Switchback Hill Tires + Hookless Carbon Rims + Tubeless

[Andrew Squirrel]

Has anyone tried building up some 584 wheels with hookless carbon rims & tubless Switchback Hill Tires yet?

I'm ready for the future.

http://www.light-bicycle.com/hook-less-control-carbon-29er-rims-is-ready.html

Thanks,

Andrew Squirrel

[HillDancer]

I have them mounted on 40mm (34mm internal width) Derby hookless carbon 584 rims with tubes. http://www.derbyrims.com/technical-specs---faq-s.html

I've had more than a few Panaracer made tires mounted tubeless on these hookless rims for many thousands of miles.  I recommend wider internal width than 22mm for tires like these.

[Nick Favicchio]

GAH!!!

[Justin Hughes]

What is the attraction of these rims? Aero properties? 

On Friday, May 20, 2016 at 12:30:09 AM UTC-4, Nick Favicchio wrote:

GAH!!!

[Alex Wetmore]

The width makes the tires wider and nicely supports the sidewall.  To me the tire feels less like it wants to roll off of the rim when you are running at really low pressures.  I can notice this difference between my two mountain bikes, one of which has 27mm interior width rims and the other of which has 18mm interior width rims.  I often run my MTB tires at under 20psi and use tires with supple casings.

The carbon fiber makes a rim that wide a lot more manageable weight wise.

As an example of rim width mattering in final tire width, some friends were over at my house on Saturday and we had a bike with Rat Trap Pass tires and Switchback Hill tires there at the same time.  The RTP (26" version, supposed to be a few mm wider) were mounted on 18mm interior width rims (Sun CR18 and Mavic 317).  The SBH tires were mounted on 25mm interior width rims (WTB KOM i25).  The SBH (the nominally narrower tire) measured wider than the RTP by about 1mm.

I'm not up on the latest in rim technology and I'm not sure why carbon rims are going hookless, but they generally are.

alex

---

From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Justin Hughes <justin...@me.com>
Sent: Monday, May 23, 2016 11:06:27 AM
To: 650b
Subject: [650B] Re: Switchback Hill Tires + Hookless Carbon Rims + Tubeless

 

What is the attraction of these rims? Aero properties? 

On Friday, May 20, 2016 at 12:30:09 AM UTC-4, Nick Favicchio wrote:

GAH!!!

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[Justin Hughes]

Right. Just wasn't sure why these would be preferred over a Velocity Blunt SS. The linked carbon rims aren't as wide as the Blunt SS, but I guess they are quite a bit lighter by 45-75g. Strange that there is such a high variance in weight on the carbon rims.

[Hahn Rossman]

The RTP and the SBH are really the same width. It's within the tolerances of the black magic of tire mold making apparently.  Please ignore the molded in sizes as they can be misleading.  The tire prediction tool that wheel fanatyk is selling is pretty good at illustrating what you get from using wider rims.

[Andrew]

I was looking at the Light Bicycle rims for if/when I get an NFE or Ravn. I emailed them with a few questions and they said that there are less pinch flats and burping with hookless. With my weight at 100kg and with robustness being important I'd like to plan on getting their downhill-grade rims which still come in around 450g for a rim over 30mm wide internal in either 559 or 584. It's 100 or maybe 150g per rim lighter than aluminium. They have a few width options in each diameter, and there are a couple of other Chinese brands with a reasonable name too.

There's a good article on BikeRadar about hookless rims. They say it's cheaper and stronger than hooked carbon rims, and point out that beads are much stronger these days than when hooks started being used.

[Fred Blasdel]

On Mon, May 23, 2016 at 11:24 AM, Justin Hughes <justin...@me.com> wrote:

Right. Just wasn't sure why these would be preferred over a Velocity Blunt SS. The linked carbon rims aren't as wide as the Blunt SS, but I guess they are quite a bit lighter by 45-75g. 

Because the ultralight Velocity rim is a fragile race day product, to make a ~400g aluminum rim that wide the extrusion has to be thin and use a soft alloy to keep it from cracking. They beefed up the spoke bed so that it can at least take real spoke tension now, but it's still easily dented or tacoed.

I replaced my old 650b rando/adventure bike three years ago so I could switch to disc brakes, not because the brakes were any better (they weren't), but so I could switch to carbon rims. I was tired of dealing with regular dents and destroying the rear on an annual basis. I've ridden the new bike *so* much harder and I'm still on the original wheels with no truing. Mine are now at least four generations old, the new models are even better in every way.

http://www.velocityusa.com/product/rims/blunt-ss-584

http://www.nextie.net/mountain-asymmetric-NXT27AS33

These two cutting edge rims are the same 26mm inside width at the same weight, but it's only the carbon one that I'd feel comfortable running low pressures on and hitting roots/rocks with. Just on material properties the carbon is several times stronger and stiffer, but then its construction also allows it to be 50% taller with sidewalls are twice as thick.

$180 each is a lot to pay for rims, but the lightweight aluminum option is still at least $90 and isn't anywhere near as durable

[Justin Hughes]

Great info. Thanks. 

[omarcowow]

I just thought I'd chime in on this subject. I'm running this exact combo of tubeless switchback tyres and LB carbon rims.

They were a nightmare to get seated properly but once I'd cracked it they worked very well... except that they have burst off the rim twice now with pressures of around 40psi according to the pressure gauge on my track pump. Thankfully both times the bike has been stationary.

It's freaked me out a bit to be honest so am contemplating returning to tubes... reluctantly.

[Steven Frederick]

Honestly, I don't like to go much over 30psi tubeless. Make sure that
blow offs didn't damage your beads and make them prone to blowing off
easier.

Steve

[omarcowow]

the beads seem okay, I'm gonna hold my breath and try 30psi for a while.. the thought of a blow out whilst moving is pretty terrifying/distracting.

The first one actually blew at about 50psi whilst I was inflating it like mad trying to seal up the bead. The second one (today) went whilst the bike was sat in the sunshine, I'd left it at 40psi but I think the heat on the tyre must have increased the psi enough to blow it off.

I also run rock n roads on a blunt SS rim which is a much tighter fit and have had no problems with at all - also around 40psi.