This one is going to be short, it’s going to be about cutting your forks and bars down to size. Simple, right? Ehhh sometimes.
A lot of people say to just hacksaw it…I really do not suggest that at all. A hacksaw can cause a jagged cut. I’ll throw it out there, the cut on your steerer does not need to be flush, nor does your seatpost. So, using a hacksaw and getting it “close enough” to straight and flush is just fine.
Reasoning behind “close enough” being good enough for seatpost:
Simply, the clamp doesn’t hold the end. The end does not matter, as long as it can go in to your frame A-OK. After you cut it, you may want to file down the edges a bit, just to be sure that your seat post will go in just fine. (Put a little bit of grease on the post, yeah, really).
Reasoning behind “close enough” being good enough for forks:
The part being cut down on forks is the steerer tube, the part that goes through the headtube, and the stem mounts to.
If you have an old 1” threaded headset, stop, and do NOT cut your forks down. Just leave them. If you have a 1 1/8” fork, then you’re good to go.
When you cut it, the cut doesn’t meet up against anything that’s straight. It gets pulled up in to place by the compression bolt/cap. When you tighten the stem, it gets locked in place, without meeting up against anything. For this reason, a DECENT cut is alright. If you go TOO rough, it may damage your stem.
Edit 16 Dec 2010: Someone left a comment, and I would like to thank them for pointing something out to me. The phrasing is a little weird at this point. "DECENT" cut is REALLY vague, and I would like to define it more specific.
Flush is ideal, but that's with ALL cuts. If you can't cut it flush, most shops are able to do it for a few bucks (maybe a few more if they need to measure the cut themselves). If you're a regular, they might be able to do it for free real quick, even, so if you are about to cut your steerer with a hacksaw, check with your shop first.
The general leeway on a steerer should be about 1mm of error in the cut. Much more than that might be a little sketchy to use.
Like with seatposts, cut and then file.
Now comes the fun part. Bars. Cutting down your bars is not as simple as measure, mark, and hack. I’ll draw out the scenario:
New bars. 28x8.25. Brilliant, love the rise but would prefer 27” width (I know, call me crazy, I don’t want 50” width). I cut them down. 1” on the left, 1” on the right. YAYYY—Woops. Your bars went from 28 to 26, since you cut off a cumulative 2 inches.
Figure out how much you want to cut off, divide that length by two. Measure the divided length for each side of the bars, mark, and cut.
So you read the guide, and cut ½” off of each side. Yippee. Put your bar ends on, and go ride. Or not—your bar ends are completely off? The bottom touches but the cut was at an angle. Awww crap :(.
Simple solution: Make a straight cut. There are many methods you may hear about, but I have to take in to account feasibility. Yeah, sure, a CNC would be AWESOME and make a decently straight cut. On the other hand, not everyone owns a CNC or can afford to gain access to one, and know how to use it.
Hacksaw. Well, I just explained why that was a bad idea. On the ends of your bars, you want to have a fluch cut. Sure, maybe a bump or burr here and there isn’t a huge issue, but if the cut is at an angle, then there’s an issue.
The solution: A pipe cutter.
The choice is yours: Spend 100$ once, or spend 6$ every year or so when you buy bars. If you own your own shop, MAYBE a more expensive model would be your option. For the home do-it-yourselfer, spending 6$ is probably the way to go.
As far as how to operate the challenging piece of equipment (challenging used sarcastically, in case you were wondering), I could TRY to explain it but right now I’m tired and would probably mess something up. Instead, I would find a website, and copy what they said on there. So, that’s what I’m going to do!
Better than a hack saw is to use a pipe cutter. There are various designs but they consist of a cutting wheel which can be adjusted with rollers mounted opposite. Initially the cutter is unwound so that the pipe can be inserted, then the cutter is screwed back so that the wheel sits on the pipe where it needs to be cut. The tool is then be revolved around the pipe,being tightening after each turn. This causes the wheel to cuts though the pipe producing a right angle cut.
When you tighthen the cutting wheel, do it maybe 1/4 turn. Go slow with it, and take some patience. If you try to speed it up by tightening it more, you can and probably will screw up the cutting wheel, making a dull spot. One dull spot is not the end of the world, but if you continue to over-tighten the cutting wheel, eventually the dull spots spread like bacteria, and the whole wheel is a dull spot.
I’m sure it’s possible to sharpen them as well, but I do not know how you would go about that, so I will just throw it out there: It is probably possible to sharpen the cutting wheels. That’s all I’m going to say on that.
I know I said you can use a hacksaw for your seat and forks, but if you have the pipe cutter, use it for the forks. A ROUGHLY uneven cut isn’t all that bad, but a 35 degree angle is bad. Don’t use it for your seatpost though, that will just cause the wheel to become dull where it really does not need to be used.
Alright, I think that’s it for the night. I need some sleep, waking up early tomorrow morning for the England vs. Germany match for the world cup. Gah I am so excited to see this. I [honestly] don’t really care who wins it anymore, but it shall be intense.
As usual, any questions, hit up the home page, follow the “Submit a question” links and headers.