CyclingFool95 

Anyone ever used Mother's Polish (or similar) on aluminum rim braking surfaces? I figure it would return the new rim shine to them but will it affect braking performance?

Phil_gretz

I've used Mother's for years, but I have to admit that I haven't used it on the braking surface of polished rims. I would guess that you'll follow up with a cleaner of some sort and wiping with a clean cloth. If you use an ammonia-based cleaner, be aware that this may dull or darken a polished finish. It's never been a problem for me, though.

CargoDane

Don't polish braking surfaces, regardless of what product you use. Clean it if you want, but use something that cleans but no polish (i.e. Isopropyl alcohol).

If you want shiny rims, get some disc brake wheels. Then you can polish the rims to your heart's content. But be careful you're not getting it on the rotors.

dsbrantjr

Most polishes and compounds have a wax-type base so will leave a residue which will likely interfere with braking. It may or may not come off with a solvent like acetone or brake cleaner; silicones are especially difficult in this regard.

tkamd73 

Bought some new Velocity A 23s a couple of months ago, big delay for the polished ones, so took the unpolished aluminum ones. Really wanted polished silver ones, so used Mother’s metal polish on the rims, including the brake surface, before having them built up, Wiped the braking surface with isopropyl alcohol before riding on them, no issues, could have thrown myself over the bars on the first pull if desired. Mothers will work fine.
Tim

TiHabanero

I polish silver rims before building them, but always wipe down the brake surface with alcohol after the build is complete.

elcraft

BITD, I hand polished ( with a rag and my fingers) Weinmann rims with Simichrome. People always asked me why I had steel rims instead of alloy.....

Moe Zhoost

Simichrome is my long-time preferred compound for polishing Al. Braking surfaces should be sanded with fine grit paper, not polished.

LV2TNDM

The brake pads will quickly render the polish moot, especially after the first wet ride. I agree with the later posters, but ultimately, all that polishing will be for naught - your rims will quickly become scored and that dull aluminum/scrapes/residue look will return. But enjoy it while it lasts!

Bigbus

1200 grit and wet sand if you want them to shine. If you're putting polish on and then using acetone or alcohol to remove the polish, all you've accomplished is cleaning the rim.

LV2TNDM

This was the tried-and-true method for addressing the DREADED Dia Comp 986 cantilever squeak nightmare! Some brakes simply will NOT comply! Toe in, greased canti posts and everything else fail. Seems to be the combo of the brake pad compound and new anodizing. Scrub through the anodizing to fresh aluminum and you're good.

masi61

Were the un-polished ones anodized or non-anodized? Just curious.

BTW: I ride polished (non-anodized) A23’s on my Flyte SRS-3. I polish the entire rim, including the sidewalls with Mother’s mag wheel polish. They look stunning and the polish application to the sidewalls improves my braking performance as well.

CargoDane

Brakes stop you by generating friction as pressure is applied. If you polish it - especially with things such as polish, wax etc. - you reduce friction. There is no way polishing your brake surface will somehow magically make the brakes work better. Maybe if you haven't ridden the bike and you "test" it by applying the brake without moving the bike. In that case, I can imagine that something feels sticky.

The mentioned product (Mother's mag and aluminium polish) is for the rims (on cars and motorcycles) and not for the brake rotors on the mentioned vehicle. I know your rims are rims, but with rim brakes they are also the rotor.

masi61

Everyone states their opinion on here as if is a fact. I am telling you that by polishing my machined braking surface I have improved my (dry) braking performance. I do use softer pads and probably wear them out quite a bit sooner than the standard black Shimano ones. I have my own thoughts about why this works so well for me. I also clean the dirt off my pads petty regularly as well.

CargoDane

I know, you're telling it as if it is a fact: That smoothing-out your brake surfaces and covering it with something that is supposed to make a surface as slick as possible so dirt and brake dust won't stick to it, somehow makes your brakes work better.

Cleaning dirt off your pads is a good idea, regardless of whatever else you do. Just like removing polish, oil from the road and so on from your brake surfaces is also a good idea. Both the cleaning of the pads and the softer pad itself improves performance, regardless of whatever else you have done to reduce friction. However, if you hadn't reduced the friction, your clean and soft pads would work better.

