650b equivalent of Open Pro or MA2?..

[Max]

Dear 650b Braintrust,

I currently ride wheels using Velocity Synergy (Australian made, polished), running 38m tires, rim brakes. They're just fine. However, as a winter project (or maybe over the next year), I'm looking to build a lighter 650b wheel set, hoping to find a reasonably ligh rim, also polished, perhaps an equivalent in terms of width of Mavic Open Pro, Ambrosio Montreal, Campy Omega Strada, Mavic MA2,.. you get the idea.

(I'll probably run 32/34 mm tires on these. And I will probably want to source 32 or 28 hole Ultegra or Dura Ace 8/9 speed hubs. And, since everything I like tends to get discontinued, I'd probably want to load up on a few spare rims and tires... Project, indeed!)

Any suggestions?

Thanks!

[Peter Adler]

Pacenti Design's superlative PL23 dual-layer dual-eyelet box rims are about as close to MA2 as you're going to get: 23mm wide, and marvelously light at 480g in 700C form. I don't recall what the 650B weight was, but the older/lighter-generation PL23s were 420g in 700C, so I'm guessing the second-gen 650Bs were in that neighborhood. Sadly, the PL23s appear to have been discontinued; Kirk's been blowing out the leftovers most of this past year, and the 650Bs are long gone. Maybe somebody here would be willing to part with some of their hoard.

Velo Orange appears to have discontinued their 650B PBP model; the only 650B rim they still sell is the Diagonale model, a beefier rim that weighs in at 550g. Similarly, SOMA has the Weymouth at 540g. Both are about 24mm wide, while Velocity's Atlas (a more rugged rim than the Synergy by all accounts, and boxier-looking) is a very wide 25.4mm. Velocity also has a much wider (30mm) polished box rim with rounded corners called the Cliffhanger at 625g.

HPlusSon doesn't make a 650B rim at all, but their TB14 would be a logical MA2 substitute if anyone's ever able to talk them into making 650B.

Kirk, if you notice this: Is the PL23 being redesigned/re-engineered, or are you done with box rims altogether? Your retro-fetishist fans need to know...

Peter "retro-fetishist, and not too embarassed about it" Adler

who loveloveLOVEs his 700C PL23s in

Berkeley, CA/USA

[Jeff Bertolet]

I'm using the diagonales and they are very prone to squealing with the polished surface. I roughed them up with some sandpaper and that helped, but they are still occasionally very noisy. I'm going to try some SL23's to see if that helps. I've tried a few different caliper/pad setups and am convinced it is mostly the rim that is causing the noise.

[Steve Chan]

   Lightweight 650B polished rim brake rims are a niche these days. As Peter mentioned, Kirk Pacenti did a run, but he seems to be shrinking the portfolio of products he offers, and the roadie rims seem to be one of the cuts.

   Velocity seems to be in the game for the long term, and their A23 rim is lightweight and comes in high polish. It isn't rated as highly as rims from other manufacturers due to finish vs price complaints.

   The Compass and Velo Orange rims have been mentioned, but they aren't really lightweight. For example, the Grand Bois 650B rim is 468g, while the larger Mavic 700C rim is 30 grams lighter at 435g. The Grand Bois rim is compared to an MA40 in this photo:

   It should give you an idea what type of use case this rim is for. The Compass is lighter than the Velo Orange and SOMA rims.

   The Pacenti SL23 is a very nice, lightweight polished 650B rim, and is 420g for a wide rim, but selection is limited. If 28H is good for you, then I could grab them now before all of Kirk's stock is gone:

http://pacenticycledesign.com/index.php/products/rims/sl23/sl23-650b-28h-1-detail

   The HED Plus 650B is the high end lightweight rim that is still in production, but it is expensive, and doesn't seem to come in a polished finish:

http://www.modernbike.com/hed-belgium-plus-rim-650b-x-25-32h-with-msw-black

   Personally I think if you're trying for either more compliance or lower rotational inertia, you'd be better off shaving the weight off the tire/tube combo by going with an extralight tire and tubeless.

--
You received this message because you are subscribed to the Google Groups "650b" group.
To unsubscribe from this group and stop receiving emails from it, send an email to 650b+uns...@googlegroups.com.
To post to this group, send email to 65...@googlegroups.com.
Visit this group at https://groups.google.com/group/650b.
For more options, visit https://groups.google.com/d/optout.

--

"Sow a thought, reap an action. Sow an action, reap a habit. Sow a habit, reap a character. Sow a character, reap a destiny." - Samuel Smiles

[Anthony King -- Longleaf Bicycles]

On Saturday, January 2, 2016 at 12:01:24 PM UTC-5, Max wrote:

Hoping to find a reasonably ligh rim, also polished, perhaps an equivalent in terms of width of Mavic Open Pro, Ambrosio Montreal, Campy Omega Strada, Mavic MA2,.. you get the idea.

