Alex DA22 rims for offroad touring?

[stevage]

The stock rim (Alex ACE-19) on my Spec. Tricross Sport rear wheel finally wore out, so I went to an LBS with a good reputation, and walked out with a new wheel: Alex DA22 with a Novatec hub. I explained my requirements pretty clearly: tough enough to survive lots of fully loaded touring on dirt roads, plus mountain biking, and general abuse (I commute around 70km/week).

In fact, one reason I bought it in such a hurry was I just broke a couple of spokes on that kind of 5 day tour last week (caused by rim wearing out, I think), and am doing a 100km mountain bike race next weekend (in the cyclocross category).

Looking up the rim (http://alexrims.com/product_detail.a...=1&cat=1&id=48), it looks like it's basically a road bike rim - not intended to go near dirt, nor to carry any significant load. It's also perhaps too narrow: just 14mm internal width, whereas I normally run 35mm rear tyre.

So, would appreciate advice: should I take it back? Is it of any use to me?

[10 Wheels]

What is the spoke count?

[stevage]

What is the spoke count?

32.

[10 Wheels]

I would take it back for a 36 spoke count wheel.

[Chris Pringle]

Sun CR18 with 36h, for the price, are hard to beat. Get Mavic or Velocity if money is not an issue. Whatever you get, make sure it comes built with double-butted spokes and brass nipples. If the wheelset is factory built, have an experienced whelbuilder go over the tension.

[MassiveD]

Wouldn't be my choice. I like the Dh22 from Alex, with 36 spokes. Not overweight but a very tough rim.

[stevage]

>Get Mavic or Velocity if money is not an issue.

Well, money is an issue in the sense that rims wear out, and I don't want to spend too much on replaceable components. The LBS had some Mavic rims but they were going to cost 50% more, and not last any longer.

[cyccommute]

I'll create a firestorm but here goes:

Spoke count and the spokes are far more important to the wheel's strength than the rim. The spokes do all of the heavy lifting while the rim is just along for the ride. If you build the wheel with 36 (or more) spokes like the DT Alpine III, Wheelsmith DH13 or Sapim Strong combined with just about any rim, you'll have a strong wheel. If you build a wheel with a heavy rim and weak spokes, you'll just have a heavy wheel. The broken spokes on your current wheel are a prime example of this.

Rim width isn't all that critical either. I run 17mm rims on my mountain bikes with 2.2" (54mm) without problems. A 35mm tire can easily be run on a 14mm rim. You might not be able to pump it up to 120 psi but you probably don't want that kind of pressure for off-road riding anyway.

[LeeG]

my requirements pretty clearly: tough enough to survive lots of fully loaded touring on dirt roads, plus mountain biking, and general abuse (I commute around 70km/week).

In fact, one reason I bought it in such a hurry was I just broke a couple of spokes on that kind of 5 day tour last week (caused by rim wearing out, I think), and am doing a 100km mountain bike race next weekend (in the cyclocross category).

I wonder if the shop heard you say "cyclocross race wheel" and "not expensive" as anything more durable would have been a custom build.

I'd go with SunCR18, Mavic 319 or Alex Adventurer in 36spokes. Doesn't have to be butted as rough use will eventually ding the rim flange or bend the wheel long before the spokes fail due to fatigue.

just checked Alex website, yep that's weird, they replaced a 510gram 22.6 wide rim with a 435gram 19.6 wide rim. btw your link is to a DA-16 not a DA-22(er, or it's Alex showing the wrong rim) It looks like a fine road rim but I don't see it as a heavy duty touring wheel where you're going to be running 35mm tires, definitely not a rear wheel. Seriously you aren't going to notice riding on a heavy rear wheel touring and if you are planning on racing you should have a separate set of wheels. Now is a good time to learn to build a wheel using your old hub. I'd use this wheel for racing then order up an Alex Adventurer and build a new touring wheel. Once you ride on that new wheel it's yours.

[LeeG]

I'll create a firestorm but here goes:

Spoke count and the spokes are far more important to the wheel's strength than the rim. The spokes do all of the heavy lifting while the rim is just along for the ride. If you build the wheel with 36 (or more) spokes like the DT Alpine III, Wheelsmith DH13 or Sapim Strong combined with just about any rim, you'll have a strong wheel. If you build a wheel with a heavy rim and weak spokes, you'll just have a heavy wheel. The broken spokes on your current wheel are a prime example of this.

