For a bit of a change, there are no moving parts involved in this week's maintenance wibble. Not in the gears/whirly bits/small easily lost parts sense, anyway. Instead we're looking at bits of carefully shaped tubing, largely. You may think there's not much to a bar and stem and, well, you'd be right. But there's a bunch of things worth remembering when you fit them...
1. It's Basic Tools Ahoy for this one - Allen keys, grease. You might need a small half-round file, but then again you may not.
2. Stems are pretty easy. The back end clamps around the steerer tube of the fork, the front end clamps around the bar. You'll want to put a bit of grease on the steerer before sliding the stem on - in its spare time it keeps the headset bearings correctly loaded so it doesn't want to be sticking vertically. The bolt in the top adjusts the headset - do that one up before tightening the clamp bolts or it won't work.
3. If your stem only has one bolt on the steerer clamp just do it up. Don't go mad, it should just need snugging down with a regular length Allen key. If your stem has two bolts, tighten them alternately until they're both snug. Make sure there's some grease on the clamp bolts before you tighten them, and check that the stem's pointing straight ahead.
4. Now turn your attention to the bars. Check that there are no sharp edges around the clamp on the front of the stem - no problems with this Race Face one, but you may find pointy corners on some stems. If you do, get a half-round file and put a small radius on the edges. Pointy ones concentrate stress on the bar, which is bad.
5. Pop the handlebar in and put the front cap on the stem. Generally these are held in by either two or four bolts. Again, make sure there's grease on the bolt threads. Don't do them up properly tight just yet - make sure the bar is central in the clamp and just nip them up so that the bar can rotate in the clamp.
6. Bar angle makes a big difference to comfort. Different riders favour different angles but a good starting point is to have the ends of the bars sweeping up and back, with the plane of the sweep at 45degrees or so. On most riser bars, positioning them so that the rising part is vertical is usually a good starting point.
7. Now tighten the bar clamp. It's important to tighten the bolts evenly. If you've got a two bolt clamp, alternate between the two bolts rather than doing one up and then the other. If it's a four bolt clamp, work around from one to the one diagonally opposite, then across, then diagonally again. Keep doing them up a little at a time until they're all tight. Again, don't heave on them - snug with a normal Allen key is sufficient.
8. With the bars in place, it's time to think about the controls. Just like the stem, sharp edges on shifter and brake lever clamps can cause problems, so round 'em off with your trusty file if you find any. Slip the controls on to the bars but don't tighten the bolts just yet as chances are they're not in the right place.
9. Fit the grips. There are all sorts of ways of doing this, but most non-knackered grips will go on fine with a squirt of WD-40 and then stay put once you've left them overnight. If they won't stay, there's a host of other things you can use to get them to stick - hairspray, car paint, patch glue, lockwire - but we find that new grips is the best bet. If you really have trouble and fit and remove grips a lot, try some Lock-On grips with Allen-screw locking collars.
10. Now position and tighten the controls. Again, control positions and angles are down to your preference. As a starting point, butting everything up against the inside of the grip and angling the levers at 45degrees below horizontal is good. Then adjust from there. Don't overtighten the bolts - the controls want to stay put in normal use but it's a good idea to have them so that they'll spin in a crash. If they don't something's likely to bend or break. Stick some plugs in the end of the bars and you're done.
More maintenance
There's hundreds of top maintenance tips in the BM archive.
Mike! :¬)
