mtnbke

Okay, I'm thinking about building up our C'dale with 630 rims/wheels (27").

The only "tandem" rated rim I can find in 27", currently being manufactured, is the Velocity Dyad.

Now the Dyad is a fine rim, but by no means is it a tandem rated rim in my book. The Velocity Chukker is a much better tandem rim and the Velocity Psycho trumps even the legendary Mavic Module 4. However, the Velocity Chukker and Velocity Psycho are both only available in 622 (700c).

Does anyone have a secret stash of something truly bombproof like old Mavic tandem rated rims? I don't know if the Mavic T519 or T520 or even the Mavic A719 or A720 ever came in 630. However, if they didn't I'd still be interested in Mavic Module 3 or Mavic Module 4 rims or something similar and bombproof in 630 (27").

Thanks for reading. Post if you know a source, PM if you are the source.

steve53mg

I don't know about 27", but I built a set of 40 spoke wheels for my Santana, last year with Dyads. They seem to be very commonly used on tandems. I've had very good results. We are a 360 pound team. The only limitation that I see, is that they are limited to 28 mm or larger.

swc7916

You could try eBay:

https://www.ebay.com/itm/Wolber-M59-2...item519b458782

https://www.ebay.com/itm/SUN-48-HOLE-...item27c031390b

https://www.ebay.com/itm/MAVIC-27-RIM...item2a1535278c

etc....

specbill

mtnbke, just curious..... why 27's for your C'dale? what year frame?


Bill J.

steve53mg

mtnbke, I should have mentioned that the Dyads that I used on my Santana were 700C. I have never heard anyone mention that they were not sturdy enough for a tandem. After lacing them up and having ridden them for about 2000 miles, I couldn't imagine a strength issue, unless you are an unusually large team. I'm just curious why you consider them unsuitable.

mtnbke

Well the Dyad isn't really a weak rim, but they certainly aren't deserving of their reputation. It most certainly is not a particularly strong tandem rim. Don't get me wrong, Velocity builds some great rims, and the Dyad is an absolutely great rim. It just isn't a great tandem rim. The fact that it can be used on so many tandems tells you how great of a rim it actually is. However, never ever lose sight of the fact that in 622 (700c) the Dyad is a 480g rim. For tandem use I'd always always always recommend the Chukker, and if need be the Psycho. The Psycho is by far the strongest most bombproof rim ever rolled. Peter White doesn't even bother with carrying the Psycho (even considering his reputation for building touring/tandem wheels) as the Chukker is actually in its own right so freakin' strong (which he does build with).

The Dyad is what it is. It is a great rim, just not by any means a bombproof rim for a tandem load. I would say it is a bombproof single rim, with no reservations. I've used the Dyad in 700c with a 48h build using double butted 14/16 spokes on our tandem and it failed within five miles. Now I knew the spokes were completely insufficient for our build, but Andrew at Yellow Jersey in Madison, WI swore that this was the way to build 'em. I got tired of arguing with him, and he said he would stand by the wheel before money changed hands. Anyway after it failed, and after trying to retension/true and round out the wheel it failed within three miles with just me on the tandem on its second ride, which should have given the rear wheel more weight balancing than it had any right to expect. Then again, the rim was already compromised from the first failure.

To be fair, though, I did just order a Dyad to rebuild a wheel for my touring single. I do like the Dyad rim, for what it is, and what it is for. However, it is NOT really up to snuff as a strong tandem rim in my book compared with what else is out there. The Mavic A719 is a much stronger rim, and the Velocity Chukker and Psycho are incomparably more rim. However, there are plenty of tandem teams that don't need that much rim.

The Mavic A719 is very similar in its extrusion to the Dyad, and while the Dyad weighs in at 480g, the A719 is 565g. The Velocity Chukker weighs in at 650g and builds a stupid strong wheel. The Psycho (in 622 or 700c) weighs in at only 606g. However strong the Psycho might be, like the Mavic Module 4, it is probably too wide for the tires many want to run on their road going tandems. For off-road tandems, you can build a bombproof 29er tandem, believe it or not, with that Psycho. It would probably be the first 29er tandem.

