Rim brake rim for Switchback Hill?

[Derek Z]

Any suggestions for a rim brake rim to best support the width of the Switchback Hills? I’m leaning heavily towards Pacenti Brevets but wondering if internal width of 19mm is less than ideal.
If I recall correctly, Jan stated in his interview on Path Less Pedaled that rim width isn’t really an issue. I’m pretty sure he said he rode 48’s on open pros and they felt fine. I have read conflicting reports though and others feel this tire needs a wider rim...
Thanks in advance for any recommendations,
Derek Z

[Justin Hughes]

I'd say the ideal internal width rim for the SBH is 23-27mm and tubeless setup. Given the choices available for rim brakes I would choose the Brevet or Belgium+ depending on whether I wanted silver or black. 

You can certainly ride this tire on narrower, older rim designs and be just fine. That doesn't mean that a wider rim isn't perceptibly better. 

Justin

[Derek Z]

This will be on frame with canti beakes, guessing the external width can’t be much more than 25-26mm? I was wondering if there was a nice option that was a few mm wider than the PB. I’m aware of the HED but for the difference in price I’d choose the PB (also strongly prefer the aesthetics of the PB)
Derek Z

[njh...@gmail.com]

The Velocity Cliffhanger is 25mm internal width, and claims to be tubeless ready.

Nick

[Derek Z]

Nick,
I think the Cliffhanger will be too wide for canti brakes...
Thanks,
Derek

[satanas]

If you're only prepared to consider a narrow, silver rim that leaves Brevets and A23s, or maybe something obscure ex-Europe. Me, I'd get the HEDs and not think twice about any of the others. As for Cliffhangers being too wide for cantis, they shouldn't be unless the brakes and/or the boss placement are weird; nobody is likely to use such a wide rim (and matching tyre) with caliper brakes.

Later,
Stephen

[Justin Hughes]

Disagree. The Cliffhanger is 30mm wide. I'm not sure what cantilevers would line up properly (without whacked out angles and poor mechanical advantage/modulation) with modern standard cantilevers spacing. I know a guy who built up a blinged out polished White Industries/Cliffhanger wheelset for a new Soma GR with Tektro 720s. He wen't to cable it up and. . . . no sir. Even with Thinlines it's too wide. He rebuilt the wheelset with Pacenti Brevets. What's more is that any hoop for rim brakes available that's wider than 25mm is going to be very heavy. The Cliffhanger is listed at 625g. Nuts to that. 

Yes, OP, I realize the widest rim you can consider is probably 25mm and that's not an ideal width for the SBH. Ideal SBH rim width and rim brakes just doesn't compute. But, we all settle for less than ideal plenty. You'll be fine and if you don't have experience with that tire and wider rims you won't really know if or what you're missing out on so no big deal.

Justin

[Scott Stulken]

Literally *millions* of mountain bikes shipped with 2.1" (54mm) tires on rims with internal widths of 13-19mm.  You'll be just fine. There's a lot of overthinking going on in the bike rim and tire world these days.

- Scott

[Derek Z]

Justin & Scott,
You stated both what I expected to be true and what I wanted to hear, thanks!
Derek Z

[Stephen Poole]

On Tue, 29 May 2018, 03:19 Scott Stulken <thermio...@gmail.com> wrote:

Literally *millions* of mountain bikes shipped with 2.1" (54mm) tires on rims with internal widths of 13-19mm.  You'll be just fine. There's a lot of overthinking going on in the bike rim and tire world these days.

^ And a hell of a lot of arguing too! FWIW, I've been happy with up to ~54mm tyres on i17-18 rims in the past (60+mm not so much), but nowadays using a nominally 57 mm/actually 55 mm tyre on an i23 rim causes howls of derision in some places since the rim "obviously isn't wide enough."

Re 30mm wide rims and cantis: I've used 28-32 mm external width rims with cantis without problems, though not recently - has something changed? FWIW, I currently have a Rhinolite XL (e29.2 mm) on the back of the trials bike with a V-brake and it works fine.

Later,

Stephen

[Adem Rudin]

On the other hand, back in the days of 17mm MTB rims you had to keep the pressure pretty high to keep the tire from "flopping" in turns. Switching from 17mm rims to 25mm rims on my 2.1" to 2.3" MTB tires was a revelation!

But yeah, there aren't a lot of good rim-brake rims available in much more than 19mm internal width. 

-Adem

[Stephen Poole]

On Tue, 29 May 2018, 18:05 Adem Rudin <adem....@gmail.com> wrote:

On the other hand, back in the days of 17mm MTB rims you had to keep the pressure pretty high to keep the tire from "flopping" in turns. Switching from 17mm rims to 25mm rims on my 2.1" to 2.3" MTB tires was a revelation!

