Schwalbe Marathon Plus woes

[Browser]

Don't know if anyone can help or not, but I fitted wifeys 20-some year-old Raleigh Pioneer with some Marathon Plusses as I wanted her to have good punture protection, despite her commute being less than a mile. Seemed OK 'til just before the summer hols when she called me to say her 'wheels had exploded'
When I looked, the tyres had bulged off the rims on one side and the 'tubes had blown, I thought because it had been parked with one side to the hot sun. Replaced the tubes and all was well until recently when we went to go out and I pumped the tyres up (using my nice shiny-new SKS Rennkompressor track pump ) and we had bulgy tyres again, fortunately this time without explosions. Checked the tubes later and they were 700c 35-47 sized, when the tyres were 32. Blushing and alopogising I went to the bike shop local to work and then remembered that where I'd got the last ones, plus which the guy offered me these again, claiming they'd be OK. I switched to slimmer Presta-valved ones, 28-32 I think and fitted the front one tonight and blow me if the same bloody thing didn't happen again, tyres bulging off the rims.
Marathon +'s are well-known for being a bugger to get on and these were no different, so can anyone tell me why I'm having this problem and what I can do?


Help

p.s. wheels are 700C Rigida steels.

 

[PatrickPending]

http://www.youtube.com/user/SpaCycles

are you checking the inner is correctly seated and not trapped by the tyre?

I usually slightly (I mean just a bit of air to give the tube some shape) inflate the tube before fitting in the wheel/tyre. The guide (link above) should help.

 

[Moodyman]

You say 20-year old Raleigh bike?

Could it be that your bike has 27" wheels. 700c is close to 28" so a little wider.

Me thinks your tyre too big for rim.

 

[Browser]

Checked 'em this morning, meant to post it last night but was too frickin' tired (14-week-old Labrador in the house ), wheels are Rigida 28 x 1 5/8 x 1 1/8 700C, Tyres are Schwalbe Marathon Plus 32-622 (28 x 1 5/8 x 1 1/4 - 700C x 32), tubes are 700 x 25-32C (27 x 1 1/4).

Tubes verified as being seated correctly before fitting PatrickPending, but thanks for the sugestion. The thing that's p*55ing me off more than anything is that when I used to fit cheapo Duro tyres I had no problems at all

 

[MartinC]

You say they are steel rims. Are they hook bead rims (does the rim project inwards at the bead making a hook that traps the tyre bead)? Old rims often aren't and can't hold tyres on at modern tyre pressures.

 

[Angelfishsolo]

You say they are steel rims. Are they hook bead rims (does the rim project inwards at the bead making a hook that traps the tyre bead)? Old rims often aren't and can't hold tyres on at modern tyre pressures.

That is a very good point. Also if the rims are 35-47 and the tyres are 32's they will not sit properly on the rims.

 

[tyred]

The lack of hooked edges is irrelevant unless you run 85+ psi. Doing so would negate the advantages of using a wider tyre in the first place.

 

[MartinC]

The lack of hooked edges is irrelevant unless you run 85+ psi.

I admire your confidence. It doesn't match my experience though. The OP said the tyre was easy to fit so I guess we're at opposite ends of the bead diameter tolerance ranges - rim at the low end and tyre at the high end.