The Super Champion Model 58, and the Wolber versions including the 59 had a reputation of being a very stout touring/tandem rims. However, compared to modern rims it is revealed to be an undeserving reputation. There are much much stronger rims out there now. Even the Dyad should be a stronger rim.

Take a look at the actual cross section of the Super Champion 58, (now owned by Wolber):

https://www.equusbicycle.com/bike/wol...20-%200003.pdf

There just is nothing structurally there. If you had to compare it to a Velocity rim, it wouldn't be anything tandem rated, but rather comparable best with the likes of the Velocity Twin Hollow which at 540g is almost the same rim as the 555g Super Champion 58.

The Sun CR16 is not at all a tandem rated rim. I'd compare it to a Mavic MA40. The Mavic MA40 is the same cross section and extrusion as the Mavic MA2. These are definitively not tandem rated rims. I'd call 'em single training rims. The old BikePro database actually called 'em "racing rims." They did come available up to 40h, but tandem rims they are not. Back in the day a lot of bikes in Europe were spoked 36h in front and 40h in the rear, even what we would call "racing bikes." Later this became 32/36.

To me a "tandem rated" rim has to be able to reliably carry an average sized team, say a two hundred pound man and a buck fifty stoker forever absent road hazards. The rim needs to be a forget about it rim. Something that is strong enough that it will never be a problem for the team. Our team is an outlier, certainly, which is why I'm searching out secret stashes of 630 (27") Mavic tandem rims.

The Dyad isn't strong enough for our team and appropriate spokes for the application isn't going to change that, a Mavic MA40 (or MA2) wouldn't even come close. I don't know if a Sun/Ringle Rhyno Lite was ever made in 27", I'd be interested in that if I could find it. However, its a brute force rim, not the most elegant or engineered design (read heavier than it should be). Very old design. Believe it or not the Dyad is the only 48h rim I know of being made in 630. I don't know of anything being made in 630 in 40h, currently.

As for why I want to put 630 wheels on my Cannondale? That's a good question. Admittedly, all other things being equal, a bigger wheel is always weaker. A 622 (700c) wheel would be stronger than a 630 wheel (27"), even if only marginally. By the same token 584 wheels (650B) are stronger than 622s, which is why I think they are prevalent in Europe for touring bikes and tandems, but not in the US so much. I've never even seen a 584 tandem. Triples and Quads are usually built on 559 wheels (26") unless the third/fourth (second and third stoker) are kids. My Cannondale tandem is unusual in that it actually accomodates both 700c and 27" wheels, believe it or not. The tandem looks ridiculous in the way it is built up. I just don't like the way it looks. I ride a 68cm-70cm single, but nobody makes a non-custom tandem that big. My '91 C'dale tandem measures out a little over a 34" standover for me, and is really similar to a 25" C'dale touring bike. Well that makes it between 5 and 8 cm too small. So I've built it up as a Frankenbike with a hi-rise Salsa stem and a ton of seatpost. The thing is that the wheels just "look too small" even though the tandem isn't as big as it should be. I think the 630 wheelset would look incrementally more proportional.

I actually might consider just using a 630 up front. I'm not sure I'd appreciate how the handling of the bike would be affected, but it would create a poor man's compact geometry (giving me a bit more bar height, although exacerbating the existent problem of too much seat angle). Thoughts? Stupid idea?

steve53mg

Mtnbke, I'm sorry if it appears that I am asking you to beat a dead horse, but I am still curious about the Dyad rims. When you say that the rim failed after 6 miles, how did it fail? (Obviously, it didn't break) Or was it a spoke failure? It seems odd to me that a newly built wheel with 48 spokes would fail so quickly, even with underspeced spokes. It would seem that there was something very basically wrong with the build. I don't want to jinx anything, but I have about 2000 miles on my dyads with 40 straight 14 ga spokes. We've hit all manner of pot holes, etc, with no issues. My old tandem was a Burley duet that wore the same 27" 48 hole Sun Chinook rims for 20 years! They weighed a ton, and I felt that 48 spokes were overkill for us, since we do no loaded touring.

Dean V

It seems crazy to build a 27" because it will look better when really I doubt you would even notice the difference when looking at the bike.
In reality all you will achieve is giving yourself a very limited selection of tyres and rims.

waynesulak

Sorry if i missed it but what is your team weight?