I have two of the new extrusion PL23's left in 36h, and a few older extrusions (the ones that are lighter) than I can use for front builds. A good wheel builder shouldn't have a problem with the older, lighter models cracking on front wheels.

But with 11spd hubs being shoved down our throats, someone would have to be foolish to produce a very lightweight box section rim now. They won't take the spoke tension necessary on the drive side spokes of 11spd hubs needed to bring the non-drive side spokes up an acceptable tension level. The 11spd hubs force the use of assymetric rims or stiffer rims for most riders. The best way to make the rim extrusion stiffer without adding weight is to make the extrusion triangular at the spoke bed. I don't think that a manufacturer would be willing to make a sub ~450g box section 650b rim knowing that they'll be laced to 11spd hubs by builders of varying experience and skill. It only takes a few to crack before the rim gets a bad rep on the internet. 

Anthony

[Max]

I hear you on the variability In wheel builder experience and skill. I'd be really curious to know what percentage of dollars in wheels go to human vs. all-machine built wheels...

The issue of 11 speed componentry is another real one -- but we are in the midst of a transition in the high end of the market, where the 11 sp stuff is becoming prevalent, yet not so ubiquitous that it's getting cheaper. Costs aside and in terms of usage, its probably to the point now that an 11 sp chain and cogset might have nearly the same longevity as an 8 speed set, due to better alloys and treatment being used on the newer stuff. I personally would be perfectly happy on a 6-speed, freehub (not freewheel) set-up, if this beast could be made with modern alloys.

Come to think of it, one could imagine using the largest 6 cogs of an 11 sp modern cogset on a custom hub, producing a dish-less and well triangulated rear wheel. A lighter rim could be used (with thin 15 gauge, 36 spokes). Modern chain sets could be used easily, sprocket and chain wear would be mitigated somewhat by larger diameter rings and cogs.

Hmm... Time to talk to Phil Wood or White Ind. or Paul Comp. about a custom new hub design?..

[Kieran Joyes]

Compass sells the hub you describe, albeit in 120mm OLD format. I would think the design minimizes the dish required of the wider cassettes under discussion.

Short cassette body that carries a custom 6spd cogset.

https://www.compasscycle.com/shop/components/hubs/grand-bois-120mm-cassette-hub/

KJ

[Nick Payne]

I have a 650b rear wheel build on an old Deore XT 7-speed hub with 135OLN spacing. With an OC Synergy rim, there is virtually no dish in the wheel, and by discarding the smallest sprocket from a 9- or 10-speed cassette, the cassette will fit on the 7-speed freehub. Here's the wheel in my Bleriot - the cassette here is a Shimano 9-speed 11-32 with the 11 discarded, giving 12-32.

--

[Justus]

Some mountain bikers use single speed free hubs in a similar setup. My American classic SS hub can fit 6 cogs on its shortened cassette carrier, 7 would fit with ten speed cogs. I have my wheel built up with a pl23 (the lighter 400gram one) and 2.0/1.5 spokes. It built up as easily as a front wheel, with no need for high tension.

[Harold Bielstein]

A 120mm rear spaced hub makes it more difficult to fit a 42mm tire between chain stays on a lugged BB.

> --
> You received this message because you are subscribed to the Google Groups "650b" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to 650b+uns...@googlegroups.com.
> To post to this group, send email to 65...@googlegroups.com.
> Visit this group at https://groups.google.com/group/650b.
> For more options, visit https://groups.google.com/d/optout.

Hal Bielstein
Rapid City, SD

[Max]

Nice! Proves once again that everything has been done already. :-)

To bring this back to rims, any reason to not use the CL25 (394 grams) with rim brakes??

http://www.pacenticycledesign.com/index.php/products/rims/cl25/pacenti-cl25-650b-28h-detail

[ted]

The eighth item down under details says disk only

[ted]

[Steve Palincsar]

I know the hubs aren't any wider, but are the 11 speed cassettes wider than 8-10?

[Chris Cullum]

Yes, with more resultant dish.

[mitch....@gmail.com]

Shimano yes. 11sp cassettes are not compatible with 8/9/10speed hubs.

Campagnolo 11speed cassettes fit onto regular 10speed Campagnolo compatible hubs though. Campagnolo took the dish hit back with 10speed. Shimano waited to take the hit with 11speed. 

