Technical specifications and the purchasing process by Pat Greene and Chris Witt
We test-rode many new and used production and a few custom bikes as part of our self-administered customer education and product research program. These included steel, ti and aluminum frames; the latter of course were not a strong contender since BTCs are not currently available in Al. The research process was long but a lot of fun and we were in no hurry; we started test-riding in June '97 and we didn't place an order til December. During this period we received assistance from many LBSs, to all of whom we are indebted, especially the people in Dick Powell's Bicycle Outfitter of Los Altos, and Vance Sprock, the proprietor of Cupertino Bicycles. Another reputable frame builder, Bilenky, who was not then represented in our area, put us in touch with a private owner in Modesto, who kindly permitted us, total strangers, to test ride his beautiful Aermet machine. We bugged Co-Motion, Bilenky, Burley and Santana with questions by email and phone, and we visited the Ibis factory in person. Eventually we decided that we wanted a ti frame with BTCs and that narrowed the field down a lot. Many builders just don't work in ti; some who do, don't incorporate BTCs. One or two builders who work in ti with BTCs have little or no tandem experience. We preferred to work with a builder who had at least some track record.
The ti-BTC configuration means the frame is custom built to order, or virtually so, which in turn means it's not really possible to test-ride a bike exactly like the one which is going to be ordered. One of the important rules of tandem purchase is to test-ride before one decides, so we resolved to try to ride at least an example of a prospective vendor's product before making a decision. When Clay Mankin, the proprietor of City Cycle of San Francisco, let us ride his personal Seven Cycles ti tandem, we knew we had found what we were looking for.
With Clay's expert and thorough fitting assistance, the specification and ordering process went smoothly. Like any trailblazing endeavor, it also took longer than most of us expected, but this is completely normal for such a complex undertaking. Clay conferred frequently with us and with the Seven Cycles designer and proprietor, Rob Vandermark, to assure the frame configuration corresponded to our needs. Many phone conversations, faxes and email messages occurred during this phase.
Since we are similar in leg length but a few inches discrepant in torso and arm length, we thought it would be feasible to design a frame that we could both ride either front or back. Rob agreed and produced a frame that accommodates us on either seat with the adaptation of a Look Ergostem in front, adjustable for both height and reach.
The boom tube is another interesting design feature. Initially Rob informed us that because ti BTCs are not available for tubing larger than 1.5 inch o.d., he would need to design a double boom tube similar to the Santana Stowaway frame. This design would be needed to ensure adequate boom stiffness. At almost the last minute, days before the tubes were to be cut, exciting news came from S and S Machine: a 1 3/4 inch ti BTC was soon to go into production! Rob concluded that he could redesign the boom into a single tube of this diameter, with no perceptible sacrifice in stiffness. Several hundred miles of test-riding to date indicate that he was right. Further delays were incurred as a new BTC was fabricated and shipped, and a custom tube milled by Ancotech. We were only too happy to wait a few extra weeks for this unexpected bonus. Throughout the design and fabrication process, we assured Clay and Rob that we didn't mind a few delays here and there in exchange for the peace of mind to be derived from assuring that every irreversible step was taken with due consideration and forethought. And in fact it is possible that if other delays hadn't set back the shipping date by a few weeks, we would have missed out on the newly-introduced larger BTC.
One of these delays occurred as a result of a protracted discussion initiated by Chris about the merits of several different types of bottom bracket eccentric shell designs, such as the split-shell clamp, the internally expanding wedge, and the allen-head setscrew anchors. Eventually, after much discussion and consultation, four setscrews in two pairs were used. At Chris's suggestion, these were located at the top of the shell, indexed behind and in front of the seat tube, in a position calculated to more nearly harmonize with the pedaling forces exerted on the shell. So far this arrangement has worked faultlessly.
Another interesting design feature arose from the decision to use the Look Ergostem to make the front cockpit adaptable to either co-pilot. This stem is available for only one-inch steerer tubes, yet because of the added stress of tandem duty, Rob felt it advisable to design the frame for a one and one-eighth steerer tube. This seeming incompatibility was handily resolved with a tubular split shim or bushing expertly machined by Rob to fit into the steerer tube. The Ergostem fits precisely into the bushing and the assembly has given excellent service to date.
Seven Cycles ordinarily fabricates their own forks, but for reasons related to the unique needs and anticipated applications of the bike, a decision was made to have a fork custom fabricated by Co-Motion.
