Tandem Cycling - Velocity Dyad rims

This is a cross-post from another forum I belong to. I was suspecting that the Velocity rims were undersized. Just wanted to share my experience.

For those of you who have been following Madame Butterfat's wheel saga from last weekend (http://teamalameda.com/forums/index.php?showtopic=642), here's an update.

Eden Bicycles finally got to do some research on the wheels and it turns out that I was right about the rims: they are indeed undersized. Tim, at Eden, called Velocity and spoke to someone about them after having the same mounting issues I did. The Velocity rep admitted to having released a batch of undersized rims to market, and since Co-Motion is one of their largest customers, many of those probably made their way to the final product. He did not go as far as defining the size of the fault, and nor did he mention that they were out of tolerance.

What that means for us is probably at least a month on the bench, awaiting the parts from the warranty claim I made today at Bicycle Outfitter in Los Altos. It also means that we will not be riding the Wine Country Century as planned this weekend. :(

A quick recap of what happened: after a triple blowout on Saturday, I determined that the flats were caused by the tubes pushing the tyre bead off the rim and extruding themselves in a way that a pinch flat was possible. I needed confirmation on this theory, so we took the tandem to Eden later on Saturday and explained the situation to Chris. The bike was due for a tune up there on Tuesday anyway. The reason why it took the tyre/wheel combo so long to fail is still undetermined; the tyres were mounted 800 miles ago, and had flat repairs done last weekend at Sea Otter, and a tube replacement Friday night before this last ride. In any case, the wheel assemblies are now at the Outfitter awaiting action from Co-Motion. No notice of a recall regarding the rims has been posted.

This type of defect is extremely rare, and none of the mechanics I've spoken to so far have ever encountered it before. I told Jim @ the Outfitter that I would like credit for the warrantied rims and purchase another brand just to be on the safe side. Because of the timing of the incident, I've lost faith in Velocity's quality control and am not confident riding on another one of their rims.

I wish our bikes were compatible, I'd lend you my stock wheels (unfortunately they are 140mm 7spd). :(

What tire was being used here? Tires make a difference, of course. With 2006 CoMotion running on Dyads (w/2000 mi), I am interested, to say the least.

I'm glad I'm not alone. I bought a set of wheels from Santana over the winter that came with Dyads. My favorite Vittoria Randonneur (700 x 28) tires suddenly wouldn't work. The tires appeared to be too big for the rims and would bulge out all over the place. The 'fix' for me was to get a pair of Continentals with a much more pronounced hook profile in the bead area and they work OK but still don't center perfectly. When I was asking around for an explanation from my dealer, Velocity, Santana, and this site nobody seemed to have a clue. I'm still not happy but the tandem works now and I dropped it. No Velocity rims for me ever again.

As an interim fix could you put on some tires that tend to fit very tight, such as Continental Gatorskins in a 25c, or Michelin Pro race's. I can testify these are a bugger to get on and off.

This was reported a lot on the 29 mtb forum a few years ago.

I think it is specific to the Dyad,or at least the Deep V is not small.

I've had 6 or 8 Deep V rims and all fit all the tires I've ever mounted snugly.

I have Continental UltraSports 700x28 on Dyads. They have not had this problem. It could be the tires or it could be that the rims on not "bad". But I gots to know. I have Continental Ultra Gatorskins 700x28 on order. What should I expect?

We were using Schwalbe Marathon 700x28c tyres. It's not just the tyre/wheel combo, because I had the same issue on a Vredestein Fortezza Tri-Comp Quattro tyre as well.

For those of you who have this problem, I urge you to take the bike into your LBS and have the mechanic do an evaluation on the wheels. Once they do the research, they should learn that Velocity is replacing these rims, but you have to ask!

This is a safety issue.

I can hardly see what a "mechanic" at a bike shop can do to evaluate these rims that is different or more in depth than what I can do. We know the bead seat diameter is supposed to be 622mm. Is this the value that is considered "small", or is the height of the rim shoulder the problem, or what?

