What Tyre for Tandem?

[Harnell]

We are currently touring in the Loire on our tandem. I originally had the tandem set up with 26 x 1.5" Schwable Marathons but 2 days into the tour the rear tyre burst. Before setting out I had inflated front and rear to their max pressure of 100psi believing that when carrying a heavy load this was the thing to do but the Schwable seems to have been unable to take the pressure which has surprised me with a quality tyre like the ones originally fitted.

When we were having the bike originally spec'd the makers advised 1.95's but I went with 1.5's for the reduced rolling resistance. With retrospect this seems to have been a mistake or have we just been unlucky? We are now running with a 1.95 on the back and a 1.5 on the front which I am hoping will give me the best of both worlds.

Are there any other tandem tourers out there and what tyres do you use? Is 1.5 too narrow for a fully laden tandem?

[Brucey]

if the sidewall blew out because of splitting near the rim edge, then it is possible that the tyre was faulty, that the rim edge had a very sharp radius, or you were just unlucky.

IIRC Schwalbe have recommendations for the maximum load on their tyres. I've not tandem toured on them myself, but I note that 1.5" is very close to the section width of 650Bs, so 'too narrow' seems a bit of a stretch to me.

cheers

[fizz]

We have 26 x 1.5 marathons on our tandem, and inflate at around 100psi. No problems at all in 18 months on road and trails.

Perhaps you have been unlucky or the tyre faulty?

[willem jongman]

I think you have been unlucky. Having said that, when we had a tandem with 26 inch wheels, we progressed from 1.5 inch High Roads to 1.75 Pasela's to 1.95 Marathons. Only the latter survived. At the time I asked Schwalbe what they thought about the 50 mm Big Apple on a tandem, and they advised against it, favouring the Marathon for this use. Tandems really benefit from wide tyres, and need strong ones.
Willem

[Deckie]

We have 700c wheels on our tandem, I've fitted Schwalbe Marathon Supremes to it, 32 section so a bit less than 1.5". I am exceptionally happy with them, I find I have a grat deal more confidence in them, especially in the wet, than I have had with any other tyres I can remember.

We had one tyre "fail", well part of the bead shed it's covering. Most likely due to lack of proper care re-fitting after a puncture causing damage.

I pump them to around 100psi and have no problems laden or otherwise.

[Harnell]

Bruce's that is exactly how the tyre failed. Since fitting a 1.95 to the back inflated to a mere 2 bar my stoker is a lot happier with the softer ride and I have not noticed a significant increase in rolling resistance so I think I will stick with the current combination of 1.95 on the back and 1.5 on the front although I wish the rear was a road tyre and not the MB tyre currently fitted but that was all that Monseur had at the time.

Thank you to all who have commented sounds like we have been unlucky with the Schwable Marathons although the one on the front is holding up fine.

Edwin

[Si]

I go the other way, following Pete Bird's advice I inflate them over the stated max 'cos the stated max is, so he said, based upon there only being one person on the bike and so much less weight. That way it rolls better and we are less likely to pinch-p*nct*re. Obviously the stated max will be well under what the tyre can really take otherwise they'd be tyres exploding all over the place. But if you follow this advice you do need to monitor the condition of your rims for obvious reasons.

[bikes4two]

Now there's a coincidence, we are just nearing the end of a tour in France and we had our first ever blowout, on the rear and with a Schwalbe, albeit a Supreme.

The tyre bead (a flexible one as it's a folding tyre) has started to pull away from the sidewall - the inner tube then pinched against the rim and we had our first flat for at least two years. As a temporary repair we used a piece of nylon/PVC material cut from my wash bag, say 4 x 8cm, got some quick setting 2-part epoxy resin (that I had in my repair kit), spread on one side of the patch and wrapped it around the affected area, ie stuck on the outside of the tyre wall, folded it over the bead and over the innerside. When the resin went to it's tacky stage the tyre was replaced and inflated to about two bar and allowed to set for 30mins before full inflation and back on the road. That was 250km ago and all is well but am now in possession of another tyre and tube for a swapout soon.

