Tyre fitting problem

[E-wan]

Just swapped to my marathon dureem 2.0 tyres on my nomad And I can't seem to get him to sit straight on the rim at one point. The rimm is perfectly true in all directions but if I spin the wheel round and put my fingernail above the tyre, once per revolution the tyre moves away from my nail by about 1 cm. when rideing I can notice to bike lolloping forward and backward. when you look at the side wall you can see the reflective strip almost touches the rim at the Lowpoint.

The only thing different I can think of is that the only tubes i had were 26x2.0-2.5 rather than the tubes i previously used which were 26x1.5-2.0. might this make a difference or does anyone have any other suggestions for rectifying this problem.


thanks

Ewan

[JimK]

Could be a tyre defect but the first thing I would look at is to be sure the tyre is seated properly on the rim. Also good to be sure the tube isn't caught by the bead at any point.

Sometimes I will put the pressure at maybe 15 psi and then go around the wheel to grab the tyre and pull it away from the rim, to get the bead to pop up properly out of the rim's well.

I worked for a little while as a bike mechanic, 45 years ago! The fellow who ran the place was really good. Mostly I was changing tyres. We had this jar of soapy goop that we'd pull out to lubricate a feisty tyre bead so it would seat properly.

That bike shop is still in operation! http://www.kiddlessports.com/

check out: https://www.youtube.com/watch?v=MCEjqI96meU

[martinf]

I'd second the "soapy goop" suggestion. I have the proper Schwalbe tyre-fitting liquid, but I reckon washing-up liquid or somesuch will do just as well.

The "soapy goop" makes it easier to move the tyre beads - usually I don't need to.

With 1.9 - 2.1 inch tyres I inflate to about 60 psi, which generally pops the beads into the right position. I then reduce to running pressure (usually 28 to 35 psi).

Sometimes this doesn't work and I then let most of the air out of the tyre and go round the circumference pulling it until it is more or less evenly seated.

With the wide Duremes/Supremes it is never completely even, but 2 or 3 mms of hop doesn't seem to be perceptible. 1 cm is too much.

[onrbikes]

I'll 2nd and 3rd the two above but you need to give the youtube thing a miss.

He's one seriously annoying guy, "The Bikeman"

[Swislon]

The soapy gloom worked for me too!

[E-wan]

I lready tried reseating the bead with talc, will try soap next.

Ewan

[Danneaux]

Ewan,

The previous posters have all offered good suggestions, and they're well worth trying -- particularly the soapy water, as the beads sometimes catch prematurely before they seat fully under the bead.

The 1cm of runout is pretty extreme, making me think a section of tube is caught beneath the bead. You didn't mention where the high spot is, but this can sometimes happen if the valve is not fully seated in the rim.

That said, I have noticed all my Duremes do have some native wobble (see: http://www.thorncycles.co.uk/forums/index.php?topic=3861.0 ) compared to Supremes, Marathon Deluxes, or other tires by different makers. It hasn't been to the same degree as yours, and is not noticeable while riding, but it is still there, worse on my rigid beads, still present on my folders.

Best of luck on the reseating; please let us know how you fare.

Dan.

[Slammin Sammy]

I was going to point out the same irregularities in Duremes, Dan. I have also found that the reflector strip is sometimes laid on very unevenly, leading the eye to see a lumpy tyre which isn't really there.

Having said all of the above, I have found folding Duremes (my go-to tyre on all of my 26 inch bikes) extremely easy to mount on 559 rims, never requiring levering over the lip. I use Schwalbe high pressure rim tape (25mm on the Andras) which almost completely lines the tube bed between the beads, and the Schwalbe tubes and tyres seat easily and without lube.

I operate the tyres at 55 to 60 psi in most cases, dropping to 40 if warranted off-road.