Changing bike tyres and compressor capacity

[Rannsachair]

To make life easier changing bike tyres, I bought myself one of these:

Makes light work getting the tyres on and off the rims.

Spent half a day trying to seat the bead on the rear though, had it on and off the rim, extra tyre soap, filed down some imperfections on the alloy wheel, tried ratchet straps and unseating opposite side, all to no avail.
I have a 50 litre compressor that I took it up to 70 psi. Had a thought that it may not be banging the air in fast enough, so nipped up to my dads to use his 200 litre compressor, 5 minutes later sorted!

 

[fenman]

try taking valve core out seat beads replace core inflate as normal

 

[Rannsachair]

try taking valve core out seat beads replace core inflate as normal

Yep, thats what I was doing, when bead did seat it was like gunfire!

 

[Chris Stevens]

Small compressor simply doesnt have the power to seat tight beads.

 

[CompoSimmonite]

Next time try a ratchet strap around the tread.

 

[pedrobedro]

Bounce the wheel and tyre on the floor a few times to centre the tyre in the wheel well.

 

[Rannsachair]

Next time try a ratchet strap around the tread.

Tried that too

 

[Rannsachair]

Bounce the wheel and tyre on the floor a few times to centre the tyre in the wheel well.

Yes, akways do that.

 

[ford34/2]

You need to pump air in quicker than it can get out, possibly more pressure,-direct off tank, bigger compressor, bigger receiver. Other than what you are trying dosnt leave much to suggest.
Stan

 

[octo0072000]

you want one of these easy to make gives you another project

http://www.ebay.co.uk/itm/20-Litre-...097497?hash=item4649933f59:g:YMYAAOSwuAVWz-3x

 

[Bill Edwards]

You must remove the valve core.

You need a large diameter pipe directly from the tank to the valve with minimal restrictions, some inflators are restrictive.

You need far higher pressure than 70 psi in the compressor - 150 is ideal.

A bead cheater linked to above can be almost essential on stubborn tyres.

 

[the snooper]

Small compressor simply doesnt have the power to seat tight beads.

It should if the air flow isn't restricted through narrow bore pipe and fittings, I use a small compressor on my tyre changer sometimes if I'm only doing 1 tyre

 

[Rannsachair]

You must remove the valve core.

You need a large diameter pipe directly from the tank to the valve with minimal restrictions, some inflators are restrictive.

You need far higher pressure than 70 psi in the compressor - 150 is ideal.

A bead cheater linked to above can be almost essential on stubborn tyres.

Thanks for that, I have a 25 foot length of standard pneumatic hose on the compressor, suspect that did not help.
I removed the core and the pressure was at the inflator on the valve stem, was nervous going above that as I googled the max pressure for motorbike rims and found some scary stories.

My 50l compressor is set to 120 psi and my dad's 200l compressor, 150 psi - it certainly did the job, it was using different inflators, I suppose mine could be more restrictive,

 

[dannyp]

lighter gas

 

[Bill Edwards]

A piece of rubber pipe from the airline fitting which is a snug fit onto the valve stem is great. As I do them as part of my living I enhanced mine a little with a ball valve and T'd off pressure gauge but it's the same idea, getting it straight from the air hose into the tyre.

A long air hose will always restrict more than a short one, but the diameter makes a big difference. Many cheap hoses are 6mm ID which is useless for a lot of things, 10mm is good for stubborn beads, air tools etc.

Until the pressure in the tyre starts to build nothing can go bang as the air is leaking out as fast as it goes in. But having more air pressure at the tank means you get a higher flow into the tyre which is what it's all about. Once the tyre is taking air and no longer leaking you're just waiting for the beads to pop, that's when you need to keep an eye on the pressure so as not to have an accident.

I don't know about bike tyres (I'm into agricultural stuff) but generally you don't need massive pressure to make the beads pop on, though I have found a few quad tyres which are a pain. Sometimes (mainly when they're old and I daren't take them high) I have to break the bead and sort of hold one side down so it comes up later which helps it to pop on at the opposite side first. But that's pretty rare, generally by the time there's 20 psi in a tyre it pops. But as I say, motorbike tyres aren't my thing so could be different in the aspect.

 

[Member 66061]

Small compressor simply doesnt have the power to seat tight beads.

I used to seat beads with a twin barrel foot pump, i have a 24L 2.5hp 116psi compressor now and it seats beads.

 

[dannyp]

a lot depends on the tyer.

some heavyly reinforced tyers like inplement tyers with high weight ratings and high performance road motorsport tyers with very stiff sidewalls, can need quite a lot of help to start them seating

 

[Rannsachair]

I should add that I have done dozens of bike tyres in the past, mainly much smaller ones on 1940's to 1960's Triumph's, Ariel's, BSA's, but also on a KTM 950 adventure without a problem, all tubed though.

 

[Rannsachair]

Did you soap the bead?

The last bike tyre I did was the stiffest tyre in the world - I could stand on it (unfitted) and it wouldn't deflect more than few mm.

Was a total b to get on the rim - then seated the bead with a pushbike track pump.

I would have used a compressor, but it was nearly midnight and I was fitting it on the front path - seemed like a good idea after a few beers

Those remote reservoirs that can dump air into a tyre are plain dangerous imo - the volume of a bike tyre (or average car tyre) means you can take it from 0-150 psi in a couple of seconds - I would never use one nor condone that sort of use (and seriously, I use unguarded table saws, gloves on lathes - and I think they're dangerous)...

I guess they seem like a good idea if you've never seen a tyre let go with a person in close proximity.

Yes, had a bucket of proper tyre soap.
My dad worked with a guy at the quarry who decided to crowbar a rock trapped between the twin tyres on his truck. Was horrific, lost an eye and most of his face. So I was wearing safety glasses and had a big old tarp over the tyre when inflating ( not sure it would have done any good).

 

[Bill Edwards]

I should add that I have done dozens of bike tyres in the past, mainly much smaller ones on 1940's to 1960's Triumph's, Ariel's, BSA's, but also on a KTM 950 adventure without a problem, all tubed though.

Well there's the thing, tubed...
It's impossible to have a problem seating a tyre with a tube as there is no seating to be done, the air can't leak out! A hand pump would do a tractor tyre if you kept going for long enough.

pdg, if you think it's dangerous to use a cheater then it isn't necessary to fill them to a high pressure if only doing a small tyre.
But I can tell you that on small (but non motorbike) tyres they don't leave much pressure in the tyre at all, I would say a huge amount of the air is wasted but there's still enough going into the tyre to make it sit against the rim.