For a definition see https://www.sheldonbrown.com/gloss_ta-o.html#tpc . Modern cartridges offer a drop-in replacement. This is best left to a bike shop unless you want to buy a crank extractor and torque wrench. The drive side cups are often in pretty tight; a benchtop vise is helpful.

Noises down there are sometimes not the bottom bracket. Check for loose chainrings. Are you sure it's not your saddle? Etc.

Good luck, let us know how it goes...

pityr

You are eerily similar to me... Im 225, ride 4 days a week with a total of 50-100 miles.

My BB died after 2.5 years and had around 5k miles on it. Not bad I guess but the new one doesn't appear to be going to last that long and is already creaking after 2k miles. Its a Truvativ Isis BB and it doesn't get good reviews. Both the LBSs that I go to have said I should probably upgrade if Im going to be putting that kind of mileage on it. One LBS mentioned I could find a good deal on Ebay or Craigslist instead of trying to sell me one.

Velo Dog

You're home free. As the other post said, the bearings in a bike of that vintage are almost certainly loose, and they should be plentiful and cheap at any decent bike shop.
Assuming it's a three-piece crankset and not an Ashtabula (one-piece) model, pull the cranks (a crank puller costs about $15, and you should have one) and remove the BB cup on the right side of the bike, then take out the races, bearings and spindle. Count the bearings on each side (I used to know the number, but it's been years since I worked on one of those). If the races (the rings that hold the bearings in place, against which the balls rotate) are still smooth, you don't need a whole new BB, just new bearings. Take one of the old ones to a shop and ask for a few more than you need, to allow for dropping a couple on the lawn or behind the workbench.
The cup on the left side of the bottom bracket shell can stay in place--it's called the "fixed cup" because it's not movable. Clean everything out well, then smoorg some grease against the fixed cup and push the bearings into place. Carefully insert the spindle to hold them, then grease the race on the right side of the bike and put those bearings in, around the spindle. Screw in the other cup and there you are.
Full disclosure: It's been a long time since I did this, and I can't quite picture the entire process in my mind, but it's not complicated. As you take things apart, you'll see how it all fits together, and you can put it back the same way. Grease every place that things rub or rotate. For adjustment, try tightening the right-side cup by hand until the bearings bind slightly when you rotate the spindle, then back off JUST until they run freely. You should feel no lateral movement (called "sideplay") when you try to wiggle the spindle, but it should rotate without notchiness.

harpdog

I truly appreciate a useful word - grease DOES want to be smoorged, doesn't it?

I let the bike shop do the work - THIS time. Both the bottom bracket (cone type bearings) and the rear axle, both of which were in sad shape. The bike is about 25 years old, so no complaints.

Sure runs smoooooooth now.

I'm going to start buying tools as needed. Next one I'll be on top of!