Rim width isn't all that critical either. I run 17mm rims on my mountain bikes with 2.2" (54mm) without problems. A 35mm tire can easily be run on a 14mm rim. You might not be able to pump it up to 120 psi but you probably don't want that kind of pressure for off-road riding anyway.

given that wheel longevity is also a function of how much rim can be abraded away from braking before it's strength is compromised a thicker sidewall will make for a longer life wheel. Lighter rims will also have lighter flange holding the bead which will be more susceptible to being bent when bottoming out on sharp edges. Building with 15/17 butted spokes and low spoke count on a heavy rim wouldn't make sense for a heavily loaded wheel and neither would a light rim with heavy spokes.

There's more reasons than marketing that different weight/dimension rims are used for different applications.

[cyccommute]

given that wheel longevity is also a function of how much rim can be abraded away from braking before it's strength is compromised a thicker sidewall will make for a longer life wheel. Lighter rims will also have lighter flange holding the bead which will be more susceptible to being bent when bottoming out on sharp edges. Building with 15/17 butted spokes and low spoke count on a heavy rim wouldn't make sense for a heavily loaded wheel and neither would a light rim with heavy spokes.

There's more reasons than marketing that different weight/dimension rims are used for different applications.

I don't measure wheel longevity as a function of how fast the rim is consumed nor do most people. I measure wheel longevity by the spoke life. If you read what stevage wrote above he considered the wheel to be worn out because of the number of broken spokes rather than thinned and broken braking surface.

I look on a rim as a consumable that can be relatively easy to replace. Spokes, on the other hand, aren't impossible to replace but if you start popping more than a few (three or four seems to be the popular limit), it's time to rebuild the whole wheel.

Bottoming out any rim is a maintenance issue that is related to improperly inflated tires and not a rim strength issue. Even the heaviest rims can be very easily bent if you don't keep the tires inflated. I've seen far too many steel rims with giant blips on them lately to believe otherwise. A heavy aluminum rim isn't going to resist bending due to bottoming out the tire better than steel rims are.

As for building a wheel with a low count of lightweight spokes and a heavy rim, if the rim had much to do with the overall wheel strength building up such a wheel should be perfectly acceptable for touring. Why isn't' it? The reason it is due to the number and strength of the spokes not the over all strength of the rim...as it is for any wheel. If the rim strength was what mattered most for a strong wheel, you should be able to use a steel rim...arguably the strongest rim you can buy...and use very few spokes which should result in a wheel that is strong enough for any application. Obviously that is silly, as you've pointed out above.

On the other hand, if you used 40 strong...they are heavier but only marginally so...spokes and the lightest rim you could buy, the wheel would never be in danger of breaking a spoke. The rim might wear out a little faster but that's not the death knell for a wheel.

[LeeG]

I don't measure wheel longevity as a function of how fast the rim is consumed nor do most people. I measure wheel longevity by the spoke life. If you read what stevage wrote above he considered the wheel to be worn out because of the number of broken spokes rather than thinned and broken braking surface.

I look on a rim as a consumable that can be relatively easy to replace. Spokes, on the other hand, aren't impossible to replace but if you start popping more than a few (three or four seems to be the popular limit), it's time to rebuild the whole wheel.

On the other hand, if you used 40 strong...they are heavier but only marginally so...spokes and the lightest rim you could buy, the wheel would never be in danger of breaking a spoke. The rim might wear out a little faster but that's not the death knell for a wheel.

I said "is also a function of" not "defined by". Wheel longevity is how long the wheel functions "as a wheel". When spokes break, it's no longer functioning, when the rim wears down to compromise strength it's near failure, when multiple blips occur from bottomed tires (full inflation isn't always optimum and some impacts damage tire sidewalls and rim without taking entire wheel out of true) repairs don't always bring the braking surface back to 100%.

Sure you can consume rims, build up a light rim with plenty of spokes and you can have no spokes break but cracking can occur at nipples.

I wouldn't want to rebuild a wheel using spokes where adjacent spokes have broken.

I am guessing Steveage wheel had simply gone through enough damage where the rim is bent and spoke tension can't get it back to true so some spokes are simply cycling through too large of a range of tension. A heavier tougher rim will be less likely to get whacked out sideways and less likely to need uneven spoke tension to get it back to true.

