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Celticgirl 08-13-19 02:34 PM

Rim Brakes Wearing Out Rims
 
I read somewhere that rims do in fact wear out. Is there a way to slow down this wear? I have aluminum rims on my MTB If and when this happens are new rims expensive and how hard is it to rebuild them.

Thanks

gregf83 08-13-19 02:43 PM

Depends when you ride. I used to go through a rim in 2yrs commuting in the winter. The rain and muck formed a grinding paste that would wear the rims down.

I haven’t worn out a rim on a summer bike so if you don't spend much time in the wet I wouldn't worry about it.

Cost to replace the rim is roughly 50 to 150 plus labor.

HTupolev 08-13-19 02:47 PM

It does happen. How fast it happens depends on how clean the rims and pads are, the particular rim and pad materials, the conditions you're riding in, and how much you're braking.

Drizzly weather in the PNW covers the world in an abrasive grime that eats rims. Just a few thousand miles of wet hilly road riding can sometimes destroy a rim.
On the other hand, clean dry riding can easily take tens of thousands of miles to eat through a brake track.

Cost to replace a rim depends entirely on the particular components.
Basic reasonable rims can be had in the ~$30 range. Fancy aluminum rims can get into the ~$200 range. Decent round spokes and nipples tend to run a little over $1/spoke, although nice bladed spokes can be over $3/spoke.
Alternately, it's frequently cheaper to just buy a new wheel... You'll want to check hub adjustment and spoke tension on any wheel that's not made carefully by a good wheelbuilder, though.

ksryder 08-13-19 02:52 PM

One winter of lots of miles on gravel in the midwest was enough to trash a nice set of H + Son rims in less than a year.

On the other hand, I have road bikes with 30-year-old rims that are still good.

So if you want to avoid undue wear, then avoid water + dirt.

CliffordK 08-13-19 02:55 PM

If the spokes and nipples are good, and it is just rim wear, one may be able to simply swap rims, assuming one finds one with the same dimensions.

Of course, building a wheel is a fiddly job that takes some work.

I wore out a rim years ago commuting in the winter in Portland, but I think the rim had already been partly worn when I bought it used.

I've wondered if the newer aluminum alloys wear slower than the old ones.

kingston 08-13-19 02:59 PM


Originally Posted by HTupolev (Post 21073908)
...Basic reasonable rims can be had in the ~$30 range. Fancy aluminum rims can get into the ~$200 range. Decent round spokes and nipples tend to run a little over $1/spoke, although nice bladed spokes can be over $3/spoke.
Alternately, it's frequently cheaper to just buy a new wheel... You'll want to check hub adjustment and spoke tension on any wheel that's not made carefully by a good wheelbuilder, though.

You usually don't need new spokes and nipples to replace a worn out rim. It's pretty easy to just swap out the rim. If you do need new spokes, they are available for a lot less than a buck a spoke.

ThermionicScott 08-13-19 03:01 PM


Originally Posted by Celticgirl (Post 21073884)
I read somewhere that rims do in fact wear out. Is there a way to slow down this wear? I have aluminum rims on my MTB If and when this happens are new rims expensive and how hard is it to rebuild them.

Thanks

I've read that, too, and it undoubtedly happens to some people. It concerned me enough at the time that I invested in replacement rims for a few of my wheels. Thousands of miles later, I still haven't worn out a rim, and the replacements collect dust in my basement.

So I would worry about it if and when it happens. In the meantime, you can feel your brake tracks to check if they are becoming concave. And if you really need to know, you could take off your tires and measure your rim thickness with an inexpensive "Iwanson gauge." :thumb:

Unca_Sam 08-13-19 03:10 PM


Originally Posted by ThermionicScott (Post 21073931)
I've read that, too, and it undoubtedly happens to some people. It concerned me enough at the time that I invested in replacement rims for a few of my wheels. Thousands of miles later, I still haven't worn out a rim, and the replacements collect dust in my basement.

So I would worry about it if and when it happens. In the meantime, you can feel your brake tracks to check if they are becoming concave. If you're curious, you could take off your tires and measure your rim thickness with an inexpensive "Iwanson gauge." :thumb:

Good advice.
Unless you'll battle the elements regularly, it's not something that happens overnight. Depending on your wheels, a replacement wheelset could be more efficient.

freeranger 08-13-19 04:28 PM

You could use softer brake pads, something like Kool-Stop Salmon pads. The pads will wear quicker, your rims will wear slower. If you're picking up lots of dust and grit, well, there's no way to change that.

Bandera 08-13-19 04:46 PM

In decades of cycling on the road, 'cross and trails the # of rims replaced due to brake pad wear: 0.

