Super light alloy clincher rims?

Everything about building wheels, glueing tubs, etc.
alcatraz
Posts: 1889
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

A 28h rear can maybe be laced 2:1 21 spoke.

A display bike with convenient rims. I guess this is what people have hard to understand.

Slammed
Posts: 87
Joined: Sun Feb 01, 2015 12:32 am

by Slammed

alcatraz wrote: ↑
Fri Mar 29, 2019 11:56 pm
A 28h rear can maybe be laced 2:1 21 spoke.

A display bike with convenient rims. I guess this is what people have hard to understand.
Now that I think about it I don't really care about being practical. I really just want a 4.5kg bike with clinchers because why not.

by Weenie


nachetetm
Posts: 82
Joined: Fri Aug 18, 2017 8:54 pm

by nachetetm

I don't see the point of building a bike that cannot be ridden properly, but I am interested in seeing the results. As they mentioned above, American Classic rims are in the 350-360g ballpark, although I always heard they need 32 spokes to be rideable. 16/21 sounds like a nice challenge and will be very light indeed. What spokes and hubs are you using to reach such a low weight?

Slammed
Posts: 87
Joined: Sun Feb 01, 2015 12:32 am

by Slammed

nachetetm wrote: ↑
Sat Mar 30, 2019 12:25 pm
I don't see the point of building a bike that cannot be ridden properly, but I am interested in seeing the results. As they mentioned above, American Classic rims are in the 350-360g ballpark, although I always heard they need 32 spokes to be rideable. 16/21 sounds like a nice challenge and will be very light indeed. What spokes and hubs are you using to reach such a low weight?
I actually just won some American Classic Mag wheels on Ebay. If I go with the absolute lightest setup I can probably go under 800g. That's if I use an M5 front hub which I'll probably avoid because that would make the whole wheelset more show only. If I strip the paint on the rims and use the tuned Extralite hubs I have with Berd spokes I should be able to be right around 850g.

The idea of trying 21 spokes on the rear is interesting. Who makes a light 21 spoke triplet rear hub? My current rear hub is 120 grams so the replacement would have to be under 135g to make the lower spoke count worth it.

alcatraz
Posts: 1889
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

A carbon wheelset would at least be rideable. Alloy rims at those weights will crack/break rim/spoke/flanges if you can get them true in the first place. Alloy can't hold its shape. When you put your body weight on those wheels it's like you just laced a noodle. The rim will buckle completely or between two spokes on the first ride or bump in the road.

No serious builder would ever consider the build to be more than a model wheelset to put in a display window and on a scale.

I like your determination though. You need that to push boundaries. If you later want make a second attempt you can make big improvements.

If the rim ERD is the same as a good light carbon rim, you will be able to reuse the spokes and save the investment.

Slammed
Posts: 87
Joined: Sun Feb 01, 2015 12:32 am

by Slammed

A guy on here has already built the exact wheelset I'm trying to build so it's not like this hasn't been proven at all. Like I said before, I'm 135 pounds and plan on exclusively using these wheels on flat coffee shop spins. Carbon may be better but magnesium clinchers are cooler so my hands are tied.

biwa
Posts: 115
Joined: Fri Sep 21, 2018 8:39 pm

by biwa

Slammed wrote: ↑
Fri Mar 29, 2019 6:46 pm
It will be more of a show/project bike than something ridden daily. I'll probably ride these no more than 1000km a year on flat coffee shop spins.
I thought people build light bikes for climbing.. :wink:

bm0p700f
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by bm0p700f

Just because Donald has built silly light wheels does not mean you should too. The spoke count is low for such a light clinher so ti or Sapim superspokes would be needed and then the wheel would be flexible and perform poorly. It is simply not worth building. There are also no clincher rims available below 385g now in alloy. The magnesium ammerica. Classic rims are difficult to find.

If you want light go tubular. You can have sub 300g rims then and fit light tubs.

I don't give a shot how much you weigh. It too much for wheels like that and they would be a pain to build.

I am all for light but do it right or go home.

Stiff wheels build easily and and relaible. What the op want is literally flexible and therefore spoke fatigue will happen at a faster rate.

You can have a lighter wheelset with carbon tubular rims. And the braking will be just fine. Let's not do the old tropes of carbon is for disc brakes.....

If you have 280g hubs and spokes then farsport tubulars 20mm wide and 22mm deep will be about 265g each.

There you go a super light set. What are you waiting for. I have even done the thinking for you.

shimmeD
Posts: 487
Joined: Thu Jun 28, 2012 10:52 pm
Location: eNZed

by shimmeD

I have the Farsports carbon tub rims weighing 532g ie 266g for 25x23W, which the OP can go for after he has tried the 16/21 AC rims he has already bought and will have the rear 2:1. Best of luck :beerchug:
Less is more.

Slammed
Posts: 87
Joined: Sun Feb 01, 2015 12:32 am

by Slammed

bm0p700f wrote: ↑
Fri Apr 05, 2019 1:02 am
Just because Donald has built silly light wheels does not mean you should too. The spoke count is low for such a light clinher so ti or Sapim superspokes would be needed and then the wheel would be flexible and perform poorly. It is simply not worth building. There are also no clincher rims available below 385g now in alloy. The magnesium ammerica. Classic rims are difficult to find.

