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Old 09-13-10, 07:01 AM   #1
SUX Vision R40
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Split Rim

My front rim has a crack or split along the surface where the brake makes contact. I know it cannot be repaired, that is not the reason for this post.

The rim is an aluminum alloy "V" rim, the brakes are "V" style. A while back I was discussing with my LBS owner about changing to a steel rim. We were just spit balling and talking about differant materials, there were no problem with my rims at the time. He advised if I do that I would have to change to differant brakes. I did not ask and do not know what he meant by that.

My questions here, before I call the bike shop today are: Did he mean I would have to change the type of brake pad material? Or would I have to change to side pull vs the "V" brakes? Any advise would be helpful before I call.

Thanks.

Last edited by SUX Vision R40; 09-13-10 at 07:06 AM.
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Old 09-13-10, 07:38 AM   #2
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We can't know what he had in mind - just ask him! Keep in mind that no matter what the brake (as far as I know) steel brakes pretty lousy in wet conditions. If you care it will also look a bit odd paired with an alloy (aluminum) rear wheel.
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Old 09-13-10, 07:51 AM   #3
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.. Keep in mind that no matter what the brake .. steel brakes pretty lousy in wet conditions.
+1

Going from aluminum to steel is just about NEVER done, because of this. There are cases when a change of brake pads is recommended to go with a certain type of rim (carbon, ceramic...), but switching from one type of rim brake to another due to rim material is another first.
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Old 09-13-10, 08:00 AM   #4
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Steel rims are the absolute biggest pieces of crap in the world. I always just CRINGE when somebody can't afford even the cheapest aluminum rim because it means I have to sell them a steel rim, which sucks, because I hate selling crap that is no good. Aluminum rims are: Stronger, Rust-free, more true, lighter weight, brake better, etc.
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Old 09-13-10, 08:19 AM   #5
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Steel rims are the absolute biggest pieces of crap in the world. I always just CRINGE when somebody can't afford even the cheapest aluminum rim because it means I have to sell them a steel rim, which sucks, because I hate selling crap that is no good. Aluminum rims are: Stronger, Rust-free, more true, lighter weight, brake better, etc.
Aluminum is stronger than steel? Since when? I was always under the impresison that steel is atronger than aluminum.

Not trying to cause an argument, but if you take a steel support beam for a building and an aluminum one of the exact same dimensions and put them both under the load limit meant for the steel beam, which is a higher limit than the aluminum one can handle, wouldn't the aluminum one fail? If it does doesn't that make steel stronger than aluminum? Doesn't this mean in order for the aluminum beam to handle the same load limit the steel one can, the dimensions have to be increased to match the load bearing limit of steel? If I am wrong, correct me.
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Old 09-13-10, 08:29 AM   #6
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In some regards steel may be a stronger material but in bicycle wheels aluminum tends to be stiffer and less prone to taco. As mentioned, it is also lighter and provides a far better breaking surface due to better friction, which is hugely better when wet, and better heat transfer.
Steel rims are generally pure crap and the first clue the bike they are on is a dept. store junker. In fact even many junkers are sold with aluminum rims nowadays. I suspect due to liability issues related to wet weather braking.
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Old 09-13-10, 08:55 AM   #7
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Aluminum is stronger than steel?
For the application, a bicycle wheel rim (apart from the friction issues), you can't really use steel in a way that'd put the higher strength to good use. Aluminium extrusions, as most rims are, simply fit the bill better WRT stiffness, thickness ASO.
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Old 09-13-10, 09:08 AM   #8
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The rim is an aluminum alloy "V" rim, the brakes are "V" style.
I get "v" brakes but what is a "v" rim?

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Originally Posted by SUX Vision R40 View Post
A while back I was discussing with my LBS owner about changing to a steel rim.
why? People don't usually have problems with aluminum rims, even with all sorts of heavy use.

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We were just spit balling and talking about differant materials, there were no problem with my rims at the time. He advised if I do that I would have to change to differant brakes. I did not ask and do not know what he meant by that.
I suspect he mean different brake pads. Steel rims suck for braking when wet.
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Old 09-13-10, 09:13 AM   #9
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Doesn't stiffer also mean less able to give and flex? Doesn't this translate into less giving and bending and in some cases goes right to breaking or cracking? Steel gives an awful lot compared to aluminum and has a lot higher stress point before it cracks or breaks.

I am well aware of the issues with braking in wet conditions with steel and the heat transfer compared to aluminum. But that may be an acceptable switch if the rim is stronger than aluminum one, meaning it will last longer.

