Bicycle Mechanics - Updating Trek 7200
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About 3 years old and just seems to take so much energy to keep it moving. Lots of really dusty trail riding. Stock components.
Couple of questions.
Chain, have cleaned and lubed, any benifit to replacing, would really like to be able to get it off to clean.
Bottom bracket, sealed cartrige, no noticble looseness, or noise, any benifit to replacing.
Front hub, took apart and it had a very course feel to it. Cleaned and lubed (loose bearings) and it's much better but not the smooth/fast spin I was expecting. Any additional maintainance here or does the entire wheel/hub have to be replaced?
Rear hub, have not gotten to that, any comments.
09-18-12, 05:26 AM
For the chain, there are lots of post about chain length on BF, search for them, if it isn't skipping / jumping on the cassette, would keep it, but would also look at the condition of the cassette as well. have a look here for detailed info http://www.parktool.com/blog/repair-help/chain-length-sizing
BB, just keep it till it wears out, no benefit in pre-emptively changing, unless say doing an extended tour.
For the hubs, what did they feel like when new? You mention they have loose bearing, this indicates they are cup and cone, have you got the pre-load on the cones right?
09-18-12, 07:31 AM
What type and size tires do you have? Do you keep the tire pressure at the maximum sidewall rating? If you are only riding on roads or Rail-Trails with a firm surface and the bike has knobby tires, swaping them for slicks or small tread tires can make a huge difference in perceived effort. Knobbys are required in mud and soft surfaces but a great drawback on hard surfaces.
09-18-12, 08:25 AM
Three years old and lots of dusty trail riding, but how many miles? Is this the first time you have serviced your hubs? I'd replace the bearings, repack with grease (I prefer a silicone based synthetic but any decent grease will do), and make sure you tighten them just to the point of getting rid of play. When you reinstall, check how true the wheels are and make sure the brakes are adjusted so that you don't have any drag. As mentioned, proper tire inflation is also important to prevent that riding through mud feeling.
If you haven't checked you bike fit in three years, you might want to do so. As your fitness improves you may find that you need to tweek positioning from time to time. Adjustments also have a way of migrating a bit over time if things aren't periodically checked and tightened. Even seemingly minor adjustments can make a significant difference in comfort and pedaling efficiency.
Take the chain off, or have your LBS do it and use a caliper or chain gauge to determine how worn it is. Replace if it is at or near the end of its expected life, which is determined by wear, not age. While the chain is off, clean and inspect your rear cassette and chainrings looking for any damage or wear. With the chain still off, slowly spin the cranks holding on to each pedal one at a time. Feel for any drag or roughness in the pedal spindles or the bottom bracket. Then give the crank a good hard spin while holding onto the seat tube (make sure your hand is clear of the spinning cranks) to feel for excessive vibration or grinding. The crank should spin several revolutions freely when given a good hard spin. Check your crank arm bolts/nuts for tightness. Lean over the top tube of the bike putting some weight on it and grab the cranks. Feel for play with the chain off. Clean and lube the rear derailleur. Clean and lube or replace the chain and reinstall. Put the bike on a rack or suspend it from a rafter in the garage so that you can spin the drivetrain freely and adjust both derailleurs.
This whole process should take just an afternoon or so and should be completed about once a year along with a good general cleaning, inspection and lubrication of cables, pivots, shifters, brakes etc. I do my major maintenance in the fall on the two bikes I have that are stored during the winter. My winter bike (which is also my trail bike) gets serviced in the spring.
A Trek 7200 is never going to be a fast road bike, but these steps will keep it running smooth. Here are some links with more detailed info:
I suggest that you perform a complete cleaning and maintenance on your bike before considering "upgrading".
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