A bit off topic, sorry, just hopefully useful info for others.

Despite this tyre wall failure which is something that in hindsight I should have spotted (loose yarns of thread etc), I will be sticking to Supemes, 2.0" front &rear, running at 4 bar.

[tippo12]

Hi
Try the new Dureme tandem specific tyre from schwalbe, they sent me one free after the wire bead in my previous schwalbe tyre came through the sidewall, and the new tandem rated Dureme tyre is made for the maximum load of any tyre on the market.
If not using the dureme tandem go on the Schwalbe USA or germany websites where they list all the maximum loads for sidewalls, the 1.5 marathon is rated for significantly less load than the 1.9 from memory.

After 54 years on tandems I have some eeperience of tyre matters, the usual reason that the tyre bead parts from the wall as you describe is under inflation not over inflation, which is exascerbated under touring loads. the tyre flexes under sideloads and fails, it used to be the bane on Conti top touring tyres on tandems.

Whatever, enjoy and keep touring while you can.

[Chris&Roy]

'Loire à Vélo' on a tandem
Out of interest we did a small section of this last year--Tours to Samur--also out of interest SNCF allowed our tandem on the train from Samur.
We had three punctures along the way, picked up on the last lap on the gravel sections back to Samur. Finally had to buy a replacement tyre in Samur.
This year we will carry a spare tyre plus usual repair kit.
I really recommend this cycle route for those wanting a leisurely scenic ride with interesting chateaus en-route. This year we plan to visit one when a tomato festival is on!
We stayed at Chambre d'hotes along the way finding them as we went along was no problem.Always a welcome for cyclists.
Looking forward to our return this September with hopefully some sunshine.

[reohn2]

To the OP,What kind of load are you carrying that you need 100psi in a 1.5in tyre,when we were on 26"x1.5 Marathons I never felt a need to have more than 80psi front 85 rear in them when loaded with160 to 165kgs all up weight.
We've never had sidewall problems with Marathons,we currently run 700cx32s at 85front and 95psi rear at the same all up weight without problems on tarmac and light offroad (towpaths etc) duties.

[Harnell]

once again thanks to all for contributing.

Si - interesting thought deliberately over inflating the tyre isn't going to increase the chance of the tyre bursting is it? One imagines that it would

bikes4two - ours was a standard tyre but failed in exactly the way you describe. Thanks for the tip on an emergency repair although I am not sure my wife would appreciate me cutting up her North face wash bag. Somewhere though I have some rubber for mending an inflatable mattress.

Tippo - I think we will take your advice and go for a tandem specific tyre for the back when the current tyre wears out or when we next go on another big tour. i am thinking of running a 1.75 on the back and a 1.5 on the front. what do you think of this combination?

Chris&Roy - I wish we had found booking chambre d'hotes an easier proposition. Everywhere we went seemed to be booked solid including in the large cities. On one occasion we narrowly avoided staying in F1 hotel not an experience to be recommended. The tourist info places were a mixed bag some were quite helpful others less so being distinctly unwilling to help us find anything outside their particular region. Best solution an i phone and the using the hotel where we were staying free wi fi. We had great difficulty finding a good web site on which to book chambre d'hotes most are not listed on trip advisor so it was a case of finding a place at the Tourist information and then e mailing or calling them from the hotel room.

reohn2- about 200Kg all up. I was also surprised that the tyre failed but there you are.

[Si]

Si - interesting thought deliberately over inflating the tyre isn't going to increase the chance of the tyre bursting is it? One imagines that it would

Well, having two people rather than one sat on the bike will do that anyway I only repeat what I was told and don't express an opinion as to whether it's right or wrong, but he reckoned that the Max printed on the tyre was commonly half of what the tyre could take because they build such a safety margin in.

[gaz]

Resurrecting this thread as I need to give thought to replacing the tyres on the tandem.

700x32/35 Mavic Module 4 rims, riding mostly tarmac lanes with the occassional rough but not muddy tow-path. Day trips not touring. Currently shod with Conti Top Touring / Top Touring 2000; broadly happy with Marathons on the solo.

