Chancy

Folks,

This is my first post so go easy. We been riding tandems for 15 years, mostly for fun & exercise and have started doing unsupported credit card touring in the last couple of years. That said we (mostly me the captain) have wanted a lighter, more responsive, and comfortable tandem. After much research and test riding several nice bikes at Tandems Ltd, thanks Jack, we finally pulled the trigger and ordered a new coupled Santana Team Scandium. We currently have Continental Gatorskins in 700x32 wirebead on our S&S Arriva and are satisfied with them. Santana normally equips the bike with wirebeaded Gatorskins in 25mm but will put 28's on if requested, they don't stock anything but 25's & 28's. Our dealer (Tandems Ltd) is offering these additional options as well (for no charge):Gatorskin 700x28 steel bead--320g, Gatorskin 700x32 steel bead--380g, Gatorskin 700x32 folder325g, Grand Prix 4Season 700x28 folder--260g, GrandPrix 4Season 700x32 folder--325g.
Helpful info:
Team weight = 350 lbs (on a good day)
Team Age = 121
Local Terrain: Flat (South Louisiana)
Bike will be equipped with 10" rear disc and Spinergy wheels
Santana says frame & fork will fit 32's and Spinergy rep. told me the wheels could handle 32's as well.
We are leaning towards the Grand Prix 4 Season in 28mm and we'll probably go up to 32mm while on tour. I also have a set of 40 spoke Hadley hub/Dyad rim wheels that we may use on tour. Seeing as how we are getting a lighter, more responsive bike, thought we'd get your input on these tires. What say you? Are the Grand Prix 4 Season tires noticeably different in ride quality and performance than the Gatorskins (both tires folders)? Puncture resistance is not tops on my list, it is behind stoker comfort.

Tailwinds,
Charlie

marciero

GP Four-season should be noticeably better ride than the gatorskins. But I would go with Compass 32 tires for even nicer ride. Two other ideas:
1. Thudbuster seatpost (if you dont already have one) for stoker. Makes a world of difference, probably more than the tires.
2. If your Santana has discs on both front and back, and assuming you have clearance, you can put 650b wheels on it, which allow bigger tires with approx the same outer diameter. I am building a set for my Cannondale; 42mm Compass tires will go on that. I have these tires on a single bike. They are wonderful, and just as fast as skinny 700c (though not all seem to be convinced of this) Not sure if your Santana has disc front-I recall them advocating rim brake fronts...

Just re-read your post. If these are no-charge options I would go with 32 GP 4-season folders.

Carbonfiberboy 

Well, that's a funny business because as you can see here:
continental bicycle Grand Prix 4-Season

Conti doesn't currently make a 28 or a 32 in the 4 Seasons line. Conti used to make this tire in 28mm, but never AFAIK in 32mm. I wouldn't buy a NOS 4 Seasons because the rubber they used to use was poor IME in wet weather. We used to use the new 25mm version in winter. However we've been seduced by the comfort and low rolling resistance of the Conti 4000 S II, which measure ~32mm on our 23mm outside measure rims. They are the current cats's meow in our experience. We really liked the smooth ride of the 4000 S II, which contrasted greatly with the 4 Seasons.

Currently in winter and for touring, we are using NOS Rubino Pro-Tech in 28mm because of their bead-to-bead reinforcement and good wet weather performance. They measure 29mm on our 23mm rims. They ride OK. The current incarnation of that tire is called Rubino Pro Control.

If the road maintenance, including shoulder sweeping, is decent where you live, I'd go with the Conti 4000 S II. If your sources won't supply them, wear out what they do supply and then switch.

Goldrush

We currently have Conti 4 seasons in 28 mm on our bike. Maybe they no longer make them, but they are still available on the net.

Chancy

Carbonfiberboy- They must make a GP 4 Season in 32mm for Tandems Limited and Precision Tandems both stock them. From searching the net it appears Continental come out with a GP 4 Season 28mm & 32mm about a year ago.

Tailwinds,
Charlie

Gtmather313

Does anyone know if Conti publishes a maximum load/weight per tire? I know Schwalbe does (most of their road tires are about 70-75kg max per tire/wheel) and based on my experience it extremely important not to exceed it.

reburns

I would guess that quite a few tandems would easily exceed 75kg on the rear tire. I think of our team as middle weights, maybe 310 lbs naked, but with clothes, bike, rack, tools, water, etc. etc., and a 40/60 F/R weight distribution, our rear tire carries about 100kg. I have never had a catastrophic blowout, though, using either Schwalbe or Continental tires. Currently running Continental GP4000 SII 28 mm on narrow rims, 110/120 psi F/R.

Carbonfiberboy 

Linky? As yo can see:
https://www.continental-tires.com/bic...-prix-4-season
Conti lists neither of those sizes.

Chancy

In regards to to the Discrepancy between Continentals website and what Tandems Limited and Pecision Tandems have in stock, It is possible that the 32 millieter tires may be relatively "NOS"...then again, don't believe everything you see on a website-. When I get the new bike (in late January) and if we go with GP 4 Seasons in 32mm, I'll know the "rest of the story".
As for tire load limits: 70-75 kg on the rear wheel would eliminate 90% of the teams out riding, successfully I might add, and 100% of the triplets and quads. I once measured the load on our Santana Arriva with us on it along with rear rack, trunk bag, water bottles, etc. and it came to a tad over 101 kg and we are a 350 lb team.

Tailwinds,
Charlie

Gtmather313

"As for tire load limits: 70-75 kg on the rear wheel would eliminate 90% of the teams out riding, successfully I might add, and 100% of the triplets and quads. I once measured the load on our Santana Arriva with us on it along with rear rack, trunk bag, water bottles, etc. and it came to a tad over 101 kg and we are a 350 lb team."

Tailwinds,
Charlie[/QUOTE]

I agree with your point that 90% of tandem teams weigh over 75kg per tire and strongly believe that probably 95% of 700cc road tires are NOT designed for tandems use! Most triplets and quads have stronger 26 inch wheels and tires.

Here's my experience and warning to my fellow tandem brethern....I recently had a Schwalbe One 28mm tubeless tire fail on a descent at 40+ mph that resulted in serious injuries to both me and my stoker. I've used the same Schwalbe tire on two road bikes for thousands of miles and having confidence in this set up recently installed them on my tandem.

Our total team AND bike weight was 380 lbs or 86 kg per wheel if you assume equal weight on front and back which isn't accurate. The tire had less then 100 miles on it, was properly installed & inflated, and on a downhill gradual turn without warning instantly developed about a 12 inch sidewall tear. It did not roll off the rim it simply just torn the sidewall and the bead stayed in place.

Other details...I was not braking (have dual discs) and the tandem specific rim was not under significant side load. Talking to Schwabie they claim that each of their tires has a published specific maximum weight limit. The Schwabie One tubeless 28 mm is 70 kg and their new Schwabie One Pro 28mm is 75 kg per wheel. I'm trying to see if Connti tests and publishes a per tire weight limit.

Have fun, be safe, and just because other people are using equipment on a tandem without failure doesn't mean we should too.