Our Calfee Journal

Well, having logged another 150 miles or so on the Calfee with the 36° conventional wheel set I'm confident the initial handling issues with our tandem have been resolved. Summary: We joined a local club for a short 50 mile ride near Rome, Georgia, today and this was the first time that we had the Calfee out for a ride on something other than the loop rides that we ride from our home. Again, the Calfee does not disappoint. Although we didn't encounter any significant climbs or descents, the moderately rollling terrain on a variety of different road surfaces in various stages of repair -- from smooth as glass fresh asphalt to rutted and crumbling chip-seal -- all felt great on the Calfee: even the occassional big jolts at bridge crossings. The tandem also felt rock solid and spirited on the several short, out-of-the-saddle climbs. Again, it's hard to describe the actual ride characteristics in a meaningful way other than to note the tandem is just so darn comfortable while still being spry and nimble when you push it hard. So, what about those low spoke count racing wheels? As John Lydgate wrote, "You can please some of the people some of the time and all of the people some of the time, but you can't please all of the people all of the time. At this point I must conclude that, for whatever reason, this particular set of low spoke count racing wheels are simply a poor choice for us. I'm not sure if it's just my expectations based on over a decade of riding tandems fitted exclusively with very robust 36° wheel sets or if perhaps it's just my riding style. My dealer and the manufacturer have shared a number of Emails regarding my findings with the wheels and they too have simply concluded that we are apparently better served by wheels that have less lateral deflection. It's noteworthy that they freely admit the design objective was to build the lightest and fastest tandem wheels, not the stiffest. However, they did note I was purportedly the first owner who ever reported an unacceptable, adverse impact on the handling of a tandem fitted with their wheels: a dubious distinction to be sure. The latter makes me wonder how many folks are simply unaware of how their tandems might handle with a stiffer, conventional wheel set? Oh well, not really my concern... There was obviously some concern as to whether or not it was a fair comparison, e.g., same size tires, same psi, same skewers, etc. My initial answer was an unequivocal YES. Although, on reflection I did recall the low spoke count racing wheels were fitted with a set of 700x23 Vredestein Fortezza SE tires inflated to 145psi, whereas the conventional wheels were fitted with a set of 700x23 Vredestein Fortezza tires inflated to 145psi. While I initially considered doing a re-test with the 'exact' same tires I realized that the 'juice just wasn't worth the squeeze' as the handling issues I experienced could not have been caused by the ever-so-slight differences that could exist in how these two tires casings were made. For the record, the comparison wheel set was as follows: Front: White Industries MI5 hub, 36°, laced to Velocity Fusion rims with Sapim 2.0mm Leader spokes tensioned to 126 Kgf. Rear: White Industries MI6 disc hub, 36°, laced to Velocity Fusion rims with Sapim 2.0mm Leader spokes tensioned to 126 Kgf. Total weight with Titanium cassette carrier: 1,950 grams Why No Naming Names? Some readers of my journal and related posts have asked why I have not come right out and identified the brand name and model of the low spoke count racing wheels that I evaluated. It's a good question and one that I wrestled with a bit. In short, I do not have an axe to grind with these wheels: they simply don't work well for us. Moreover, handling is a rather subjective matter and given that hundreds of tandem teams have been using these wheels for several years now, the prima fascia evidence seems to suggest my issues with the wheels represent an issue with me and my hyper-sensitivity to bike handling, and are not a problem with the wheels. Therefore, I have elected not to name names so as not to add any fuel to the brand debate and would note it's not all that hard to establish which brand of wheels I have been using by those who are interested or in the market for wheels like these. Update: Once all was said and done, I finally disclosed the first set of low-spoke count racing wheels to have been '08 Rolfs. We've since sold the '08 Rolfs and acquired a set of '07 Rolfs with the 34mm deep section rim and they seem to be a bit more robust than the '08's. However, they're still not nearly as laterally stiff as a set of conventional wheels or even a set of Topolino Technology AX 3.0-T wheels that were subsequently acquired. Not All Disc Hubs Are Created Equal: It turns out there may not be enough clearance between the Calfee's left rear chain stay and the 203mm rotor mounted to the White Industries MI6 disc hub's rotor mount. What I discovered was that when the rotor is bolted up to the MI6 there is not more than 1mm of space between the rotor and the Calfee's chain stay rotor recess. Further investigation did reveal that this particular MI6 hub was a little out of spec in that instead of the rotor mounting face being the International Standard (I.S.) spec. of 15.25mm from the inside face of the drop-out, it was ~14.8mm. Admittedly this is only a little bit of variability; however, when you're dealing with tight tolerances a little can seem like a lot. Interestingly enough, the 20mm thread-on disc adapter that we used on the low spoke count racing wheels provided adequate clearance. Although I opted not to bother the folks at Calfee with this as I merely saw it as a component integration / selection issue, the tight clearance did become a topic of discussion on the Hobbes tandem discussion list. While various different list members weighed in with observations on their own disc clearance dimensions I felt compelled to note that the variability one can see in disc installations is substantial, which is why I chose to include the photo of the also quite narrow disc clearance on our Ventana off-road tandem to give some context to the Calfee's disc clearance. While other tandems may have very wide rear stays or perhaps narrowed disc rotor mounts to create larger gaps between the stays and disc rotors, the bottom line is you don't need a lot of clearance for the disc rotor, you just need enough clearance. My comments were apparently reinforced when I discovered that Craig Calfee had weighed into the discussion with the following observations / comments disc interfaces, hubs, and the like and it's pretty straight forward: We like the chainstay to be as fat as possible there so the stiffness of the chainstay is as high as possible for solid brake feel.   The clearance between rotor and chainstay does not have to be very much at all. The [disc rotor to chain stay] clearance may vary from 1.5 to 3 mm on our frames.   There is an International Standard for locating the disc mounting surface relative to the inside surface of the dropout. It's 15.25 mm. If [disc hubs] are designed for IS (International Standard) then [they] always clear.   Thread on adapters [can also] be selected to achieve this distance. There is quite a bit of leeway with the Avid caliper if you don't have the exact one.   I personally like the hubs that don't use threaded adapters: [the threaded adapters] can be very difficult to remove.