--Mitch 

[Chris Cullum]

On Jan 4, 2016 3:23 PM, <mitch....@gmail.com> wrote:
>
>
>
> On Monday, January 4, 2016 at 3:18:31 PM UTC-7, Steve Palincsar wrote:
>>
>>
>>
>> On 01/03/2016 01:03 PM, Anthony King -- Longleaf Bicycles wrote:
>>>
>>> On Saturday, January 2, 2016 at 12:01:24 PM UTC-5, Max wrote:
>>>>
>>>> Hoping to find a reasonably ligh rim, also polished, perhaps an equivalent in terms of width of Mavic Open Pro, Ambrosio Montreal, Campy Omega Strada, Mavic MA2,.. you get the idea.
>>>
>>>
>>> I have two of the new extrusion PL23's left in 36h, and a few older extrusions (the ones that are lighter) than I can use for front builds. A good wheel builder shouldn't have a problem with the older, lighter models cracking on front wheels.
>>>
>>> But with 11spd hubs being shoved down our throats, someone would have to be foolish to produce a very lightweight box section rim now. They won't take the spoke tension necessary on the drive side spokes of 11spd hubs needed to bring the non-drive side spokes up an acceptable tension level. The 11spd hubs force the use of assymetric rims or stiffer rims for most riders. The best way to make the rim extrusion stiffer without adding weight is to make the extrusion triangular at the spoke bed. I don't think that a manufacturer would be willing to make a sub ~450g box section 650b rim knowing that they'll be laced to 11spd hubs by builders of varying experience and skill. It only takes a few to crack before the rim gets a bad rep on the internet. 
>>>
>>
>> I know the hubs aren't any wider, but are the 11 speed cassettes wider than 8-10?
>
>
> Shimano yes. 11sp cassettes are not compatible with 8/9/10speed hubs.
>

Presumably you could put a spacer on the 10/9/8 speed freehub and run 10 of 11 and ditch the inevitable 11t small cog for a 12t. The good thing about 11 speed is that Shimano, SRAM and Campy wheels all work with each other's shifters/derailleurs.

> Campagnolo 11speed cassettes fit onto regular 10speed Campagnolo compatible hubs though. Campagnolo took the dish hit back with 10speed. Shimano waited to take the hit with 11speed. 
>
> --Mitch 
>

[Nick Payne]

On 05/01/2016 09:18, Steve Palincsar wrote:

I know the hubs aren't any wider, but are the 11 speed cassettes wider than 8-10?

Yes, wheels for 11-speed Shimano come with a spacer ~2mm thick that you place behind the cassette if using a 9/10 speed cassette, so the freehub is ~2mm wider and the dish in the wheel is that much greater. OTOH, you can mount 11-speed XT and XTR cassettes on a 9/10 speed hub, as the part of the cassette that mounts to the freehub is no wider than that on 9/10 speed cassettes and the largest cog overlaps to the inside. They can do this as the large cog on the cassettes is either 40t or 42t, and with such a large cog, the dish in the wheel means that the entire cassette can be closer to the spokes without the derailleur fouling the spokes in bottom gear as would happen with a racing-size cassette if it were in the same position.

Nick

[Kieran Joyes]

Interesting! I hadn't considered that aspect of the dish/cassette body/spoke angle relationship.

KJ

[Will Vautrain]

I just got off the phone with Kirk a while ago, because I scrambled to get some 28h SL23's before they were all gone. I have some unlaced 32h versions, but only the pair, so now I plan to build them up as 28/32 with a pair to spare.

Anyway, without going into details (not sure what Kirk wants to divulge publicly yet), he's honing in on what sells best. He's not dropping 650b rim brake support, but as you noted, he probably won't offer a super light roadie option in the future. Plus, super light rim brake rims will become less of an issue as adoption of disc brakes continues, though one could argue us 650b fans will be among the last to make that switch. Anyway, as long as there are 650b tires, there will be demand for heavier 650b rim brake rims.

Also, what a super nice guy he is to talk to on the phone! I doubt he's any different in person.

[Mike Klaas]

Kirk's website lists ~80 650x28h silver rims and a whopping 800 black rims still available—why did you need to scramble to get them?

It's sad that he is abandoning the light rim brake rims.  I love my pair of SL23s

[Chris Cullum]

I took that as abandoning the box section PL23. I think the SL23 is a popular rim in both 700c and 650b. Maybe I read that wrong?

[Mark Bulgier]

Mike Klaas wrote:

> Kirk's website lists ~80 650x28h silver rims and a whopping 800 black rims still available—why did you need to scramble to get them?

Kirk has said on at least one occasion that the website's reporting of numbers remaining is unreliable. Don't count on it.

Mark Bulgier
Seattle

[Steve Chan]

I seem to remember lots of the 32h 650B polished SL23 rims being
reported as available, until suddenly they were gone.

It would be great if they made the new 2015 extrusion of the SL23
available in 650B - that rim is a little wider, albeit a little
heavier. But the only thing I see are 28H SL23's in the 2014
extrusion.