I did some poking around regarding the Dyad as what I was reading just didn’t make a lot of sense. I suspect there may be a problem, but I’m not sure I’d be pinning it on the Dyad rim… at least without knowing who at Velocity purportedly confirmed a production error and as someone else asked, just what dimension was used to determine the rims were undersized.

History on the Dyad from a reliable source goes like this: A few years back tandem rim offerings were becoming few and far between and issues with the Mavic T217 caused it to fall out of favor. Velocity was producing some excellent rims and one of the rims that stood out as a good candidate design for a default tandem rim was the 26” Aeroheat rim. Therefore, to make the Aeroheat into a 700c tandem rim, a slightly oversized hoop was spec’d to compensate for the extra-deep spoke bed of the original 26” rim extrusion and, in fact, the diameter of the Dyad is now ~1.5mm larger than a typical 700c rim.

Because of the unusual and extra deep spoke bed, many folks -- to include bike shop mechanics who aren’t familiar with the Dyad rim – may think it’s undersized because of how easy it is to mount tires. The illusion is created by the extra-deep spoke bed’s ability to swallow the opposite side of the tire’s bead during installation: anyone who’s ever installed a tubeless MTB tire will have an intimate understanding of this often overlooked aspect of fitting tires to rims.

Anyway, there are certain tire/rim combinations that just don’t work well; however, that doesn’t automatically translate into a ‘problem with the rim’ or a ‘problem with the tire’; it’s just an incompatibility problem between the tire’s bead design and that of the rim’s hook bead. Because the of the unusually deep spoke bed and slightly larger rim diameter of the Dyad, some additional attention is required when installing tires to make sure that the tire bead is fully seated. It’s also noteworthy that the Dyad is not made for narrow tires; even certain tires labelled as 25mm can be too narrow for the Dyad.

In closing, if the OP can find out the name of the Velocity employee Tim from Eden spoke to that would be of help in running the purportedly ‘bad batch’ of rims to ground. In the mean time, there are a LOT of Dyads out there and I’ll be darned if I’ve ever heard of a problem with one, never mind a systemic quality issue. From a personal perspective, we’ve been running Velocity Aeroheat AT, Deep-Vs, and now Fusion rims on our road and off-road tandems for about 8 years… and I can’t imagine using anyone else’s rim for a component-built tandem wheel.

Just my .02.

I'm glad to read your assessment tandemgeek. I just built a new rear wheel for our Santana using an Aeroheat 26" 40 hole hoop. The wheel came out great but I haven't mounted it yet.

[QUOTE=TandemGeek;6619474]I did some poking around regarding the Dyad as what I was reading just didn’t make a lot of sense. I suspect there may be a problem, but I’m not sure I’d be pinning it on the Dyad rim…

Thank you very much for the background info on the Dyad. Very interesting. I was possibly being overly harsh about the product on my previous post....

Thanks for the insight, TG. I read your post yesterday, and spoke to Jim @ the Outfitter later that day, and he essentially told me the same thing. However, he told me that the fix is to 'properly mount the tyre onto the rim.' This still doesn't help me, and it certainly didn't help us at Sea Otter where a professional mechanic took 1/2 hour and 2 tubes to get it mounted 'correctly.'

Maybe we're just not cut out to be using Velocity rims. :(

Oh, and it doesn't help my confidence on riding them if I fear they may be blowing if I didn't 'properly' seat the bead.

EDIT: tyre choice is a priority over rim choice for me. If a rim doesn't like the tyres I want to use, I see no reason to use it.

EDIT: tyre choice is a priority over rim choice for me. If a rim doesn't like the tyres I want to use, I see no reason to use it.

Please don't take my comments as being anything more than providing you and other interested readers the extent of my personal knowledge and experience with this particular manufacturer's products and this rim in particular. My comments would have been different and may end up being premature if a rash of similar reports comes to light or if the purported admission by Velocity regarding defective rims could be corroborated. But, at least at this point, I can only speak to what I know.

Bottom Line: At the end of the day, every person who captains a tandem must have confidence in their equipment and their ability to properly maintain it. Once that confidence is lost in a product, it's nearly impossible to regain. Therefore, I can appreciate your sentiment.

