Part of tyre won't seat properly on rim

[NewHorizon]

Going OT slightly, I abandoned using Pasela TG's, because good though they were, I found the sidewalls broke down from UV exposure quite quickly (and certainly well before the tyre was well worn) and there were always peeling threads because of this. Moving on to Gator Skins I've been pleased with them but they can be terribly skittish in the wet.

[CJ]

I've never failed with talc and over-inflation until it goes POP up onto the beadseat. Then let the tyre down to a safe operating pressure.

The reason for not wanting to overstretch an inner tube is resistance to punctures, not tyre seating. I don't think the feeble attempts of an undersized inner tube to stay small will be enough to hinder inflation. Whenever I pump one up really big without a tyre, to search for a slow punctures, the pumping doesn't become significantly difficult. I must try that with my track pump for a change, its digital gauge will reveal just how little extra pressure is required to overcome the elasticity of the inner tube.

[glueman]

On the Pasela point, I've found some to be quite heavily distorted in the shop, the walls and tread gathered. The side walls are a bit fragile too and from memory, have all failed before the tread goes. Rubbing on car racks sees them off, as does not stopping immediately after a deflation. A one day old Tourguard was written off on the tandem after a downhill puncture.

However I persevere with them because they are one of the few lightweight style tyres available in bigger air pockets. Most tyres begin to get an industrial feel as they get larger with deeper stipes or blocks. The pleasure of a free rolling 35 or 37mm Pasela combines comfort with good acceleration.

[CJ]

Most tyres begin to get an industrial feel as they get larger with deeper stipes or blocks. The pleasure of a free rolling 35 or 37mm Pasela combines comfort with good acceleration.

You're right, but also look at Vittoria Randoneur Pro: 120tpi carcase, kevlar beads and pretty smooth tread, only in 37-622. The 28 and 32 sections come only in plain vanilla Randonneur, with coarser 60tpi and heavy steel bead, so this is one model where you get a choice of something less industrial in the larger touring size.

[glueman]

look at Vittoria Randoneur Pro: 120tpi carcase, kevlar beads and pretty smooth tread, only in 37-622.

Those will certainly be checked out. Anything that looks like a 1920's TdF tub will do for me . Mind you, those frames looked pretty sensible too!

[PW]

My Paselas are a bit narrower - 28C - so the mode of death may be different, but mine last fine for 2,000 - 2,500 miles with absolutely no bother. Then all of a sudden I get 3 punctures in a week & I bin them. Usually the sidewalls are fine, just the tread starting to feel a shade thin when I take it off the wheel & run a finger round it.

[Georgezippybungle]

question on a similar topic. Why are some inner tubes over massive. So when you place say a 26 inch tube in a 26 in tyre/rim, there's lots left and you are left wondering if you have to fold some over. Its as if the 26 in tube would fill a 30in wheel (if such a thing existed). I'm very tempted to start buying 24 in tubes for my mtb wheels. Is it just me or what?

They vary wildly despite having the same size on the packet, had that yesterday, fitted one with 2 inches of slack, was very difficult to get in then the valve suddenly failed so it went in the bin. A different brand, fitted perfectly.

[Cowsham]

I had problems like that with a Schwalbe Marathon Plus the other week. I put it down to an over-narrow tube not filling the tyre on the opposite side.

Just bought a set of Schwalbe Marathon greenguard and having this sort of problem. Got one to seat after much manipulation but still yet to tackle the rear which is still in the well of the rim in one 6" section ( both sides )

I also had the problem with the gaitorskins I've had on the bike for 3 years each time I change or fix a tube but usually eventually get the tyre to seat.

One morning last week I got a snake bite puncture from a bad pothole and the tube was completely bucked but I didn't have a tube ( I always carry one in my backpack but think I had forgot to replace it last time ). Fortunately a passing cyclist ( a chap who I see on my commute regularly ) was kind enough to loan me a tube but it was a little large for my 28mm gaitor skin tyre ie it was for tyres 28 to 47mm but the surprising thing was that the tyre seated first time.

I swapped the heavy tube for one of my lighter ones when I got home but again had a lot of trouble seating the tyre. I'm starting to wonder now if a bigger tube is the answer.

[Brucey]

...... I swapped the heavy tube for one of my lighter ones when I got home but again had a lot of trouble seating the tyre. I'm starting to wonder now if a bigger tube is the answer.

if the skinny tube is also a slightly smaller dia, perhaps part of it is getting trapped between the tyre and the rim? It makes good sense to fit such tube/tyre combinations only after rounding out the tube a bit, even if you have to deflate it again to get the last bit of bead over the rim edge.

[531colin]

……..It makes good sense to fit such tube/tyre combinations only after rounding out the tube a bit, even if you have to deflate it again to get the last bit of bead over the rim edge.

Are there any circumstances when it’s best to fit the tyre/tube with NO air in the tube?
I can’t think of any. (Unless fitting a new tube with the wheel in the frame using “Dutch pliers”?)
If the tube is undersize, a bit of air rounds it out.
If the tube is oversize, a bit of air means you can see and smooth out any pleats.
I always put some air in the tube, put the tube in the tyre, and put the tyre and tube on the rim.

[Brucey]

……..It makes good sense to fit such tube/tyre combinations only after rounding out the tube a bit, even if you have to deflate it again to get the last bit of bead over the rim edge.

Are there any circumstances when it’s best to fit the tyre/tube with NO air in the tube?
I can’t think of any.....

neither can I. It doesn't seem to stop folk from trying, of course......

[Moderator note - Latest posts have been edited to add the subject title from the original post.]

[Cowsham]

...... I swapped the heavy tube for one of my lighter ones when I got home but again had a lot of trouble seating the tyre. I'm starting to wonder now if a bigger tube is the answer.

if the skinny tube is also a slightly smaller dia, perhaps part of it is getting trapped between the tyre and the rim? It makes good sense to fit such tube/tyre combinations only after rounding out the tube a bit, even if you have to deflate it again to get the last bit of bead over the rim edge.

I understand and agree with all that and that's what I do and check but the new tyres are particularly tight but the gaitor skins do it too even when 3 years old.

As an update I've managed to get the rear one popped out now too. I pumped it to about 120 psi and gave the stuck bit a massage with my thumbs pulling it outwards although nothing happens until a few mins later. You'll hear a crack and hey presto tyre is seated. Same thing happened with the front tyre -- there's a delay -- crack and it's out.

The tubes are the recommended for that tyre

[531colin]

Pump it up and bounce it can pop the bead out.

[Cowsham]

Pump it up and bounce it can pop the bead out.

Tried all those techniques described above -- was wondering if there's any sure fire way of doing ?

Is it the advent of tubeless tyres that makes this a problem and how does that affect the tubeless situation ? ie will the tyre go straight back down or not hold any air at all ?

[531colin]

This thread is from 2007, long before tubeless bike tyres.
I have just one bike tubeless, no issues at all ( so far!) fitting or using.
Maybe rim and tyre sizing is better controlled now?
Years back Rigida Chrina rims had a (deserved) dreadful reputation for being oversize, and even longer ago 27” Michelin zig-zag tyres were so loose on Weinmann rims that you always got a bump-bump unless you put tape on the bead seat to increase the effective diameter