[Nick Favicchio]

Minor correction to NickP's comment earlier. If you wanna run 8/9/10 on a 7 speed body, you don't have to ditch the smallest cog. You can ditch any cog not attached to the carrier if you'd like to keep the smallest cog.

I like the 11t smallest cog. Personal preference, keeps the range massive and allows for smaller rings up front. Pulling the 14t cog is prolly what I'd do.

Will do, think I've got a 26" 7 speed wheelset headed my way.

[Johan Larsson]

The braking surface would be a bit narrow, there is no inbuilt way of checking how worn the sidewalls are, and the braking would maybe be inconsistent until all the anodizing has worn off (if you don't sand it off beforehand, which would be a good idea). But those are just minor issues, and I wouldn't hesitate to use those rims myself with a rim brake setup.

Johan Larsson,

Sweden

[Brad]

The Confrerie des 650B has you in mind.  They have pushed to get the equivalent of the Sphinx rim made to their specs.  The current model is manufactured by Ambrosio.  http://www.xxcycle.fr/jante-ambrosio-keba-650b-argent-36-trous-confreriale,,fr.php
Routens has them in stock.
http://www.routens.com/navig-ttc/388-route/459-roues-et-pneus/548-jantes/5007-ambrosio-jante-keba-650b-argent-36-trous.html
How cool is that?

[Steve Chan]

  Any idea of the weight on that rim?

--

[Alex Wetmore]

http://www.ambrosiospa.com/index.php/en/cerchi-mtb

Not light, probably around 560 grams (525g in 559mm, 610g in 622mm).  It's hard to see much reason to import this over buying a Velocity A23.

alex

---

From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Steve Chan <sych...@gmail.com>
Sent: Tuesday, January 12, 2016 6:31 PM
To: Brad
Cc: 650b
Subject: Re: [650B] Re: 650b equivalent of Open Pro or MA2?..

 

[Chris Cullum]

It's heavy and nothing special. I hope Pacenti keeps making the SL23 in 650B. That's the best rim brake 650b rim out there IMO.

[Nick Favicchio]

The sl23 is the best looking 650b option but the struggle getting tires on and off is the only reason I'd say a23 over sl23. The sl23 built up lovely, it's light and the finished wheel goes like the dickens (hub has a lot to do with that), but mounting tires is a TRIP. I really worry about flatting out in the world with that thing.

[satanas]

If the SL23 is anything like the PL23, and the A23 is in fact easier to mount tyres on then I'd stay away from the SL23. I had a flat towards the end of PBP (and another in the parking area afterwards) and it was almost impossible for me to get the tyres on or off, even with a VAR "tyre-jack" lever. The A23 is also supposed to be tubeless compatible, if that matters to you, and can be had with an asymmetric rear for less dish.

The newer SL23 extrusion (available in 700C) has a deeper well which should make things easier, but there's no sign of this becoming available in 650b; Kirk has lots of the old ones still in stock.  :-(

Later,

Stephen

[Nick Payne]

I have several pairs of 650b wheels using Velocity Aerohead, Velocity Synergy, Grand Bois, and Velocity A23 rims, and the A23 are by far the hardest to get tyres on. The other three I can usually manage without needing tyre levers, but there's no way I can get any of the tyres I've tried onto the A23 rims without needing levers...

--

[Max]

Really good info all around, though not all of it encouraging! The OC A23 rear sounds tempting, but then this tire mounting issue... I've no interest in tubeless, I patch my tubes, and prefer regular clincher rims that don't make it impossible to get tires on and off. Hmm...

[Nick Favicchio]

I'm surprised people have had trouble with the A23. I have a Synergy wheelset as well and the Synergy mount too easily - as in I worry a bit about blow-off. The A23 seems like the proper balance. Getting one side of the tire on is typically pretty simple and getting the second side on, as long as the other side is nicely centered in the channel, isn't a struggle with thumbs only.

This has been more or less the case with mounting Cazaderos, Baby Shoes, Pari-Moto, Quasi-Motos and a Thunder Burt.

[nm matt]

my experience with the A23's mirrors nick's. adding hetres to his list of tires. at the risk of restating what has no doubt been mentioned many times, one needs to use tubeless rim tape, even when running tubes.

[franklyn]

I have used the following rims:

Velocity: Synergy, Dyad, A23

Pacenti: SL23, PL23

Weinmann: Zac 19

The SL23 is very light and beautiful, and when Kirk was closing out his old stock the price made it an incredible deal. The tire-mounting is tough. I have begun to use Orange sealant in my tubes to stave off minor puncturing threats. I might go to a tubeless set up with these rims.

The PL23 is also very great, and slightly easier to mount and dismount tires. I also use tubes with sealant for it.

