I’m trying to fit a specialized purgatory to a Dt Swiss 30mm rim which is a right pain, I’ve never had a combination that took so much wrestling!

I can just get it on if I use massive tyre leavers and some washing up liquid but every single time I do so I hear the hiss of a pinch puncture or a snake bite. It has now happened 4x! I am obviously rather hacked off now. I’m not sure if it’s the tyre leaver or the bead that’s doing it. What am I doing wrong? I managed to mount them on some narrower rims without any problems before.

I know that I should go tubeless but please put that aside for now as it’s not an option.

Any relevant advice will be greatly appreciated

Probably trapping the tube with the tyre lever. Are you working the tyre on as it goes round – you can kind of stretch it to give you a bit more ‘give’ for the final bit to pop on.

Make sure the inner tube has a little bit of air in it for shape but not too much.

Then also try to get the inner tube up inside the main part of the tyre where it can’t easily get squished.

The real answer is of course ‘tubeless’! 😃

Some tyres and rims just might not work. As joebristol says get some air into the tube first and that should avoid some potential punctures. Can you tell from the failed tube where the puncture is and what size it is. Might give an idea where the problem is. Also maybe going for a heavyweight tube might save it.

Lots of ifs in the above though. Different tyre maybe?

Possible you are catching the tube with the levers but are you sure there isn’t something in the tyre or rim (sharp edge, uncovered spoke hole)

My technique…..

1/ slightly inflate inner tube for shape and coat in talcum powder

2/ fit one bead of tyre into the rim

3/ valve through hole and fit tube around the inside of the tyre

4/ start putting tyre on OPPOSITE to the valve (I know you were probably told different but they’re all wrong and I’m right)

5/ Sat down and with wheel resting on your lap start working equally around feeding the tyre onto the rim until you get to the last bit that won’t go on, at the valve hole

6/ go back and repeat but this time pushing the bead into the well of the rim and stretching the tyre away from you….ideally creating enough slack so the last bit can go over. By starting opposite the valve you have maximum use of the well of the rim

7/ if it still won’t….. stand up and do it again but this time really stretching the tyre away from you to create even more slack.

8/ if the last bit won’t go on, then use 2 tyre levers, one either side of the valve and make sure the tube isn’t pinched betwixt rim and lever

9/ Once on, push the valve stem up into the rim/tyre so you can then get the bead in under the valve.

10/ rather than 8…… get one of these which is far betterer and makes it practically impossible to pinch a tube

https://www.sjscycles.co.uk/tools/var-tyre-levers/

There is a workshop version too with a girt big lever on it for leverage too, but that won’t fit in a pocket.

First make sure your rim strip isn’t too thick and the rim has a decently low central channel.
Next mount one bead.
next insert the tube’s valve (but not fully through the valve hole. (as putting it right through limits the bead sitting in the centre of the rim)
next tuck the tube (uninflated) into the tyre all the way round.
next with two hands close together start at the bottom pop the other bead over the edge of the rim making sure you push it into the centre of the rim channel each time you push it over the rim edge.
move your hands apart and repeat until your hands meet at the top of the rim.
et voila!

to remove any tyre simply let as much air as possible out (folding the tyre over to push more out) then push the bead into the central rim channel all the way round. hold the tyre at the top and you should see it’s loose enough to push over the rim edge. push it over bit by bit until half of the tyre bead is over then just pull it off the rest in one go.

you can now throw away your pointless tyre levers

Hmm, thanks.

The punctures are always on the inside of the tube where it goes in the rim, opposite the valve where I’ve been popping the last bit of the bead over. It’s a brand new wheel with factory fitted rim tape but I guess I should have checked it already.

I’ve always lightly inflated the tube in the past and 4th attempt I tried putting more air in to see if that helped (it didn’t).

I’ll try going at it the other way round and finishing by the valve and also concentrate on getting the bead into the well as much as possible. Might try having a go with no air in the tube too if I have to… And I have enough patches left.

Thanks again

Don’t do the valve nut up until the tyre is fitted. That will let you slip the “fat” part of the tùbre into the tyre as you pop on the last bit of bead without catching the tube in the process.

Good lord this question makes me feel old! Chuck some some talcum powder inside the tyre and move it around so the whole inside is coated. Then try to fit the tube and it should avoid getting trapped by the bead.

And..

If you have a workbench/shelf/table handy, lay the wheel horizontally with the valve furthest from you.

Put the axle against the table edge.

Press your stomach against the bit of tyre wheel nearest you.

Start feeding the tyre into the well at your stomach, moving round bith sides with your hands, squeezing the tyre into the rim and away from your body as you do so.

By the time you get to the valve you should have enough spare tyre to slip on with your hands.

It helps if you have thin rim tape. I prefer the Stans/WTB type even if I’m using tubes as it is thin and shiny.

is that for folk who have too fat a gut to allow gravity to hold the bead in place?

As above, and – if you’re still struggling – one of these

The key difference I’ve found between success and failure – once the first bead is on, make sure it sits in the middle, low part of the rim. You’ll be amazed how much difference it makes

I carry one of those tyre jacks in my under saddle pack…just.

The tyre / rim fitting is just sooo tight. (Fulcrum 7 and Panracer Gravel King, tubed set up).

I carry one of those tyre jacks in my under saddle pack…just. Might need to do a trail side repair. Would be totally stuffed without it.

The tyre / rim fitting is just sooo tight. (Fulcrum 7 and Panracer Gravel King, tubed set up).

The key difference I’ve found between success and failure – once the first bead is on, make sure it sits in the middle, low part of the rim. You’ll be amazed how much difference it makes

very, very much this. I’ve had recalcitrant tyres that will suddenly pop on without levers at all simply because I’ve ensured the bead is well into the central channel