Hot answers tagged

51

Rims are worn out when the groove disappears. If the groove is clearly visible, well-defined and of uniform depth all the way around, the rim is not quite worn out and certainly not dangerous. New brake blocks will cause less wear as they will be free of hard particles of grit and metal that get embedded in the relatively soft rubber over time. Given the ...


31

As long as you can see the dimple, the rim is still thick enough. When you brake, the rim gets worn. Eventually it is worn so thin that it can break. The dimples help you identify the wear so that you can replace the rim before it breaks.


28

Not enough points to comment, so here is an answer instead, based mostly on my own experience. I've been using a bike as my main, if not sole, mean of transportation for the last 20 years or so. During that time, my weight changed a lot (from 80 to 130kgs (176 - 286 lbs)). When I was 80, I nearly never broke a spoke (maybe once per 10 000km), and only after ...


21

The real answer is you need inner tubes with longer valve stems. Tubes come with various length stems to accommodate deep section rims. There are screw-on valve stem extenders available for both Presta and Schrader that you could use to extend your stems. (I think some Schrader ones are actually for car tires, but they would still work for a bike.) With ...


19

It's a wear indicator. The friction of the brakes gradually abrades the rim away and the track lets you see how fast that's happening. Once the rim has worn enough that the track is very shallow, the wheel is starting to lose strength and should be replaced. For wheels that don't have a wear indicator groove, you can detect wear by holding a straight edge ...


19

I suggest you get the wheel rebuilt properly, once and for all (probably by a different bike shop). A well-built wheel should be able to handle even riding off kerbs or small unavoidable potholes without breaking spokes. You should unweight the saddle and take the weight on your feet, but even if you don't it should survive an occasional hit. A hybrid like ...


17

This is a more detailed answer. I cautiously don't agree with Chris that the OP needs to stop riding the wheel, but it does depend on how the rim is constructed. Basically, the aluminum piece is a sleeve of some sort. The sleeves are structural elements in some but not all rims. I believe it is not a structural element in this rim, which the OP described as ...


15

To me, it looks like whoever (or whatever, as it was likely machine built) used the wrong size tooling to hold and screw the spoke nipples as the wheel was built. Not a rim manufacturing defect but a wheel building defect. If it's still under warranty, I'd get the wheel replaced. Any cracks are bad cracks and could propagate. If it's not under warranty, I ...


14

In case you really want to drill, the only thing you need is a 10mm drill bit, and a sandpaper to give a smooth finish. It is true that the rim gets weaker, and very narrow rims should not be drilled, but I have performed this enlargement a couple of times and rode the wheels some honest hundreds of km in every kind of terrain, with no problem. I did this ...


14

Lower spoke numbers are primarily of interest to weight weenies (though for a given price, a lower spoke wheel will probably use a heavier rim offsetting the spoke reduction weight savings). As usual, Sheldon is some good reading. There is also a whole book on how to build wheels well and design decisions, by Jobst Brandt, called "The Bicycle Wheel". What ...


13

Drilling out your rims will reduce the strength of the rim and increase the likelihood of cutting the valve stem on your tube. For a few dollars you can buy two of these: This adapter threads onto a Presta valve and effectively turns it into a Schrader valve. Presta valve tubes are the same price and are as widely available as Schrader valve tubes, so you ...


13

Especially when seating a new tire for the first time (and probably more so on a "virgin" rim) it's wise to inflate to about 1/3 or 1/2 final pressure and then roll/bounce the wheel around quite a bit, to work the bead into position. Then deflate, break the bead loose all around, and repeat the process. Then, as you're doing the final inflation, watch the ...


13

If you take the rim tape off you should be able to shake it out through one of the holes that you insert the nipples through. I've dropped a few inside rims and never had a problem getting them out this way.


13

When a rim is extruded, the shape of the material can give added strength to the rim. There are many rim types, but the two most common are single-walled and double walled. A single walled rim uses a simple U shaped extrusion. A double-walled rim adds a cross brace across that U shape, creating a D-shaped extrusion. Triple hollow construction add extra cross-...


13

This particular rim strip absorbs color from everything, and it is not a problem. Mine have turned green in use from something leaching from tubes. In general, rim strip should be replaced if it splits, stretches deep into the spoke holes or exposes the spoke holes. Discoloration happens, but since rim strips aren't usually visible this is not much a ...