I am function over fashion type and have a 700C converted to 650B tandem. 650B wheels would look small on your big bike but 700C wheels with 35-38mm or bigger tires look as big as any 27" wheel with the smaller tires that are available in 27 inch. The added tire selection as well as wheel strength would make 700C the way to go.

Wayne

mtnbke

Combined we are about 550 pounds. However, we also load the bike, and pull a Chariot double trailer (two kiddos). Trust me, we are an outlier in terms of what we ask a rear wheel to do. The Chariot places additional stress on a rear rear. I'm 348 lbs on my own. My stoker is 200 lbs.

We'd LOVE to get back on our tandem. Velocity will be rebuilding our wheel for us to make it right. I can't recommend Velocity enough. They really do stand behind their stuff. Again, I love the Dyad, I just ordered another Dyad rim in 630 for one of my singles. I absolutely do not believe it is a bombproof tandem rim. I don't think you can have a bombproof tandem rim at 480g. Again the Mavic A719 weighs another 100g, and the Chukker 100g over even that. The Velocity Chukker is a world class bombproof tandem rim.

When the Dyad failed, and it was properly tensioned, I checked tension before mounting the wheel it completely taco'd into the left cantilever. The spokes felt like the wheel hadn't even been properly laced, let alone tensioned afterwards. They Dyad rim had a seam (I think) running down the middle. If we had been descending instead of climbing we could have been killed. We hit over 55mph on a previous descent. I still get nightmares thinking about that. My son was less than a year old at the time. Since then I have NEVER taken the kiddies on the road, only off street paths.

I'm not a fan of 650B. I think a lot of people drink too much Kool-Aid believing nonsense about ideal wheel sizes for touring/tandeming. Which makes about as much sense as their being an ideal FRAME size for touring/tandeming. In reality 630/27" wheels on our tandem are probably proportional to 650B wheels on someone else's. It really is about the proportional relationship of the wheel size to the frame, not something inherent to the wheel size itself.

A 650B wheel on my 68cm bike is not the same experience as on someone else's 56cm.

You should read Jobst Brandt's and Zinn's comments regarding building wheels for outlier applications/loads. Trust me on this, it wasn't just the spokes. Albeit, there is no way that 14/16 Keirin spokes were going to work for a 550 lb. team on a 48 drill lightweight rim, while pulling a skewer mounted trailer. Keep in mind that we weren't carrying racks/panniers or gear when this happened. It was a charity century ride.

As for the difference between the 622 and the 630 wheelsets, I do notice. The bikes look like they have little clown wheels anyway, and the 8mm difference is less awkward. I can't say I notice any difference while on the bike. However, a key point here that shouldn't be lost on anyone is that I use custom 200mm cranks our tandem. Our Cannondale tandem is NOT a custom, and wasn't designed with a higher BB to accommodate the longer cranks. The 4mm of clearance I would gain from using 630 wheels is significant, in that sense. The point about the larger tires on 700c wheels doesn't make sense, as I use larger tires anyway. A 32-38mm wide tire on a 622 (700c) wheel is not going to look bigger than an identical width tire on a 630 (27").

I disagree completely about being able to find adequate tire selection. I don't need a hundred and eighty-four different tire choices. I just need about three. I can get lightweight Panaracer Pasela's in 630-25.5mm (27x 1 1/8) and I can get Continental Gatorskins in 630-27.5 (27 x 1 1/4). Additionally, I can get Schwalbe Marathon's and Continental TourRides in 630-32. What else do I need for how we use our bikes? What other people can buy in my wheel size of choice isn't relevant to me. People don't not build with 650B wheelsets because they can't get a good selection of racing tires for them. It doesn't matter that they can't, they are choosing 650B specifically because they are NOT going to be racing the bike, but touring/tandeming with it. As long as you can get a decent selection of tires for how you want to use the bike, and the tires that you like, what else really are you looking for?

Besides I have a secret stash of a pair of NOS German handmade gumwall Top Touring 2000 630-32 tires. Those should be good for 10,000 miles.