If you want light go tubular. You can have sub 300g rims then and fit light tubs.

I don't give a shot how much you weigh. It too much for wheels like that and they would be a pain to build.

I am all for light but do it right or go home.

Stiff wheels build easily and and relaible. What the op want is literally flexible and therefore spoke fatigue will happen at a faster rate.

You can have a lighter wheelset with carbon tubular rims. And the braking will be just fine. Let's not do the old tropes of carbon is for disc brakes.....

If you have 280g hubs and spokes then farsport tubulars 20mm wide and 22mm deep will be about 265g each.

There you go a super light set. What are you waiting for. I have even done the thinking for you.
Like I said before I'm 135 pounds and live in the prairies. I'm also using Berd spokes which don't really fatigue in the same way ti or stainless would. I'll probably build up a set of farsports tubulars with a set of Extralite hubs I have anyway. I just love super cool and rare stuff so bulding a set of 800g clinchers when the oppirtunity came up was just too tempting.

bm0p700f
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by bm0p700f

Since you don't want to listen why area you asking?

Also since tubs would be lighter why are you Pershing the heavier option.

The wheels are 28h lace that way. Don't try and so the 2:1. They need to be 27h for that and 2:1 will make the wheel unrideable and awkward to build as the spoke lengths will be all over the place.

With 28 spoke the rims will be rideable but I would not go for the lightest spoke. In fact I would not change the wheel spec at all.

Your weight is too much for what you want to build it is not too much for tlwhat I have suggested.bwhat do I know. This is only my living. I am done trying to advise here it is pointless. Everyone thinks they known it all.

Slammed
Posts: 87
Joined: Sun Feb 01, 2015 12:32 am

by Slammed

bm0p700f wrote: ↑
Sun Apr 07, 2019 9:12 pm
Since you don't want to listen why area you asking?

Also since tubs would be lighter why are you Pershing the heavier option.

The wheels are 28h lace that way. Don't try and so the 2:1. They need to be 27h for that and 2:1 will make the wheel unrideable and awkward to build as the spoke lengths will be all over the place.

With 28 spoke the rims will be rideable but I would not go for the lightest spoke. In fact I would not change the wheel spec at all.

Your weight is too much for what you want to build it is not too much for tlwhat I have suggested.bwhat do I know. This is only my living. I am done trying to advise here it is pointless. Everyone thinks they known it all.
I'm not listening to your advice because it's not good. I'm trying to build a super light set of project wheels that will barely be ridden, and you're giving me advice like I'm a 200 pound bloke doing fondos.

I have some fatsports rims on the way for another set of hubs I have but that's not what this thread is about. I'll let you know in a few weeks how my "unridable" wheels are though.

alcatraz
Posts: 1889
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

It's easy to get bad ideas looking at available hub configurations.

Wheels used to be 36 spoke because rim stiffness was simply terrible. :D

As rims got stiffer it allowed for spoke counts to go down. They got a lot better in fact. The rule is however that the lower the spoke count the stiffer the rim needs to be.

Second issue:

In a clincher the rim weight is concentrated around the brake track to be able to contain the tire pressure. Very little is left to keep the rim from buckling in a light clincher. You have razor thin (relative to alloy) wall thicknesses around the spokes and thick around the brake tracks. It's the only way to make them light. With a high enough spoke count (24f/28r and above = light alloy rim count) you could still ride such a rim although it will perform poorly.

By combining an awful rim stiffness with poor buckling strength, with a carbon level spoke count and odd spoke material, the design is so far beyond extreme it's hard to even describe it.

I've angered bmp0 many times. He doesn't like a customer returning with issues. It's understandable from his perspective as a wheelbuilder. The forum sadly has more amateurs than professionals so it makes things a bit frustrating for the pros. I'm an amateur but I want to learn how to build custom wheels for different riders.

Many people here have asked for light alloy clinchers. I did that 3 years ago :lol:

Etienne
Posts: 158
Joined: Tue Aug 23, 2005 11:41 am
Location: France

by Etienne

Slammed wrote: ↑
Sun Apr 07, 2019 10:00 pm
I'm not listening to your advice because it's not good. I'm trying to build a super light set of project wheels that will barely be ridden, and you're giving me advice like I'm a 200 pound bloke doing fondos.

I have some fatsports rims on the way for another set of hubs I have but that's not what this thread is about. I'll let you know in a few weeks how my "unridable" wheels are though.
Sometimes I feel that bm0p700f's advices are a little bit on the definitive side but I have to admit that he thinks like someone who's liable for the quality of the wheels he builds and then the security of his customers ... for that he deserves respect.

Now, I think most of us (some of us experienced wheelbuilders) gave you the same advice : be careful with such wheels, even if you are light and don't plan to use the wheelset for any substantial riding. You just need to fall once to hurt you, period ...

Now it's up to you to assess the risk you're taking ...

by Weenie


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WinterRider
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Joined: Tue Feb 05, 2013 2:46 pm

by WinterRider

bm0p700f wrote: ↑
Sun Apr 07, 2019 9:12 pm
. Everyone thinks they known it all.
Go... look into the mirror.

The OP clearly defined his parameters... just a lark for some fun. :beerchug:

How.. is this project coming along?
Litespeed 2000 Appalachian 61 cm
Litespeed 1998 Blue Ridge 61cm
Miyata 210 25" circa 1986

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