??? - tire-rim lock (security bolt) and wheel weights

so, i'm getting into changing out the rear tire on my 74, and I have this "rim lock-security bolt" thing. this may be a dumb question and I think I understand WHAT it's supposed to do, but, sorry, i'm not seeing HOW this thing is supposed to work, that is, lock the tire to the rim, keeping it from rotating under hard acceleration and/or keeping the tire secure to the rim during a loss of air/tire failure - ??? unless i'm missing something - I just don't get it. I don't see how it "locks" anything in place. do these things actually work, or are they some sort of old technology gimmick? from my limited forum search, i'm seeing about a 50-50 mix on folks using or not using the rim lock.

don't want to start another discussion on whether to use it or not, as I most likely will be reinstalling mine. just not seeing how this thing is doing anything other than adding weight and complicating tire change. if it's a safety thing, why no front tire?

speaking of adding weight - I did a simple, old school, static balance on my front wheel/tire assembly. I had to add one (1) ounce of weight to the front opposite the valve stem. curious what folks are using for weights? I just used quarter-oz. stick on's - two each on each side of the spokes. I'm seeing everything from fancy, spoke, screw on's to adhesive. my original was a crimp-on spoke lead weight that would look more at home in someone's fishing tackle box than on a motorcycle.

If installed correctly it clamps the bead of the tyre against the rim. Yes, I believe it was/is a guard against tyre movement under acceleration, though stalling (who me!) can also strain that dynamic too. I think the main reason was to stop these circumstances leading to tyre valve movement/damage and hence loss of air..
Many disregard them, though....

Yes, if installed correctly they pick the tyre to the rim and help stop ‘creep’ under acceleration. If the tyre creeps, the valve can rip out of the tube leading to a flat.

Modern tyre compounds do not need them unless you’re lowering the pressure for trials riding, sprinting, etc.

Regarding weights, stick on weights work fine, proper clamp on ones that crimp around the spokes are probably the neatest. I’m one of those that simply wraps some plumbers solder around the spokes.

The rim lock will add quite a bit of weight to the wheel, and to achieve balance you'll need a few ounces worth of weights. My wheels are far too pretty to uglify them with stick-on lead weights - so I use these: spoke weights
Not cheap, but really nice.

If you delete them but want to keep a stock look (at least from 8 feet away), a round head carriage bolt will do.

Rim locks are not all that necessary unless running very low pressure in tires or if you have a torque monster. Rear only as that is the tire applying torque at tire patch. I use brass weights for balancing. They come in a variety of sizes and can be trimmed. They look (IMHO) pretty good. In picture I have one lead weight that has to go.

When balancing for the first time make note of the red and yellow dots on a new tire. Used for match-mounting. Red dot for uniformity, yellow for weight mounting (most common)Yellow mark on the tire, indicating the point of lightest weight, should be aligned with the valve stem on the wheel assembly, which represents the heaviest weight point of the wheel assembly.

myron1950 said:

Rim locks are not all that necessary unless running very low pressure in tires or if you have a torque monster. Rear only as that is the tire applying torque at tire patch. I use brass weights for balancing. They come in a variety of sizes and can be trimmed. They look (IMHO) pretty good. In picture I have one lead weight that has to go.

When balancing for the first time make note of the red and yellow dots on a new tire. Used for match-mounting. Red dot for uniformity, yellow for weight mounting (most common)Yellow mark on the tire, indicating the point of lightest weight, should be aligned with the valve stem on the wheel assembly, which represents the heaviest weight point of the wheel assembly.
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yellow circle-dot on my Dunlop tt100 - aligned with the valve stem (front). brass weights do look good!