If the rim "wears out faster" then what the op is concerned about , longevity and cost, it doesn't meet his goal by replacing his old wheel with one that will need more frequent replacement.

[billyymc]

Here's a stupid question - how do you check your rims for wear from the brakes?

[LeeG]

Here's a stupid question - how do you check your rims for wear from the brakes?

Some rims nowadays have wear indicators, either a scalloped section on the inside that will show up as a hole on the outside or a defined machined slot on the outside that will disappear as adjacent material is worn away. Then there's putting a straight edge across the braking surface and measuring how concave it is assuming it was flat to begin with.

[billyymc]

Thanks Lee. I'm sure the answer to my next question is "it depends" - but how many miles can one reasonably expect out of front rim? I've got 7k on mine (well, I will on my ride home tonight)....try to keep my rims and pads clean.

[LeeG]

Front wheels last a long time, yes, it depends.

[cyccommute]

I said "is also a function of" not "defined by". Wheel longevity is how long the wheel functions "as a wheel". When spokes break, it's no longer functioning, when the rim wears down to compromise strength it's near failure, when multiple blips occur from bottomed tires (full inflation isn't always optimum and some impacts damage tire sidewalls and rim without taking entire wheel out of true) repairs don't always bring the braking surface back to 100%.

A wheel can function "as a wheel" far longer than an aluminum rim can. The very nature of a rim brake equipped wheel is that some of the rim material gets removed each time you use the brakes. But once the rim sidewalls reach a point where they can be used for braking anymore, the rim can be replaced and the wheel, i.e. the important bits like the spoke and hub, can continue to function. You are correct that breaking too many spokes leads to wheel in which the systemic problem must be addressed which, usually, means that the wheel has reached its useful life. But having to replace the rim, doesn't mean that the wheel is done for.

As for blips, there is absolutely no reason to run a tire at such a low pressure that it can't provide impact resistance, especially when carrying a touring load. In fact, running it too low will lead to the more immediate problem of pinch flats. Even when running low pressure like in a mountain bike, the tire is meant to protect the rim by having a larger volume.

Sure you can consume rims, build up a light rim with plenty of spokes and you can have no spokes break but cracking can occur at nipples.

Again, not an issue where the wheel has failed but a replaceable part of the wheel has failed. And, if you build the wheel properly, cracking won't be an issue. Cracking isn't really caused by too much tension but by too little and the movement of the spokes in the hub...another problem that is fixed by the larger diameter head of the spokes I mentioned.

I wouldn't want to rebuild a wheel using spokes where adjacent spokes have broken.

And why not? Because the spokes do all the work and a dead wheel is defined by the number of spokes that have failed due to fatigue.

I am guessing Steveage wheel had simply gone through enough damage where the rim is bent and spoke tension can't get it back to true so some spokes are simply cycling through too large of a range of tension. A heavier tougher rim will be less likely to get whacked out sideways and less likely to need uneven spoke tension to get it back to true.

If the rim "wears out faster" then what the op is concerned about , longevity and cost, it doesn't meet his goal by replacing his old wheel with one that will need more frequent replacement.

I don't see anywhere that stevage says that the rim was bent. He said "I just broke a couple of spokes on that kind of 5 day tour last week (caused by rim wearing out, I think)" which says to me that he replaced the wheel because of broken spokes which he misdiagnosed as a worn out rim. I suspect that the braking track on the old wheel isn't actually worn out, however.

And a stronger spoke would resist damage that might make the wheel go out of true far better than a heavy rim would. The way you true wheels isn't by bending the rim into a straight shape but by adjusting the tension forces on the rim with the spokes to straighten the wheel. The actual rim is rather pliable and easily bent...even steel rims aren't that strong as just a rim.

[cyccommute]

Thanks Lee. I'm sure the answer to my next question is "it depends" - but how many miles can one reasonably expect out of front rim? I've got 7k on mine (well, I will on my ride home tonight)....try to keep my rims and pads clean.

The brake track on a wheel can last for 10s of thousands of miles or for only a few thousand. It's largely a function of the road conditions. The thickness of the brake track all that different from rim to rim. A 'lightweight" rim isn't really that much thinner in the brake track than a 'heavy' rim.

