Rims: Machined vs. non-machined sidewalls. Any real difference?

Discussion in 'Cycling Equipment' started by Patrick, Jan 23, 2003.

Thread Status:
Not open for further replies.
  1. Patrick

    Patrick Guest

    Just wondering if it really makes any difference. Some manufacturers don't even advertise whether
    the sidewalls are machined; others do. Velocity for example, makes both, but I believe they're the
    same price. What gives? Just marketing hype?
     
    Tags:


  2. In article <[email protected]>, [email protected] says...

    >Just wondering if it really makes any difference.

    Yes it does. Machined rims will have a shorter life span because they have had material removed from
    their sidewalls.

    >Some manufacturers don't even advertise whether the sidewalls are machined; others do.

    Most do because they think it is a feature and can then charge extra for it.

    >Velocity for example, makes both, but I believe they're the same price. What gives? Just
    >marketing hype?

    Yes, hype.
    -----------------
    Alex __O _-\<,_ (_)/ (_)
     
  3. Paul Kopit

    Paul Kopit Guest

    I mistakenly got a set on non annodized Velocity Aerohead rims. They are great. I rode a couple of
    thousand miles before they looked like machined rims. I've had similar experience with older
    Wolber 59 rims. I wasn't crazy about it on Mavic Open 4s because the sidewall didn't loose the
    color evenly.

    I vote non machined.

    On 23 Jan 2003 09:45:24 -0800, [email protected] (Patrick) wrote:

    >Just wondering if it really makes any difference. Some manufacturers don't even advertise whether
    >the sidewalls are machined; others do. Velocity for example, makes both, but I believe they're the
    >same price. What gives? Just marketing hype?
     
  4. --------------080704090501090409080000 Content-Type: text/plain; charset=us-ascii; format=flowed
    Content-Transfer-Encoding: 7bit

    I'll just put my oar in on the other side of the argument.

    I appreciate the merits of non-machined sidewalls (longer life), and maybe it's just bad luck on my
    part but I had three successive front wheels with poor joints that no amount of sanding would
    improve and it drove me nuts. I know everyone says it's a rare ocurrence but 3 outa 3 is too much
    for me. Offroad in particular a grabby spot on the front is a royal PITA when you're doing slow,
    steep stuff on loose surfaces.

    I've had a few welded and machined rims since and they've all been nice and smoooth. I don't wear
    out rims too often nowadays so I'm happy to accept a wheel lasting 5 years instead of 7 or 7 instead
    of 10 or whatever and get smooth, controllable braking.

    Other folks obviously have better experiences with non-machined rims but that has been mine to date.

    Duncan Bourne

    Paul Kopit wrote:

    >I mistakenly got a set on non annodized Velocity Aerohead rims. They are great. I rode a couple of
    >thousand miles before they looked like machined rims. I've had similar experience with older
    >Wolber 59 rims. I wasn't crazy about it on Mavic Open 4s because the sidewall didn't loose the
    >color evenly.
    >
    >I vote non machined.
    >
    >On 23 Jan 2003 09:45:24 -0800, [email protected] (Patrick) wrote:
    >
    >
    >
    >>Just wondering if it really makes any difference. Some manufacturers don't even advertise whether
    >>the sidewalls are machined; others do. Velocity for example, makes both, but I believe they're the
    >>same price. What gives? Just marketing hype?
    >>
    >>
    >
    >
    >

    --------------080704090501090409080000 Content-Type: text/html; charset=us-ascii
    Content-Transfer-Encoding: 7bit

