Singlespeed & Fixed Gear - Non-machined velocity rims and brakes?

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thiskidgotmoxie
06-09-06, 04:21 PM
I noticed on the very beautiful all gold nagasawa that the guy has non-machined velocity deep vs, and a brake. Does anyone else run non-machined rims with a brake? If so, how is the braking?


Landgolier
06-09-06, 04:28 PM
There were rim brakes long before there were machined rims, but all high quality rim brake rims are now machined. What does that tell you?

You can do it, your bike will stop, your rims will get nasty looking, and others will have better brakes and longer-lasting rims.

sivat
06-09-06, 04:50 PM
I still like the form follows function look of machined in the front and non-machined in the back.


operator
06-09-06, 09:42 PM
There were rim brakes long before there were machined rims, but all high quality rim brake rims are now machined. What does that tell you?

You can do it, your bike will stop, your rims will get nasty looking, and others will have better brakes and longer-lasting rims.

If you're implying that because everyone does it -> it must be teh ****. Then you are mistaken.

humancongereel
06-09-06, 09:55 PM
they'll be loud as hell, too.

edit: brakes on non-machined rims.

wearyourtruth
06-09-06, 09:58 PM
it will wear off the anodizing or powdercoating. and it won't wear evenly... it'll be patchy... i have an old campy rim that looks pretty ugly because of that

p3ntuprage
06-10-06, 07:28 AM
it will wear off the anodizing or powdercoating. and it won't wear evenly... it'll be patchy... i have an old campy rim that looks pretty ugly because of that
my non-machined wolbers are going like that too

thay're also a bit grabby in the wet.

some non-machined rims also go straight into the profile, without having a vertical section, so there's no physical area for the brake pads to hit.

but i can't afford new wheels right now, soooooo... meh.

fsnl
sparky

d_D
06-10-06, 08:07 AM
There were rim brakes long before there were machined rims, but all high quality rim brake rims are now machined. What does that tell you?

That high quality rims are welded at the join and the welds need to be machined smooth.

11.4
06-10-06, 08:28 AM
There are really good rims that are pinned and not welded. Back in the 70's the sidewalls of rims were pretty narrow, but brake blocks were very narrow as well. As equipment manufacturers tried to get better braking, one way they did it was to go for bigger brake blocks. You can only go so much longer before you actually have to curve them to fit the radius of the rim (a la some MTB brake blocks) but you can make the braking surfaces wider and use a taller brake shoe with very good effect. That's basically what happened.

The welding was actually a more cost-efficient way to assemble a rim. It creates a point in the rim where if you're lucky you have a smooth continuous surface or, if you aren't, you have a slight dip or bobble. As a result, many top wheelbuilders prefer pinned rims (look at the number of top builders who like to recommend Velocity rims, or who love to use old vintage Mavic tubular rims, for example).

As for the machining itself, it was partly a way to address a hassle with welding, but also in the search for taller sidewalls to improve braking, it became hard to make an extrusion that had reasonably flat surfaces. On older non-machined rims you'll notice that the braking surfaces are rarely flat, and when you go to a bigger braking surface, your rim cross-section either has to have very thick walls (and thus be quite heavy) or it starts to have the cross section of a burrito and has to be machined. Flat grinding the sidewalls of a rim is inexpensive to do -- it's done on both sides at once and in a fixture that ensures everything is ground in a flat plane. A byproduct is that it makes a rim that starts out basically reasonably true; it also takes some weight off in an area where the extrusion die can't control wall thickness as well.

As for Deep V's, they use rather thick wall thicknesses so even the non-machined rims aren't too irregular at the braking surfaces. If the rim is anodized, there's a very slight difference in braking, but remember that many rims have traditionally been anodized anyway and the anodizing on Velocity's isn't a deep hardening anodization. The gold rims are anodized, as are all of the tubular rims (because tubular rim cement doesn't stick reliably to powdercoating and you can't powdercoat the sidewalls and not powdercoat the rim bed as well). Powdercoated rims will have more flaky braking (pardon the pun) as long as there's powdercoating left on the braking surface and predictably when your hot red powdercoating is half worn off, it'll look messy.

kyselad
06-10-06, 08:38 AM
holy thread homicide

dirtyphotons
06-10-06, 10:13 AM
just another guy who uses a front brake on his (non machined) deep vees. works fine, cheers.