Evening Gents

Can anyone give me some tyre advice please.

I have seen several discussions about 900 x 20 tyres and split rims but my RML has (Dunlop SP 321) 10 R22.5 144/142L tubeless tyres and presumably not split rims. Was this a later change to overcome the shortage of the original type if that's what the 900 x 20 tyres were.

I have seen there appears to be a shortage of the 900 x 20 but a simple search found companies advertising a number of types in this size, the difference being some are 6 and 8 ply and lots 14 ply. Some look tiny others look like they should be on an armoured vehicle. Prices are from around £150 to £800.

What does this all mean? (apart from how little I know)

David

My bus number (if any): RML 2276 M1001 T806

You need the 14 ply tyres for your bus. Tread patter varies, it depends whether you want them for front axle, rear axle with chunky knobbly bits or a general purpose tread for front or rear.

The 10R225 tyres are for tubeless rims and are the metric equivalent of the 900x20.

900x20 are still available, one of the chjaps in my depot got one the other day for his East Kent Reliance, cost about £300 with new tube and flap, but is made in China. The Chinese seem to be the only ones making old size tyres these days.

Thanks Roy


The 900x20 is for someone else. I take it the flap is something to do with the split rim.

My Titan has chunky looking tyres on the rear. Almost look like off road tyres

My bus number (if any): RML 2276 M1001 T806

The tubeless tyre and rim is also considerably lighter than the older 3 piece rim, tube, flap and tyre. It made enough difference over the six wheels on a 2 axle vehicle to warrant an advertising campaign back in the 1970s when the tubeless style first started to become popular.

About 2 or 3 years ago a freind paid ISTR about £900 for two Michelin 900s. Very nice they were too. But they were old stock. Probably perfectly safe if stored correctly. But you can never be certain of that. I didn't check the date marks, but I believe MOT stations are now giving advisories if front tyres are over 10 years old. They could have been that when fitted! So then you have Chinese imports for £2-300. \"Double Coin\" seem the most popular and seem OK. Depends how you feel about such items.

The split rims look much better I agree. But many are seriously worn or rusted now. Mobile tyre fitters are often not keen on them. They must be inflated in a cage by people who know what they are doing. Their lethality has been more than well proven. One piece tubeless rims with modern metric tyre sizes are easier to work with, safer, cheaper to get tyres for- IF the totally original look isn't your thing. Just like AEC engines, they were replaced for a reason.

I would strongly urge every reader to simply type "split rim explodes" into YouTube and watch the safety videos to see what can happen.

My bus number (if any): RM531

Thanks Steve

Very informative. I think this video says it all!

http://www.youtube.com/watch?v=YErigPBPlrA

I think originality has a limit where practicality and safety is concerned

Roy, I take it the flap is the equivalent to the old bicycle tyre strip (name escapes me) that protected the innertube from the spoke ends.

When did Routemasters begin to have modern rims and tyres fitted?

David

My bus number (if any): RML 2276 M1001 T806

This poor guy in the video looks almost comical in his attempts to get that tyre off.

I remember my farther doing this for a living in mid 1970's but not with little toy wheels like the "red neck" is stripping down. He would buy worn 9.00/10.00/11.00/12.00 wheels & tyres from haulage companies and manually strip off the tyres to sell to remould companies like Vacu-lug, i can honestly say to date i have never seen anyone work as hard as he did to get those tyres off.

I think his tools are still around somewhere: 20lb sledge, a couple of 1/4" x 1-1/2" x 3' flat bar steel tyre levers, 2 pairs of tyre spreaders for crossply & radials and a couple of 3' crowbars for removing the lock ring and bead, oh and a tread cutter for my older brother to do the re-grooves at the weekend (poor sod)!

I don't believe they are as dangerous as they make out if done properly, we have a customers RF that has just been fitted with a full set of new "Mitas" (Czechoslovakian) cross-ply's on the original wheels and i believe the fitter walked away without any injuries at all!