    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title></title>
    </head> <body> I'll just put my oar in on the other side of the argument.<br> <br> I appreciate the
    merits of non-machined sidewalls (longer life), and maybe it's just bad luck on my part but I had
    three successive front wheels with poor joints that no amount of sanding would improve and it drove
    me nuts. I know everyone says it's a rare ocurrence but 3 outa 3 is too much for me. Offroad in
    particular a grabby spot on the front is a royal PITA when you're doing slow, steep stuff on loose
    surfaces. <br> <br> I've had a few welded and machined rims since and they've all been nice and
    smoooth.<br> I don't wear out rims too often nowadays so I'm happy to accept a wheel lasting 5 years
    instead of 7 or 7 instead of 10 or whatever and get smooth, controllable braking.<br> <br> Other
    folks obviously have better experiences with non-machined rims but that has been mine to date.<br>
    <br> Duncan Bourne<br> <br> Paul Kopit wrote:<br> <blockquote type="cite"
    cite="[email protected]"> <pre wrap="">I mistakenly got a set on non
    annodized Velocity Aerohead rims. They are great. I rode a couple of thousand miles before they
    looked like machined rims. I've had similar experience with older Wolber 59 rims. I wasn't crazy
    about it on Mavic Open 4s because the sidewall didn't loose the color evenly.

    I vote non machined.

    On 23 Jan 2003 09:45:24 -0800, <a class="moz-txt-link-abbreviated"
    href="mailto:[email protected]">[email protected]</a> (Patrick) wrote:

    </pre> <blockquote type="cite"> <pre wrap="">Just wondering if it really makes any difference.
    Some manufacturers don't even advertise whether the sidewalls are machined; others do. Velocity
    for example, makes both, but I believe they're the same price. What gives? Just marketing hype?
    </pre> </blockquote> <pre wrap=""><!----> </pre> </blockquote> <br> </body> </html>

    --------------080704090501090409080000--
     
  5. Alex Rodriguez wrote:
    >
    > In article <[email protected]>, [email protected] says...
    >
    > >Just wondering if it really makes any difference.
    >
    > Yes it does. Machined rims will have a shorter life span because they have had material removed
    > from their sidewalls.

    That alone doesn't mean much. If they "start" with more material before the machining, they can end
    with more or the same as other non-machined rims. Foe example, the Mavic Open Pro weighs about the
    same as the older Open 4 CD. One is machined and one isn't and both have eyelets and approximately
    the same cross section. So the amount of material depth on the brake track could in the end be about
    the same. Of course, I don't really know.

    It does probably make a difference in the price. I don't know how much that is either, but I don't
    think I would pay for a machined rim, all other things equal.

    > >Some manufacturers don't even advertise whether the sidewalls are machined; others do.
    >
    > Most do because they think it is a feature and can then charge extra for it.
    >
    > >Velocity for example, makes both, but I believe they're the same price. What gives? Just
    > >marketing hype?
    >
    > Yes, hype.

    They are nice and "straight" usually, but I don't know if it is worth
    it. A lot of people seem to think it is worth it and do pay Mavic a premium, for example.
     
  6. Ant

    Ant Guest

    [email protected] (Patrick) wrote in message
    news:<[email protected]>...
    > Just wondering if it really makes any difference. Some manufacturers don't even advertise whether
    > the sidewalls are machined; others do. Velocity for example, makes both, but I believe they're the
    > same price. What gives? Just marketing hype?

    Far be it from me to claim any expertise here, but I would venture to guess that in certain cases
    the machined rim can make a big positive difference. Take, for example, my bike. With cantilevers up
    front, it is a serious squealer. Only with frequent rim cleanings, toe-in, and all the other tricks
    does it keep quiet in normal braking. With koolstop bmx pads nothing i did could make it stop, so i
    switched back to the stock avid pads. I would guess that if the rim were smooth it would squeal even
    more than it does now. i suppose if you are running a canti brake it could possibly make sense to
    have a machined sidewall. or perhaps, if you are having uncurable squealing, you could rebuild your
    wheel with a machined rim (or you could just sand it, i suppose..)

    anthony
     
  7. mango-<< Just wondering if it really makes any difference.

    Mostly marketing. i rode with non-machined sidewall rims for years w/o problem. Some manufacturers
    say they increase wall thickness before machining, maybe that's true.

    Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
  8. Mark Hickey

    Mark Hickey Guest

    The Pomeranian <[email protected]> wrote:

    >Alex Rodriguez wrote:

    >> Yes it does. Machined rims will have a shorter life span because they have had material removed
    >> from their sidewalls.
    >
    >That alone doesn't mean much. If they "start" with more material before the machining, they can end
    >with more or the same as other non-machined rims. Foe example, the Mavic Open Pro weighs about the
    >same as the older Open 4 CD. One is machined and one isn't and both have eyelets and approximately
    >the same cross section. So the amount of material depth on the brake track could in the end be
    >about the same. Of course, I don't really know.

    The way I look at it is you have two choices if you want to machine a sidewall.

    One, you want to end up with at least the wall thickness of the non-machined rim. That means the
    thinnest portions will be the same, and the thicker portions thicker (which serves no practical
    purpose). End result = heavier rim.

    Two, you want to end up with the average or maximum wall thickness of the non-machined rim. This
    means you end up with sections of the wall that are thinner, meaning the rim will wear out sooner.
    We've read reports where a machined wall left the factory in a virtually "worn out state", failing
    within weeks due to brake track wear.

    Either way, you end up with a non-optimum distribution of material.

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
  9. Mark Hickey

    Mark Hickey Guest

    [email protected] (ant) wrote:

    >Far be it from me to claim any expertise here, but I would venture to guess that in certain cases
    >the machined rim can make a big positive difference. Take, for example, my bike. With cantilevers
    >up front, it is a serious squealer. Only with frequent rim cleanings, toe-in, and all the other
    >tricks does it keep quiet in normal braking. With koolstop bmx pads nothing i did could make it
    >stop, so i switched back to the stock avid pads. I would guess that if the rim were smooth it would
    >squeal even more than it does now. i suppose if you are running a canti brake it could possibly
    >make sense to have a machined sidewall. or perhaps, if you are having uncurable squealing, you
    >could rebuild your wheel with a machined rim (or you could just sand it, i suppose..)

    A new rim will always fix a squealing brake problem. Until it's dirty like the old rim it replaces -
    whether you're changing to or from machined sidewalls. Either way, the braking surface of either
    type of wheel will "devolve" to the identical surface.

    About the only advantage in regards to squealing brakes is that any anodizing has been removed from
    the brake track. Of course, I'd never purposely buy an anodized rim anyway... ;-)

    Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
     
  10. Matt O'Toole

    Matt O'Toole Guest

    "Mark Hickey" <[email protected]> wrote in message
    news:[email protected]...

    > About the only advantage in regards to squealing brakes is that any anodizing has been removed
    > from the brake track. Of course, I'd never purposely buy an anodized rim anyway... ;-)

    Unfortunately, about ten years ago, you couldn't buy anything else. At least the sidewalls
    are machined these days. I'm no fan of machined rims, but I'll take them over anodized
    sidewalls any day.

    Matt O.
     
  11. Mark Hickey wrote:
    >
    > The Pomeranian <[email protected]> wrote:
    >
    > >Alex Rodriguez wrote:
    >
    > >> Yes it does. Machined rims will have a shorter life span because they have had material removed
    > >> from their sidewalls.
    > >
    > >That alone doesn't mean much. If they "start" with more material before the machining, they can
    > >end with more or the same as other non-machined rims. Foe example, the Mavic Open Pro weighs
    > >about the same as the older Open 4 CD. One is machined and one isn't and both have eyelets and
    > >approximately the same cross section. So the amount of material depth on the brake track could in
    > >the end be about the same. Of course, I don't really know.
    >
    > The way I look at it is you have two choices if you want to machine a sidewall.
    >
    > One, you want to end up with at least the wall thickness of the non-machined rim. That means the
    > thinnest portions will be the same, and the thicker portions thicker (which serves no practical
    > purpose). End result = heavier rim.
    >
    > Two, you want to end up with the average or maximum wall thickness of the non-machined rim. This
    > means you end up with sections of the wall that are thinner, meaning the rim will wear out sooner.
    > We've read reports where a machined wall left the factory in a virtually "worn out state", failing
    > within weeks due to brake track wear.
    >
    > Either way, you end up with a non-optimum distribution of material.

