Notes on Pacenti sl23 and Schwalbe Pro One Tubeless Build

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shonanmike
Posts: 40
Joined: Mon Nov 17, 2014 11:27 pm

by shonanmike

FWIW quick notes on my latest build.

Pacenti sl23 28H and 24H (2015)
Tune Mag 170 28H Mig 70 24H
CX-Ray
Schwalbe Pro One 25mm
Schwalbe High Pressure rim tape 25mm
Stan's Valve

Built quite easily. Initial spoke tensions at approx. 120kgf DS and 60 NDS.

Pro One tire mounts onto the rim without too much difficulty but of course not as easy as a regular clincher.

Tires inflate easily using Bontrager Flash Charger pump. Soapy water on beads. Loud snap and ping as the beads lock into the rim.

90 psi rear 80 psi front.

Ride quality is subjectively good and wheels feel fast. Tubulars (Vittoria CS3 25mm) on Chinese carbon rims seems a bit smoother but the difference is not massive. Cornering as good as any other tire I've ridden.

When Pro One tires are locked into the bead, the spoke tension drops by about 20kgf uniformly. This is with an un-inflated tire. Removing the beads from the rim and sliding them into the center channel causes the spoke tension to change back to the original values.

Regards

velomane
Posts: 243
Joined: Sun Jun 27, 2004 1:44 am
Location: Winnipeg, Canada

by velomane

Did you happen to weigh your wheels prior to mounting the tires?

by Weenie


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TheDarkInstall
Posts: 725
Joined: Sun Jan 26, 2014 3:44 am

by TheDarkInstall

shonanmike wrote:When Pro One tires are locked into the bead, the spoke tension drops by about 20kgf uniformly. This is with an un-inflated tire. Removing the beads from the rim and sliding them into the center channel causes the spoke tension to change back to the original values.


This is something I have been looking at more and more recently. The effect of this is very pronounced with Clinchers, and less so with Tubulars.

I found that it was inflating that caused most of the tension drop, rather than just mounting. I wonder also, how this manifests itself in riding; do the tensions stay where they are, or are they constantly changing, as the wheel rotates and the weight of the rider + bike causes the air inside to be shifted away from the contact are of the tyre, thus allowing the spoke tension to increase back up, at the bottom of the wheel. If this is the case, how also does this affect the spoke tension at the opposite side of the wheel from the point that is going through the contact area...?

shonanmike
Posts: 40
Joined: Mon Nov 17, 2014 11:27 pm

by shonanmike

velomane wrote:Did you happen to weigh your wheels prior to mounting the tires?


Front wheel (mig 70 24H, CX-Ray, alloy spokes, no rim tape) at 604 grams.

Rear wheel (mag 170 28H, CX-Ray, alloy spokes, no rim tape) at 736 grams.

Rgds,

shonanmike
Posts: 40
Joined: Mon Nov 17, 2014 11:27 pm

by shonanmike

TheDarkInstall wrote:
shonanmike wrote:When Pro One tires are locked into the bead, the spoke tension drops by about 20kgf uniformly. This is with an un-inflated tire. Removing the beads from the rim and sliding them into the center channel causes the spoke tension to change back to the original values.


This is something I have been looking at more and more recently. The effect of this is very pronounced with Clinchers, and less so with Tubulars.

I found that it was inflating that caused most of the tension drop, rather than just mounting. I wonder also, how this manifests itself in riding; do the tensions stay where they are, or are they constantly changing, as the wheel rotates and the weight of the rider + bike causes the air inside to be shifted away from the contact are of the tyre, thus allowing the spoke tension to increase back up, at the bottom of the wheel. If this is the case, how also does this affect the spoke tension at the opposite side of the wheel from the point that is going through the contact area...?


In this case (sl23 and Schwalbe Pro One), most of the tension drop seems to be caused by the tire bead locking into the rim. Inflating the tire after it has locked into the rim doesn't make a significant difference.

Rgds,

kulivontot
Posts: 1163
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

How the hell did you get this tire on the rim? I'm doing this exact combination (V1 pacenti) and I can't even get one side of the tire onto the rim. There's like an 8 inch section that needs to be lifted on and the moment I start to use a tire lever it actually rips into the stan's tape underneath. Any tips and tricks? Already using soapy water, starting opposite the valve stem, pushing the tire bead onto the center locked channel. I'm going to order kool stop bead jack and the crank bros speedier lever to see if either of those can help.

peted76
Posts: 433
Joined: Mon Jun 23, 2014 10:30 pm

by peted76

kulivontot wrote:How the hell did you get this tire on the rim? I'm doing this exact combination (V1 pacenti) and I can't even get one side of the tire onto the rim. There's like an 8 inch section that needs to be lifted on and the moment I start to use a tire lever it actually rips into the stan's tape underneath. Any tips and tricks? Already using soapy water, starting opposite the valve stem, pushing the tire bead onto the center locked channel. I'm going to order kool stop bead jack and the crank bros speedier lever to see if either of those can help.


I run SL23's (2015's) with 25mm Pro Ones and they go on okay. I'm on my third tyre all have no issues.

Is the tape pushed right down into the bead? You are using stans 'yellow' tape right?

I ordered one of those tyre lever thingy's a while ago when I tried fitting some veloflexes to a set of wheels - what a waste of a tenner that was.

kulivontot
Posts: 1163
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

I use 3m strapping tape off amazon, 10x more, 10x cheaper.
I bought the kool stop bead jack today, worked like a charm. I hope the sealant works, because these suckers are never coming off this rim.

by Weenie


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