Rim brakes on track/fixed gear wheels?

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  • Hello all,

    I'm pretty much a complete amateur when it comes to bikes but I recently purchased a Motobecane 84' Mirage Sport (I think... the respray makes it hard to be sure about the model). Only the frame is original. It was sold with Ofmega wheels, they're painted black, with rims which are not machined or tracked at all, so I assume they're for track/fixed wheel use?

    I have Gipiemme Crono Sprint calipers installed and even though they do work... they're incredibly squeaky.

    So my questions are, if anyone could share their thoughts/expertise...

    1) Is it safe to continue using rim brakes on these rims which I assume aren't designed for brakes?

    2) Will the paint wear away over time, exposing the raw metal, giving better brake power and less noise?

    3) Should I remove the paint myself?

    4) Should I try different pads?

    5) Should I just save myself the time and buy new wheels with a proper machined surface for rim brake use?

    6) Has anyone else here installed rim brakes on a fixie?

    I've attached some photos for reference.
    NOTE: I know in one photo it looks as if the pad would contact the actual tyre, but the caliper has simply slipped out of alignment while I'm installing new cables.

    Much, much thanks in advance. I appreciate your time to help me out here...


    3 Attachments

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  • You need new wheels that have a machined braking surface

  • looks like a cassette on the rear, with derailleur?

    and QR levers?

  • Hi Sumo,

    I did wonder if buying new wheels would have to be my next move, seems to be too much hard work to get these brakes to work with these rims... simply incompatible!

    Thanks for your imput, I appreciate

  • Hello, MCamb

    Yes, there are QR levers on front and rear.

  • I think they’re just road wheels, and someone’s painted over the rims. If it’s too much work then buy some new wheels, but you could also remove the paint from the braking surface and use these.

    I’d also get some better brake pads, will reduce squealing.

  • Not sure how / why someone will have painted over them... maybe that’s just how they are. Could be a combination of the surface wearing down gradually and brake pads being a bit hard and squealing.

  • The guy who sold me the bike is a car mechanic, perhaps he took it upon himself to paint the wheels for what he assumed to be an aesthetic improvement, but I feel as if this layer of paint (it has chipped on the spokes) will be a bit of a bugger to work with these brakes. I do admit that the pads need replacing, they are almost rock hard, but since these rims show no sign of manufactured brake tracking, they're going to wear thin quicker than machined rims purposely designed for rim brakes...

    What do you think? New wheels and new pads or try new pads first?

  • The rims aren't a matched pair: the front has a machined sidewall (MSW), the rear doesn't: I wonder if someone has taken two different wheels and sprayed them with a rattlecan (perhaps with what was left over from doing the forks).

    The paint (or possibly anodising) will quickly wear-off if you brake on them, but the braking won't be hugely improved.

    People were riding on rims long before MSW were invented and didn't burst into a ball of fire, but the roads weren't so busy then.

    The main reason for the poor braking and noise is that you have single-pivot brake calipers: the action is weak and the arms flex.

    But, again, people managed well enough until the early-Nineties when dual-pivot brakes were invented.

    If you trawl eBay you should be able to find Koolstop salmon brake pads to fit your calipers and compressionless outer cable will help, but the upshot is that you have a modest and out-dated (but rather smart and tidy) bike and should only expect it to perform comparably.

  • Hi Scilly.Suffolk,

    Thank you for your reply.

    I can see why you would think the front has MSW but I can tell you that for the few rides I did have before I could no longer tolerate the squeaking, there was only the front caliper installed, hence why there is marking on the front rim and not the rear. I've since installed the rear caliper, as you can see, and the rear rim is still untouched. I'm pretty sure the wheels are matching, both are titled ofmega on the hubs.

    Effective braking is pretty important for me at this early, newbie stage, and riding in London requires quick reactions at times, so I'd really like to give myself the best chance of survival!

    Essentially, I'm gathering that it would be possible to continue using these wheels, while tolerating poor braking power and wearing down the paint to access the base metal, and in the meantime, buy some new pads. I do actually have some Ashima RPMx pads, and some compatible shoes, but their longer length demands that I extend the caliper away from the frame... and that's getting into technical ability/knowledge I just don't have. Visit a bike shop, I know.

    It's a little superficial, but I immediately fell in love with the frame first, it is indeed smart!

  • You're welcome.

    And it took me so long to reply, that I didn't see what you posted about the car mechanic, which sheds some new light on things.

    Firstly, perhaps we're not talking about the same thing, but the front rim definitely has a MSW and the rear doesn't.

    Look at the shape of the front rim from the spokes towards to the tyre. It starts as a "V" and then the sides become parallel to each other: that's the MSW. The rear doesn't have that.

