Bicycle Mechanics - Rim Brakes Wearing Out Rims

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View Full Version : Rim Brakes Wearing Out Rims


BikeToWork
01-02-07, 04:14 PM
I have an old UAV (urban assault vehicle) Trek 990 that goes through rear wheels about once a year. The pads on the v brakes wear a groove into the rim which eventually weakens it to the point where I need to true the wheel every other ride. Then the rim cracks. It's the same pattern regardless of the rim. My last rim was a 26" 32 spoke Sun Mammoth which lasted longer than most but eventually cracked. I commute on the bike in all weather conditions and often load lots of weight on the rear. I ride on pavement only.

My question is whether or not there is a way to retrofit a bike like my Trek 990 to take disk brakes. Would it be prohibitively expensive to replace the dropouts with disk brake compatible ones and what is involved? Replacing rear wheels every year is getting kind of pricey anyway.

Question two is whether anyone here has a home remedy for sniffles. I sniffle constantly while biking in cold weather, even though my body is sweating. It sure is annoying but it seems impossible to control.


TimJ
01-02-07, 04:20 PM
I think you have a pad problem more than anything else, wearing through a rim that quickly sounds very unusual. Also maybe you're just relying too much on your rear brakes. The front brakes are more powerful and take less force to get the same amount of stopping power.

motorhommmer
01-02-07, 04:43 PM
I have an old UAV (urban assault vehicle) Trek 990 that goes through rear wheels about once a year. The pads on the v brakes wear a groove into the rim which eventually weakens it to the point where I need to true the wheel every other ride. Then the rim cracks. It's the same pattern regardless of the rim. My last rim was a 26" 32 spoke Sun Mammoth which lasted longer than most but eventually cracked. I commute on the bike in all weather conditions and often load lots of weight on the rear. I ride on pavement only.

My question is whether or not there is a way to retrofit a bike like my Trek 990 to take disk brakes. Would it be prohibitively expensive to replace the dropouts with disk brake compatible ones and what is involved? Replacing rear wheels every year is getting kind of pricey anyway.

Question two is whether anyone here has a home remedy for sniffles. I sniffle constantly while biking in cold weather, even though my body is sweating. It sure is annoying but it seems impossible to control.

Use kookstop brake pads, big difference. Fit cartridges and then to replace pads just slide out old ones and slide in new

Try Vasaline on the bridge of your nose before you head out .


Rowan
01-02-07, 04:45 PM
Koolstops...

Plus... if you are using your rear brake *that* much, you aren't using your front brake *enough* like Tim said.

As to the sniffles... no idea other than to have gloves with a terry towelling insert along the thumb and index finger (and to wash regularly). The Winter forum might be a good place to ask the question again.

Old_Fart
01-02-07, 04:46 PM
How many miles do you put on the bike in the average year?
What type of brake pads have you been using and how often do you change them?

I know that rims eventually will wear out but a wheel per year seems excessive. Using softer brake pads (I like the Kool Stop salmon pads), cleaning them often, and replacing them before they are worn out are good ways to make rims last longer. I only put a couple thousand miles per year on my commuter and change pads a couple times a year. Brake pads pick up lots of abrasive crap in daily use. Sand, small rocks, and little pieces of metal get stuck in brake pads and make the rims wear out much faster than they need to.

As to your original question, front brakes could be changed to discs by getting a new fork with disc brake bosses. This is easy if your bike has a 1-1/8" threadless headset/steerer. Not as easy if it is 1" and/or threaded headset as it would be harder to find a suitable fork with disc tabs. Rear brake might be possible with a kit from braketherapy.com. In any case, it will get to be an expensive project fast with new wheels, fork, adapter, brake calipers and hardware, etc. And it could very well be cheaper to buy a new bike with disc brakes already on it.

The runny nose thing is hard to get around other than frequent blowing and wiping. As noted above, gloves with the terry cloth backs and frequent cleaning is one way to deal. A face mask or balaclava can also help.

BikeToWork
01-02-07, 04:50 PM
Thanx for the advice.

hmm...I ride at least 100 miles per week, including rainy days. I think what happens is the road grit acts like sandpaper on the pads and eats away at the rims. I go through drivetrains at about the same rate also. I actually get something like 3500 miles out of each rim. Are Koolstops a softer compound than the Ritchey cartridge pads I've been using?

I'll let you know how that vaseline works.

BikeToWork
01-02-07, 04:54 PM
btw: Old Fart, I already have Avid mechanical front disk brake and it works great. I am a little paranoid about grabbing too much front brake since I've washed out a couple of times going around turns. At least I can control a rear brake induced fishtail...