Sorry guys, this is kind of a sore subject at the moment. :p My wife/stoker is so passionate about our tandem that sometimes we both take certain problems too personally. Like I said, thanks for the analysis, TG. Your explanation makes sense, and had I not read it before speaking to Jim, I wouldn't think I could have understood his explanation.

May or may not be germane, but this resonates as I had a problem with the Velocity
rims 406 sized that came with my Rotator Pursuit single bent in '00. It was extremely
difficult to mount and unmount tires (I also had a set of bad tubes and went through
5-6 flats in the first 500mi before getting another set of tubes). Apparently Velocity
had a batch of slightly over sized rims in the 406 range per Steve Delair at Rotator.
Subsequently I replaced the wheels with another set of Velocity/Ultegras and it was
noticeably easier, though not easy, to mount tires on the new wheels.

My head spins with the technical information. I changed a rear tire on our Velocity Dyad's today during a 50-miler. The deep V made removing and replacing the tire a breeze. Where the rubber meets the road, as it were...

Cheers!

My head spins with the technical information. I changed a rear tire on our Velocity Dyad's today during a 50-miler. The deep V made removing and replacing the tire a breeze. Where the rubber meets the road, as it were...

Cheers!

Yeah. I rebuilt the wheels for my Santana with Dyad rims last year. I was over-the-moon with how they came out. After tensioning, I had to do virtually no trueing at all on either rim. That smacks of pretty good production tolerences to me. The ease of installing and removing tires is a bonus.

I did some poking around regarding the Dyad as what I was reading just didn’t make a lot of sense. I suspect there may be a problem, but I’m not sure I’d be pinning it on the Dyad rim…

Glad you're on the case, TG! :p Seriously, if anyone can track this thing down I'm sure you can, and if there's something to this I think the community ought to know. And if someone needs to print or verbalize a retraction, that needs to be said, too.

As for any who may feel that they now lack confidence in Velocity, remember that there are no manufacturers of anything who *never* had a bad run of product of which a certain amount slipped thru QC before it was caught. The measure of a company is how they behave *after* it's been discovered.

That having been said, I personally can't believe the current state of "acceptance" of incompatible and poor quality components. Twenty years ago, there was no such thing as "tire and rim combinations that just don't work well together", and the term "caustic sweat" as an excuse for poor quality finishes that corrode to pieces in 6 months was unheard of!

But don't get me wrong, although these issues irk me, I'm not one who longs for the "good old days"! I welcome the innovations, but just want them done right! ;)

As a society we've become a lot more forgiving of others, because either we're more informed and educated, or because it's too difficult to pursue a fix from those who were at fault.

My loss of faith in Velocity comes from the fact that their rims just don't work for me. Who is to say that after the rebuild, the same thing won't happen because their rims just don't like my tyres? I risk another week or two, waiting for parts to come in. TG could be right, and this whole thing could just be a tyre/rim combo problem--any tyre.

Update: the Outfitter called me and told me that Velocity's prez would be calling me regarding this issue. I would have hoped that the shop handle this with Velocity, but if I really need to talk to him, then I guess I will.

Twenty years ago, there was no such thing as "tire and rim combinations that just don't work well together"...

Twenty years ago we put our hands and eyes on things as part of making informed assessments vs. attempting diagnosis with incomplete or sometimes imperfect information long distance and blindfolded.

Moreover, twenty years ago we didn't put as many things in writing to people we really don't know that get shared in public forums where graceful 'outs' are more appropriate compared to what you might say to someone in person and without an audience.

Therefore, when in doubt (see above) we occassionally give all concerned the benefit of doubt pending better information or additional facts that yield a better answer to an unusual or infrequent problem.

Bottom Line: "Don't work well together" does not necessarily imply a technical incompatibility, it just allows that a few others have encountered difficulty with a similar product or combinations of products, e.g, carbon part failures due to excessive or insufficient torque. Better technique or more experience often times mitigates those difficulties.

I have Continental UltraSports 700x28 on Dyads. They have not had this problem. It could be the tires or it could be that the rims on not "bad". But I gots to know. I have Continental Ultra Gatorskins 700x28 on order. What should I expect?