Dean V

I don't think you can say it isn't a tandem rated rim just because it can't survive under a 550lb team.

waynesulak

I agree with a lot of what you say:
- Stronger rims make a stronger wheel - more spokes at a higher tension is great but will not substitute for a stronger rim.

- A few good tires are a good enough selection. I did not know you could get 38+mm road tires in 27". With your weight I would go as wide as possible.

We went to 650B because I like wide tires and there are some really good tires at that size right now. We are a small team and toe overlap with 700C is also an issue. I have it on all my bikes but it is more difficult on the tandem since we rarely coast. Plus the second rule of tandeming thou shall not drop your stoker. I did make sure our tandem could go back to 700C in the future just in case tire selection goes away.

Good luck. It is not fun if you are outside the mass manufacturers' target market.

Can you post a picture of your bike or better yet both of you riding it?

Wayne

mtnbke

You forget that after the Dyad wheel was rebuilt, it failed with just me riding the bike (no stoker) within three miles. That's a 350lb "team", and why I say it isn't tandem rated. Again, I think its a stretch that a 480g rim had the reputation it does. The Velocity Chukker is a world class bombproof tandem rim, the Mavic A719 is as well. I consider the Velocity Dyad a light duty tandem rim, but a bombproof world class singles rim. It is a great rim. However, there is no great 480g aluminum tandem rim.

waynesulak

I think what we have here is a difference in perspective. Dean V may be like us. We are a 280lb team and for someone like us the Dyad is a great very strong tandem rim. Some in this forum use much lighter rims that I would ever use on our tandem but it is their bike and they swear by those wheels. See the wheels on this bike which are loved by some.

https://www.paketabikes.com/index.cfm...keta_v2_tandem


For you the Dyad is not a great tandem rim. For us it is a great strong rim. Others think it is way overbuilt.
Hope you find a rim for your needs. Sounds like you are more aware of the rim options than most people.

Wayne

ftsoft

I agree with waynesulak. It's difference of perspective. There are probably many on this forum who like us run Dyad's and are happy with them. I have to say that the poster has every right to question the sturdiness, especially for his team weight. We are only a 250 lb team and we blew 2 Dyad's in a pothole at speed a couple of years ago. It was a significant incident and while we didn't crash, it was touch and go. Still, if we were 550lbs I can see a scenario where descending on bad roads like the Ann Arbor MTR this year, we could destroy another pair. I don't understand the 27" issue though.

Frank

mtnbke

I think it is somewhat disingenuous to say that for a team of combined 280 lbs the Dyad makes for a great tandem rim. So let's introduce a little dose of reality to the conversation. I sure the heck don't define a "tandem rated rim" to necessarily have to be able to bear the load of what one would expect of a triple, quad, or even a quint. However, I also don't consider it reasonable to consider 280 lbs. to be anything in the neighborhood of what the average tandem team resembles.

Most tandem teams I know fall into two categories: A cyclist husband with a much much less fit stoker, a stoker whose weight typically makes captaining the tandem for the taller but not "larger" captain a challenge. The second group I usually see are older past their prime, but still enjoying everything life has to offer couples who are loving their tandems in retirement. Usually never a tight tummy to be seen.

Unless you're suggesting most men are five foot nothin' or their wives are merely a hundred pounds, let's try and bring the conversation back to reality. If a particular wheel works for you, and you (or your team) represent an outlier, that is not to say that the wheel/rim isn't perfectly appropriate for others. I am however, saying that while my team is an outlier, that aside, I do NOT believe the Dyad to be a "tandem rated" rim.

A tandem rim undergoes incredible stress. First of all a non-eyeleted rim is never a good choice for touring bikes or tandems as properly tensioned the increase of pulling a spoke increases anyway (even with eyelets). There is no such thing as a proper tandem rim at 480g, period. The Mavic A719 is a proper tandem rim, the Velocity Chukker is a proper tandem rim. The Velocity Dyad is a lightweight rim. I'd even call it a Tandem training/racing rim, but not a general duty "tandem rated" rim. It just is too lightweight and not stiff enough.

