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Discussion Starter · #1 ·
Can I use a carbon rim with an offset (2.6mm) on any rear hub (142x12)?
Or does a rear hub have to be compatible with offset rim? And does it matter if I choose J-bend spokes or straightpull spokes to use with an offset rim? which type of spoke is better in term of durability? planning to go with a hub with 28h.

Or should I not bother with asymmetric rim and just stick with traditional non-asymmetric rim?

This rear wheel will be for a hardtail mtb. My current wheel only has 24h and it keeps going out of true so I would like to build a new tougher wheel with 28h.
 

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...Or does a rear hub have to be compatible with offset rim?
Bill Mould built up my Ultegra rear hub on an offset Velocity A23 rim, so I would say the hub probably doesn't need to be offset specific.
 

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I believe the hub will dictate whether to use j-pull or straight pull spokes, nothing to do with the rim.
 

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Discussion Starter · #4 ·
Bill Mould built up my Ultegra rear hub on an offset Velocity A23 rim, so I would say the hub probably doesn't need to be offset specific.
Thanks. Interesting. I'm aware of the Vel A23 is alu, and I've heard one guy said that alu rims benefit more from offset than a carbon rim would. But that was just his words.
 

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Discussion Starter · #5 ·
I believe the hub will dictate whether to use j-pull or straight pull spokes, nothing to do with the rim.
yes. The hub I have in mind is DT 240, and this comes in both straightpull and j-bend types. So if I were to go with an offset rim, does it matter which type of DT 240 I choose?
 

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There's no requirement to "match" a hub to an asymmetric rear rim. As long as there's a cassette on the rear hub, the drive side flange will always be offset, and an asymmetric rim will have a positive effect on the resultant wheel build. Use any asymmetric rim you like.

I'd use J-bend spokes because it's easier to find replacements.
 

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Can I use a carbon rim with an offset (2.6mm) on any rear hub (142x12)?
Or does a rear hub have to be compatible with offset rim? And does it matter if I choose J-bend spokes or straightpull spokes to use with an offset rim? which type of spoke is better in term of durability? planning to go with a hub with 28h.

Or should I not bother with asymmetric rim and just stick with traditional non-asymmetric rim?

This rear wheel will be for a hardtail mtb. My current wheel only has 24h and it keeps going out of true so I would like to build a new tougher wheel with 28h.
Since this is a disc wheel, I wouldn't even bother with an asymmetric rim. There won't be that much tension disparity. I also would go with a 32H for a rear wheel - especially for a mountain bike. Believe me, you won't notice the difference in weight of 4 extra spokes.

I'd use J-bend spokes because it's easier to find replacements.


^^^This.^^^


 

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There's no requirement to "match" a hub to an asymmetric rear rim. As long as there's a cassette on the rear hub, the drive side flange will always be offset, and an asymmetric rim will have a positive effect on the resultant wheel build. Use any asymmetric rim you like.
^^^ This. The hub can't tell anything about the rim beyond spoke pattern (if it is one of those G3 or whatever). Using an asymmetric rim improves wheel durability and does indeed make for an easier time for the rim because there is less relative tension on the DS spokes, so the rim is less likely to be damaged by high spoke tension.
 

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^^^ This. The hub can't tell anything about the rim beyond spoke pattern (if it is one of those G3 or whatever). Using an asymmetric rim improves wheel durability and does indeed make for an easier time for the rim because there is less relative tension on the DS spokes, so the rim is less likely to be damaged by high spoke tension.
In theory, yes. But I have to respectfully disagree on the importance of this.

On an 11-speed rim brake build, a good quality rim can easily handle a 130kgF DS tension where the NDS tension will end up around 55kgF which is quite adequate. I have a build like this which I have almost 7000 miles on and have never had to re-true after the initial build.

A similar asymmetric build would up that NDS tension up to arpund 70kgF which is anout the same as a symmetric disc build.