Regardless, this discovery simply reaffirmed my plan to go ahead with having one more set of wheels built for our Calfee... the final set of wheels that will be our "do-all" wheels as there's just no reason to have different sets of wheels for our needs. As for my solution, I'll simply go with a White Industries Daisy tandem hub with left-side threading for a thread-on disc adapter. Given that the 20mm thread-on adapter used with our low-spoke count wheels gave us enough clearance for the disc, I should be able to use it on the new wheels. Update: The Daisy Hub / Velocity Deep-V wheelset with thread-on disc rotor does provide about 2mm of clearance for the rotor, which is acceptable given that our frame is unpainted. The thread-on disc isn't my first choice, but it seems to be the most flexible in terms of managing rotor off-set. On the bright side, when we're not using the disc the wheel set will be a bit lighter. However, the down side is that we'll once again be faced with the use of a thread-on disc adapter. In the past these worked just fine until I went to remove one after a full season of use, at which point things got interesting. I'm told the newer disc rotor "donuts" incorporate features that make removal less dramatic and I hope that's the case. So, why did you bring up this disc clearance issue? It was my hope that others might also benefit from this information which is why I have shared my experiences and discoveries as candidly and openly as I have in this journal. The point in bringing up the rotor clearance was, in fact, something that I thought would be of interest given that discs on tandems, even though relatively common, still create issues and questions. As some readers have noted in their posts to the Hobbes list, their perceptions regarding disc spacing is based on what they've seen on their own tandems, e.g., custom installations using narrow disc adapters or perhaps tandems with very wide chain stays and larger gaps between the stays and rotors. My own comfort zone is around 3mm - 5mm. As already noted, you don't need a lot of space around the disc rotor and stay, you just need enough. For me, and having gone into this cold I've simply learned that not all I.S. disc hubs are created equal and being off by .5mm where 1.5mm of spacing is needed can grab your attention. Moreover, and remembering that my journal is intended to educate those who may venture down a similar path in the future, the point in bringing up these little nuances is to illustrate some of the things others might want to take into consideration as they work up their specifications with a dealer or builder, and/or what to think about as they make certain component choices. Again, there are work arounds -- simple workarounds -- that would allow me to use the MI6 hub on our Calfee if I was committed to keeping these wheels: a washer between the hubs end cap and drop-out adds 1.0mm: problem solved. Of course, I could also request a replacement hub that has the exact I.S. spacing of 15.25mm. Update: Following publication of this edition of our Journal I have heard from other Calfee owners who have also experienced some very tight quarters between the caliper, rotor, and stays. Calfee states so long as the rotor is not rubbing no worries. However, consumer perspective seems to be that it's disconerting to have it that close and that invariably the rotor will chip any paint on the inboard side of the left stay during rear wheel removal and reinstallation. Are these things normal issues that come up with all tandems? Hey, I've said before and I'll it say again: custom and high-end tandems take a bit of a different mindset than buying production models. You may think that it shouldn't be that way, but it is. Custom and one-off tandems are just that: one of a kind. They aren't built to suit a wide range of potential buyers they're built for a specific client and will often times have features that make them a bit different. Frankly, I've been having a ball going through the discovery process with the new tandem. It may not seem like that to some readers, but to me there has been new knowledge and information at every turn that has often times even challenged a lot of what I thought I knew while searching for answers to my own questions, e.g., low spoke wheel stiffness and their influence on handling, Also, it's interesting to see how new and different things work. For example, this is our third road tandem with a rear disc and our fourth different rear disc installation (our '02 Erickson started off with a Hope disc and was converted to an Avid BB7 Road). Each of these installations was a one-off custom job with all kinds of unique tweaks or machined parts that made them work. Therefore, in looking at how this particular disc installation was designed, it's really the first one that really conforms to I.S. standards. Am I happy about having to use the thread-on disc adapter? Not really but, then again, I had already resigned myself to using a thread-on disc adapter with the low spoke count wheels since that's how they are made. Therefore, I can't be too upset or disappointed about the use of the thread-on adapter at this juncture. However, you can bet your boots that I'll make a point of removing it now and again just to make sure that it will come off. So, what's next? I've gone ahead an ordered up a 3rd and hopefully final set of wheels built for the Calfee. In addition to the rear hub change, this wheel set will most likely use my all-time favorite: a pair of Velocity Deep-V rims laced to the White Ind. hubs with