A general duty tandem rim needs to support, at minimum, around a three hundred and fifty-pound team (190c/160s). Anything intended for tandem touring needs to be considerably stronger. The Dyad, unfairly has earned a reputation as a "bombproof" rim. It is a bombproof singles rim, it is NOT a bombproof tandem rim. The Velocity Chukker is. The Velocity Psycho is stupid ridiculously strong. Velocity makes great rims. The Dyad is a great rim. It is not, however, a great tandem rim, except for very lightweight teams (sub-300lbs) and with no loaded gear.

As for the 27" issue, it's okay if you don't understand. I doubt most will ever bother using 180mm captain's cranks, let alone 200mm cranks. Trust me, I can use all the cornering clearance I can get. Also 26" wheels on your 700c frame would look silly. That is what 700c wheels look like on frames larger than 60cm. Our tandem is a Cannondale 25"/23". I show a TON of post, and have a ridiculous frankenstem to build the captain's compartment up closer to a 68/69cm bike. The little 700c wheels make the bike look ridiculous. The marginal difference of the 630 wheels certainly doesn't hurt. However, this is a minor point and not one I'm particularly interested in defending. Quite frankly each team gets to keep their own counsel regarding how they want their tandem to "look."

DubT

Just for the sake of curusioty, how long have you and your stoker been riding a tandem. How far do you typically go and what kind of speeds do you average and what type of terrain do you ride?

Wayne

waynesulak

I would say we are pretty typical height. I am 5 foot nine inches and my stoker is 5 foot six inches. Total combine height is 11 ft 3 inches. The average height in US of people over 20 years old is 5'.95" for men and 5 ft 4" for women totaling 11' 2.25". Link below.

https://en.wikipedia.org/wiki/Human_height

Weight wise we are below average considering the total population but we are not talking about the total population. We are discussing people who ride a tandem. I see a lot of tandems here in North Texas and while there are some big teams out there most seem to be with 50 lbs of us and almost all within 100 lbs. This is especially true if you limit it to teams that ride over 1,000 miles a year.

To sum up the size issue I would say that for 98% or more of our encounters with other tandems - that team would be well served with the Dyad. Your situation is different and I understand your frustration. The Dyad does not work for you any more than small cars do, Small cars do however sell in the millions to the mass market.

Back on the tire issue. I don't think 1.25 inch tires are all that wide for the load you are carrying. 1.25" is 31.75 mm. With your weight it would be nice to run 38mm tires that would put about 140% more air under you. 42mm tires hold 175% more air than a 1.25 inch tire. That is one benefit of 650B although I agree small wheels do look funny on a tall bike. If you can get 38mm+ tires on 27 inch rims then great. Keep in mind that 27" rims are only 8mm bigger in diameter than 700C rims while 40mm tires are about 16mm larger in outside diameter than 1.25" (31.75mm) 27" tires. You would gain more crank clearance with large 38mm or 40mm 700C tires vs 1.125" 27" tires. I have tried 38mm 700C tires and those wheels do look huge compared to 700C 30mm tires.

Wayne

Chris_W

We are a 300 lb tandem team, but have also given up on the Velocity Dyad rims. I'm much happier with the Mavic A719s that I replaced them with. The Dyads were not great at staying true, but the bigger issue was that two separate front rims both developed bulges in the rim after long, steep descents with lots of rim braking. The rim actually became slightly wider at one point, causing the front brake power to give a pulsing feel. I've had no such problems when using Mavic A719 rims (36 hole on the front and 40 hole on the rear).

As for average team weight, Wikipedia claims an average male in the US weighs 190 lbs, and an average female 165 lbs, making 355 lbs total. The total for the average male+female in Germany is 25 lbs less, and there are other European countries where I'm sure this would be reduced by a further 10-20 lbs.

p2templin

I just don't understand the "logic" of comparing wheels by weight. It's not the raw weight that creates the strength, it's the engineering of the wheel. The Chukker is a wide wheel, so it's going to have more weight than a narrow wheel. However, that width exposes the wheel to more stresses, so you'd expect more weight to maintain comparable strength with a narrow wheel, and would need even more weight to be stronger than the narrow wheel.