When the magic day came, the frame arrived at Clay's shop in a relatively small box. Shipping a BTC frame is a lot easier! The frame segments were assembled and hung on display in Clay's shop while awaiting a few last components. This excited much interest among shop visitors and generated at least one more order.
Final assembly included Hope 40h hubs with stainless 14g spokes on Mavic T517 rims, da Vinci cranks all around with SPD single-sided pedals in the rear and double-sided in the front (it's advisable to make the pilot's clip-in routine as fast and nondistracting as possible), a Tamer Post Centrik in the back with a solid Control Tech post up front, the same bullhorn bars as used by Santana in the back, DiaCompe 287 levers pulling XTR cantis, bar-ends with an XTR RD and a Campy T FD, 11-32 in back and 28-50 in front. Because we are not strong and our local terrain is rather hilly, we decided to sacrifice higher ratios for a lower granny. Gian Clavuot, Clay's mechanic, reports this is the best-shifting tandem he has ever assembled, and based on our extensive testriding experience of many other machines we do not disagree. Handling, as well, is all one could ask from a tandem in this format. Bruce Gordon cable splitters on both shifters and the rear brake ease the disassembly process immensely. Chris celebrated the arrival of the tandem by folding it easily into the trunk of a Geo Metro.
We are not a very heavy team at 270 lb, nor particularly strong, so 40h rims might have been more than we needed, but the overdesign affords peace of mind. The Hope rear hub is threaded for a hub brake but because we are not heavy and are not hauling heavy gear (yet), installation of a drag brake has been deferred. So far we have not heated the front rim enough to provoke anxiety.
Assembly was rounded out with six King stainless cages which nicely match the frame finish. The attention to detail lavished by the mechanics at Clay's shop is evidenced by the soldered control cable ends. Pat's bathroom scale tells us the bike weighs 36 lb with Tamer post, Ergostem, pedals and cages installed, but no pump, tools, bottles or computer. This is an accomplishment for a frame with six BTCs and 1.4-inch Ritchey Tom slicks. We plan to experiment with fat knobbies on dirt and skinnier road slicks for pavement.
This bike draws a small crowd wherever it goes. The crowd is of course attracted by the the appearance; while the Beaux Ti does not sport the gossamer ephemerality of 700Cx14 pavement slicers, the visual effect is a very authoritative air of businesslike yet suave competence. And its performance more than fulfills the promise of its appearance.
Officially this was a ROAD tour, but you are doubtless aware that in viet nam a ROAD is sometimes defined merely as the strip of land where most of the vehicular traffic occurs. (and in monsoon season may be defined as the strip of water marked by a row of utility poles, but we didn't have THAT problem)
Pat spent a higher proportion of the bikeborne miles at the helm than she ever has in the past, and having weathered some of the most continuously toothjarringest surface combined with some of the most harrowing of motor traffic conditions over hundreds of miles (VN highway One is a true test of the cyclist's mettle), we feel qualified to state without equivocation or reservation that we continue to be impressed with the BT's savoir-faire and aplomb under pressure. on more than one occasion we found it necessary to depart from the ideal line of travel, for example off a steep pavement shoulder drop or through a large pothole we would have preferred to miss, except that the only alternatives at the moment appeared to lie under the wheels of a speeding freight truck or one of the ubiquitous inter-city busses. through it all the BT never missed a beat. those ritchey tom slicks didn't hurt either.
The only visible aftereffects are a few decal casualties and a small ding in the front seat tube.
Anyway the bike came through like a hero and I am writing this to say I retract what I said earlier about rear top tube length, after fussing with the rear stem adjustment somewhat, I changed my mind and I've decided the top tube is just right after all. and we've encountered no additional problems with the BB eccentric loosening up again, it all seems to hold together nicely and after 6k miles we have never had a problem with creaking (except for when I failed to lube the pedal spindle thread and torque it appropriately, that's operator error not a design problem). also the BTCs never loosened up, once I put the right torque on them. if those vietnamese "roads" didn't shake something loose, nothing will... I did break a home-made fender bracket. one other incidental observation, are the eyelets and braze-ons threaded M5x.8? the co-motion fork appears to have 10-32 threaded eyelets and braze-ons. we must pay attention here. almost the same, but not quite...."
9-2002 After Viet Nam, France was a piece of cake. MMmm,MMMM! and a lot of other gourmet delights too. Here we are on the summit of Ventoux, a couple of months before Lance's day of glory. It took us quite a bit longer of course, than it did him.
5-04 "The Beaux Ti now has about 20K miles on it and the BTCs are doing fine"
Pat Greene and Chris Witt , Cyclists
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