Tubeless tyres

[peterg]

I'm finally taking the plunge and replacing the 30 year old cross plies. I thoroughly enjoyed the progressive slip they gave but not the tramlining and deminishing tread.

I'm getting Michelin taxi tyres unless anyone can persuade me that KingPin remoulds are a better buy.

My questions are:

Does anyone run their 401/3 wheels tubeless? On several other car forums the contributors say that they run tubeless tyres on 'standard' rims without problems whereas the official line is that the rim should have a safety shoulder to prevent the tyre edge from breaking away from the rim.

Can anyone tell me the size of the valve hole on the wheel? My car is 30 odd miles away so I cannot easily check it, and can anyone advise on tyre pressures to use. I was running the cross plies at 30 lb all round.

Oh, and will a taxi tyred wheel fit in the spare wheel tray?

That's it for now. Regards, Peter

[dave dale]

Peter,

As far as I am aware, the standard 401 / 403 rims are rivetted and therefore not airtight. Thus tubes have to be used. I am prepared to be corrected.

Dave Dale

[dkleeman]

Originally Posted by peterg

Oh, and will a taxi tyred wheel fit in the spare wheel tray?

I cannot tell you definitively if the taxi tyre will fit in the spare wheel tray, but I would be very careful as it is pretty skinny. I recently bought 4 x 550HR16 Michelin X and 1 x 165HR16 Avon Turbosteel for my 401. The former did not fit in the tray but the latter did (which is why I bought one). The Avon is distinctly thinner than the Michelin. I think that we have used tubes.

I bought my tyres from Longstone Tyres and they were very helpful allowing me to try the tyres for size before buying them.

Unfortunately I cannot report how they drive as my Bristol is still off the road.

Daniel

[Des]

I've seen riveted wheels work with tubeless, put a couple on an old Rover a year ago and have been fine, may have been down to luck or perhaps a good sign of the wheels sound condition, but the danger of sudden deflation years hence by inner tube chaffing inside a tubeless is greater than that of a slow leak via rivets. I think we need the 'big' valves as used on Rover P5 / VW Beetle. I believe the only real issue with taxi tyres is the speed rating, I've run taxi tyres, on an ancient taxi, it had a petrol engine so could hold 80 on the big roads, and I used to throw it around in a manner I'm now ashamed of without any problem, shouldn't think there would be an issue on a Bristol, half the weight / refined suspension. Insurance companies may get a bit la-de-da so could be worth ringing around to find one who doesn't get all funny. You'll pay a grand for a set of the 'correct' tyres, good quality cab rubbers are about a Vanessa a pop.
As I'll be putting my car into daily use will have to buy a set of tyres soon, I have 4 rims that have been converted to 15 inch so will have to see if they would be viable, the tyres would need to be big to get the rolling diameter right, so would this make the car handle a bit spacehopper, or maybe the compliance of fatter tyres would be a benefit to a car designed with crossplies in mind.

[peterg]

I've done the dirty deed. One set of Michelin's. It was a close call with King Pin remoulds at half the price. 'W' pattern tread and all the tram lining and gitteryness has gone. Took it up to 70 on the way home without worrying where it was going to go and around the slip road without the customary tail stepping out. Mmm, not going to be such an exciting ride in future.

Currently I am running at 30 psi all round (same as the cross plies). Any other suggestions?

I had them fitted as tubeless, so will let you know how they stand up.

In the spare tyre tray was a new (suppose it would be called new old stock) Indian tyre. Sad that it sat so long without use.

One annoyance, it ticks over at about 800 rpm (just above the 1,000) but when the clutch is depressed it drops off and often stalls. I guess it is vacuum assisted and reduces the vacuum in the inlet. Is there a cure that doesn't result in too high a tick over?

[peterg]

Well, the tubeless tyres have been on a month without loss of pressure and the car behaves SO MUCH better. Going upto 70 mph iis now a joy!

[dave dale]

peterg - i also use 30 psi all round on my 403 since changing to radials. I followed advise from Bellerophon and it is spot - on ( as expected ! ).

Currently I am running at 30 psi all round (same as the cross plies). Any other suggestions?[/quote]

Dave Dale.

[peterg]

For anyone worried about fitting tubeless tyres to the original riveted rims, mine have now been on for three years and I have only needed to pump up one wheel a couple of times during that time.

They have stayed up much better than the tubeless tyres on my Skodas!