-Bandera

rydabent 08-13-19 05:18 PM

Hmmmmmm the anti disc brake types says this dont happen.

BTW they are losing the argument to all the new road bikes coming with disc brakes.

Bandera 08-13-19 05:27 PM


Originally Posted by rydabent (Post 21074154)
Hmmmmmm the anti disc brake types says this dont happen.

Who mentioned disc brakes?
Is this the same old tired dead horse you're beating once more yet again?
Did "going fast is stupid", "you are wasting $ on cycling kit" and "only recumbents are comfortable" fall out of your re-re-re-post rotation for "disc brakes" once more?
Snipe away, the negativity seems to be what you thrive on.

I'll still just stick with:
In decades of cycling on the road, 'cross and trails the # of rims replaced due to brake pad wear: 0.


-Bandera

Gresp15C 08-13-19 06:24 PM

My family fleet includes bikes that are used during the winter on salted / sanded roads. Over the space of a decade, we've worn out exactly one rim, on a bike whose brakes were neglected and loaded up with grit by going through a construction zone every day. We were lucky to find a rim with the same ERD, just swapped it in. Building a wheel does take some practice and patience, but is not too difficult if you start with a new rim that's not already warped, and follow decent instructions or a friend who has done it.

I don't sweat it. With that said, my dedicated winter bike now has a coaster brake.

Gresp15C 08-13-19 06:29 PM


Originally Posted by rydabent (Post 21074154)
Hmmmmmm the anti disc brake types says this dont happen.

BTW they are losing the argument to all the new road bikes coming with disc brakes.

In the same way, road bikes with disc brakes are losing the argument to hybrids, cruisers, and WalMart BSO's, which dominate the market, all of which are going to be surpassed by e-bikes.

A market trend is not the same as an argument.

trailflow1 08-13-19 07:18 PM


Originally Posted by Celticgirl (Post 21073884)
Is there a way to slow down this wear?

Yes. Clean the rims thoroughly on a regular basis. Scrub the brake surface and pads with a scourer pad + warm water and dish soap.

terrymorse 08-13-19 07:33 PM


Originally Posted by freeranger (Post 21074079)
You could use softer brake pads, something like Kool-Stop Salmon pads.

Kool-Stop salmon pads aren't softer. They are less prone to having abrasive junk embedded in their surface, which turns a brake pad into a rim sander.

JohnDThompson 08-13-19 08:26 PM


Originally Posted by rydabent (Post 21074154)
Hmmmmmm the anti disc brake types says this dont happen.

BTW they are losing the argument to all the new road bikes coming with disc brakes.

Sure, but if your frame isn't designed for disc brakes, this is irrelevant.

Brocephus 08-13-19 08:35 PM


Originally Posted by Celticgirl (Post 21073884)
I read somewhere that rims do in fact wear out. Is there a way to slow down this wear? I have aluminum rims on my MTB If and when this happens are new rims expensive and how hard is it to rebuild them.

Thanks

What bike do you have ? How much wear has the bike seen, so far (in other words, how old is it, and how's it been used?)
What brand/model wheels do you have on it now ? Are they expensive/high end ?
You can find very solid, brand new whole wheelsets, for under $200, much less than buying new rims and having the wheels rebuilt.
All this may be a concern that is many years down the road, and your cycling interests could change significantly by the time this becomes an issue (if it ever does).

79pmooney 08-13-19 09:42 PM

Celticgirl, rims wear out from caliper brakes over time. Fact of life. It's part of the stopping process. (Discs do too.) How fast depends on a lot of factors mentioned above. Riding in the wet speeds up the wear a lot. Likewise riding in abrasive dust, sand and gravel. (Now, not all dust, sands and gravels are alike. There are places famous for really abrasive rock, sand and dust. Where I live and ride, the Pacific northwest, is one. All of us here know we go through rims at a rate we are frequently told is impossible by those in other areas. I kill rims in less than two winters commuting 60 miles/week.

Also as said above, with a well built wheel and an identical (at least for ERD, effective spoke diameter) replacement rim, swapping the rim over and reusing the spokes is very do-able. I go 3 rims per set of spokes. I don't know what you are riding now and if they qualify as a "good build". A good wheelbuilder could assess that. But if rim wear is real for you and your riding, have your first re-rim done right, by someone good who knows you are going to use his spokes on the next rim.

The simple test for rim wear - place a straight edge across the rim. (A credit card will work as well as anything.) Look at the hollow. I can't give you hard numbers to go by, but if small bugs can get through, replace it. (Rim walls vary in thickness and I don't have easy access to those numbers. I have seen rims that have been ridden too long. Don't! It isn't pretty. Both you and your bike could see significant damage if the sidewall blows off. If you see lengthwise crack or even the merest start of a hole along the middle of the rim wall, don't ride another inch and let the air out of the tire.)

