650b rim brake rims - what's the widest?

[Nick Favicchio]

Looks like the HED Belgium plus are 25mm on the outside. Ambrosio whatsits are 24mm outside iirc. Lots are 23mm.

Two questions - is the HED the widest rim brake option at 25mm? Any other more affordable 25mm option?

Other question is about inside vs outside rim width. How much does this really vary rim to rim? Are 23mm rims generally all gonna have the same interior measurements as all the other 23s? Or no?

[Justin Hughes]

Velocity Cliffhanger is 30mm. Why I'm not sure as this is simply too wide for standard cantilever spacing. A centerpull caliper may be able to accommodate that rim, but I have to think mechanical advantage/modulation suffer. Seems to me that for most rim brake setups you need to stop at 25mm wide max. Velocity Atlas is 25.4/19.8 and has beefy sidewalls and spoke bed. 

The relationship between outside and inside width varies slightly (4.0-5.5mm difference). Presumably, the smaller difference the shorter the life of the rim re: brake track wear.  

Would I rather have i20 rims over i18 rims for 42mm tires? Yes, but I'd rather have i23 rims still.  

[njh...@gmail.com]

VO Diagonale are 25mm as well...

[Nick Favicchio]

Here's what I'm looking at...

https://goo.gl/images/Io5Ftg

According to the European Tire and Rim Technical Organization Standards Manual (lol), a 48mm tire (I'm running Switchbacks now) should be run on at least a 27mm wide rim.

The look and feel of the Switchback on A23s, along with the tire/rim width charts I see make me feel like I'm not really set up quite right for the 48mm tire. My first ride with them yesterday was a hoot, but tire roll from side to side on the rim was a thing. Doesn't ruin the ride or feel bad or scary but experience going from a 21mm rim to a 29mm rim with Rat Trap Passes let's me know I'm not getting the full effect.

Didn't know the Cliffhangers came in a 584 option. I'm running XT parallel squish V brakes on 29.2mm Rhyno Lites on another bike and it works very well but is on the cusp. I could take some brake boss measurements to see if those brakes would work on the custom w/ 30mm wide Cliffhangers.

Why can't the Cliffhangers weigh the same as the a23s? Stupid physics!

[William Lindsay]

Nick showed a table of data:  https://goo.gl/images/Io5Ftg

What I see in that table for both 47mm and 50mm tires, there are a range of rim widths that are good.  13c and 15c are too narrow, so those cells don't have an X in them.  17c is good for both a 47mm and a 50mm tire.  That's why it gets an X.  Every width from 17c up to and including 27c are all good.  29c is too wide, and so it doesn't get an X.  

Am I reading that table wrong?  If not, does that change what you are looking for?

Bill Lindsay

El Cerrito, CA

[Ed Braley]

My NOS Raleigh Portage had Araya 650B rims that measured 27mm across the
outside, and the bike came with 35mm tires.

We've got the big tires now, but it seems like we're still playing catch-up
on the rim thing.

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[Justin Hughes]

No, we're not. But, the market for wide tires WITH rim brakes is shrinking. Start shopping for 584 ERTRO disc rims and you'll see there are oodles of nice rims. As light and as wide as you can handle. For what should be obvious reasons practical rim width is limited for use with rim brakes. 

Nick, since you are using V brakes it's possible you could get away with the Cliffhangers using Kool Stop Thinlines. I know for a fact that they aren't compatible with a Soma Grand Rando and Tektro 720s. Those polished rims with a polished SON and tan wall Babyshoes, though, is one fine looking combo. That tires wider than 42mm (and really even those) aren't optimal on i19 rims is just the breaks. Rims wider than that with a decent brake track are just going to be heavy or else super expensive (carbon). Were I married to rim brakes I'd choose the Pacenti Brevet or HED Belgium depending on desired aesthetics. 

[Mike Schiller]

I've been searching as well for something with a good tubeless tire design ( so not Velocity) and about 20 to 22 mm inside diameter.  The  HEDs look decent, just pricey.  I was hoping Pacenti would add come out with a replacement for the SL23 in black but nothing so far.  

~mike

Carlsbad Ca

[Nick Favicchio]

Wow, thanks Bill. I've no idea what my brain was doing when it looked at that chart.

Failing. Think the word is failing.