Many split rim wheels are rusted or corroded. I had an enquiry from one of my German customers about the is recently. I got him a price for modern metric wheels, around £300 a piece. The alternative was to needle gun or shot blast his old wheels which is what he ended up doing, and the German tyre company was quite happy to fit new tyres to those.

Many thousands of tyre fitters haven't killed themselves inflating split-rim type wheels over the years, it's only with the advent of internet scaremongering that this has been brought to the fore.

My bus number (if any): RML2532

Timely discussion, thank you gentlemen, I've had a few wheel and tyre decisions to make recently. Here's my observations, for what they are worth.

Earlier this year I paid £300 for 2 part used 900s fitted to the inside rear split rims. They are still ok and raised no concern at mot. The inner tube on an outer wheel perished and had to be replaced last month £100 including call out.
The day of setting off for RM 60 I discovered cause of a fast slow puncture , on front wheel with modern tyres, was a porous wheel. Not a problem I'd heard of before or with tubed split rims of course. Luckily, found a conical nut type, long abandoned, but still inflated, tyre and wheel on which to swap my relatively new tyre for £10 mates rates all in

so, that's 4 out of 6 I've attended to this year, who's to say if age related wheel or tube failure will occur today or next year....I've been warned.

As an aside regarding safety of split rims...Twenty years ago, when I had an issue, the part used tyre dealer man changed tyre without any visible safety equipment, dressed all in white on a hot summer day without breaking sweat and keeping his clothes immaculate. I guessed he'd done it a time or two and had that most useful of safety aids, experience.

Conclusion.... tyres are important, buy the best you can afford after consulting with someone who knows ;-)

My bus number (if any): 1842

Split rims offer no real problem if they are well maintained and tyres replaced/repaired with the correct tools and in the correct way.

In all honesty only a skilled tyre fitter should be doing this as it can be dangerous.

But it is well worth having a few split rim spare wheels minus tyres , and as long as they retain integrity, have them media blasted of all paint and rust and etched primed with a zinc coating to protect them.
Then when required, swap them with the wheel the tyre is being replaced on and renovate the offcoming wheel as well.

In other words rotation with a float.
Of course this could be done with existing wheels but the bus would be without a wheel for a week or more.

According to our local test station it appears that VOSA are issuing advisories for steering axle tyres over ten years old for class 6 tests presently - as of January they are due to fail them. Having said that the latest VOSA issue I can find is January this year and seems to be a 'VOSA strongly recommends' rather than a law change. Probably best not to upset them by not complying as it won't look too good on your record.

Class 5 tests don't appear to have been included yet possibly as these are often done by independent stations ?


https://www.gov.uk/government/publications/public-service-vehicles-tyre-age-recommendation

Just found a link for a bill that is going through parliament now to make it law if successful, it appears to relate to all tyres on buses and coaches

http://services.parliament.uk/bills/2014-15/tyresbusesandcoaches/stages.html

On the subject of split rim tyres I read somewhere that Michelin are going into partnership with Double Coin in China so hopefully this will maintain a decent quality.

My bus number (if any): RML2747

does anyone know if there is a supplier for Michelin 900x20s
or any owners have any in stock im after 2 ,ive tried ATS who are Michelin main dealers but no luck,any ideas

My bus number (if any): RCL 2238,RM,RT,RF now sold

Hi David Colin

Not regarding tyres but trying to get in touch regarding the invoice you are sending as we have tried email with no reply and have posted on the link regarding schrader valves but no reply so thought i would try this new thread you have started.

Regards

Dave.

if any bus owner is interested in Michelin 900x20 tyres ive just purchased
three for our bus contact T.D Tyres,Malvern ,WORCESTER
TEL 07545 735303 PRICE £360 plus vat for each one ,contact mark Williams
I know a lot of you will say they are dear but you pay for what you get
and these will last for a few good years .thanks to Peter for the info
most grateful

My bus number (if any): RCL 2238,RM,RT,