    That makes sense, thanks. I only buy machined rims anymore when other factors come into play and
    overide the machining aspect. I've never had much trouble with non-machined rims and it seems like
    it is probably unnecessary and would mainly add cost. Welded non-machined rims do sometimes have an
    uneven section near the weld that is "grabby." I don't know how much it matters in practice, but
    because of this I question the weld technique of joining too.

    I wrecked a racing rim in a crash awhile back and think I will try the Torelli Master as a
    replacement. I'm not sure about all the construction details. What I'd really like is an old
    non-anodized Open 4 CD, but that isn't in the cards.
     
  12. Matt O'Toole

    Matt O'Toole Guest

    "Mark Hickey" <[email protected]> wrote in message
    news:[email protected]...

    > The way I look at it is you have two choices if you want to machine a sidewall.
    >
    > One, you want to end up with at least the wall thickness of the non-machined rim. That means the
    > thinnest portions will be the same, and the thicker portions thicker (which serves no practical
    > purpose). End result = heavier rim.
    >
    > Two, you want to end up with the average or maximum wall thickness of the non-machined rim. This
    > means you end up with sections of the wall that are thinner, meaning the rim will wear out sooner.
    > We've read reports where a machined wall left the factory in a virtually "worn out state", failing
    > within weeks due to brake track wear.
    >
    > Either way, you end up with a non-optimum distribution of material.

    This is in fact the main problem. Rim extrusions are not perfectly straight, varying by a thou or
    two here and there. So when the sidewalls are machined flat, it leaves them with thick and thin
    spots. If left alone the thickness would have remained uniform. As the rim wears, this variance in
    thickness becomes greater, in relation to total thickness. This results in a rim that won't stay
    straight because it's stiffer in some places than others. It requires uneven spoke tension to keep
    straight, so its overall strength is compromised too. It's likely to fail sooner, and without
    warning. An unmachined rim will stay straight until the sidewalls are so thin there are detectable
    bulges around the spoke holes. Not only will it last longer, it gives plenty of indication of its
    state of wear.

    I have worn out several sets of rims of each type, and observed the behaviour of one type vs.
    the other.

    Most people's rims last longer than their biking careers, so there's little incentive for bike
    companies to consider this issue -- especially if they think customers may be attracted to pretty
    colors and machined sidewalls.

    Keith Bontrager, who built the first-ever lightweight mountain bike rims and is now a bigshot
    engineer at Trek, has posted here on this issue. He says it's actually easier and cheaper to build
    rims with consistently good joints by welding and machining, vs. just cutting and pinning. Not
    having run his production line I'm not in a position to second-guess, but I don't think he'd lie.

    Matt O.
     
  13. In article <[email protected]>, [email protected] says...

    >I wrecked a racing rim in a crash awhile back and think I will try the Torelli Master as a
    >replacement. I'm not sure about all the construction details. What I'd really like is an old
    >non-anodized Open 4 CD, but that isn't in the cards.