The A23 is not hard (for me) when paired with tubeless rim tapes. I use tubes with it and can get tires on and off easily.

Tires mount easily with bare hands (no levers) on the Synergy and the Dyad rims (and the Zac 19). I do have fear that the tires might blow off them. Two layers of tape (one tubeless to close off the deep well and a cloth tape on top) make them mount tires more evenly and more secure

If I can get the Grand Bois more cheaply, I would use those.

Franklyn

[Max]

Conventional clincher design has little to do with the tightness of mounting and all to do with the retention of the bead under the rim hook by tube pressure. For the typical pressures being run, that design works. Why make things more difficult for marginal / questionable benefits?.. :-/

(Carmudge... Carmudge... Carmudge)

[Charlie Cho]

On 1/15/2016 7:03 PM, satanas wrote:

The newer SL23 extrusion (available in 700C) has a deeper well which should make things easier, but there's no sign of this becoming available in 650b; Kirk has lots of the old ones still in stock.  :-(

There is a SL23 650b 32h available with the new, deeper-welled profile. It's not listed on the Pacenti website yet. As for the older ones, Kirk doesn't actually have 773 of these in stock, despite what the page says.

In other news, the Weinmann ZAC19 650B 36h is back at J&B Importers, so now there's a budget choice available again.

Charlie

[Jeff Bertolet]

J&B has conveniently listed the ZAC19 under 26" instead of 650B.

[satanas]

How or where can these rims be obtained? I need to get some more rims soon and would go for these if I could get hold of them. (And if the deeper well actually works.)

[mitch....@gmail.com]

This has been a very useful thread and led me to look up weights for the MA-2.

460g is reported by Sheldon as the manufacturer 's claimed weight for the MA-2.

444g,451g,466g,454g,481g,481g are actual weights of MA-2 samples he weighed, showing there is a range (at least partly resulting from extrusion wear batch by batch).

Steve Chan reported above that MA-2s weigh 435g. Not sure whether 460g or 435g is correct for MA-2s and maybe both are accurate for a rim that was produced for decades with some variation. Steve also showed a very useful cross-section photo above comparing MA-2 and Gb rims, and showing the somewhat thicker GB rim extrusion. I agree with Steve that the GB rim seems a little more heavily built than the MA-2, but the conclusion I come away with is the GB rim is more similar to the MA-2 generally than dissimilar. The GB is not a true lightweight but neither was the MA-2. 

http://www.sheldonbrown.com/rinard/weights.htm 

Here are some other weights for comparison (just to pull together some of the rims we've talked about here):

480g PL23 700C-36 (don't have the weight for 650B, probably c. 465g)

420g SL23 650B-28

450g A23 700C

425g A23 650B

435g A23 650B OC

468g GB 650B

What I take away from this is mid-400g is pretty typical for general use light rim-brake box-section rims, like the PL23 and GB. You can remove some material and get lighter weights with a triangular section like SL23 and A23 which still come in the low-400g range. The difference is 35-45g savings. That's enough savings to me to prefer one rim over another but not enough to cancel out other differences: ease of tire installation/change, ease of initial build, durability, brake-track longevity, etc. A 100g difference begins to be enough weight savings to take a compromise in one of these other characteristics, but a 40g difference doesn't, to me, feel like one rim is light and one is heavy. Other characteristic differences may be larger than that small weight difference. 

I'm fairly new to 650B and have built wheels with PL23, Synergy, and GB rims. I'm also using an A23 OC wheelset. (I've also built dozens of MA-2 wheels over the years).

--PL23 built easily and smoothly, even with a 11sp Campagnolo rear, but are really difficult to get tires on and off of. Am using thin rim tape but will switch to thinner Stan's rim tape and see if that makes enough difference. 

--A23 are not as bad for installation as PL23 but still way too hard. These came with rim tape that could be thinner so I'll try Stan's and maybe review my technique, since others report no problems with A23. Maybe it's me. 

I really like the A23 OC feature and it's enough to make me prefer this rim over another with other advantages. 

--The SL23 may be the best looking 650B rim but my polished A23 are close and between the OC feature and easier tire on-off I might prefer A23 next wheel build even though I'm itching to try out the SL23. 

My retro preferences led me to choose PL23 for a couple recent builds. But since then I've seen how good SL23s look (Chris Cullum's recent MAP build), and they seem perfect with a round BSP--tire and rim in an integrated teardrop shape. Also, I didn't realize before that a triangular shape at the spoke bead stiffens the extrusion, as Anthony King explained above. I thought it was for looks and minimal aero advantage so the extra engineering info is useful for me and makes the SL23 even more attractive. Especially if the new extrusion accepts tires better.