One thing I have not disclosed is the rim is 9 years old and is a 20" wheel. Maybe that is the life expectancy of a 20" aluminum alloy rim. Would anyone here say I have gotten a good amount of life and time out of the rim?
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Old 09-13-10, 09:20 AM   #10
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A pinned rim will have a butt seam , the compression of the rolling method , + spoke tension, holds it together .
the extrusion has a place for a pin to keep the ends aligned, and a little hand labor will smooth the seam.

additional cost gets you a welded aluminum rim, which is further machined to make the welded joint
uniform with the rest of the rim, In Both Cases, the material is Aluminum.
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Old 09-13-10, 09:31 AM   #11
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Aluminum is stronger than steel? Since when? I was always under the impresison that steel is atronger than aluminum.
You're right, steel is stronger than aluminum. But I did not compare the strength properties of the metals specifically. I referred to their respective applications in bicycle rims. Ever seen an extruded/box-section/double-wall steel rim? Me either. Aluminum rims are stronger.
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Old 09-13-10, 09:38 AM   #12
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I just called the bike shop and am going with the same make, model and style of rim I used for the last 9 years. I could have gone with a high quality BMX steel rim. The reason I am going with the same type of rim I have been using is a BMX rim not a quick release.
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Old 09-13-10, 09:55 AM   #13
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One thing I should also mention is the rim has over 10,000 miles on it.

Also a few years ago the brake were so worn the metal that holds the rubber pad on ground or cut into the rim. When this started I stopped riding for that day and had the pads replaced, but the damage had already been done, grooves had been "cut" into the rim. It occured when I was applying the brakes to slow/stop on a steep downhill. Over the years the groves had been pretty much smoothed down from normal use.
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Old 09-13-10, 10:02 AM   #14
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If the crack is a ring around the rim where the brake pads grip, You have thinned the sidewall of the rim down..
your miles of stopping have added up.
buy another rim and have the wheel rebuilt.. get a welded seam machined rim this time.
A BMX Aluminum rim .. if the new rim needs a different spoke length, so Be It.

In the future Remove any grit embedded in the brake pads..

No, You should not look for a " high quality BMX steel rim" that is an oxymoron,
as the steel stuff is relegated to the cheapest end of the coaster brake kid's bike market.

If you have the front wheel rebuilt around a Drum Brake Hub, then there will no longer be a friction between brake shoe and pad stopping the bike,
and wearing down the rim sidewall..

Last edited by fietsbob; 09-13-10 at 10:10 AM.
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Old 09-13-10, 01:06 PM   #15
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The rim is an ALEX DA16. As I said I am going with the same type, an ALEX DA16. the only differance is the original rim is silver, the new one will be black. I decided to change it up a little and make my bike more unique. the rear ALEX rim is still sliver. The bike is red with a primer gray seat frame and a black seat cover.
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Old 09-13-10, 01:10 PM   #16
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Alex is a pretty cheap rim, that's why OEM often use them , good enough without pushing the price point up .

may be able to re-lace with the same spokes .. a + ..
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Old 09-13-10, 02:44 PM   #17
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Alex is a pretty cheap rim, that's why OEM often use them , good enough without pushing the price point up .

may be able to re-lace with the same spokes .. a + ..
When you say cheap, do you mean cheaply made, or inexpensive in cost, but still a good quality rim? If you mean cheaply made what are you comparing it to?

A new rim, with parts and labor is going to cost $100. The hoop is about $32, spokes are $1.00 each with 36 of them and there is the labor. My original hub is going to be used. I can probably save a little on the labor by taking the hub out of the original wheel myself. I have a spoke wrench and it is not that difficult to take a wheel apart.
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Old 09-13-10, 03:02 PM   #18
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One thing I should also mention is the rim has over 10,000 miles on it.

Also a few years ago the brake were so worn the metal that holds the rubber pad on ground or cut into the rim. When this started I stopped riding for that day and had the pads replaced, but the damage had already been done, grooves had been "cut" into the rim. It occured when I was applying the brakes to slow/stop on a steep downhill. Over the years the groves had been pretty much smoothed down from normal use.
So between the metal brake shoe cutting the rim and normal wear you have a crack. Sounds reasonable. The big advantage with aluminum rims is in the braking, either wet or dry.
I have wheels with over 40,000 miles on them, but I am rarely in the hills to wear them out.
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Old 09-13-10, 03:20 PM   #19
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Things cost less when you order a thousand.. OEM get a lower prices even than wholesale to retail stores.
feature brands like Mavic cost more , Welded and machined, and have different alloys and feruled holes
and some of those added features ..

shop would get out the bolt cutters and cut the spokes so no real labor charge on a moment long job.

so you are able to save the spokes if you unscrew the nipples ..

If the hub is not prestige level,

You might find a replacement machine made wheel,406- 20" is pretty common
and have the shop do a trifle of touch up truing, before handing it to you..

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Old 09-13-10, 03:39 PM   #20
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Steel rims pretty much went away in the early 80's far many good reasons, most of which were mentioned already. The only reason I can see for going to steel rims if you might be restoring a 70's and earlier bicycle.....for dislay only(?), because the biggest reason not to use steel is their poor braking performance in the wet which despite of many efforts to improve with patterning or dimpling of the rim braking surface only made for very slight improvements (if any) in some cases.

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Old 09-20-10, 10:07 AM   #21
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I did some wet braking tests with a friend in the early 80's and found the dimpled steel rims were actually worse when very wet. Seems the dimples held water and fed it under the pads.
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