So according to the European fancy dancy pantsy commission, my a23s are kosher.

For the time being I think my set up is just fine, but for bikepacking mode I'd like to play with wider rims, Tektro 520 long pull drop bar levers, the XT parallel squish V brakes and 9 speed indexed bar end shifters on Salsa Woodchippers.

Gonna go take measurements.

[Andrew]

The Ambrosio AK30 rims are also quite wide - 29.5mm external with a machined brake track and 24mm internal between hooks with some level of tubeless compatibility.

Is there any updated or similar table for hookless rims?

[Harold Bielstein]

630 grams!

Sent from Hal's iPad

> On Jan 13, 2017, at 7:18 AM, Andrew <andrewd...@gmail.com> wrote:
>
> The Ambrosio AK30 rims are also quite wide - 29.5mm external with a machined brake track and 24mm internal between hooks with some level of tubeless compatibility.
>
> Is there any updated or similar table for hookless rims?
>

[Nick Favicchio]

I know. The Ambrosio and the Cliffhanger look to be identical in terms of width and weight. Lighter would be nice, but the tradeoff is durability, no?

Going from a 362g tire (EL BSPs) to a 478g tire (non EL SBH), I'm flabbergasted by just how much I can't tell a lick of diffence in terms of how hard it is to turn the cranks and do the speeds I did with the narrower, lighter tire. They're just as fast but now I throw single track into my loops cause I can and it's FUN!

Really digging the 48mm tires. Shocked. Rotational weight really does appear to be no different than adding weight to your Handlebar bag or setting out with a fuller bladder.

Madness!!

[satanas]

One of the relatively recent BQs said that with lightweight, supple tyres the rim width didn't really make any difference. With stiffer tyres, yes more so, especially (I'd guess) at low psi. So for road use light = good, narrow is okay; maybe things might be different for  more technical offroad use, but for gravel/dirt roads I'm guessing it's not going to matter much.

Later,

Stephen 

[wg...@yahoo.com]

+1 on the SL23's!

geoff

[Justin Hughes]

Even though Jan says BQ and Compass are completely independent and there are no conflicts of interest it's worth noting that Compass makes and sells rim brakes and rims only and wider rims are by and large only practically possible with disc brakes. I'm not convinced that an i23 rim is vastly superior to an i18 rim with regard to running a 48-584 tire on pavement, but I am confident that the narrower rim is not the superior choice. 

[satanas]

Hmmm. All else being equal, a narrower rim is going to be lighter, and on pavement that certainly isn't going to hurt. If we're talking about very low pressure on rough terrain then things are different, no question.

Later,
Stephen

[Justin Hughes]

Sure. But, all things aren't equal. You can have a much lighter disc only rim for the same internal width as a rim brake version. I'm not saying that narrow rim brake rims suck with or without fat tires. I am saying that wider is better. Whether that degree of better is pertinent to your interests I can't say. If you have discs then your entire bike is, by some amount, heavier than it would be with rim brakes. But the rotational mass of the wheel should be less and at the same time feature a wider rim. Just a horse for a course is all. 

[Stephen Poole]

Agreed, but I'm not fond of disc brakes for non-MTB use; I don't like super stiff forks unless there's a 60+ mm tyre attached.

Those light disc rims, unless carbon, also have the problem in many cases that they won't handle road pressures unless tubes are used, which kills things a bit offroad.

My problem is that I'd like one bike and wheelset to be capable of handling most brevet and touring use, plus a bit of light offroad use; tyre swaps are okay but travelling with multiple wheels isn't feasible. This implies a comfy fork (so no discs) and the ability to run 38-42 mm tyres at road pressures, and also 50-ish mm tyres at offroad pressures, occasionally.

I'm not sure we're actually disagreeing, except perhaps about priorities. If a stiff fork or suspension is okay then for sure discs will allow lighter, wider wheels.

Later,
Stephen

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[Nick Favicchio]

Jan has opinions and I have mine :). I felt my RTPs were vastly improved by a wider rim. Less fussy wrt tire pressure, easier/safer to run @ lower pressure, and considerably less tire squirm which is a real bummer when things get technical or fast.

The Switchbacks are lovely on A23s. But I'm thinking something wider would be better. Especially for trickier terrain, loaded bike, safer lower pressures, &c.

