Stan's ZTR Alpha 340 rims question...

Discuss light weight issues concerning road bikes & parts.
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teamtrinity
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by teamtrinity

I'm a 135 lbs road rider (125 lbs during the summer). Mostly recreational riding...with 2-5 races a year (road or crit). I have a set of Circus Monkey hubs(20h/24h). I'm thinking of using them to build up a set of ZTR Alpha 340's. I'll be using them as standard clinchers, not tubeless.

A couple questions...

1) What's the narrowest and widest tire I can safely use on this rim?

2) Will this rim built up 20/24 with Sapim CX-Ray spokes be sturdy enough for my weight and intended use?

3) I've read a couple threads about an unusually high amount of spoke detensioning after you mount and inflate tires. Is this a real issue? How can it be avoided?

Thanks!!!

j_gantzer
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by j_gantzer

1) 22mm - upto a cyclocross size tyre (35ish mm)

2) They should be ok at your weight. I would recommend prolock nipples or wheelsmith spoke prep and building the rear up to 110kfg. Ya thats more than stan's recommends. If you want the rear to be a little stiffer you could go with heaver drive side spokes.

3) Only if you run carbon bead tubeless tires

audiojan
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by audiojan

I'm 165 and has a pair of Alpha 340/Alchemy wheels with 20/28... more than strong enough for me, so I would guess that you could get away with 20/24.

I've been riding them with Conti GP4000s for most of the year and just recently switched over to Micheline Pro3 tubeless. Honestly, go tubeless, the feeling is just awesome!
"Suddenly the thought struck me; my floor is someone elses ceiling" - Nils Ferlin

j_gantzer
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by j_gantzer

Dont run a non-tubeless road trye tubeless unless you want to die!

artray
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by artray

I got some stans with american classic hubs and revolution spokes ,20/24.
weight is 1182grms , zx tyres,aircomp light tubes .I weigh 13 stone solid and the wheels are superb no issues.
good luck

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Zen Cyclery
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by Zen Cyclery

Concerning spoke count, a 20/24 would be good for your weight (in most cases). But with this rim, it is a really good idea to overbuild considering how soft this hoop can be. So, with that in mind, I would say go 20/28.

Regarding the loss of tension, I have read about that as well. I have yet to talk to any of our customers who have had issues with it, but I know some of my fellow builders have had some issues with tension loss when setting it up tubeless. I think that the reason we haven't seen it is because none of our customers who bought that rim have had a desire to run tubeless (as far as I know).
You should get in touch with Ron at White Mountain Wheels or Jason at Fairwheel Bikes though. Both of those guys would be great resources to answer your question about tension loss.

rruff
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by rruff

I replied on another forum. The tension loss varies depending on how tight and stiff the tire bead is, and how the casing is woven (ie how much it contracts when inflated). Tubeless tires seem the worst. The reason is the "shelf" inside the rim that the bead pops onto when you inflate. It compresses the rim a lot.

Just tension it a bit higher than normal when you build the wheel (and dished slightly to the NDS), or true it with the tire installed and inflated. I just checked mine and the DS tension is only ~92kg on the DS with a tire installed, and I've not had a bit of trouble with it in ~8k miles. It's a 24h Alchemy hub laced heads-out radial on the NDS and I weigh 170.

wholefive
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by wholefive

rruff wrote:I replied on another forum. The tension loss varies depending on how tight and stiff the tire bead is, and how the casing is woven (ie how much it contracts when inflated). Tubeless tires seem the worst. The reason is the "shelf" inside the rim that the bead pops onto when you inflate. It compresses the rim a lot.

Just tension it a bit higher than normal when you build the wheel (and dished slightly to the NDS), or true it with the tire installed and inflated. I just checked mine and the DS tension is only ~92kg on the DS with a tire installed, and I've not had a bit of trouble with it in ~8k miles. It's a 24h Alchemy hub laced heads-out radial on the NDS and I weigh 170.


rruff:

did you lace that 24h 2x or 3x on the drive side?

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bikerjulio
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by bikerjulio

OP you've probably seen my thread on this

http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=97281&start=15

we have the hubs & rims in common but in other respects lets just say I'm more of a test for these wheels.

Narrowest tire is 23mm i'm sure. I'm running PR 3's. widest tires would be at least as wide as a normal rim - 32?.

I'd think your build would be OK for you.

My experience (and I've built wheels, but not an expert), has been that if I got the wheel tensioned and destressed right the first time, it looks like it's going to be OK. When I've got a bit more time on the bike I'll report further.

So far I'm quite pleased.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

droptop
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by droptop

Built up a stans alpha 340 to white industries hubs. the front had enough tension loss to detension a few spokes entirely after a few rides (3), my wheel builder put some tension back into it to get me home, then said unmount the tire and drop it off, he will double check it. Should i be concerned with the loss of tension?

FWIW, its laced 3x 32 spokes, front and rear. the rear hasn't given me any problems. spokes are sapim laser (2/1.5/2), except for rear DS which is the sapim race (2/1.8/2). rear is campy.

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bikerjulio
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by bikerjulio

I'm six months into riding mine - both 3X 32 spoke.

I have to say that these are not rims I'd recommend to a friend.

1. I must have retensioned the rear wheel at least 3 times now.

2. For the money the quality was frankly, crap. Hard to build. Poor joint quality leading to excessive radial runout and rough braking.

On the plus side - I have not broken them yet, the ride is good, and they are very light.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

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WMW
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by WMW

bikerjulio wrote:Narrowest tire is 23mm i'm sure.


20mm tires are totally excellent on these rims.
formerly rruff...

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WMW
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by WMW

Probably got ~10k miles on my 18f and 24r set, @170 lbs and they are holding up fine. If your rear rim was off that much it was probably defective. There is no good way to "fix" a rim that isn't straight. Of course none of them really are, but it is a matter of degree.
formerly rruff...

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