Steev
01-02-07, 04:54 PM
Let me guess, you live in the Pacific North-west. Pad type may help, but if your wear is due to the grit and muck that gets everywhere in the wet, disks are about the only answer. I don't know why the rear seems to wear worse than the front in wet conditions, but I've found the same thing. I do use Koolstops, salmon if I can get them, and the front is my primary brake, and it only occurs in the wet season.
As for the dribbling nose, snot rockets. Takes some getting over the aversion to ejecting bodily fluids in public, but keeps the nose clear.

HillRider
01-02-07, 04:56 PM
Thanx for the advice.

hmm...I ride at least 100 miles per week, including rainy days. I think what happens is the road grit acts like sandpaper on the pads and eats away at the rims.

That's exactly what happens and, oddly, rear rims are more vulnerable than front even though the front brakes do most of the work (if you are using your brakes correctly). Apparently, the front wheel throws up a lot of wet grit that gets sprayed onto the rear rim and brake pads and they abrade each other away.

One suggestion is to fit fenders if the bike doesn't already have them. They will help keep the rear rim cleaner.

matthew_deaner
01-02-07, 05:07 PM
Thanx for the advice.

hmm...I ride at least 100 miles per week, including rainy days. I think what happens is the road grit acts like sandpaper on the pads and eats away at the rims.

Do you clean your brake pads? This is a must to keep the grit and shards of aluminum off of them.

I slide my pads out of their holders every month or so or whenever I hear brake noise, and then I rub off the grimy, aluminum-laden layer with sandpaper and slide the pads back into the brake holders. It only takes about 5-minutes for both wheels.

Rowan
01-02-07, 05:07 PM
Thanx for the advice.

hmm...I ride at least 100 miles per week, including rainy days. I think what happens is the road grit acts like sandpaper on the pads and eats away at the rims. I go through drivetrains at about the same rate also. I actually get something like 3500 miles out of each rim. Are Koolstops a softer compound than the Ritchey cartridge pads I've been using?

I'll let you know how that vaseline works. The other thing is a little more messy, but... a frequent wash down of the pads with a water bottle squirt after a ride, and inspection of the pads and removal of scintered alumunium from the rim and road grit might help, along with a quick wash around the rims with a wet soft-top dishmop.

Also, don't be afraid to "refinish" the surface of the pads with a bastard flat file... it doesn't need much, but can get rid of ridges easily and efficiently to spread the braking area further over the rim. Sandpaper is not the thing to do it with -- it leaves grit in the pad compound.

oldokie
01-02-07, 07:23 PM
Runny nose...try the terry cloth wrist sweat bands. Typically found in tennis supplies. Buy a bunch and put on a clean one on each wrist for each ride plus some extras in your pocket if necessary. Throw then in the wash when you get home.
Another option is to take a pair of cheap cotton gloves and cut off fingers and any other excess material then put them on over your biking gloves.
Be the first in your neighborhood...set fashon trend!

Cannot help you on your brakes...unless you want to avoid brake wear and drag your feet.

BikeToWork
01-03-07, 02:03 PM
I tried the "snot rockets" on my ride last night. It snot the most socially acceptable method and I felt like a phlegmboyant phlegm fatale but it sure works. Just be careful where you launch. I looked both ways but ended up having a pedestrian walking by mid launch. The pedestrian wasn't hit but a little taken aback.

rmfnla
01-03-07, 02:17 PM
Thanx for the advice.

hmm...I ride at least 100 miles per week, including rainy days. I think what happens is the road grit acts like sandpaper on the pads and eats away at the rims. I go through drivetrains at about the same rate also. I actually get something like 3500 miles out of each rim. Are Koolstops a softer compound than the Ritchey cartridge pads I've been using?

I'll let you know how that vaseline works.

Bingo.

One suggestion; Scott-Mathauser pads. They are a bit harder than most all-weather pads so they do not retain road grit as much but they still work well in the wet.

JoeT
01-03-07, 06:04 PM
My question is whether or not there is a way to retrofit a bike like my Trek 990 to take disk brakes.

A2Z makes a rear adapter to add disc brakes to a frame without the tabs. I see them on ebay occasionally. Not sure where else you can find them...

The front, of course, requires a fork swapout, but that's not too difficult.

snot rockets work for me :)

Rowan
01-03-07, 07:15 PM
Sorry to prolong this, BikeToWork, but I am fascinated at how you are actually going through these rims so rapidly. In past years I have done around 10,000km on a bike in all sorts of conditions and in hilly country and over wet gravel roads, and the least of my worries has been wearing through rims.

Just how much weight are you toting around regularly, and what sort of terrain are you in? It's obvious that the rear wheel might get a bit more wear if you haven't got a front mudguard and mudflap, but it sure indicates to me very fast riding up to stops, huge speed downhills, or not enough use of the front brake.