Which is what we were all using back in the 1980s. I remember seeing 12psi front and 18psi rear during long tours without any tyre flop, this on Araya 7x, or RM-20 rims with 2.125-2.2" tyres and 24x1 3/8" tubes. The newer 17mm rims were lighter, but for me needed 25-30psi to stop things feeling wrong, and 2.35" Z-Max WCS tyres never felt right on them. These had relatively light casings, though not as paper this as Compass/GB ELs, so I'm not convinced a lighter casing will solve everything; rim width still matters.

Later,

Stephen

[Alex Wetmore]

I rode a lot of those mountain bikes, but I don't think that what worked on them is what works with these tires.

I do think that the Switchback Hill and Rat Trap Pass benefit from a wider rim.  A narrow rim (here I mean 23mm wide external, ~17mm internal, like the CR18 or A23) works, but only for very narrow pressure bands.  If you run too low the tire feels like it wants to roll off of the rim in tight cornering.  That was less of an issue on mountain bikes because the knobby tires didn't allow for as aggressive cornering as the stickier tread compound and slick tire profile of the Compass tires.

If you make the pressure too high the tires bounce in corners, which also reduces traction.

I have more experience on the RTP (for which there are also better rim options if you want to run rim brakes) but find that the difference between a 23mm (external) and 28mm (external) rim can be the difference between 20-30psi working and 27-30psi working.  This is for my body/load/bike combo.  That wider range is a lot nicer because it's the difference between checking tire pressure on every ride and doing it once a month or so.

With the wide tire pressure range what I do is pump it up until it feels write (with finger pressure) and ride it.  If it is too bouncy I let a little air out.  A month or two later when it feels wallowy (probably not a real word) I put some more air back in.

I run Sun Rhyno Lite rims for the RTP, and switched from the CR18.  These are the same rim design, except that the CR18 is 23mm wide externally and the Rhyno Lite is 28mm wide externally.

My bike with Switchback Hill tires has WTB KOM i23 rims (around 30mm external width).  It had an A23 front rim and I also found that too narrow.

Sorry, I don't know where to find wide 650B rims for rim brakes.  Can you run disks or use 26"/559mm rims?  There aren't that many rim brake bikes around that fit 50mm 650B tires with fenders, but the time these tires existed disk brakes were also pretty common.  Compass tested the Switchback Hill tires on my "Gifford" which uses canti brakes and could fit them with no fenders, that bike has Synergy rims (23mm wide).

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Scott Stulken <thermio...@gmail.com>
Sent: Monday, May 28, 2018 10:19:42 AM
To: 650b
Subject: [650B] Re: Rim brake rim for Switchback Hill?

 

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[Derek Z]

Well, the PB is i19mm so it has a smidge more internal width than most rims close to 23mm wide. I'm committed to rim brakes on this build so I'll likely try the PB and SH combo - we'll see how it goes.

Thanks all,

Derek Z

[Alex Wetmore]

I don't know what a PB is.

I also remembered the Velocity Atlas this morning, which is 20mm wide internally (25mm externally).  It is a bit porky though:

http://www.velocityusa.com/product/rims/atlas-584

That made me check the Velocity website for other choices and they have the Cliffhanger at 25mm internally:

http://www.velocityusa.com/product/rims/cliffhanger-584

That might be the widest rim brake rim in 584mm.  Kudos to Velocity for easily dividing their rims into rim brake and disk only.

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Derek Z <zei...@gmail.com>
Sent: Tuesday, May 29, 2018 4:43:23 PM
To: 650b
Subject: Re: [650B] Re: Rim brake rim for Switchback Hill?

 

[Justin Hughes]

I gather he is abbreviating the Pacenti Brevet rim that he mentioned in the opening post. 

Cliffhanger was discussed earlier in the thread as well and I'd caution anyone considering it to make sure a 30mm wide rim is going to work with their frame/fork/brakes.

Too bad they don't make a 650b version of the Quill. 

Justin

[Derek Z]

Thanks Alex!
PB = Pacenti Brevet
I think the Cliffhhanger is too wide for most canti brakes... I had a 25mm external rim that was too wide for my 84’ Expedtion. True, the canti posts were close together on that bike and I ultimately had them moved.
Both of those Velocity rims are a bit porky for my taste so they’re non-starters for this project.
It occurred to me that I’m running 48mm tires on CR18 rims (i17.5mm) on my Bike Friday with zero issues. While the Tioga Powerblocks on that bike aren’t as supple as the Switchback Hill, they are 120tpi and fairly supple...
I’m thinking the PB/SH will be fine for me