13

In the days before factory built wheelset, rims where produced without being specifically for front or rear wheels. On most general-use standard bicycles it is still that way. The only difference was the spoke-hole count. But many rear wheel rims today are no longer symmetrical, meaning the right side is different from the left. This is mainly due to the ...


12

Check the spokes - its likely one or more has broken ("I felt a shock, like a snap....".). The ones to check are ones that got from the rim, where the rubbing is occurring, to the hub on the opposite side of the rubbing (in your case, the right side of the hub). If these have let go, there is nothing stopping the rim being pulled to the left. It may be ...


12

No you will not be able to use your 700x23c tire on a 650c rim. The bead seat diameter of 700c rims is 622mm, this will also be the bead diameter of the your 700x23c tire. The bead seat diameter of a 650c rim is 571mm (see Velocity's Spec section). Your 700x23c tire will be 51mm too wide.


11

Hub Width On road, mountain, and hybrid, the front hubs are 100mm in width. On road bicycles the rear is typically 130mm, where on a MTB it is typically 135mm. Measure this from your old hub, and DON'T stretch/force a different hub width. Wheel (Rim) Diameter The most typical road rim is a 700c which will mean the bead seat diameter of the rim is 622mm, ...


11

You can (theoretically) mount any 700x(something) tire on any 700c (ISO 622) rim. However, you need to make sure the frame (and brakes if rim brakes are used) can clear the tire without rubbing. You generally want to match the rim width to the tire though -- too narrow or too wide of a tire on a rim can lead to tire/rim damage or bad handling. In your ...


11

You have the correct tires. This does not have anything to do with tire width. The diameter determines whether tires will fit or not, unless there is a huge width mismatch. Rims and tires are both made to a tolerance, and you just happen to have an unusually large rim and small tire. I have had the opposite problem with some Schwalbe tires, they were so ...


10

I would be very careful with a deal that sounds too good to be true. Take a look at what happend to this carbon wheel in another question: Carbon Wheel Heat Bending I wouldn't buy from a company I've never heard of before and will never hear from again (like when the wheel deforms from the heat of braking and I'm trying to get a refund). Even the tagline ...


10

I figured out a solution. The thing that is supposed to stop the inner tube from expanding into spoke holes is called a rim tape. The tape that came with the bike is really flimsy. I'll purchase and apply a high pressure rim tape. Hopefully that would fix the problem. Update: I've decided to go for a cotton rim tape as they're more durable than rubber ...


10

Is the cut always the same distance around the tube from the valve? If so then you have something wrong in your rim. Use the punctured tube to measure where the damage is coming from... that will give you at most two positions, one in front of the valve hole and one behind. I think you'll find a cause in this very small sector of the rim. BTW - had you ...


10

Not all tires are hard to put on (depends on type) and rims also have a variation in size (both between different types of rims and sample to sample variation within one model). In fact, I'd say many tires for urban and mountain bikes can be mounted without tools if you know how to. There are obviously counterexamples that are notorious for being tight. ...


10

Yes, stronger wheels will be more resistant to damage and going out of true. Wheel strength is a combination and balance of of rim strength, number and gauge of spokes, spoke tension and the quality of the build (spoke tension evenness etc.) If you are denting your rims on bumps, or they are going out of true there are some things you should do before ...


9

These 38/50/60/88 numbers are the 'depth' of the wheel's aerodynamic rim, in millimeters. Let's take 38 for example. This means that from where the tire meets the wheel, the rim extends an additional 38 millimeters towards the hub. When you see 88, that means the rim extends 88 millimeters from the tire. Why does that matter? One of the biggest benefits of ...


9

Some disc-brake specific wheels use rims that are not designed for rim brakes. To accomplish what you want you need a wheel with a a disc-brake hub and a rim-brake rim. With that setup, assuming the fork widths are the same, you should be able to switch wheels between bikes without problems. The only drawback is the slight increase in rotating mass from ...


9

I'd actually lean toward a shallower rim, but the important bits are going with a high spoke count and either 3x or 4x pattern (both drive and non-drive sides). With a deeper rim, you are changing the angle in the cross patterns and reducing the length. This means that the spoke has to deflect more to handle the cross. This is more noticeable with really ...


9

Yes. The shorter spokes go on the drive side. Satisfy yourself by looking at the picture below: Imagine two right-angled triangles sharing a common side (the red-dashed line). The hypotenuse of the left triangle (non-drive side) is longer than the hypotenuse of the right triangle (drive side). Generally only by a couple of mm, but it makes a difference. ...


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