--The GB rims from Compass were the easiest to build with and definitely the easiest for tire on-off. The weight is well comparable to the MA-2 as I see it (above). This and the PL23 are box rims like the MA-2 and are similar in weight, look/finish, eyelets, and overall result. Living with the wheels side by side, I really prefer the rounded shape of the GB rims over the sharper corners of the PL23. The GBs look a lot more like the MA-2 wheels they stand near in my bike parking. Most of my MA-2s have a curved spoke bed somewhere between the flattish PL23 bed and the rounded GB bed but just look a lot more like the GBs. I wonder if the rounded spoke bed of the GBs has some of the extrusion-stiffening advantage of a triangulated spoke bed--compared to a flatter bed anyway?

Here is what Jan and BQ say about rim weight:

There are some components where you cannot save weight without undue compromises, and rims are a very good example. A well-designed clincher rim weighs about 450-500 g (650B) and 480-530 g (700C). To reduce this weight further, you only can remove material in four ways:
Thinner sidewalls. Example: 1.3 mm instead of 1.6 mm. Savings: 30 g.* The rim sidewall abrades as you brake. You need at least 0.7 mm of sidewall thickness to keep the tire from exploding. With the thinner sidewalls, your rim can lose only 0.6 mm until it is worn out, instead of 0.9 mm. That means your rim will last only 2/3 as long.
Narrower rim: Example: 20 mm instead of 23 mm. Savings: 24 g. On the down side, the rim no longer supports wide tires well.
Thinner rim “floor” (the side facing the hub): Example: 0.9 mm instead of 1.0 mm. Savings: 11.4 g. Now there is less material to counter the stresses imparted by the spokes, and the rim is more likely to crack.
Bottom of the well (the side facing the tire): Most rims already have the bare minimum here, so there are no further savings possible.
Rim shape: A more triangular shape can save material over a traditional box section, but the brake tracks are much shallower. You will have to adjust your brake pads frequently as they wear, otherwise they will cut into the tire (with sidepull and centerpull brakes) or dive under the rim (with cantilevers).
None of these weight saving options are very appealing. In the end, a good rim has a certain weight, and there is little you can do about it.
https://janheine.wordpress.com/2012/05/09/rim-weight/ 
The first four BQ bulleted points seem to substantiate what Anthony King said above about why we're unlikely to see new super-light box section rims. The fifth point "Rim shape" is what Anthony said about the triangulated spoke bed advantage. The cross-section images of the SL23 look to me like it's an optimized design for lightweight. It's hard to see how you would use less material. If it's strong enough and the brake track lasts well enough, it looks like the lightest rim-brake rim we could expect from aluminum. I like the curved SL23 triangle shape but the similar A23 seems to have all or most of the SL23 advantages, is almost as light, and has the great OC feature for use with modern rear hubs. The GB seems closest to the MA-2 and the best (rounded/arched) box section classic looking rim we're likely to see, and is only 48g more in weight. Whether some of those grams add brake track durability is another question, but the cross sections photos make it look likely.
I plan on using 650B rim-brake rims for years to come. Let's hope these good ones stick around.
--Mitch

[Steve Chan]

On Mon, Jan 18, 2016 at 1:48 PM, <mitch....@gmail.com> wrote:
> This has been a very useful thread and led me to look up weights for the
> MA-2.
> 460g is reported by Sheldon as the manufacturer 's claimed weight for the
> MA-2.
>
> 444g,451g,466g,454g,481g,481g are actual weights of MA-2 samples he weighed,
> showing there is a range (at least partly resulting from extrusion wear
> batch by batch).
>
> Steve Chan reported above that MA-2s weigh 435g. Not sure whether 460g or
> 435g is correct for MA-2s and maybe both are accurate for a rim that was
> produced for decades with some variation.

Sorry, I was unclear. Between the MA2 and the Open Pro, I consider
the Open Pro the "lightweight" rim and the MA2 more of a middleweight
rim. So I used theOpen Pro as the baseline for a lightweight rim.
The Open Pro's reported weight is 435g.

> Steve also showed a very useful
> cross-section photo above comparing MA-2 and Gb rims, and showing the
> somewhat thicker GB rim extrusion. I agree with Steve that the GB rim seems
> a little more heavily built than the MA-2, but the conclusion I come away
> with is the GB rim is more similar to the MA-2 generally than dissimilar.
> The GB is not a true lightweight but neither was the MA-2.

Again, my unstated context was the open pro as a lightweight rim.
The cutaway cross section showed that the GB seemed beefier than the
MA2/MA40, which is in turn beefier than the Open Pro - hence, imo, the
GB isn't a "lightweight" rim in the sense of an Open Pro.

