Quick Inner Tube Size Question
 

For years now I’ve been riding road bikes on tubeless. My new (to me) TT600RE is the first bike I’ve had since I was a lad with a tube. To be honest, I’ve not changed a tyre since I was a lad :rolleyes2: now I’m 43 and slowly remembering how to do all my own work.

The bit I can’t remember is tube sizes…

My rear tyre is a
Pirelli MT 70 130/80 -18 66R
Front tyre is
Pirelli MT 70 90/90 -21 54R

Am I correct in thinking the tube size MUST match the tyre size

Also, is a heavy-duty tube ok for the road? Few sites I’ve looked at say “not for highway use” Why is that?

This place has Michelin HD for £12.99 – seems a lot for a tube, or am I just old

Michelin Heavy Duty Motocross Inner Tubes Motocross Gear from Dirt Bike Bitz

also they have 18 4.00/4.5 tubes for 5 quid…. They any good ?

Nutrak Motocross Inner Tubes Motocross Gear from Dirt Bike Bitz

regards
Shaun

Tube size
 

What I have found through the years is that there is a bit of leeway in which innnertube size you can use . For starters , the tube absolutely must match the wheel size i.e. 16inch only on 16inch rim. 18 on 18 , 21 on 21 etc. etc. However in an absolute emergency you can get away with stretching a near match smaller tube into the tire and pumping it up. Do replace with the correct size as soon as possible. Never put a larger diameter tube inside a tire e.g . no 18inch tube into a 17 tire. That is inviting tube failure due to creasing.
What can be allowed to vary is the tube ** fatness** for want of a better description. Some tubes come with instructions which say that the tube is okay for use in several different tire widths .A skinny tube will expand to fill the space . However never put a **fat** innertube in a narrow tire. This may restrict the tube from expanding to its full roundness , cause creasing, folds of rubber and result in a leak or catastrophic blowout.
Heavyduty tubes probably tend to build up more heat under strenuous use, this may be why they are not recommended for street use . But if you are not going racing racing I don 't see why not,

Tubes are in imperail sizes .. ie inches

Your tyres are in metric sizes

The 130 is about 5 inches so 5.00 18
and the 90 is about 3 inches so 3.00 21

And yes the tubes have a range ... say 2.75-3.25 for example.

Prices always go up .. or is it my money just going down?

"Not for Highway Use" ie not for continuous high speeds ... should be fine on the B roads.

must do it now
 

all my tyres and tyre kit just showed up in the post... now, do my first change in about 20 years :rolleyes2:

A couple of tips.

Start to take the tyre off at the valve, push the opposite part of the tyre into the centre of the wheel rim.

I put the tube in the tyre, add a small amount of air, then insert the valve in the rim then put the first half of the tyre on; this can be done by hand. Then mount the second part of the tyre starting opposite the valve.
After mounting the tyre before inflating, push the valve in so the tube is in the tyre.

Tyre soap, I use the proper stuff, but on the road I make up a solution from hand soap or similar. Washing up liquid will work but has salts which can promote corrosion of the rim.

I have use a 21" tube in a 17" tyre in an emergency, (two punctures in one day) and if on a long trip always carry both tubes.

good luck

Steve

I think with inner tubes you get what you pay for, just be careful not to put 'snake bites' (pinch) in an expensive tube! Some of the cheap ones offer you less protection than an out of date used condom.
I have always used in emergency an oversize tube, a 21" in an 18" offroad bike.
I use talcum powder when fitting.....tubes not condoms that is!
:confused1:

While we are on the subject anyone know what’s the deal with repairing a Butyl tube as opposed to a Rubber tube.

Steve

thanks
 

thanks for the tips chaps !

shaun

I would look out for natural rubber tubes if you can - they stretch more and build up less heat. Have never had a puncture using TKC80's and conti natural rubber tubes

I've just thrown a FOX innertube as far away as I possibly could wang it ,the dog brought it back with only a few more holes than it originally had.
It was so thin you could almost see through it .
It was replaced with a Bridgestone [ which was marked in metric size 90/90/19 ,which is the first time I've seen a metric marking , I usually use 3.25- 3.50 x19 ]
The Bridgestone was about 3 times thicker .