Recommendations please.

[Brucey]

FWIW if you choose a tyre it should have a load rating that is adequate for the intended load. The load rating will be in the published tyre specifications.

However the tyre will only meet its specifed load rating if it is also inflated to its maximum pressure. At lower pressures the load rating of the tyre is reduced. At higher pressures the tyre is not rated for use; this is as much about manufacturing variations and damage tolerance as it is about the basic strength of the tyre.

Tandems are problematic; most seasoned tandem crews will have run tyres outside of the manufacturer's recommendations for load or pressure. Most will have had tyre problems at some point, within or without the manufacturer's recommendations.

Years ago with non-hook bead rims, tyres could and would blow off rims if they were overinflated. These days that doesn't happen so much because such rims are not commonplace. Most tyres will not blow off or fail under a static pressure of at least 50% more than the stated maximum. In many cases the rim will be in danger of splitting before the tyre fails. However that doesn't mean to say that it is safe to ride an overinflated tyre; any small damage to the tyre carcass (e.g. a tiny cut or a lay-up error) will probably cause the tyre to fail immediately.

However the most common tyre failures on tandems seem to be ones where the tyre may not have been at a high enough pressure; the tyre flexes excessively immediately adjacent to the rim edge, and this leads to tyre failure. In this case another important factor is the rim design; many modern rims have edges with a small radius to them; this seems to cause higher stresses in the tyre nearby, or at least to cause more damage. Note that the rim edge usually doesn't so much cut or wear into the tyre (although this can happen...) as cause the tyre to flex excessively in a localised region. Like any other fabric-reinforced structure, excessive flexing eventually causes damage. Bumpy roads, and any tendency for the crew to 'bob' also work the tyre harder.

Car and motorcycle tyres are invariably reinforced near the rim edge, and rims are designed with a carefully specified edge radius. Both these things are intended to avoid tyre damage in this region. Neither applies to bicycle tyres/rims; a few tyres have an external chafer ply (that often falls apart in service, leaving 'string' wrapped round the hub ) but I've not seen any where there are additional plies etc within the tyre structure which are intended to improve the tyre's strength or damage resistance.

Tyres vary in quality because each one is laid up by hand and then moulded. Small lay-up variations and small differences in rubber compounds or curing conditions/chemistry can make a huge difference to the tyre properties.

Looking at Schwalbe tyres, in recent times many tyres seem no longer to have the wire bead consistently bonded to the fabric carcass by rubber flowing through the carcass plies during moulding/curing. This can be detected by flexing a new tyre; there will often be a creaking sound which is the wire moving around inside the carcass. If movement or flexing occurs in service, bead edge failure is very likely and there are several examples of such tyre failures reported on this site which look like they may have occurred in this way; typically the carcass seems to split beneath the wire bead, in a place where gross sidewall flexing per se does not occur. Another 'feature' I've seen in recent Schwalbe tyres is what looks like a cut in the tread of worn tyres; the thing is, it isn't a cut. It appears to be the joint in the tread band ( a separate strip of rubber that is laid into the mould that eventually becomes the tread surface) where it has not been sufficiently consolidated. A further fault is that many Schwalbe tyres that are subjected to daily use seem to suffer severe sidewall cracking in the rubber; this is harmless up to a point, but once the cords are exposed the tyre can fail. This can take less than a year. All these faults (which do not apply to every tyre) seem to indicate a change in the moulding conditions used or perhaps just a process QA failure.

In case anyone thinks I am unfairly knocking Schwalbe here, I' see many more Schwalbe tyres than any one other type at present. They have a very good range of tyres (including several with load ratings that are good for tandems) and they have good published data about their intended performance. I don't know of any tyre maker that at some point hasn't produced tyres that at least 'vary from the usual' or are just downright faulty.

So even if the tyre is being used as per the manufacturer's recommendations, it isn't guaranteed that problems won't occur; tyres vary, so do rims and useage conditions. And if tyres of a given type have been shown to work OK in particular conditions, there is no assurance that the same will apply in future.

cheers