    A non-MSW rim on a geared hub, means it is either really quite old (Seventies) or has been replaced: how many sprockets are there? Only five mean it may, at a push, be original; any more and I'd warrant that the rim has been replaced with whatever was on the shelf.

    Ofmega made "second tier" (in terms of price and quality) components that were fairly common and wouldn't have been out of place on the bike when it was new, so are likely original to the bike.

    All told, I think the odds are that the rear rim has been replaced.

    Either way, it's academic: you have to deal with what you have (as interesting as unpicking the bike's history might be).

    Knowing that you bought it off a car mechanic (and that the paint has chipped in places), suggests to me that he had access to and used a relatively hard and durable paint (rather than a rattle-can). And not really knowing much about bikes, just sprayed over the whole wheel: black components post-date this bike.

    In which case, no amount of braking is going to wear the paint away.

    Like as not, the brake pads are original and thoroughly dried-out which won't help. You could try new pads, but if I'm right about the paint, then you're pissing in the wind.

    And a quick search suggests that the pads you have are intended for V-brakes or cantilevers (which explains why they are too long) and aren't compatible with your calipers.

    TL/DR
    New wheels (and brake pads).

    PS FWIW your bike is a prime candidate for a fixed conversion.

  • Again, you're very kind to reply with such effort.

    So in response to the MSW, I've had a closer look at the rims, and even with my untrained eye... the shape appears the same on the front and the rear. They both start from a V indeed, but the paralleling on the front you mention, I just can't tell the difference on the front from the rear except the shiny, smoothed surface as a result of riding with only the front caliper fitted. Both rims seem to curve up around towards the tyre, and if anything they continue curving to meet the tyre. And I hope we're still talking about the same thing...

    I did notice a ridge on the rear rim, you can see it still visible even with the paint coat on top. Could this be a machined surface lurking?

    I've taken some photos on my phone, I hope they can show the surface and shape a little better than my original photos and above description...

  • Front rim

    Notice brake pad wear


    2 Attachments

    • front rim.jpg
    • front rim2.jpg
  • Rear rim

    No brake wear


    2 Attachments

    • rear rim.jpg
    • rear rim2.jpg
  • No problem and I owe you (and Sumo) an apology: you're right there is no MSW on the front: I suppose it's just the light/shadow (on the very first photo you posted).

    That being the case I'd guess the wheels are original, as rims with a MSW are more expensive than those without and your bike would originally have been quite modest: I don't think Motobecane ever made anything else and another clue is that the rear dropouts are stamped, rather than cast.

    Removing the paint isn't a practical option: it'll take a lot of effort, the end result will look poor and it won't improve the braking much.

    I'm afraid you really need new wheels.

    How many sprockets are there? No more than seven I expect, which means it's a screw-on freewheel rather than a cassette.

    If there are six or seven sprockets, then the rear OLD will be 126mm; if five it's 120mm. The front OLD will be 100mm.

    You can use any front wheel as the standard OLD hasn't changed. But the rear standard is now 130mm. Rear wheels that take a screw-on freewheel are still available and they're relatively cheap, but the price reflects the quality. You'll probably find something nicer second-hand, for the same money as a new set will cost you.

    Have a look at the tyres for some numbers: you should find something like "700 x 23" or "23 x 622".

    Check the number of sprockets and the size of the tyres and I can confirm what you're looking for.

  • There are rims with nmsw's like the ambrosia nemesis which brake very well. So a machined brake track is not essential. Msw's wear at a faster rate.

  • :) It was indeed the trick of the light.

    I'm not sure these are the original wheels. I've only just discovered through hours of sifting through websites and catalogs, comparing frame details, which model this Motobecane is likely to be... a Trainer from the late 80s/early 90s (see photo below) and the original wheels look quite different.

    But anyway... I've since dropped off my Moto to a bike shop to let the professionals to their magic. She has returned with pumped tyres, new brake pads, cables, and tweaked derailleur and BB. They say the new pads are squealing a little, but work fine on the non machined rims, and after a while the paint should wear off and noise should decrease.

    Haven't tested her yet, as it's raining and my recently sprained ankle is still healing... but soon!

    Thank you for taking the time to write and offer your assistance, it's nice to know there are people out there willing to step in and help. When I've wrapped the bar, I'll post a photo. Even the mechanics in the shop commented on how jazzy she looks...


    1 Attachment

    • Trainer MBK 2.jpg
  • Thank you, cycleclinic!

    Yes, the guys in my local bike shop agree that a machined surface isn't always necessary. The paint will wear away eventually, and a new set of pads should help. Thanks again

  • I'm glad you've got it sorted: it does look sharp (just a shame he got carried away with the spray gun).

    Happy to help and hope you found some of it useful, but do remember that "it's an empty tin can that makes the most noise" (especially on the internet).

    ;)

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Rim brakes on track/fixed gear wheels?

Posted by Avatar for Emordna @Emordna

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