Replacing Bottom Bracket
 

The BB in my trusty Schwinn hybrid is starting to creak and groan.

http://i.imgur.com/9r7jil.jpg

Rather than simply replacing it (again) I'm considering a swap for something better. My question is this:

Should I replace the crankset for another MTB setup, or should I consider an entry level (e.g., Sora) road bike setup? I ask because I've seen other bikes set up this way with road gearing up from and MTB in the rear. What is the advantage? Is it worth the time and trouble? What parts would I have to change besides the FD?

I live and ride in a relatively flat area, and never haul anything more than 50 lbs. or so... besides myself that is.

Thanks for any and all replies. :thumb:

For commuting and touring I just run a 1X7 or 1X8 combo with a wide spread... I prefer simplicity over the micro-steps in gearing that a multi-chainring crank with narrow spread cassette offers. What kind of BB does your Schwinn have? I find that BBs with cartridge bearings can creak and groan even when the sealed bearings are still OK because the retaining rings loosen and no longer hold the cartridge body securely so they merely need to be torqued down again.

Do you spin your current big ring out? If not, there's no reason to change, unless there's something else wrong with it. I'm guessing it's a square taper BB. Just buy a shimano UN-55 (or whatever the current 5X model is), install it, and forget about it.

Most Shimano road front deraillers don't play well with Mt. shifters. Rears do

That's pretty much what I was thinking. If something is wrong with the crankset, SRAM and Shimano both have decent square taper MTB and hybrid cranksets in the less than $40-50 category... I'm thinking of Alivio and whatever the SRAM equivalent would be, both of which would be sufficient IMHO. Sadly Deore didn't seem to be available in square taper last I looked, but I like the old STX RC crankset Ice got on my bike now. All that said, if I were to replace, I'd probably save up for a nice Sugino touring crankset.

I find with my current crankset, even with a big chainring of only 44 teeth, It'd need to be coming down quite a hill to have problems spinning out with my 11-32 cassette.

I switched from the old cup and cone bottom bracket to the Shimano cartridge bottom bracket about a year ago, and replaced the cranks with the new parts having the same ratio about a month ago. I would have wondered the same things you are if both parts wore out at the same time, but ended up staying with the same cranks based on the parts availability at the LBS.
I too live in a flat area and rarely haul more than 50 pounds, please don't tell me later that you switched to road gearing up front and found that you can now cruise effortlessly at 20 mph, never miss a light and never have to deal with traffic. ;)

The simplicity of a 1x8 setup sounds intriguing; I rarely come off the middle ring, and even then it's only ever to the big ring in top gear when speeding down the occasional hill. I can live with having to coast for the infrequent times that I experience that situation.

The bike does indeed sport a square taper BB and an 11-32 8-spd cassette. Any recommendations for a SS crankset? Should I get a new chain? It could probably use a new one, anyway.

Thanks again for all the suggestions! :thumb:

Replace your bottom bracket with a mid-line BB from Shimano or any other source, then forget about it. I have several bikes, and only 1 time have I worn out a BB.... it was on a MTB with about 3,000 miles on it (I'd guess 30% single track, 70% road). I have nearly 8,000 miles on my CrossCheck with the original BB. A new one should last you a while.

If you're concerned about it not lasting, I've heard Phil Wood makes some that last forever.

To answer your questions:

Road gearing in the rear = lighter cassette and tighter range. This really only matters for elite racers who are trying to spin a specific cadence for optimal efficiency. A MTB rear cassette will generally be (marginally) heavier, have a greater gear range, but also larger steps between gears (which, of course, impedes that perfect cadence). Unless you're an elite racer, or think you need to mimic them to optimize your performance for your weekly club ride, it won't make a difference.

You should only need to replace the front derailleur if you're moving from a double up front to a triple. And then, it may not need to be replaced, depending on the range of your front derailleur.

Road gearing up front usually means a double chain ring set-up. You should be able to use the limiter screws to convert the FD from a triple to a double.