> The difference is 35-45g savings.
> That's enough savings to me to prefer one rim over another but not enough to
> cancel out other differences: ease of tire installation/change, ease of
> initial build, durability, brake-track longevity, etc. A 100g difference
> begins to be enough weight savings to take a compromise in one of these
> other characteristics, but a 40g difference doesn't, to me, feel like one
> rim is light and one is heavy.

A Schwalbe 650B inner tube is spec'd at 140g. A valve stem seems to
be something under 10g. So you're adding 130g by using an inner tube
instead of going tubeless.

> --PL23 built easily and smoothly, even with a 11sp Campagnolo rear, but are
> really difficult to get tires on and off of. Am using thin rim tape but will
> switch to thinner Stan's rim tape and see if that makes enough difference.

If you're using a tubeless ready rim and not using tubeless rim
tape, then there is an argument that you're just setting yourself up
for hardship when mounting tires. I don't think its fair to complain
about the usability of a tubeless rim when your using the wrong kind
of tape.

> There are some components where you cannot save weight without undue
> compromises, and rims are a very good example. A well-designed clincher rim
> weighs about 450-500 g (650B) and 480-530 g (700C). To reduce this weight
> further, you only can remove material in four ways:

I'm curious about the effect of alloy composition on wheel weight.
There are a lot of observations about some rims being made of softer
alloy that abrades quickly. With bike frames, a higher end steel
alloys a thinner tube wall that still resists dents comparable to
thicker tube walls.
And there seems to be surface treatments that increase the abrasion
resistance of rims - it seems that ceramic brake tracks can be very
long lasting.

The 650B road rim niche is kind of small, and we may not see all
the possible rim innovations on the products available to us.

[mitch....@gmail.com]

On Monday, January 18, 2016 at 5:18:38 PM UTC-7, Steve Chan wrote:

On Mon, Jan 18, 2016 at 1:48 PM,  <mitch....@gmail.com> wrote:
> This has been a very useful thread and led me to look up weights for the
> MA-2.
> 460g is reported by Sheldon as the manufacturer 's claimed weight for the
> MA-2.
>
> 444g,451g,466g,454g,481g,481g are actual weights of MA-2 samples he weighed,
> showing there is a range (at least partly resulting from extrusion wear
> batch by batch).
>
> Steve Chan reported above that MA-2s weigh 435g. Not sure whether 460g or
> 435g is correct for MA-2s and maybe both are accurate for a rim that was
> produced for decades with some variation.

   Sorry, I was unclear. Between the MA2 and the Open Pro, I consider
the Open Pro the "lightweight" rim and the MA2 more of a middleweight
rim. So I used theOpen Pro as the baseline for a lightweight rim.
   The Open Pro's reported weight is 435g.

That makes sense. I always preferred the MA-2 because it's a little wider but there came a time back then when the MA-2 seemed a little out of place in performance riding compared to the Open Pro. Not so anymore since the Open Pro itself seems old school now, and given what performance wheels are today. 

But if the difference is only 30g that seems like not enough to distinguish between them on its own if there are other preferences too, like width. Lighter is always better and it adds up. But things are seldom all-else-equal and I would have a hard time preferring one rim over another for no other reason than 30g. Others are different I know and it's a point-of-view issue. 

Rim width does seem highly relevant to the originally posted question though since many of us wouldn't want to run any of the 650B tires we ride on rims as narrow as an Open Pro or MA-2. For this discussion I think we'd want to compare an imaginary 23mm wide 584 Open Pro, and the SL23 seems as close as we can get, probably much better.

 

> The difference is 35-45g savings.
> That's enough savings to me to prefer one rim over another but not enough to
> cancel out other differences: ease of tire installation/change, ease of
> initial build, durability, brake-track longevity, etc. A 100g difference
> begins to be enough weight savings to take a compromise in one of these
> other characteristics, but a 40g difference doesn't, to me, feel like one
> rim is light and one is heavy.

   A Schwalbe 650B inner tube is spec'd at 140g. A valve stem seems to
be something under 10g. So you're adding 130g by using an inner tube
instead of going tubeless. 

Agreed and it's always interesting to me to see the reasons people go tubeless or not; it usually seems weight savings is not the first reason. That's probably only because there are several good reasons to go tubeless, including weight savings. But it does seem like a decision generally made on other grounds. 

 

> --PL23 built easily and smoothly, even with a 11sp Campagnolo rear, but are
> really difficult to get tires on and off of. Am using thin rim tape but will
> switch to thinner Stan's rim tape and see if that makes enough difference.

   If you're using a tubeless ready rim and not using tubeless rim
tape, then there is an argument that you're just setting yourself up
for hardship when mounting tires. I don't think its fair to complain
about the usability of a tubeless rim when your using the wrong kind
of tape.