Many rims have a groove along the sidewall. Look now for that groove. It is a a wear indicator. When you now longer see it, you've arrived at replacement time. (No, it won't blow up tomorrow, but that is your service reminder.) If you go the wheelbuilder route, seriously consider buying replacement rims at the same time. Then, 4 years from now, you go back to him (or someone else) with your dusty brand-new rims in hand and pay him for just labor. No risk that rim is now unavailable and new, different length spokes must be used.

Ben

Jeff Wills 08-13-19 10:40 PM


Originally Posted by 79pmooney (Post 21074544)
Celticgirl, rims wear out from caliper brakes over time. Fact of life. It's part of the stopping process. (Discs do too.) How fast depends on a lot of factors mentioned above. Riding in the wet speeds up the wear a lot. Likewise riding in abrasive dust, sand and gravel. (Now, not all dust, sands and gravels are alike. There are places famous for really abrasive rock, sand and dust. Where I live and ride, the Pacific northwest, is one. All of us here know we go through rims at a rate we are frequently told is impossible by those in other areas. I kill rims in less than two winters commuting 60 miles/week.

Here's what happens when you let a rim go too long. I barely felt a bump when I started the ride- 15 miles later... KABOOM. The rim let go with a louder bang than I'd ever heard. Fortunately I wasn't going fast and I was able to walk to a nice bagel shop to await rescue.

https://cimg4.ibsrv.net/gimg/bikefor...fa64e1a57b.jpg
https://cimg7.ibsrv.net/gimg/bikefor...27eebd1ea1.jpg

Unca_Sam 08-14-19 03:01 AM

Missing context
 

Originally Posted by Jeff Wills (Post 21074617)
Here's what happens when you let a rim go too long. I barely felt a bump when I started the ride- 15 miles later... KABOOM. The rim let go with a louder bang than I'd ever heard. Fortunately I wasn't going fast and I was able to walk to a nice bagel shop to await rescue.

https://cimg4.ibsrv.net/gimg/bikefor...fa64e1a57b.jpg
https://cimg7.ibsrv.net/gimg/bikefor...27eebd1ea1.jpg

How many miles were on those rims? As is the case with jetliner crashes, a few spectacular failures will hog all of the attention when there are a million non-failures.

A wheel is more likely to require replacement for worn cups or impact damage to the rim than for a sidewall blowout.

freeranger 08-14-19 06:13 AM


Originally Posted by terrymorse (Post 21074373)
Kool-Stop salmon pads aren't softer. They are less prone to having abrasive junk embedded in their surface, which turns a brake pad into a rim sander.

Thought I had read it somewhere-and I had:
Kool Stop Salmon pads are softer and work better in the wet but, even being softer, their durability is very good so they last a long time in typical use. Kool Stop does offer pads that are half Black and half Salmon and are a compromise. Any Kool Stop pad is a good choice.

Best Brake pads - Adventure Cycling Association

forums.adventurecycling.org/index.php?topic=8762.15

Bandera 08-14-19 06:46 AM

Component wear is inevitable if a bicycle is in service for a long period of time, especially if ridden hard in all weathers on lousy road/trail surfaces.
Chains, cassettes, cables, brake pads, grips/tape, bearings, grease, tires, tubes, sealant, saddles, rims, batteries, fluids, rotors, spokes and much else all have reasonable but finite service lives.
Regular maintenance and component replacement are required for safe reliable operation. This is not news.

-Bandera

ksryder 08-14-19 08:20 AM


Originally Posted by Bandera (Post 21074809)
Component wear is inevitable if a bicycle is in service for a long period of time, especially if ridden hard in all weathers on lousy road/trail surfaces.
Chains, cassettes, cables, brake pads, grips/tape, bearings, grease, tires, tubes, sealant, saddles, rims, batteries, fluids, rotors, spokes and much else all have reasonable but finite service lives.
Regular maintenance and component replacement are required for safe reliable operation. This is not news.

-Bandera

OP asked a reasonable beginner question. No need to be snotty.

terrymorse 08-14-19 08:25 AM


Originally Posted by freeranger (Post 21074777)
Thought I had read it somewhere-and I had:
Kool Stop Salmon pads are softer and work better in the wet but, even being softer, their durability is very good so they last a long time in typical use.

That article is mistaken. Kool Stop Salmon pads are made with the Scott Mathauser compound, which has a hardness of A/91.

Compare that to pads from Shimano, which range from A/89 to A/92. Or the Kool Stop Eagle Claw pads at A/89.


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