[alan s]

Think of a wheel as a chain. Eventually it will break at the weakest link. No sense in getting the best rim and skimping on spokes, for example. I've had rims crack, spokes break and hubs need replacement/rebuilding.

I just bought a set of handbuilt wheels with 32-hole Mavic XM 719 rims, Shimano XT hubs, DT double butted spokes and brass nipples. All components of these wheels are roughly comparable and fairly durable. These wheels are intended for loaded touring offroad (not singletrack) in the US, never too far away from repairs, if needed. If I was riding in the wilderness in South America, I'd get something much stronger and more expensive.

[Chris Pringle]

I just bought a set of handbuilt wheels with 32-hole Mavic XM 719 rims, Shimano XT hubs, DT double butted spokes and brass nipples. All components of these wheels are roughly comparable and fairly durable. These wheels are intended for loaded touring offroad (not singletrack) in the US, never too far away from repairs, if needed. If I was riding in the wilderness in South America, I'd get something much stronger and more expensive.

I understand the XM719 is a very strong and durable rim by Mavic. By the way you had 'em built, it sounds like you've got a bombproof wheelset. I happen to own the XM819 32h Disc (basically the same rim as the XM719) laced with double-butted spokes and Chris King hubs and have done pretty extreme singletrak MTB stuff over the years with no issues whatsoever. I am curious to know why you woudn't tour in South America with your XM719? What would you use if you wanted something even stronger for off-road touring? I guess you could go with some XM823, but they seem overkill for off-road touring. I might be mistaken though.

[MassiveD]

I agree with Cyco at least to the degree that rim weight is not important, the MA2 is a very strong rim, and weighs very little, these minimal rims are strong with enough spokes and correct tension, and some would argue with the right eyelets. I don't think spokes beyond being of generally good quality, and a good fit to the rim or hub are all that critical. Getting the right rim is critical though. There are several options that work fairly well, there have been experimental wheels built with deep rims, and low spoke count of 20 that have held up to touring though nobody is seriously suggesting them, and there are the light rim high spoke wheels. The rims like the DH20 are semi deep and should be built with 36 spokes for maximum strength.

[LeeG]

I am curious to know why you woudn't tour in South America with your XM719? What would you use if you wanted something even stronger for off-road touring? I guess you could go with some XM823, but they seem overkill for off-road touring. I might be mistaken though.

For the same reason tractors and trucks are built for heavy loads and racing cars are built for speed. When a lot of DEAD weight is put on a wheel the vertical and side forces are significant but more importantly a replacement wheel isn't available at the end of the ride as would occur for someone riding a racing mtn. bike then driving home.
Think of it this way, when a rider leaves a bike on a downhill crash most of the load on the wheels disappears, on a loaded touring bike it's always there. Sure a 719 is a strong rim for the forces experienced while RIDING, but if you have to toss the bike on a truck and someone walks across your wheels you might want something beefier. Durability isn't just what happens while riding, it's everything.

[LeeG]

As for blips, there is absolutely no reason to run a tire at such a low pressure that it can't provide impact resistance, especially when carrying a touring load. .

for the range of uses these wheels are being used for one might run low pressure for dirt/cx riding, riding around at max psi isn't always desirable. Sure for loaded touring one would want to keep the psi up but for unloaded dirt riding one might tune the psi for the conditions. He's looking for long term durability, not rebuilding wheels because the rim is a "consumable".

[cyccommute]

for the range of uses these wheels are being used for one might run low pressure for dirt/cx riding, riding around at max psi isn't always desirable. Sure for loaded touring one would want to keep the psi up but for unloaded dirt riding one might tune the psi for the conditions. He's looking for long term durability, not rebuilding wheels because the rim is a "consumable".

Racing or even riding off-road with a tire underinflated is almost the definition of making the rim a 'consumable'. You don't have to ride off-road with a tire inflated to the maximum pressure...never said you had to...but you should ride it with a high enough pressure to protect the rim. At least you should if you don't want to be constantly rebuilding the wheels.

And whether you like it or not, any rim - from the heaviest steel rim to the lightest carbon rim - that is used as part of the braking system of a bicycle is a consumable. It will eventually wear out and have to be replaced. The spokes aren't a consumable. You don't use them up, except when they have fatigued to the point where they fail. That point can be after you've consumed dozens of rims if you build them right.

[fietsbob]

Who is building the wheels ? and who is maintaining the tension
and truing during the trip?