    The non-anodized rim wasn't called Open 4 CD. The CD in the name implies hard anodized. It was Open
    something or another, I forget.
    -----------------
    Alex __O _-\<,_ (_)/ (_)
     
  14. John Albergo

    John Albergo Guest

    Duncan Bourne wrote:

    > I'll just put my oar in on the other side of the argument.
    >
    > I appreciate the merits of non-machined sidewalls (longer life), and maybe it's just bad luck on
    > my part but I had three successive front wheels with poor joints that no amount of sanding would
    > improve and it drove me nuts. I know everyone says it's a rare ocurrence but 3 outa 3 is too much
    > for me. Offroad in particular a grabby spot on the front is a royal PITA when you're doing slow,
    > steep stuff on loose surfaces.
    >
    > I've had a few welded and machined rims since and they've all been nice and smoooth. I don't wear
    > out rims too often nowadays so I'm happy to accept a wheel lasting 5 years instead of 7 or 7
    > instead of 10 or whatever and get smooth, controllable braking.
    >
    > Other folks obviously have better experiences with non-machined rims but that has been mine
    > to date.
    >
    >
    Having lived with front rims that go "bip-bip-bip-bip..." I can agree with your sentiment. A
    perfectly even surface is a nice thing. I agree with a previous post - there's no reason the
    resulting wall thickness has to be insufficient; just start with thicker material. I don't know if
    that's done but there's nothing about machining per se that mandates too-thin sidewalls. Whether the
    added expense is justified is a judgement call. But seeing how I only buy about 1 rim per year, it
    doesn't make too much difference to me. I currently have a machined rim on the back and a
    non-machined on the front (with a good smooth joint). The selection was made on other factors.
     
  15. Pete Biggs

    Pete Biggs Guest

    Mark Hickey wrote:
    > A new rim will always fix a squealing brake problem. Until it's dirty like the old rim it replaces
    > - whether you're changing to or from machined sidewalls. Either way, the braking surface of either
    > type of wheel will "devolve" to the identical surface.

    That can take a long time to happen though. Some Open Pro rims have a deeply grooved effect which
    can last a few thousand miles before they become totally smooth (albeit when used mostly in dry
    conditions). These machined rims improve braking, ime. The depth of the grooves vary according to
    the batch. The last OP I bought was nearly smooth to begin with.

    ~PB
     
  16. Jobst Brandt

    Jobst Brandt Guest

    Patrick Mangos? writes:

    > Just wondering if it really makes any difference. Some manufacturers don't even advertise whether
    > the sidewalls are machined; others do. Velocity for example, makes both, but I believe they're the
    > same price. What gives? Just marketing hype?

    What you hear and read is marketing hyperbole, but there is a reason for machining rims, and it
    isn't for your benefit. If you inspect a machined rim closely, you'll find a surface that looks as
    though a stupid machinist used a thread cutting tool to get a flat braking surface, a series of fine
    grooves that are noticeable when running a fingernail across the width of the brake surface.

    Rims are not machined to make them flat. Machining a series of LP vinyl record grooves prevents
    brake squeal on new bicycles for test rides and sales. The grooves wear off on the first descent in
    wet weather which is the cause of rim wear in the first place. Even anodizing, a hard ceramic layer,
    whether thick or thin, is far more durable than the bare machined rim. Besides, the thicker the
    anodized coating the poorer brakes will work, because anodizing is also an insulator, something that
    overheats brake pad surfaces.

    The claim that machining is for other purposes than suppressing brake squeal is far fetched. For
    instance, rim joints have been made with no perceptible discontinuity almost as long as there have
    been aluminum rims. Unfortunately, some marketing people thought rims would come apart if they were
    not riveted. Riveting nearly always distorts rim joints. Fortunately rims of a few years ago were
    made without rivets and had flawless joints.

    For practical purposes, machining only serves to make an irregular and unknown thick rim wall and
    adds a bit of sparkle to the new product, giving elegant reflections in showrooms. Mavic, for
    instance has rims listed as having "CERAMC2", "SUP, "CD", "UB", MAXTAL", all features that add
    expense on top of a plain aluminum rims that were offered at about 1/4 the price not long ago. The
    web site explains that "CERAMC2" is an insulator that improves braking. This is a tipoff to hype,
    because without special brake pads, this feature rapidly wears pads from heating that also degrades
    performance.

    Jobst Brandt [email protected] Palo Alto CA
     
Loading...
Thread Status:
Not open for further replies.
Loading...