MCC Forum

Technical Topics => Car Help => Topic started by: Richard Turner on June 22, 2016, 09:42:05 pm

Title: Fitting Innertubes
Post by: Richard Turner on June 22, 2016, 09:42:05 pm
Has anyone got any tips for fitting innertubes to tubeless tyres.  I find air gets trapped outside of the tube (but inside the tyre). Not sure if this matters but if the bead was dislodged I would lose a lot of pressure from the wheel.

Also we have had a couple of valves fail on tubes, and the valve falls inside the tyre.  Can car sized tubes be bought with metal valves with a screw thread on so the valve could be fixed to the wheel like on a motorbike or racing push bike.

Any tyre tube tips or things to avoid appreciated!
Title: Re: Fitting Innertubes
Post by: Stephen Bailey on June 22, 2016, 11:50:37 pm
Use Plastic Spacers designed for tubes in tubeless rims.

Push the valve in when inflating.

If you use screw down valves they will be ripped out...

Have a look at the next well prepped trials bike... They will have filed the valve hole oval and not done the valve nut up, so the valve can move.....
Title: Re: Fitting Innertubes
Post by: Richard Turner on June 23, 2016, 04:23:43 pm
Do you mean spacers like these

Title: Re: Fitting Innertubes
Post by: Simon Woodall on June 25, 2016, 12:49:31 pm
Those are they.
You can also get screw in valves, Google "Tractor Valves".   You have to cut off the old valve and replace them with the tractor valves in the same way that you would repair a puncture.   To stop them pulling and tearing, make sure you put lots of French chalk or talcum powder between the tube and the wheel when fitting, this allows the wheel to slip against the tube rather than pulling it round.   ts worthwhile even with standard valves.
Title: Re: Fitting Innertubes
Post by: Jonathan Laver on June 26, 2016, 04:47:23 pm
The garages that fit tyres use a lubricant to ease the tyre bead onto the rim. This is usually a form of white soap. It is a good idea to fit  them dry i.e. without this compound  since it reduces the grip between tyre and rim . Some individuals use clamps to stop the tyres spinning upon the rims. Some uses self tapping screws while some are known to bond the beads to the rims. The latter being a one way trip!  I screw my tyres to the rim having measured the right length screws to buy. Fitting 6 upon both side of each wheel rim. These are stainless steel being harder and possible to remove at any time. The heads do not round or snap. I carry an electric screw driver to be able to take them out upon an event if I have to. This is not ideal but suits me and the car. Most tyres these days are designed as tubeless and some trailers like to run with inner tubes. The question of compatibility is sometimes raised by the tyre fitting company since this is contrary to their recommended practice. To be met with "Sorry mate its more than my jobs worth" is not uncommon and to be expected. The issue with small undulations/bulges in the side wall of an inflated tubeless tyres fitted with inner tubes is not uncommon. I have always put this down to trapped air pockets. Perhaps an issue that would be reduced by the application of powder upon assembly as mentioned above. Bulges in the side wall of used tyres can be as a result of damage (perhaps on section or running flat and then reflating). Sorry for stating the obvious but one type is OK and the other type can bite you !
Title: Re: Fitting Innertubes
Post by: Richard Turner on June 29, 2016, 12:20:43 am
I have my own tyre pole and pneumatic bead breaker so I don't have to worry about tyre shops not being keen on any specialist fitting!  :D Although I did use a lot of tyre soap fitting the last batch of tyres as it makes breaking the bead easier when you need to take them off! I also soaped the inside of the tyre and wheel rim to reduce friction, but it sounds like I should have not used any soap, I will take them back off and clean them and use the chalk we were using to make chalk paint with.  I like the idea of screwing the beads to the rim, I had heard of bead lockers but not investigated further. We never checked to see if the tyres were moving on the rim on the Polo but it didn't have much power anyway.  Good tips thanks!!
Title: Re: Fitting Innertubes
Post by: Sam Holmes on June 29, 2016, 06:42:22 pm
If the tyres move much at all on the rim they will pull the valve off, so assume they weren't moving.
Title: Re: Fitting Innertubes
Post by: Jonathan Laver on July 02, 2016, 06:38:59 pm
It is good practice to keep an eye upon the valves during an event. Sometimes you see that they have kick to one side from their upright position indicating the tyre has moved. You will see some people change their driving wheels from left to right during an event. This might well be for this reason. Swopping them over cause them to rotate the opposite way. This gives you even more of a chance because if  there is only "slight" movement of the tyre upon the rim, if they move again,  the valves can come back upright and some. Not the answer but a reasonable tip.