However, you seem happy with your choices.

masi61

Velocity A23 polished rims do have machined sidewalls prior to being sent out for polishing. They are pretty high maintenance, I will admit. Any amount of riding in the rain & I usually wash them in my laundry tub with a soft scrub brush and dilute Dawn dish detergent with a tiny bit of Simple green in the bottle as well. I remount the wheels on the bike and spin them from valve to valve with a pea sized quantity of Mother’s mag polish. I am careful to not get it on the tire sidewalls. As it hazes, you polish it off with a clean paper towel which turns black. Minute grooving of the sidewalls is polished out a bit which you can feel better pad grip when you apply the brakes. It might just be that my perception is one of better modulation. This works in dry and drizzle/light rain. In heavy rain, not so much.

CargoDane

I wonder if you mostly use the rear brake when coming to a stop?
I ask because it doesn't take much pressure (friction) to make the rear tyre skid, so back there you don't apply much force compared to using your front brake to stop as quickly as possible (both, but the point still stands).

SurferRosa

Some are so old, I start with something more like 600 grit on the brake surface.

MarcusT

Aluminum foil. If you have not used it, try it, you will be impressed

Moe Zhoost

I realize that you believe braking performance to be improved after polish; however this is just a perception that won't stand up to real testing. The fact is that metal surfaces are polished to reduce friction, and friction is what generates the braking force. There are plenty of studies that confirm this. Here's a quote from one:

masi61

I’m pretty good at high speed braking. I live in a moderately hilly area. I guess I apply the brakes about 50/50 initially but then the front brake ends up providing a higher percentage. I do notice that my front pads wear out sooner.

masi61

Yeah, you might be right. I like the feel the way I do it for these particular polished rims. I’ve got them braking really well most of the time, not grabby but positive braking. I have Dura Ace 7700 dual pivots which are not as powerful as 7800’s. I have a bike with Dura Ace 7403 dual pivots (which I did a full rebuild on) and man they are some powerful rim brakes paired with ordinary Tektro aero brake levers.

I’m mot sure what to think about the 44 page scholarly article you provided. Looks like an interesting read. Not bike specific though so the takeaway for me is inconclusive. I got caught out in an absolute downpour last summer and I guess I shouldn’t be surprised that I had such a difficult time pulsing my brakes to squeegee them off. For now I’m gonna stick with my claim that these particular rims brake better in most conditions when freshly polished with Mother’s mag wheel polish. The grip with these pads; https://www.ebay.com/itm/193331590060 (inexpensive pads I have been using for the past 2 years) is enhanced a bit with no squeals or grabbiness. I forgot to mention that I do an intermediate step after (2 or 3) rounds of Mother ‘s mag wheel polish using Meguiar’s Cleaner Wax which concludes when my little paper towel squares aren’t so black any more. If I’m feeling like perfecting the shine a bit more still I use one round of Meguiar’s High Tech paste wax. These last 2 steps don’t seem to hurt the braking any and they seal the bare aluminum so that in a light rain, water beads up (for a while at least).

CargoDane

Hmm, then there isn't really any reason as to why you'd perceive the braking to be better on polished rims.

CargoDane

It doesn't matter if it's bike-specific: Friction is what causes you to stop when you apply brakes. That's also the reason brakes can get really hot. Have you tried some silicon lube on your rims (please don't!). It makes most of the friction go away.

Since you don't believe in friction is what is making your brakes work, what do you think is causing you to come to a stop?

masi61

It is a tactile thing for me. Maybe no better, but as I said I like the feel. I went through a woodworking hand tool sharpening phase about 20 years ago and did a lot of hand sharpening of chisels and plane blades. I use Japanese water stones in different grits: extra coarse (220), coarse (800), medium (1200), fine (6,000) & super fine (8000). When closing in on a mirror polished blade, there is a suction that holds the blade snugly to the wet stone, like an interference fit is created. Braking on a polished rim sidewall is a bit like that. Maybe one of the material science engineers (who absolutely ambush me here on these forums) can speak to the crystalline structure of different hardnesses and surface finishes for aluminum used in typical clincher rims.

One of these days I am going to give Velocity a call and ask about their polished rims. I thought I heard that they sub them out to a Harley Davidson motorcycle polishing shop. I purchased a set of the Aileron disc specific rims in polished for a disc bike that I really need to finish. Running a bike with these I think would look cool and also afford me the luxury of not worrying so much about the state of my rim brakes and sidewalls, LoL.