Fix up or buy new?
 

My 1996 Trek 750 Multitrack has been a very good bike (I bought it new). I have ridden it off and on as a commuter but didn't take the time to replace the chain until this year with an SRAM (originally had a Shimano IG).

Soon after, I started experiencing chain skipping (I understand that this is because of wear on the sprockets). I brought it in for a tune about 3 weeks ago (new cables, truing, adjustments). In the last week or so, it's begun skipping alot. I don't want to buy new if I don't have to because I'm content with the bike.

So is it worth trying a different chain before I start shopping? I ride about 4.5 mi. each way every day. I've been considering an internal-gear setup for low maintenance, but I'm not sure 7 gears would cut it. I usually stay seated while I ride and must use the lowest front gear on one steep portion of the ride.

Thanks for any opinions/ideas.

If the bike fits well, you're probably better off replacing the rear cogs and the front chainrings. A different chain will not solve the problem, since the gears are all worn out and need to be replaced.

A Shimano 7 speed hub has about 250% gear range, and a SRAM one has about 270%. Depending on how you set it up, it might well end up with a better gear range for your commute than your bike has now. What I would do is start by counting teeth on your current gearing. Take notes, and then visit Sheldon Brown's gear calculator. That way you'll know what your current bike has in the way of range, and what gears you actually use now. Then you can use the calculator to poke a bit at whether an internal hub will handle your normal riding.

Lot's of success stories about older iron here.......
http://www.bikeforums.net/showthread.php?t=473408

New cassette and chainrings, trivial.
On a bike you know and like.

Or spend a lot on a new bike and then find out if it does the job.

Bikes are NOT throw away items, the marketing men just like us to think that.

Richard

Why are you hesitating to make a simple replacement of the cogs and chainrings? You obviously like the bike, and you can make it run like new.

Unless, of course, you're looking for an excuse to buy another bike.

In which case he should dump the guilt trip and go dig the credit card out of the freezer :D

Richard

My car needs an oil change... or should I buy a new one??

A little research here can go a long way: http://www.sheldonbrown.com/gearing/index.html

Just change out the sprockets. ;)

Thanks, everybody. I'm perfectly happy with the bike (frame and forks made in the USA!), but don't know where to start. I'm pretty good with my hands, but I get overwhelmed by all of the parts choices/sizes, etc. I'd like to repair it myself if I can. I can do tires/tubes, I have a chain tool (although now I am using an SRAM with the quick-release link), but have never tackled this job.

So I gather that I can just take off the chainrings and cassette and replace them? What do I need to consider as far as making sure I get the correct parts? I'm guessing I can take off the chainrings with an allen wrench. What do I need for the cassette? I don't mind buying quality tools if I think I'd use them more than a couple of times in my lifetime.

Due to the need for special tools the cassette is best left to a bike shop. Do your homework to see
what ratios and parts will work then take it to the bike shop with your choices.

a Park lockring tool is all of ~$6
a chainwhip is ~$10

follow the link to find out HOW to remove the cassette...

http://www.parktool.com/repair/readhowto.asp?id=48

really easy schtuff mate.

There's nothing scary in doing the work yourself and the tools are all dirt cheap from a good lbs - you don't need professional quality stuff.

Ride the bike into your lbs, tell them what it's doing, tell them you want to do the work yourself, ask them what you need.

Then ride home, fire up Park Tools AND Sheldon Brown and go from there. It's all stupidly straightforward but it's also not unusual to find yourself a little lost. Just read through the instructions again or ask daft questions here.

It is really really hard to break something so badly it's a disaster.

With a bike that old, you may find some bits are unwilling to come apart, if so, do what everyone else does and take the bit to your lbs to take off - have no shame or fear about that. If the shop knows you're trying to learn to do the stuff yourself, and the removal proved to be trivial (which is usually the case), a good lbs will do it on the spot for nothing.

Good shops are happy to work with home mechanics because they know you'll keep coming back for parts and tools and are more likely to maintain your bike than someone who puts it in for repairs when he can afford it. If your lbs doesn't support you in this, it's not a good shop and you should look somewhere else. Seriously.

Richard

Update - I went out and gave the cranks a few spins while I watched things. One of the chain links was tight and binding. Is this common? I haven't had the chain for long. I went for the SRAM instead of a stock Shimano because Sheldon Brown's site seemed to be pro-SRAM.

I used my Park chain tool to push on the pin a little. It made a pop, and freed things up. But, the outer plate seemed to bend out a little in the process and the pin was no longer sticking out a little like the rest. I tried to push the pin back in to position from the other side, but the tool didn't seem to work very well. I ended up using channel locks to carefully bend the plate back.

I'm nervous that the link will fail on a ride. Do SRAM chains require a special tool? I noticed in the directions that came with the chain that the diagrams show a chain tool with long handles. My Park tool looks like a mini vice or clamp.

There is no sense in buying a new bike if you like the one you have. It will cost a lot less to fix the one you have and you could very well be happier in the end.

This is one I'd get the shop to look at, mainly because you need the eyes of an experienced wrench and I don't think advice over the internet is the right thing because we can't see exactly what's happening. A lot of modern chains use single use pins - ie, you can pop them out but have to replace them with a new pin (hence the popularity of quick links - this wasn't an issue with old chains). You can ride it but don't go standing and hammering on the pedals until you've had it looked at.

That 'pop' you felt was the pin pushing out of the plate. When you push the pin back in (as you tried to do), you need to have that plate sitting hard against one of the supports in the chain tool.

Don't sweat on it mate, just get it looked at before being too vigorous on the pedals.

I'm never shy about approaching a mechanic, admitting my stupidity and asking for sage advice, it's an approach that has opened a lot of doors and led to me learning stuff I probably wouldn't have otherwise. Shops that don't support this approach have discovered they don't sell me stuff either.

As for the initial problem. It's not unknown for new chains to have a tight spot and you were right in thinking that it's just the whole plate and pin arrangement being a bit tight. The usual correction is just to grasp the chain in your hands and work it from side to side - that's usually enough to free it. If you need to use the chain tool, just a little pressure then check, then some more, etc.

Richard

Get yourself a SRAM master link and replace the bad link with the master link and you're good to go. $5.

http://bicycletutor.com/ is a great site.