In the wise words of DCGriz who no longer posts here - With bicycles in particular, it is important to separate between what is merely true and what is important.
 

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In theory, yes. But I have to respectfully disagree on the importance of this.

On an 11-speed rim brake build, a good quality rim can easily handle a 130kgF DS tension where the NDS tension will end up around 55kgF which is quite adequate. I have a build like this which I have almost 7000 miles on and have never had to re-true after the initial build.

A similar asymmetric build would up that NDS tension up to arpund 70kgF which is anout the same as a symmetric disc build.

In the wise words of DCGriz who no longer posts here - With bicycles in particular, it is important to separate between what is merely true and what is important.
Depends entirely on the rim. In comparing a given rim, one an OC design and one "normal" and two wheels built on those rims, the standard rim experienced cracking on the DS after about 15K miles while the OC rim didn't crack in over 50K miles. There could be other differences in the extrusion profile, but the OC rim didn't see the damage. And the OC wheel was more stable regarding needing occasional touch-ups (every 10K miles or so). YMMV

In my experience, this is both a distinction and a difference. Critical? No. But IMO every rear wheel should be built with an OC rim. The reason OC rims are not common is that it requires the entire distribution chain to have double inventory and most riders are no where near knowledgeable enough to demand it. It's fair to say that most riders don't even realize that OC rims exist, let alone what benefits they might offer.
 

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Depends entirely on the rim. In comparing a given rim, one an OC design and one "normal" and two wheels built on those rims, the standard rim experienced cracking on the DS after about 15K miles while the OC rim didn't crack in over 50K miles. There could be other differences in the extrusion profile, but the OC rim didn't see the damage. And the OC wheel was more stable regarding needing occasional touch-ups (every 10K miles or so). YMMV

In my experience, this is both a distinction and a difference. Critical? No. But IMO every rear wheel should be built with an OC rim. The reason OC rims are not common is that it requires the entire distribution chain to have double inventory and most riders are no where near knowledgeable enough to demand it. It's fair to say that most riders don't even realize that OC rims exist, let alone what benefits they might offer.
Hmmm. I'd really like to know other details on this isolated experiment - type of rims, hubs, spokes, spoke count, nipples, wheel builder, final tensions of the build.

And in the grand scheme of things, unless the wheel is a disc brake wheel, you won't get 50K miles out of it without your brake tracks wearing out. I would say 20K miles is about it. Granted that I think a good build with quality components should not result in rim cracks at 15K miles.

And as has been noted by November Dave, asymmetric rims aren't without their own set of issues which he talks more about in post 12, 16 and 21 of this thread:

https://forums.roadbikereview.com/wheels-tires/dt-swiss-r470-db-363696.html
 

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Hmmm. I'd really like to know other details on this isolated experiment - type of rims, hubs, spokes, spoke count, nipples, wheel builder, final tensions of the build.

And in the grand scheme of things, unless the wheel is a disc brake wheel, you won't get 50K miles out of it without your brake tracks wearing out. I would say 20K miles is about it. Granted that I think a good build with quality components should not result in rim cracks at 15K miles.

And as has been noted by November Dave, asymmetric rims aren't without their own set of issues which he talks more about in post 12, 16 and 21 of this thread:

https://forums.roadbikereview.com/wheels-tires/dt-swiss-r470-db-363696.html
If asymmetric rims caused problems then front wheels would all be really bad. Because that's all they do is make things more like a front wheel by evening out the sides.

I only glanced the that Nov Dave said but it looked to me like he was putting down particular brands/models of asymetric rims not the concept in general.
 

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If asymmetric rims caused problems then front wheels would all be really bad. Because that's all they do is make things more like a front wheel by evening out the sides.
Whether asymmetric rims cause problems or not, this is a poor argument. Of course the reduced disparity between spoke tensions won't be what causes ptoblems. Come on!
 

