First to BigH.
Not exactly sure which tire you have as I'm not familiar with the "Sport 2000". Did you perhaps mean either the Ultra 2000 or the Sport 1000? It may be academic but just wanted to be sure which tires we're talking about.
That said, I used Continentals for years on my single bikes and have vivid memories of the reddish (700x19, 20 & 23MM) cloth beads ungluing and fraying on models no longer in production. These were my "bridge" tires as I migrated from my very reliable Conti tubulars to the clinchers. On the bright side, I'd usually flat or wear out the tires before the bead degraded enough to spell the end of the tire's utility. More recently, the tires I've been using since 1996 are Vredestein's tan-walled and now black-walled Fortezza tires. Interestingly enough, the tan-walled tire's rim bead cloth also exhibited a habit of coming unglued; however, the new all-black versions of the tire using a different fabrication method and thus far haven't exhibited this characteristic. Regardless, unless you wear through tires in short period of time it is disconcerting to have the bead materials break-down.
So, what to do about your tires? If you really like the tires you're using and your local rep. continues to replacement them gratis... I'd keep using them. By all means, provide your feedback to the rep. but there's nothing like getting tires for life so why ruin a good thing!! Seriously, if you're looking for a different Conti tire then, as SDS mentioned, the Ultra Gatorskin may be a good substitute: assuming the 700x28's you've been using are the "right size" for your riding it is available in a 700 x 28 with wire bead (more on that later). You might ask your local rep if he'd "comp" you a set of the Ultra Gatorskins just so you can see if they would solve your recurring problems. Just a thought and a way to get another free set of tires. ;^)
Other tires to consider would have to include the Panaracer Pasela which has always received good marks for a touring tire or the Avocet FasGrip K tires which also seem to get high marks with only an occasional thumbs down.
Now, for Scott's posting....
Originally posted by SDS
McCready noted that folders have a higher incidence of blowoffs on tandems (tire bead comes unseated, tube escapes, tube blows), and he cannot recommend them for tandem use. We hope for further explication.
As I'm sure you've discovered during your tenure on T@H, Mr. Bill's experiences are highly biased towards whatever he's selling or believes. Occasionally his views and offerings ARE really good and coincide with some aspect of reality. However, Bill tends to speak to a one-size fits all world of tandems defined by whatever Santana is selling. Some of us are just too tire/bored/uninterested to bother with rebuttal anymore and thus abstain. That said, and with regard to Mr. Bill's comments, the key to tires is figuring out what the right tire is for the types of riding and terrain a given team is encountering as well as their expectations for performance, durability and reliability.
- If you're a 500lb team you'll certainly want a larger diameter tire than a 275lb team (a lot larger, e.g., 35mm).
- If you're 275lb team that doesn't feel comfortable descending steep hills at high speeds and, therefore, ride your rim brakes (because a drag brake just adds too much weight) then you'd also better use high-volume / larger-diameter tires (32mm).
- If you're doing loaded touring or just like a "cushy" ride high-volume / larger diameter tires are also highly desireable.
If you find that larger diameter tires are right for you in a given application (noting that some of us ride with different tires on different terrain or under different circumstances), chances are you'll be able to find them in a wire bead model.
However, if you fancy-yourself as a go-fast tandem team and opt to ride 23 or 25mm wide "high performance" racing tires you'll be hard pressed to find them with wire beads. Although Mr. Bill hates it when others have experiences that defy his beliefs I will say that of all the teams we regularly ride with NONE of us have ever used wire-bead tires. I would say that there is well over 200,000 miles of tandem riding on some of the more demanding roads and mountains in the continential US and Western Europe between just the 6 teams we ride with most often and we've all been able to avoid "blow-offs". Yes, we've had "blow-outs" which occur when you cut a tire casing but that's not the same thing as a blow-off.
Blow-offs -- which occur only when a tire overheats due to excessive rim braking such as you'd expect on a long descent where someone was "riding" their rim brakes -- occur when when the tube inside the tire expands enough to break the bead between the tire and the rim which immediately causes the tube to rupture, hence a "blow-off". There are only three things that can mitigate (not outright prevent) the potential for blow-offs.
1. If you so choose, ride high-volume tires.
2. Regardless of what tires you use, make sure the bead has a snug fit on the rim -- I suspect poor tire/rim matches have caused more blow-offs than foldable tires. Note: None of the aforementioned six teams have experienced a roll-off of a flatted tire either, i.e, the kevlar beads have held the tire on the rims when we've had flats or blow-outs.
3. Don't ride rim brakes long enough to overheat the tires.
The other thing that causes a blow-off is the failure of the rim strip which ties back to Big H's comments about the cotton bead. I've personally seen two of these blow-out/off events and both happended on flat rides without provocation.
Now, in Mr. Bill's defense, given the demographic of his tour customers and some of the locales that they've toured I'm guessing he's had more than a few folks who've showed up with narrow racing tires, no drag brakes and encountered steeper hills than advertised that did, in fact, result in blow-offs. Whereas, the loyal Bill followers who by default ride Santana tandems fitted with larger diameter, wire-bead tires and either Arai drum or Formula disc brakes avoided this problem. Moreover, among devotees stories that affirm Mr. Bill's teachings seem to self-perpetuate where the one, original incident once recounted by 100 followers would have an outside listener believe that nearly 20 or so different occurances have been reported. So, yes, I can see where his experiences would be skewed towards his preferred configuration for tandems.
Bottom Line: Mr. Bill is actually right in many respects with his comments on the Conti Ultra Gatorskin tire. It's a very good tandem tire. However, because it's good doesn't necessarily make other tires bad or less desireable. I like Vredestein's tires because of the way they "feel" when I corner hard and heeled way over and otherwise like to get a lot of feedback from the road surface -- not that I don't wish I had on a set of Avocet FasGrip's when we encounter "shake and bake" roads. Gary Grommet likes and has been using sew-ups on his tandem for years and I've got friends who ride and race on Continential's GranPrix 3000 and Michelin's Race Pro's. Again, there is no "best" only "what's best for you".
P.S. Now, which rim bead material do you supposed conducts and reacts to heat more readily? Wire or Kelvar?