A Little Background:
During my Eurobike debrief with Bill McCready of Santana Cycles last week he mentioned that some 17 [sic] tandem teams from Santana’s July 31 through August 8 Burgundy & Provence Tandem Cruise signed-up to participate in an optional ride on August 4: an ascent of Mt. Ventoux.
Interestingly enough, we’d already heard about the ascent as one of the teams who were on the tour and who made the climb belong to the BikeForums.net discussion forums and contribute under the pen name akexpress penned a post-rally report on the climb back on August 11th.
Based on the report from akexpress, there were apparently as many as 50 tandem teams on the tour who signed-on for the ascent before the rally began. However, after a week of riding and looking more closely as the climb’s percent grade and total climbing involved, only 15 teams headed up the mountain and of those only 13 completed the entire ride. As for the logistics, Santana arranged for a bus to transport the riders and their tandems from their 360-foot river cruiser, the Amadeus Symphony, on the Rhone river to the base of Mt. Ventoux. Quoting from akexpress’ write up:
Mt Ventoux is one of the classic beyond category climbs in France with about 5400 ft of climbing in 14 miles with not a single ft of level road. The grade averages 6% with some extended pitches at 10%. Many stage rides of the tour de France have included Mt Ventoux. We think it may have been the largest number of tandems on the mt at one time. The professional photographers that are on the side everyday kept commenting every time a tandem went by.
Hot Brakes: And The Winner Is?
OK, now to the crux of this blog entry: how well did the various disc brakes fare on the descent? Even with Bill’s detailed, pre-ride training session on how to properly use your brakes when descending steep grades on a tandem, the teams running Avid & Winzip disc brakes all had “issues” during the descent ranging from wearing through brake pads to melting the red plastic adjusting wheel on the inboard side of the Avid… noting that all three of the Avids did in fact melt their adjusting knobs. The only disc brakes that didn’t have any issues were the new Bengal / Santana models mated to the larger 250mm Santana disc rotors.
According to akexpress, it didn’t matter what “technique” was used by the teams with disc brakes that had issue, the descent was just a tremendous challenge that tested the limits of the disc brakes. As for the Avids with the melted inner adjusting knob (#106, below), akexpress had one on their Calfee tandem but the brakes otherwise worked fine throughout the descent. After the day’s ride they were able to install new brake pads, adjust their caliper sans the plastic wheel using a torx head bit and finish the tour using the knob-less caliper. They have since acquired a set of the Bengal calipers for their Calfee.
One of the other teams with an Avid lost their inboard disc brake pad (#74, above right) and the piston (#156 left, #86 right) while riding the next day, noting that the red adjusting knob on the inboard side of an Avid BB7 is also the part that keeps the piston from moving once the brake pad distance from the rotor is set. In hindsight, it would seem that a spare inner adjusting knob + a spare set of pads would be a good thing to take along when tackling challenging climbs if your tandem is fitted with a set of Avids. Bill also mentioned that another Avid was of marginal use after the descent but I can’t recall the particulars. Our BF-brother axexpress mentioned that a third tandem equipped with an Avid (another Calfee) had the same problem that they experienced, e.g., melted adjusting knob but were otherwise able to use their brake throughout the descent and finish the rally by working around the melted part.
Again, with regard to the older Santana tandems equipped with Winzips, the only thing I saw mentioned was brake fade and pad wear but no detailed post-mortem beyond that. As for the thee (3) newer Santana’s with the Bengal disc brakes, they were apparently not adversely affected by the heat on the descent, which is goodness. I’m still not a fan of the white color that Santana chose for their brake, but what are you gonna do?
As for drum brakes, there were apparently a few tandems with drums that made the descent and other than a few heating up to the point where they started to glaze and give off some odors, they all worked as designed.
Now, it is worthwhile to note that another BF-brother who did the climb to Mt. Ventoux did so on a tandem that was only fitted with front & rear caliper rim brakes. Our friend from BF & Hobbes — bikerriderdave — wrote:
We had only standard reach caliper brakes on our Bilenky and experienced no brake-related issues on the descent. We did stop once not far from the top to let the rims cool, because we were stuck behind a line of cars who were all leaving the mountain when we were. Once traffic cleared, we didn’t have to brake very often. Yes, it probably helped that our combined net weight (i.e., buck naked) was/is only about 270 lbs.
So, What To Make Of All This?
As is so often the case with tandems, your results may vary. It sounds like the same weakness that was noted in the Avid BB7 disc brakes as far back as the late 90’s by the German magazine BIKE. The disc brake pad falling out was a new twist and something that I’d not heard reported in the past. So, that’s why I might add a spare adjusting knob kit to my tool box, about a $6.00 kit in addition to a spare set of pads. The Bengal performance is notable in light of Avid’s (owned by SRAM) lack of interest in coming up with a more heat-resistant material for their adjusting knobs given that the Bengal has been somewhat optimized for use on tandems per Santana’s specs.