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Whether asymmetric rims cause problems or not, this is a poor argument. Of course the reduced disparity between spoke tensions won't be what causes ptoblems. Come on!

You're the one that said they did "asymmetric rims aren't without their own set of issues"
 

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You're the one that said they did "asymmetric rims aren't without their own set of issues"
Yes. But that has nothing to do with your comparison to front wheels. Seriously, I'm sure you know better. Are you trolling?
 

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Hmmm. I'd really like to know other details on this isolated experiment - type of rims, hubs, spokes, spoke count, nipples, wheel builder, final tensions of the build.

And in the grand scheme of things, unless the wheel is a disc brake wheel, you won't get 50K miles out of it without your brake tracks wearing out. I would say 20K miles is about it. Granted that I think a good build with quality components should not result in rim cracks at 15K miles.

And as has been noted by November Dave, asymmetric rims aren't without their own set of issues which he talks more about in post 12, 16 and 21 of this thread:
You should stop making blanket statements that may well apply to you but don't necessarily apply to others. How long a brake track lasts depends on a lot of factors, and 50K miles is not unusual for me.

The wheels I built were on Velocity Aerohead rims, 32 spoke,, 3X, DT Competition 15/16 butted spokes, Campy Record hubs, hand built by me without a tensiometer. I've built 100s of wheels and never used a tensiometer and don't have any wheel problems that could be attributed to that. The Aerohead rims were from the early production runs when they were trying to keep rim weight right about 400 gm and the result was extrusion cross sections that were too thin. This was well documented at the time, as were frequent cracking issues.
 

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You should stop making blanket statements that may well apply to you but don't necessarily apply to others. How long a brake track lasts depends on a lot of factors, and 50K miles is not unusual for me.

The wheels I built were on Velocity Aerohead rims, 32 spoke,, 3X, DT Competition 15/16 butted spokes, Campy Record hubs, hand built by me without a tensiometer. I've built 100s of wheels and never used a tensiometer and don't have any wheel problems that could be attributed to that. The Aerohead rims were from the early production runs when they were trying to keep rim weight right about 400 gm and the result was extrusion cross sections that were too thin. This was well documented at the time, as were frequent cracking issues.
Interesting. I know there are a few people here who build wheels without a tensiometer. Do you gauge tensions by tone? I've tried that and it never worked well for me. I use the P&K Lie tensiometer - way better than the Park Tool version.

I don't doubt your experience and you give out a lot of good helpful advice. As you pointed out, it depends entirely on the rim whether an OC design is of any significant advantage. And it appears it also depends entirely on the rim whether an OC design will cause any problems. The rim you used is at the very light weight end. To be fair, November Dave did mention other OC rims besides Pacenti that had issues.
 

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Interesting. I know there are a few people here who build wheels without a tensiometer. Do you gauge tensions by tone? I've tried that and it never worked well for me. I use the P&K Lie tensiometer - way better than the Park Tool version.

I don't doubt your experience and you give out a lot of good helpful advice. As you pointed out, it depends entirely on the rim whether an OC design is of any significant advantage. And it appears it also depends entirely on the rim whether an OC design will cause any problems. The rim you used is at the very light weight end. To be fair, November Dave did mention other OC rims besides Pacenti that had issues.
I use tone to compare spokes around the wheel, and feel to gauge overall tension. My current wheels (Velocity A23 with an OC rear rim, 32 spoke, 3X 15/16 DT Competition spokes, Campy Record hubs) have 60K miles on them. No convex shape to the brake tracks. Maybe one spoke loosened and taken back up to tension with a few turns of the spoke wrench (I don't really remember if this happened with these wheels or a previous set). Minor touch-ups perhaps once per year just to keep them really true.
 