Regardless, I don't know why I'm typing this. You're already the self-proclaimed expert wheels, and it makes no sense that you're asking the rest of us for input. Why not ask Velocity?

mtnbke

The Velocity Dyad and the Mavic A719 are both heat treated and share a very similar shape in their extrusion. Comparisons are fair, considering the significant difference is extrusion thickness (that is rim weight). The Velocity Chukker is essentially the Velocity Dyad (both are 24mm wide) with almost the height of the Deep V. The Velocity Dyad is 24mm wide and 22mm tall, while the Chukker is the same 24mm footprint but 32mm tall. This translates into a much much much stiffer rim.

Regarding your point of asking Velocity, I have. Velocity is standing behind their rims. Even though in this case it is clear that the build was at least half the problem, Velocity is standing behind their product. They offered to rebuild us a Dyad using proper 14g straight spokes for our outlier application. In all fairness Velocity truly believes that a properly rebuilt Dyad stands a good chance of holding up and being a really great lightweight wheel for us. They did however, give us the option of also going with a Velocity Chukker or even the Velocity Psycho. We were going to go with the Psycho, but it just might be too wide (for our frame). Stay tuned, I may change my mind and go with the Psycho rebuild instead of the Chukker. Will be shipping out next week (have to decide by then).

Also, as I said before most of the tandem enthusiasts I know aren't in world class shape, as strangely most are in the autumn of their lives and while still enjoying all that life has to offer are sporting some tummies in their jerseys. Additionally, the other younger tandemists we know have a very fit cyclist captain but a very very very not fit stoker (who isn't a cyclist by any means). So our perception of what the average tandem team looks like may be skewed, but I doubt it. I still say 350lbs is an average tandem team.

The context of all of this is that I alone am less than 350lbs (though just barely). My experience is that our rebuilt Dyad failed with ONLY ME on the bike. A normal tandem load wouldn't be so equally displaced front/rear as ours was with just me (the captain) on it when it failed the second time after only three miles. The weight bias is much much more so on the rear wheel.

I'm glad that so many others are having such great luck with their Dyad rims on their tandems. However, the Dyad is based on the extrusion of the Aerohead, actually the Aeroheat, which is itself a beefed up version of the Aerohead. They build racing wheelsets for 110lb female racers out of the Aerohead because it is so light:

https://boulder.craigslist.org/bik/2664630222.html

There is a heck of a difference between a racing wheel for an outlier lightweight rider wanting a very lightweight wheelset and something bombproof for touring, let alone tandeming or even more demanding a touring tandem.

I think the Dyad is one of the best lightweight rims out there. For a single it is an absolutely bombproof rim. As I've stated multiple times, just bought another 48h Dyad for my 27" wheeled touring bike (not even built up yet). However for "most" normal tandem teams I just don't think the Dyad is the workhorse rim they are looking for. Heck, even for loaded touring there have been some failures for people on Velocity Chukkers (not Dyads mind you). This couple touring on singles opted to have theirs replaced with the Psychos:

https://journal.goingslowly.com/2010/...y-rims-part-3/

Obviously, people will have different experiences. Plenty of people of small stature will have great success running the Dyad, as they would with many rims that are singles rated. Heck, there are teams running rims that are racing rims for singles, and have no problems. If you are a very lightweight team (that is combined you barely weigh more than a larger cyclist) you can probably run whatever you want.

My only point is that the Dyad is not deserving of its reputation as a bombproof TANDEM rim. It is a bombproof rim, just not on a tandem. Heck, the Chukker, which is considerably stronger than the Dyad, and for which Peter White says builds the strongest wheel he's ever seen (he doesn't even carry the Velocity Psycho) has failures. Which is not to say that both aren't great rims, just that application and context are key.

The technology and engineering that goes into rims isn't all that advanced. Although, in fairness the Dyad is much much stronger than anything else in its weight class (480g for a 622) due to that ratio of height to width that Velocity has perfected. However, and again, it is a very accurate measure of a rim's strength and stiffness to compare weight, and again the Dyad, Mavic A719, and Velocity Chukker line up perfectly by strength and stiffness as they do by weight. This isn't rocket science. There are rims that are unnecessarily heavy for their strength/stiffness like the Sun Ryno Lite. Which is not to say they aren't strong or stiff, but just that they aren't modern advanced rim profiles and are a little more bloated than they probably need to be. However, even for those you can't beat the price.