double butted (2.0mm x 1.8mm) spokes. This, of course, this brings up the reason that I posted the photo of a Deep-V sitting on a scale at the top of this entry. As you can see, this Deep-V weighs in at 577 grams, which is consistent with two other spares I have here at the house. I recently sent a note to Velocity USA to mention that the Deep-V rim weights listed on their Web site seemed a bit on the low side @ 520 grams compared to the last five that I'd purchased which weigh in at 577 grams. I also shared a Web site that depicted my 3 rims sitting on a calibrated scale. The Velocity rep stated he'd pulled a silver anodized Deep-V rim off the shelf and weighed it to be 522 grams. He went on to note the anodized and machined rims would have different weights than, say, powder coated and non-machined rims, and that the number of spoke holes also factored into the rim's weight. However, to establish the catalog weight they randomly pulled a number of different Deep-V rims to come up with the average weight and that average is purportedly what they based their catalog weight against. The latter was interesting, but it seemed to ignore the point that my three (3) 577 gram Deep-Vs with their anodized with machined sidewalls still falls well off the "average". I would note that someone from the Hobbes list had just recently purchased a pair of silver Deep-V rims with 24h spoking where the rims weigh 525 grams and 530 grams, respectively. Therefore, I must conclude that what Velocity is using is the average weight of the base-model / silver rims and not an average of rims that represent the full line. Update: We received our new set of White Ind / Velocity Deep-V wheels in May and the spare rim weighed in at 520 grams on the dot. So, it would appear the current Deep-Vs are per spec, which is a good thing. Closing Thoughts: Someone who has been following my experiment with lightweight wheels who read this update asked a very good question: Why not 32° instead of 36° for the next set of wheels? Since it seems relevant to anyone following my journal, I though I'd share my reply... Having had my eyes opened quite dramatically by my little experiment with tandem racing wheels, I think I've cured myself of the allure of uber-light wheels for teams like us (285#) who will not be racing or competing in time trial events. If we were doing non-technical time trials we'd likely reap a tangible and quantifiable benefit by using the low-spoke count racing wheels because in that application, every second counts. Of course, at least based on our experience, if they were technical time trials I'm not sure we'd save any time by white knuckling and taking sub-optimal lines through the corners. Therefore, at this point and given that what we're talking about are every-day wheels that will need to contend with pot holes, mountain descents, touring and will otherwise rack up about 3,000 - 5,000 miles per year, I'd rather opt for the added durability, strength, and better value of the more robust 36° deep section wheel set similar to what we've ridden for the past decade. Will they be as light and aero as they could be? yes and no. Yes, they will be as light as a set of wheels like these can be but, no, they won't be as light as a set of racing wheels and that's the bottom line. We really don't need racing wheels since all they would afford us would be a short-lived performance boost that made going the same speeds a bit easier. Would the 32° deep section wheels be just as durable and robust? Perhaps... but I'd hate to guess wrong and find that out during a tour or after hitting a pot hole at a tandem rally. And, remember, the Fusion wheel set was built with straight gauge 2.0mm spokes instead of the butted 2.0mm / 1.8mm. Therefore, anything I will gain in stiffness from the deeper section Deep-V rim will be somewhat off-set by going back to double-butted spokes. It warrants mention here that we've subjected our tried-and-true 36° Deep-Vs to a lot of abuse over the years and they've stood up to some really hard hits that have left the rims dented and deformed, but good enough to get us home. This outstanding history with the 36° Deep-Vs a major driving force in the decision process for me (if it ain't broke, don't fix it). Therefore, at least for us, we'll just have to work harder at being stronger riders to off-set the performance hit we'll take for having those four extra spokes and that slighter heavier rim. Frankly, that's probably not a bad strategy given that one of the reasons we ride is to keep fit and healthy. Bottom Line: The trick to wheel selection is matching your needs to the available technology. I don't think there is a right or a wrong answer, but there's certainly a different answer for many teams based on their needs and expectations. 36° wheel sets are a no-brainer for most lightweight teams and at this point I think I could use a no-brainer: this stuff has made my head hurt and left a huge hole in my wallet. Update: Best of intentions; however, I was once again lured by the intrigue of technical innovation during the Tandems East Expo where Rafe Schlanger of Topolino Technology pitched his 1,520 gram Carbon Core Series AX 3.0-T wheelset. So, after selling the '08 Rolfs and swearing off racing wheels we've now jumped back in with both feet given the $1,359 MSRP of the Topolino wheels. To make matters worse, we picked up a set of new old stock (NOS) '07 Rolf Prima Vigor tandem wheels so that we could see if the '08's were perhaps a step backward and to see how they would compare to the Topolino AX 3.0-Ts.