[mitch....@gmail.com]

Like Ed I remember wider mtb rims from the 80s and have a wheelset I built long ago on Mavic 28mm outer width rims that has worked fine in various mtbs without any canti brake set up problems I can remember. There were early mtb narrow rims too because Keith (?) and others made 559 rims from MA2s but the early 80s Araya mtb rims that came on my 1981 mtb were 28mm wide and light. Seems like road-narrow mtb rims were a trend of the late 80s, early 90s IIRC, probably for the reason Stephen mentioned--that the easiest way to make an allow rim light is to make it narrow.

Most of you remember this mtb rim history too so I share your curiosity about why a reasoanlbly light 28mm rim-brake rim is not on the market. I appreciate the Cliffhanger but it stays around because trekking tourers will support a super strong heavy rim like that. Go for it Nick and see if you feel the weight.

A recent example comparison I've made is for disc only wheels so only tangentially relevant. I initially built up a Romanceur with nice but older disc wheels with 23mm rims with brake tracks. They work great with RTP ELs but I was looking forward to seeing how the same tires felt with 31mm wide Pacenti DL31s. These rims have a great profile for the RTPs and create a different tire shape--8mm makes a difference. But the DL31s have DH heritage and are 530g each for 26".

I sort of had the opposite experience Nick had since I didn't expect heavier wheels to feel slower but they did on my first flat ride. Feel of speed and actual speed are not the same so I'm not drawing any conclusions from the few rides I got on the DL31s before the heavy snow and ice has prevented further testing. Plus I did a couple rides on them with long steep climbing and they didn't feel slow there like they had initially on the flat. So that slow feeling may have been something else.

Meanwhile I look forward to using the 584 wheelset I built for the Romanceur on Pacenti TL28. 420g per rim in 584.

What I conclude from all this is 1) there should be a fairly light 28mm wide rim brake rim in 584 and 559 at least. There used to be anyway. 2) wide rims are easy for disc bikes so to some degree when you choose wide you should consider disc. 3) even with good disc rim design in alloy, wide is heavy and narrow is light. Whether heavy matters or not is up to physics and how you like the feel. For now to modify the old adage, if you want wide, light, and alloy, pick any two.

The TL28 seems like a good compromise for disc and the Velocity Blunt at 31mm wide and a hair under 400g is even better. It may break the rule.

--Mitch

[Stephen Poole]

Back when I started MTBing, there were only really Araya rims. The first bike had 7X rims (~30mm external), then I built wheels with RM25 (32mm?) and RM20 (28mm?). I was never all that impressed with the RM25s, probably because there weren't really any tyres wide enough to use the rim width back then.

The 7X rims were happy with 2.125 tyres at low pressures; after one offroad camping trip I measured 12psi front and 18psi rear. No pinch flats or tyre instability, ever, and that's with tubes.

The RM20s were okay with 1.25 Fatboys at ~100psi, and with 2.2 Hardpacks at <20psi, again with tubes, and they were reasonably light, 485g claimed IIRC. They survived a bottom to top trans-Oz on fire trails and dirt roads with no problems.

After the late 1980s wide rims became uncool, and most were ~23mm external for several years. These work okay, but as others have said more pressure is needed to keep the tyre from deforming or (IMHO) pinch flatting.

So, I agree with Mitch - there is room for a reasonably light 28mm external rim brake rim, in both 559 and 584. There's minimal weight difference from a 23mm rim, and this could be reduced by using ceramic coated sidewalls as these basically eliminate wear from braking; wet braking is vastly improved too.

Back in the early 1990s Mavic used to make 231, 261 and 281 rims, 23mm, 26mm and 28mm wide respectively, and in ceramic versions. A reissue of the 281 wouldn't be a bad thing.

@Nick: Thanks for reminding me about tyre stability at low pressure, and fussiness. I found with 42-584 that on PL23s there's only a narrow band of pressure between an uncomfortably hard ride and vague handling. Wider rims might help this, as might a decent digital gauge.

Later,
Stephen

[Rick Johnson]

I still have a set of those 559 ceramic sided Mavic Crossmaxs - to this day I think they were the best rim brake setup I've ever ridden. I would love to see a modern version in 584 and 622, that might keep me with rim brakes for a few more years.

Rick Johnson
Bend, Oregon

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