Also this is a friendly reminder that the original topic is about 630 (27") rims, not tandem rims in general of which almost all use 650B or 700c. Thanks!

waynesulak

You make a good point that the profile of the rim is an important factor. I have not seen a 27" rim with the stronger V shaped profile but maybe they exist. I agree the heavier Velocity Rims are a good option for 700C and with a Marathon 38mm tire you would get pretty good crank ground clearance and durability. Schwalbe tires are not the lightest out there but I have always been impressed with their quality control and durability.

Wayne

mtnbke

The punchline to this whole thread is that their may not be a better option in 630 (27") for tandems currently than the Velocity Dyad. The Velocity Chukker and Psycho aren't being made in 630. Mavic doesn't make the A719 in 630, and I don't even think they make it in 48h anymore for 622 (700c).

Anyone know of a store or shop that has some older Mavic 630 rims in 40h or 48h for tandem use?

waynesulak

I don't know if anyone is following this anymore but I ran across a really strong looking 700C 48 hole rim.

Really Deep V 770 gram narrow 19mm rim
Velocity B43.

mtnbke

The Deep-V is going to build an appreciably weaker wheel than the Velocity Dyad or Velocity Chukker, but for some racing/training teams that are lightweight that isn't an issue. Many of these rims aren't really all that comparable, beyond all being available in 48 drill and 622 (700c). The Deep-V is only 19mm wide but has a 30mm deep Aero section, the Dyad is wider at 24mm wide but only has a 22mm deep Aero section (while a great rim, this is why it is NOT bombproof tandem rim), the Chukker is like a taking both the width of the Dyad and the depth of the Deep-V (and why it IS a bombproof tandem rim) at 24mm wide and 32mm deep in the Aero section. Then there is the Psycho, while being the strongest rim Velocity makes it does not get its strength from the Aero extrusion like these others. It is more in the vein of the old Mavic Module 4. For loaded tandem touring the Velocity Psycho has to be the rim of choice for all but the lightest teams. The Psycho will withstand higher tire pressures for wide tires (Schwalbes) better than almost any other rim. The Psycho is 17.5mm tall and 31.5mm wide (although internally it is ~24mm wide). The narrowest tire you would consider running on the Psycho would be a 32mm.

If this wide assortment of offerings isn't going to be enough, Velocity is going to be rolling the Cliffhanger in 48h as well. It will be a wee bit wider than the Dyad/Chukker at 25mm, but with a 28mm width. What makes the Dyad "stronger than it should be" considering its weight is that near magical 'square' relationship between width/height with the Aero section. Think of the Cliffhanger as a stronger version of the Dyad, for those that need it, and want to run a slightly wider tire at higher pressures than the narrower Chukker will safely afford. Stay tuned on this great new rim.

The B-43 is really a special purpose rim. It has the same width as the Deep-Vs at 19mm, but has a 43mm deep Aero section. It's weight belies that it really is a cosmetic rim (770g) for those who like the look of the deep profile. The B-43 does build a very very strong wheel, but it doesn't have a braking surface either. It really is only intended for fixie wanna be courier bikes. You certainly could run a rim brake on it, although you'd have better luck with cantilevers than V-brakes due to the rim sides being non-vertical thus requiring more adjustment. Would work with disc brakes as well. However, the narrow rim doesn't seem to make sense for a racing/training tandem build due to the weight and the lack of a real engineered rim braking surface (not to be confused with a machined braking surface, which isn't necessarily needed). On a tandem with rim brakes the B-43 would just seem dangerous. Although, I wouldn't be surprised if it actually held up well from pad wear.

The great part of all of this, is that while Mavic is completely neglecting the tandem and tandem touring market of late, Velocity has really stepped up offer not just a great assortment of rims, but a ridiculously wide offering. Literally, if one Velocity rim turns out to not meet your needs, there are multiple other options for width/height profiles to try.

No team will need to go beyond the Psycho. Velocity is building electical assist pedi-cabs that carry over 1000 lbs (500lbs PER Wheel) and using the Psycho rim on those (in a smaller wheel size) with 12g spokes. They hold up fine.

Hopefully some of these trickle down to offerings in 630 (27"). As currently the strongest 48h offering in 630 is still going to be the Dyad.