Happiness. I wore out 3 pairs of 700c x 28' Gatorskins in over 7000 miles on Velocity Dyads. BTW, I'm a Clyde and had one flat i that time
Am now trying out 700c x32 Schwalbe Marathon Supremes. Went on fine. No problems.

@jens5: when did you order your wheels/tandem?

We were using Schwalbe Marathon 700x28c tyres.

I had three low-mileage Schwalbe Marathon Plus 700x28c tires fail on a Dyad that I purchased in 2006. In all three instances, it appeared that the rubber casing around the bead failed, preventing the tire from staying on the rim. It looked like a tire failure.

No problems with Ultra Gatorskins, Panaracer Paselas, or Avocet FasGrips on the same rim.

-Greg

I spoke with John, the president of Velocity USA today regarding this issue. He was very patient with me and heard my whole story before he explained himself. Here's what I learned:

The undersize rim design is no flaw. Velocity designed the rims this way to alleviate the pain of having to use tools to mount tyres. Using tools risks pinching the tube. The ease of mounting and removing also helps those with weaker limbs. Last year, during the 2007 Interbike show in Vegas, I believe it was Co-Motion who approached Velocity with a concern regarding the rim's diameter, and how small it was. It made pumping certain tyres a challenge due to the fact that the tyre bead wouldn't seat correctly in an undersized rim. They addressed this concern by increasing the rim diameter by 1mm radially. According to John, there have been no complaints so far. However, because we bought our tandem in January, there's a good chance that the wheel we have was built with the older Dyad rim, thus does not have the 1mm modification.

He was very apologetic about his position and our troubles, and graciously offered a complete rebuild of our wheels at no charge. He even offered to cover shipping and handling. I appreciate his sincerity and explanation. I believe that Velocity really tries hard to please those who are having trouble. I just wish there was a more direct form of communication between the company (Velocity), and the end users (us). If we could speak to these good people, I think they would probably know a lot more about what makes us happy and what doesn't.

In any case, I consider the mystery solved, and am ready to put this issue behind us.

I just wish there was a more direct form of communication between the company (Velocity), and the end users (us). If we could speak to these good people, I think they would probably know a lot more about what makes us happy and what doesn't.

Thanks for the very detailed account of the dialog with John.

Regarding contact with the folks who make many of the components and even the frames we use, most of these businesses are very small-sized operations with just a few employees and an owner with their sleeves rolled-up. Therefore, in most cases if you have a question or want to get some information you just need to call or, if you prefer, to Email the company. Chances are you'll either end up communicating directly with the owner or someone who reports directly to the owner and who is well-versed in the products.

Much of what I know about certain products related to tandems I've learned though such contacts with the folks who own these businesses and/or key staff members. They're very approachable and can provide a wealth of information to help you make the right decisions about their products or to address any issues you may have after the sale.

As you'd expect, I tend to spend as much time tinkering and experiementing with equipment as I do riding, where many rides end up being spent evaluating how this, that, or the other perform compared to other components or configurations and will frequently provide my impressions when I discover something that seems like it could be improved. I try not to be a pest or take advantage of their willingness to directly engage consumers like myself, but that's the point: I'm really just a consumer like most others, not a dealer or industry rep. However, all it takes to "speak to the man" at most of the companies who produce our bikes is a phone or Email account. Even companies like Trek and Shimano USA aren't all that 'big' and their tech support folks can usually field most of the questions you might have or know who you can contact if they don't know the answer.

Regardless, again... thanks for the follow-up.

Could everyone with Dyad's measure, as best they can, the diameter (not radius) of the outmost extreme point of the rim in mm? Please report in with that number and what year you think the rim was produced. I will do the same. This is a hard measurement to take on built wheels, and on unbuilt wheels, it is important to not deflect the rim, and measure twice, 90 degrees opposed, and average.

And, just out of curiosity, is this measure different from any other 700c clincher rims you have on hand?

Very interesting.

Could everyone with Dyad's measure, as best they can, the diameter

Good luck with that one...

IMHO, X different samplers using y different measuring devices and z different measuring techiques will not provide nearly enough accuracy to capture the very small variations you're looking to quantify. You'll end up with some data, but the integrity will be lacking.