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I use tone to compare spokes around the wheel, and feel to gauge overall tension. My current wheels (Velocity A23 with an OC rear rim, 32 spoke, 3X 15/16 DT Competition spokes, Campy Record hubs) have 60K miles on them. No convex shape to the brake tracks. Maybe one spoke loosened and taken back up to tension with a few turns of the spoke wrench (I don't really remember if this happened with these wheels or a previous set). Minor touch-ups perhaps once per year just to keep them really true.
60K miles without brake wear is amazing. Can I assume most of your riding doesn't have a lot of hills? Can I also assume you meant to say concave? :)

Unless I have something to compare to, feel doesn't work for me. I don't really have good tactile memory for a lack of a better way of describing it. That's why I always use a torque wrench while some mechanics don't.
 

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Discussion Starter · #20 ·
Hmmm. I'd really like to know other details on this isolated experiment - type of rims, hubs, spokes, spoke count, nipples, wheel builder, final tensions of the build.

And in the grand scheme of things, unless the wheel is a disc brake wheel, you won't get 50K miles out of it without your brake tracks wearing out. I would say 20K miles is about it. Granted that I think a good build with quality components should not result in rim cracks at 15K miles.

And as has been noted by November Dave, asymmetric rims aren't without their own set of issues which he talks more about in post 12, 16 and 21 of this thread:

https://forums.roadbikereview.com/wheels-tires/dt-swiss-r470-db-363696.html
Thanks for linking November Dave's posts. I read through that thread.
I get the impression that Dave's main gripe is against the Pacenti SL23's. I don't have SL23's, but I recall these rims have lots of issues due to it being too light.

My understand about offset rims is that they do have to be a tad more robust at the spoke bed due to the spoke angle to the DS spokes. This cause asymm rims to be a tad heavier than their symm cousins.

anyway, here are all the carbon mtb rims I'm looking at:
Carbon MTB Rims,Carbon MTB Rims for sale Carbon MTB Rims wholesalers,factories,sellers


specifically, i'm looking at the V-shape asymm 27.5er, with 30.5mm inner width, 380g (All-mountain) weight, in 28h drilling.
27.5er Carbon MTB Asymmetric Hookless Rims products- 27.5er Carbon MTB Asymmetric Hookless Rims factories,manufactures,27.5er Carbon MTB Asymmetric Hookless Rims suppliers

and this version of asymm:
27.5er Carbon MTB Asymmetric Hookless Rims products- 27.5er Carbon MTB Asymmetric Hookless Rims factories,manufactures,27.5er Carbon MTB Asymmetric Hookless Rims suppliers

yes, they sell TWO versions of asymm rims. Which one is more robust? Their weight in "AM" (all mountain) configuration is the same at 380g (though the latter offers a "DH" (downhill) version at 430g).

What say you? What say the builders in here? My own a bit "uneducated" opinion is that the V-shape asymm rim should be the stouter rim due to a higher depth (28mm vs 25mm) and the spoke bed looks more robust (based on their diagrams).

Could the wheelbuilders in here chime in why/what the pros/cons of the two different versions of asymm.


My current info, riding style:
I'm a lightweight (122-124 lbs), and i'm not an abuser of equipment, but I do like to huck small lips (under 2 feet) and the landing can't always be soft on a hardtail. My current rear wheel is a SRAM Rise 60, carbon
symmetric rim, 21mm inner width, 24h spokes, and running 2.25" tires. Wheel is fast, no complaints about weight. But like I said, it will go out of true on me in the course of a year (of riding 2-3 times/wk, almost year round). I've looked at my strava and some of my descents are close to 30mph top speed going down doubletrack and jeep trails, but I hardly will hit 30mph, but when I do.. and hitting a big bump.. could this be the main thing that knock it out of true more than the hucking stuff? I'm thinking if I go with 28h spoke wheel, all this will be resolved, asymm or symm! But if I were going to build a new wheel, and I have the option to go asymm or symm, then I would like to know which option is better. But on thing is for SURE, I will go carbon rims for mtb, will not go back to aluminum rims in mtb.
 
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