Inner Tubes

[florence]

Yesterday the back tyre went down suddenly, luckily on a straight bit of road and not in a corner but as I was doing about 60 it was a bit scary.

Looking at the tyre, I can't find anything that might have caused the puncture and also the inner tube has split.  I don't know whether the split happened while I was coming to a stop or if it was the cause of the sudden deflation.

The rubber of the tube seems quite thin and wonder if my tyre people put in a cheap tube last time.

With this in mind, do we have an opinion about which tubes are good?  Being made nervous by the incident, I was thinking about using a heavy duty type, like Dunlop or Michelin which I think people usually use for motocross?

[Johnwebley]

Go for the best.

I had issues of pressure dropping after a few days with cheap tubes.

New set of good tubes with the last set of tyres and the pressure dropping issue is history

Sent from my SM-A750FN using Tapatalk

[Trigger]

Don't use the thick rubber heavy duty type, they tend to over heat and blow. I think a member on here had a blow out with that type and I have had a front wheel blow out on the M1 with a heavy duty Dunlop some years ago.

[Moorey]

Most tyres used now are tubless with ridges inside which cause a lot of friction and heat in the tube. When fitting give them a good dusting with french chalk to to lubricate between tyre and tube.

[JamesH]

I use Michelin inner tubes on mine. Never had any issues. Not cheap, but quality these days isn't.

[jon stead]

Yup, I’ve just put a Michelin tube in my rear wheel, after a cheap, thin, Made in China one decided to have a pin hole for no reason.

[Spitfire]

This is all good info, so many pitfalls out there for owners of mature vehicles.

Cheers

Dennis

[mike the bike]

As Moorey said; give them a generous dusting of French chalk,  or the more easily available baby powder.
The baby dust also makes fitting easier and less likely to pinch the inner tube.

[florence]

chalk dusting a very good idea, I hadn't thought of that, thanks very much.

[matthewmosse]

Make sure the rim tape is in good condition too, I once had a tyre fitted by my local Honda main dealer and they omitted the rim tape as well as fitting a tube to a tubeless tyre. I was not impressed, whilst using a tube in a tubless tyre is ok, if you dont need to it's silly to do so, also when I looked it up last the recommendation is to reduce the speed rating of the tyre accordingly which on that tyre meant a tyre was not actually by those guidelines safe at the bikes to speed. Whatever, the result was a high speed blowout within 30 miles of the tyre being fitted - no rim tape fitted surely the cause.

[Moorey]

I've never understood the thinking behind de-rating the tyre when a tube is fitted as a tube doesn't compromise the carcass of a tyre, where the speed rating is derived from. I certainly don't bother getting a higher rated tyre just because a tube is fitted. I have never seen any damage to a tyre inner due to a tube been fitted. If anything is going to give it will be the tube surely.

[matthewmosse]

Down rating the speed rating I would assume is to do with heat build up. I dont actually know that but at the time it was the advice I could find online - cannot recall the site, probably the tyre manufacturer. 
Yes, was on a standard cb550 rim, spoked wheel. No excuse from a main dealer for missing the rim tape, and given they had a week to supply and fit the tyre no real excuse for not fitting a tubed type tyre. Bottom line is I now fit my own tyres etc, if I am going to be killed by incompetence I can do that at home for a considerable saving. It's not the worst bodge they did either, dads BMW they fitted a alloy wheel, tubeless tyre but didn't have the right valve stem for the alloy so used the valve from a tube  stuck in with those thin half nuts and gasket goo, then tried to charge an extra £7 for the time taken to concoct that bodge.
Regards tubes, not on motorbikes but I have noticed some inner tubes and tyres recently having very poor quality rubber that will not accept patch repairs, they just peel off and they also tear or split rather than slowly deflate. Might be worth if fitting cheap tubes, putting a pushbike patch on - inflating off the wheel and seeing if the patch sticks.... not sure brands like Michelin would need checking but if buying off Ebay or the like what's written on the box might not match the actual manufacturer. I doubt the extra heavy duty tubes are necessary but they should be fine for road use on a cb550. Motorworks reccomended fitting them on my BMW sidecar and I think the r80rt. I don't think I had any punctures on those bikes ever.

[K2-K6]

Speed rating as I understand it is almost entirely to do with deformation (growth in diameter)  within prescribed limits at the stated speed rating of the tire.

If you add weight with a tube,  then the centrifugal force increases in proportion to the weight added to the assembly at a given speed.  If that takes the deformation out of range you have to de-rate the tire speed rating to keep it in compliance.

The other consideration is the carcass maximum load (for example 56V) that 56 shows how much continuous load the tire can endure at a stated psi setting.
This is more to do with how much flex the tire goes through coming into and out of the contact patch area, which is what really builds up heat in the carcass if it flexes too much.  It's this that will usually cause the tire structure to fail if temperature causes the internal bonding etc to overheat.