Question about my rims and brake pads
 

Hi,

I have a question about my rims. I want to put new brakes on my bike, but my rims have this weird surface. It has tiny ribs all over the braking surface. My question is could I install caliper brakes? Or this surface will just shred the braking pads?
Currently I have Shimano "Roller brakes" apparently and they do not do the job well...

Thanks :)
http://bikeforums.net/attachment.php...hmentid=366633

there's nothing wrong with the rim. it is a consequence of the manufacturing process of machining the braking surface. caliper brakes are fine, IME, assuming the fork, which is not depicted, can handle a caliper brake.

That is strange and not looking right lol Shimano brake shoes last a long time, while eating braking surface on aluminum rims. Dirt and sand that is trapped between rim and brake shoe makes everything worse.
What I see on that pic is something I just can't explain. It just makes no sense whatsoever.
Take this to your nearest bike shop...
EDIT: I think I misread your post...Sounds like this rim doesn't have braking surface at all....The "ribs" are just a design??? If you post name/brand of your bike it will be much easier to help you.

Thank you very much. My bike mechanic was thinking because they are not a flat surface like other rims, it might eat up the brake pad. My for supports caliper brakes though.

just tooling marks from machining the brake track after welding the seam.

same finish on my Mavic EX 721 rims , also black anodized, the color goes away soon ./

no the rings are around the edge, not radiating out from the axle center
across the face..

Im running Kool Stop salmon brake pads on all my rim brake bikes .

(*) have no idea since I cannot see the places where you may mount brakes ,
perhaps you can offer up a picture on that ..

+1, in machine shop speak, these are "scroll" marks. They happen as the turning tool is moved inward while the rim spins on a giant lathe. If you look very closely or use a pin, you'll see they form a continuous spiral.

They're a natural part of the machined sidewall process, though they appear more pronounced than normal in the photo.

Odds are they'll increase initial brake shoe wear somewhat, but might also improve wet braking the way grooved pavement improves wet traction for cars.

Don't sweat either way, the normal braking wear will smooth the rims soon enough.

True they are not intended to be as agressive a braking system .
maybe you really wanted disc brakes instead.

but when the road is Icy a real abrupt brake is not so good either ..

lol!

Thanks for all of the answers. My bike is Danish. It is a make called Avenue Broadway XM. Here is a link to the model:
http://avenue-cykler.dk/works/broadw...un-metal-grey/
If I am not allowed to post links I do apologize up front. I am new to the forum and will learn the rules soon enough :)

I don't have fittings for disc brakes and would hate to weld some on there... That is why I chose caliper instead.
Here are some pictures:
http://bikeforums.net/attachment.php...hmentid=366657http://bikeforums.net/attachment.php...hmentid=366658

If this is NORMAL to you... To me its just not right, especially if it was intended to be used as a braking surface.
Few examples of how properly machined braking surface should look...no ifs or buts...

http://3.bp.blogspot.com/_P_54wPTsFh...0/IMG_1872.jpg

http://4.bp.blogspot.com/-o_wNU--iA0...0/IMG_1972.jpg

http://bikeisland.com/images/1230006.JPG

OPs rims are NOT designed for rim brakes...

If so, what might be the consequences of using rim brakes on them? Thinner sidewalls collapsing, distortion, overheating causing tire problems? I agree the machining looks pretty course for a rim braking surface, and might initially wear pads unusually fast.

It would keep eating shoes like crazy and terrible looking brake surface /silver mixed with black/. If you check manufacturer website you will see they are all about design. Their wheels are custom made for their bikes, and are using rollerbrakes. These wheels were never intended to be used with rim brakes. Avenue bikes also carry bikes with rim brakes, but braking surface is smooth like a baby butt... Personally I prefer rim brake surface that was not machined, for a longer rim life.

Nobody has to guess. The OP can contact the maker, or have the dealer do so, and/or he can measure the thickness of the rim.

Or he can mount rim brakes and possibly live with shorter shoe life, and possibly shorter rim life if the wall is thinner than typical rim brake rims.

Of course it's hard to work from a photo, but IMO the existence of these scroll marks doesn't automatically rule this rim out for caliper brakes.

I've seen many mid-1990s Treks with tool marks on the rims just as coarse as the OP's and no durability problems.

JIVE

/JIVE

Actually, the photo here:

http://cdn.shopify.com/s/files/1/016...g?v=1362557060

shows an Avenue model with rim brakes and grooves on the brake track at the same pitch as the OP's, and also anodized.

To the OP:
Your rims are compatible with rim brakes, which will probably work better than your rollers. Use good quality caliper(s) and pads.

would flipping the wheel so the scroll spirals inwards as the wheel turns, or spiral outwards, give better braking performance ?

thinking about the direction debris will get pushed, also the motion of pads as the brake arm swings...
-ie inwards spiral might draw the pads in, for a self actuating effect
on the other hand in rain, might prevent water shedding

The scroll marks are nearly concentric. There's too little spiral angle to make any difference. One way they spiral and eventually (very eventually) dirt might eject to the outside, or the inside, but we're talking about something like deciding if a quarter is more likely to come up heads or tails based on the imbalance which resulted from the different heights of the reliefs, or wear patterns of the rims.

Wait, wait wait! Groans asks if it's feasible to put rim brakes on his bike, and we are debating whether it is. But why are the Shimano roller brakes doing the job? That's the real question. Get the shop to get them to work well. You paid for a bike that works. They can't be that bad. Have the shop figure out the problem. I doubt it's a defect that plagues all bikes equipped with those brakes.

Interesting. I've never seen a "roller brake". Is that something more common in Europe than in the US?

Not at all. 99% of bikes here have either caliper or disc brakes. There is a reason why... Roller brakes have much less braking power. I can live with that because if you have a strong grip you can get both tires to skid. What I can't live with is that they have some looseness on their cooling discs and every road bum or pot hole makes a noise.

Otherwise these bikes are designer bikes and I am in love with the looks. that is why I wouldn't just switch for an other bike... But man they really heavy.. the hub doesn't help the weight either

IMO the simple fact that disc brakes do not ruin rims will mean soon almost all bikes will come with disc brakes. When you look at it logically it is really dumb to have rim brakes wear out expensive rims. An additional point is that probably a high percentage of cyclist that post here can do a full brake job on disk brakes. The disc just unbolts from the hub, and pads are easily replaced. Rim brakes on the other hand when a rim is worn or cracked calls for a new rim and a wheel rebuild.

+1

I think "roller brake" is a Shimano-specific term for a drum brake.

In general I would second noglider's comment - properly adjusted drum brakes should be quite sufficient for everyday transportation bicycling. They are never going to have the "throw you over the handlebars" power of a rim brake (though that may be a good thing), but they are very well-suited for a city bike. However, the OP's bike looks like a racer to me, and I can understand why you might want the increased braking power and lighter weight of rim brakes over a hub brake.