Need a little advice. Since a month or so I have a Magura HS33 on my KH2008 MUni, before then I rode brakeless. Today I rode in quite muddy conditions. It seems as if some sand has gotten between the brake pads and the rim, because when I brake it gives a scratchy sound. Presumably the sand grains have embedded themselves in the brake pads, since cleaning the rim doesn’t help. Now I wonder: is this disadvantageous in any way? The brake power is about the same as before (maybe somewhat less but not a problem), but I can image that the sand is so hard it eats away the aluminium rim.
It’s disadvantageous because you are sanding your rim down. Eventually, the side walls of the rim will be too thin, and you’ll need a new rim. You just need to clean the brake pads. It’s a hassle, but it needs to be done.
find something with a sharp point and scrape the brake pad
yup, one of the great advantages of disk brakes is they don’t wear out expensive rims.
Clean the pads when you clean your rim. I know that Magura says that the pads should be adjusted to hit the rim flat but I like to have the leading edge hit first to clean the rim a bit before the main part of the pad starts to brake.
“Leading” in this case means the part more to the rear, right? So that that leading edge wipes the rim clean, rather than the pad/rim gap acting like a narrowing trap for dirt?
Anyway, I cleaned my pads this morning. The cleaning act itself is a matter of seconds, but disassembling and (even more so) putting back the brake pads including the adjusting makes it a bit of a hassle. Maybe I can try next time to clean them while they are in place, without any taking apart. I’m not sure I have enough room but it’s worth a try.
Yah, cleaning is a hassle. I never do it as much as I should. And you are right I meant the edge of the pad towards the rear.
Just a brush you use for the washing up, and an old bowl and an all purpose cleaner. That what pro mechanics use to use in the century before the high pressure cleaner was invented. And before you break trough the rim, you get a new one.
When I looked up the translation for ‘Allesreiniger’ I came across a good brand for you:
Do the Maguras have a quick release like normal brakes do? If so, you may be able to loosen them enough to fit a rag in between the pad and the rim and quickly mostly clean the pads. It wouldn’t be as good as a full cleaning, but if you do that frequently, you shouldn’t have to do a full cleaning as often. It seems to work well for other parts…
I have no idea. What does a quick release look like?
I don’t know what it would look like on the Maguras. Most cable actuated bike brakes have a little lever that when you flip it the brake arms swing out far enough to remove the wheel without deflating the tire. It would be a little more complex with hydraulics. But it may give enough space for easier cleaning.
This is what a quick release on a magura would look like. It’s mostly a thing of the past.
I run V brakes, but the grit in my brake pads always seems to work itself out pretty quickly.
I think I’m glad I don’t have those quick releases. Without them the brakes are not particularly bulky, but yet my 661’s caught on the brake cilinder every now and then. As a remedy I have sown part of the middle tightening band directly to the protector so that it can’t catch anymore. Works well.
The screeching sound, once I got it, didn’t become any less in the course of a few minutes of braking. I don’t know how long I should have continued before the sand would have worked itself out, but it didn’t feel the right thing to do.
It’s not a thing of the past - it’s just that unicycles use the trials-bike type 4-bolt clamps that can’t use those quick-releases. I’ve got QRs on the Magura HS66s on my tandem - very useful, and saves having to deflate the tyre or unbolt the brake (and have to realign it again) to get the wheel off.
Anyway, @Klass - I wouldn’t worry too much about wearing the rim. The amount we actually use the brakes on unicycles you’ll never wear the rim too thin even with gritty pads. Mine are permanently wet and gritty and I’ve not had a problem. Even our mountain bikes with rim brakes don’t wear rims that quickly. Just give them a clean and use them a bit - the scrapiness soon goes away.
Rob
In muddy conditions when the rim/ brake pads get gritty a short steep section of trail with heavy braking usually cleans it up just fine. Once the mud build up is substantial enough on the leading edge of the brake just wipe it off with your finger. I doubt many people use their brakes effectively enough- let alone regularly enough to ever sand down the sidewalls of a rim. A gritty/dirty rim does change braking characteristics though- so once it gets that way don’t expect it to grip smoothly like it normally does. After one or two revolutions under heavy braking it will behave more regularly.
mark
Hot rims??
Related to this discussion, I think I may not be the only one to get a chuckle out of the last sentence in the product description for the new unicycle disc brake being sold by UDC. Anyone here on a uni (or bike??) ever had a inner tube pop because of an over heated rim from excessive rim braking?? Maybe I just don’t ride hard enough??
From the USA UDC site, Brake section:
“43” Bengal Helix 1.1 Disc Brake White
Quick Overview
There is no doubt about it: now disc brakes have become state-of-art on serious Unicycles.
Disc brakes do not pack up with mud, snow or ice and ensure an unchanged, unmatched brake power in all weather conditions. You will have no delayed brake reaction with a disc brake when you ride in the wet, but always the same reliable brake power as in dry weather conditions. You always have unchanged brake power which no longer depends on the quality of the rim wall, you can keep on riding even if your wheel goes out of true. No inner tube bursts because of overheated rims."
I’ve never heard of it. I could see it being possible on a downhill bike, maybe.
You do realize that this is a gun cleaner right? I’m not sure I would put it on a brake pad. 
If you are looking for a good cleaner for your machine gun or m-16 it does work great for carbon build up. Anyone in the Army knows exactly what CLP is.
it can be an issue with road bikes, especially tandoms.
I want to shake the hand of any unicyclist who can heat up one of our rims enough to melt a tube.
With our extra-extra-wide rims, it would be a lot harder to pop a tube on a unicycle than on a bike. I don’t know about popped tires, but I think I’ve heard of cyclists melting brake pads and tubular glue. Since I’m stuck in flatland I haven’t had that problem, and my brake pads (bike) last a long time.
Yes, CLP is da bomb for gun lubrication . . . . . and whose to say that unicycles and guns don’t go great together. At minute 2 or so, you will see this important connection:
Cheers,
Brycer