Sorry I should have been more clear--I am using a tubeless rim tape. Just looks to me like the Stan's is even thinner and I want to try it and see if it helps. 

 

> There are some components where you cannot save weight without undue
> compromises, and rims are a very good example. A well-designed clincher rim
> weighs about 450-500 g (650B) and 480-530 g (700C). To reduce this weight
> further, you only can remove material in four ways:

   I'm curious about the effect of alloy composition on wheel weight.
There are a lot of observations about some rims being made of softer
alloy that abrades quickly. With bike frames, a higher end steel
alloys a thinner tube wall that still resists dents comparable to
thicker tube walls.
   And there seems to be surface treatments that increase the abrasion
resistance of rims - it seems that ceramic brake tracks can be very
long lasting.

   The 650B road rim niche is kind of small, and we may not see all
the possible rim innovations on the products available to us.

Agree and it's too bad if we don't see more innovation. You are likely more aware of current technology of ceramic brake tracks that increase durability. My experience with them was mostly hard anodized MA-40 and SSC rims where the surface treatment seemed to wear fairly fast and the overall impression is that the brake track didn't last as long as an MA-2 without the hard ano. That's old technology though and you're likely talking about advances since. 

--Mitch 

[Mike Klaas]

On Monday, January 18, 2016 at 4:18:38 PM UTC-8, Steve Chan wrote:

   A Schwalbe 650B inner tube is spec'd at 140g. A valve stem seems to
be something under 10g. So you're adding 130g by using an inner tube
instead of going tubeless.

 A lightweight Schwalbe tube is 105g.  You should use ~2 oz (57g) of sealant.  This adds up to a savings of 38g by going tubeless (per wheel).

-Mike

[David Cummings]

I think you can go even lower to ~90g flyweight tubes and get down to about 28g (1 oz) difference between tubeless. If you have to keep adding Stan's every 3-4 months, there goes your savings.

David Cummings
Kalispell, MT

[Steve Chan]

The weight of the sealant is not directly comparable to the weight
of an inner tube. When the sealant is in liquid form, it pretty much
just sloshes around inside the tire, and isn't carried around
'rigidly' the way that a tube would be. So when the wheel is rotating,
not all of the sealant counts as "rotating mass".
And once the sealant dries, a proportion of that weight of the
original sealant has dried up. I'm sure that eventually the weight of
the dried up sealant would equal an inner tube, but its not going to
be 1 to 1 original liquid sealant to dried up sealant.

> --
> You received this message because you are subscribed to the Google Groups "650b" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to 650b+uns...@googlegroups.com.
> To post to this group, send email to 65...@googlegroups.com.
> Visit this group at https://groups.google.com/group/650b.
> For more options, visit https://groups.google.com/d/optout.

[satanas]

Much as I hate to say it, ceramic coated rims are now pretty much dead technology, replaced by disc brakes. Some claimed they caused squealing, and/or required special brake blocks, but I've never had either problem, always using standard Shimano MTB pads. Some also complained that the rims were capable of being damaged via abuse(!), with replacement then being relatively expensive compared with non-ceramic rims.

Hard anodiding was never claimed to improve braking, and in fact makes it worse unless it's worn through, or was machined off during manufacture.

Only Rigida (aka "Ryde") offers ceramic-ish brake tracks new these days, and only on quite heavy rims. :-(

Since wer'e talking about rim design, IMHO it'd be nice if more current rims had eyelets, as these make both building and later truing easier.

Later,
Stephen (who'd buy more Mavic Ceramic rims tomorrow)

[Will Vautrain]

I loved my ceramic Open Pros, they stopped on a dime, wet or dry, with Kool Stop salmon pads. Then one day a red double decker tour bus taco'd my rear wheel and I found out I couldn't replace it, I was seriously bummed.

Sent from my Master

> --
> You received this message because you are subscribed to a topic in the Google Groups "650b" group.
> To unsubscribe from this topic, visit https://groups.google.com/d/topic/650b/XGTbCPZROjY/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to 650b+uns...@googlegroups.com.

[Stephen Poole]

At least it was the rear and not the front...

[djm323]

On Saturday, January 16, 2016 at 9:42:15 AM UTC-6, nm matt wrote:

my experience with the A23's mirrors nick's.  adding hetres to his list of tires.  at the risk of restating what has no doubt been mentioned many times, one needs to use tubeless rim tape, even when running tubes.  

Ditto.  Ive found it effortless to mount and remove Compass Babyshoe Pass tires on the A23 without tools.

[Chris Cullum]

The A23 is a decent rim, the one downside is that the brake track is very narrow. Barely as wide as most brake shoes and narrower than some. As pads wear you have to watch as the pads will start to migrate partly off the brake track toward the tire or below the rim depending on I'd you're using centerpulls or cantis.

--