The reason why I ask is that ... do you expect the wear on disc brake pads to be any less? As it is, the use of disc brakes on the rear has merit because it does remove the braking surface out of a messy area, but after retrofitting (as well as the hassle of getting them to work) and regular replacement of disc pads, are you going to be any further in front financially?

edp773
01-03-07, 08:01 PM
For a rear disc brake, Boyet from BoyetWorks may have or can machine you a rear disc brake hanger. You can contact him at bytworks@yahoo.com.ph

He does really great work and is a pleasure to deal with.

Michel Gagnon
01-03-07, 08:20 PM
If you don't, do most of your braking with the front brake. Keep the rear brake (in tandem with the front) only for situations when there is ice or loose sand on the road.

And replace your pads with Kool Stop Salmon pads: much more effective in rain, and much more gentle on the rims.

Rowan
01-03-07, 09:35 PM
I've used 3 different models of Koolstops. And the bolts on all of them bent. Weak alloy. I switched to Odyssey pads and problem solved.
Huh? Where's the alloy? What alloy?

Ziemas
01-04-07, 01:01 AM
Sorry to prolong this, BikeToWork, but I am fascinated at how you are actually going through these rims so rapidly. In past years I have done around 10,000km on a bike in all sorts of conditions and in hilly country and over wet gravel roads, and the least of my worries has been wearing through rims.

Just how much weight are you toting around regularly, and what sort of terrain are you in? It's obvious that the rear wheel might get a bit more wear if you haven't got a front mudguard and mudflap, but it sure indicates to me very fast riding up to stops, huge speed downhills, or not enough use of the front brake.

The reason why I ask is that ... do you expect the wear on disc brake pads to be any less? As it is, the use of disc brakes on the rear has merit because it does remove the braking surface out of a messy area, but after retrofitting (as well as the hassle of getting them to work) and regular replacement of disc pads, are you going to be any further in front financially?
I had the same problem as the OP. I now use disc brakes on my winter bike. It's do to the sand that is put on the road during the winter, it just grinds down the rims. For my summer bike I have V brakes (as does my wife) and we have no problems with rim wear.

Sholto
01-04-07, 02:00 AM
Snot problem: Try a scarf around the neck.
I had the same runny nose problem even in a sub-tropical Brisbane winter. Anything less than 18C and the tap was on. I think that my body was detecting a chill in the thoat and then generating the snot as a barrier to bugs, but if you keep it warm no problem. I tried a cotton bandana at first, but now use a Buff.

I replaced my rear rim at 12,000 km due to the wear from the pads, was a bit surprised as if I'd thought about it I think I would have ecxpected more than two years.
I'm a bit of a woos on descents and don't have great brakes so they both get a work out. (Front wasn't an issue as I've had a couple of different wheels sharing the load.)

Jim-in-Kirkland
01-04-07, 08:36 AM
+1 for Salmon Koolstops brake pads (good prices at http://www.biketiresdirect.com)

+1 for using front brake more than back brake (takes some practice but makes a big difference with stopping power and wear on dirty back wheel)

Clean rims after a crimy ride - fast wash down of rims with bucket of water & sponge (paper towel & water from water bottle etc...) - just spash it on

In bad winter weather - weekly remove wheels & wash/check brake pads for metal chards etc....

Watch ebay (or favorite shop) for 32 or 36 hole replacement wheel with similiar hub/rim at a good price... Learn how to swap out cassette from old wheel to new to keep running...

Replace rear wheel after it will not stay true & prior to rim cracking - for your safety....

Good luck.

BikeToWork
01-04-07, 09:35 AM
Thanx for all the great advice! I am kind of a front brake whimp since I have a disk in front and I've washboarded out a couple of times from applying it too aggresively on turns on slippery surfaces so maybe I should use it more. The bike itself weighs 40 lbs with nothing on it and I'm 187 lbs myself. I routinely load it up with 50 lbs of gear for touring although 95% of my riding is commuting with about 15 lbs on the front. I never clean the bike and that is probably a big contributing factor in rim wear along with riding a lot in wet and gritty conditions.

Does anyone have advice for a really strong 26" wheel? I've bought machine built wheels and laced my own, all with the same eventual results. The last two rims I've had were Sun Rhino Light XL and Sun Mammoth, all with 32 spoke XT hub. The mammoth seems like the strongest and lasted the longest, but it is super heavy.

blamp28
01-04-07, 09:40 AM
Regular cleaning will save you the cost of wheels. Why look for a rim that will stand up to that kind of abuse? There are few if any that will do it if you insist on riding with dirty brakes and rims. A simple wipe down of the braking surface on the rim and brakes will save you hundreds per year. That would be my approach unless you like buying parts for the sake of buying them. I would prefer to get more life out of the parts and use the money for other bike type purchases. Just my .02

rbrsddn
01-04-07, 10:40 AM
I might have missed it, but I don't think anyone mentioned Ceramic rims. I have a set of Mavic 217 Ceramics, and they last a long time. I use Kool Stop pads for Ceramics.