help about machined wheels

Im thinking of getting purple velocity deep vs and if i want a front brake does it matter if the front wheel is machined or not.

If the wheel is done with a powdercoat, your brake is going to have very little effect. If it’s anodized, you’ll have a little more stopping power, but it won’t be great. A machined sidewall is going to give you your best stopping power, as that’s what they’re designed for. I guess it depends on how much you expect to rely on your front brake. I’d be using machined, plus, if you buy one non-machined, and use a brake, it’ll eventually wear away the colour, and it’ll look the same as a machined one anyway (if you’re fussed with aesthetics). May as well just get machined and be safe about it all. In future, the search function is your number one friend.

thanks so much.

quoted for truth.

if you really didnt want to get the MSW rim, then get some clear pads for your brake. they are really soft and dont leave the black streaks, BUT they can be noisy as all hell.

My non machined wheels have marks on them because I run a front brake for law abidance, even though I don’t use it, but I’ve let friends go for rides around the block and they get back and the brake pads are covered in paint dust and the paint slowly wears through.

From now on I’m always going to use machined front rims for that reason.

The Rivendell Bicycle Works website is fairly strongly against machined sidewalls (see Rivendell Bicycle Works: Know this about rims - quote: “Machining rims is a way for rim makers to justify a higher price, and the only thing it does is make a rim worse, while making it seem smoother”).

I’m willing to accept the suggestion that a rim brake will be less effective if it is clamping down on a powdercoated surface (e.g. the unmachined sidewall of a powdercoated rim), as compared to when it is clamping down on ‘raw’ aluminium (e.g. the machined sidewall of an aluminium rim). However, despite some research, it still isn’t clear to me whether rim brakes are any less effective when they’re clamping down on an anodised surface (e.g. the unmachined sidewall of an anodised rim), as compared to when they are clamping down on ‘raw’ aluminium.

If there is no difference in braking effectiveness between anodised and unanodised aluminium surfaces, and if what Rivendell says is true, then there’s no point in paying extra to get machined sidewalls on anodised rims.

the purple deep v’s are anodised, not powdercoated, so no worries with it being insanely slippery.
so no, it doesn’t really matter if you get machined or non-machined

I actually don’t mind their argument, it does raise some things that most people wouldn’t consider. I don’t necessarily agree with their points though…

They reduced the contact area between your rim and pad, so they make braking worse that way. And they’re more likely, than a smooth surface, to trap water.

I would argue that a grooved sidewall is BETTER in wet weather, as it stops the brake pad from aquaplaning across the rim surface. There’s nothing worse than grabbing a handful of brake in the wet and for nothing to happen for a few seconds. From what I’ve noticed, this seems to be worst on non-machined rims.

I haven’t yet made up my mind as to whether machined or non-machined rims have a braking advantage in normal, dry weather, but the biggest advantage I can see is that machined rims have a much better join. Some non-machined rims are better than others, but because of the imprecise nature of non-machined rims, there can be a big difference between a good rim and a bad rim, even for the same product. When braking on a bad non-machined rim, every time the brake pads go across the join, they get caught, making the brakes feel shit and inconsistent.

For the few extra dollars it costs to get a machined sidewall, I’ve never really seen the point in NOT getting the sidewalls machined if brakes are to be used.

I experienced just this. I was using a non-machined front wheel with a brake for a good few months, and whenever it was wet, it really felt like it was doing very little to actually stop me. I changed to a machined front rim and definitely noticed a different with braking in the wet. I’ll always go with a machined rim for braking on, but that’s just me. I’d be interested to see if there’s a difference in braking performance between machined/non-machined in the dry weather.

what about non-machined with cork or similar carbon wheel brakes?
any one tried this

Cork compound grips alloy, but not as effectively as a rubber/resin compound, as wears quicker when applied. However, when swapping wheels, I’m lazy sometimes and just forget to change pads. Works ok. Depends on manufacturer and dampness. Swisstop Yellow King do everything well, but are $60/set.

machined v non machined

it all comes down to the coefficient of friction and surface area between the brake pad and the rim.

If the only variance is the flat rim against the machined rim with ridges (same brake pads), the effective surface area of the machined rim will be greater, which therefore theoretically amounts to better braking*

I call bs on rivendell.

  • I should note that this is premised on the brake pad’s ability to wear to the same shape as the grooves in the rim. While the real world application of this might not be true, I don’t believe that the braking effect will be lesser for a machined side wall rim.

Be gentle with Rivendell, their opinionated outbursts are part of their value to cycling, even if not every one is sensible.

I’d always recommend a machined sidewall, in my experience they maintain integrity better than non-machined sidewalls - that is, they don’t strip bits of aluminium into the brake pads as much. Also, they’re easier to clean and don’t get as damaged aesthetically as non-machined sidewalls, especially if your rim is anodised a colour other than silver.

  • Joel

lachy you fixie1er