Model 30 Tyres

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chris goldson
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Model 30 Tyres

Post by chris goldson »

Seem to be losing tyre pressure more rapidly than I would like so winter job to change tyres and tubes on the Model 30 (1956).

Any thoughts on recommendations for tyre types and best place to get them from?
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dave16mct
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Re: Model 30 Tyres

Post by dave16mct »

There are lots of different opinions on this. I choose Avon Speedmaster front and SM rear, usually ordered from The Vintage Tyre Co. I have them fitted at my local tyre place with new Michelin tubes and rim tapes. My hands aren't strong enough to do them myself anymore amd I usually nip the tube anyway. Lots of members choose to fit Roadriders which are excellent but I personally don't like the look of them on old bikes. Some go for cheaper Mitas which are ok too. I have a friend who will only fit Dunlop K70. The speedmasters have a new compound and shape so you need higher pressures than in the manual. I usually go for 26 front and 28 rear.
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MalcW
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Re: Model 30 Tyres

Post by MalcW »

dave16mct wrote: Tue Aug 24, 2021 9:00 am There are lots of different opinions on this. I choose Avon Speedmaster front and SM rear, usually ordered from The Vintage Tyre Co. I have them fitted at my local tyre place with new Michelin tubes and rim tapes. My hands aren't strong enough to do them myself anymore amd I usually nip the tube anyway. Lots of members choose to fit Roadriders which are excellent but I personally don't like the look of them on old bikes. Some go for cheaper Mitas which are ok too. I have a friend who will only fit Dunlop K70. The speedmasters have a new compound and shape so you need higher pressures than in the manual. I usually go for 26 front and 28 rear.
Dave.
I use Roadriders on my Model 31, even though I completely agree with Dave regarding the appearance on our old bikes. But they handle very well, wet or dry. Again, it's a modern compound so you need higher pressures than the manual states. I run mine on 30 front, 32 rear, which seems about right for me.

Malc
56G80S
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Re: Model 30 Tyres

Post by 56G80S »

+1 for Roadriders and the higher pressures required. Do not use the old pressures from the manual with modern tyres, don't ask how I know.

I think it was Clive who posted a useful guide on pressures based on empirically testting the contact patch....maybe a search through his posts will show this? It certainly opened my eyes.

Johnny B
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clive
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Re: Model 30 Tyres

Post by clive »

56G80S wrote: Tue Aug 24, 2021 5:53 pm +1 for Roadriders and the higher pressures required. Do not use the old pressures from the manual with modern tyres, don't ask how I know.

I think it was Clive who posted a useful guide on pressures based on empirically testting the contact patch....maybe a search through his posts will show this? It certainly opened my eyes.

Johnny B
Well if it was I don't remember it Johnny. :headbang:
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SPRIDDLER
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Re: Model 30 Tyres

Post by SPRIDDLER »

clive wrote: Wed Aug 25, 2021 9:22 am
56G80S wrote: Tue Aug 24, 2021 5:53 pm +1 for Roadriders and the higher pressures required. Do not use the old pressures from the manual with modern tyres, don't ask how I know.

I think it was Clive who posted a useful guide on pressures based on empirically testting the contact patch....maybe a search through his posts will show this? It certainly opened my eyes.

Johnny B
Well if it was I don't remember it Johnny. :headbang:

:? I did think it seemed a scientific step too far to have been Clive.
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Which taken at the flood............'
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clive
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Re: Model 30 Tyres

Post by clive »

Absolutely Spriddler, if its a bodge you want I am your man.
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Taid
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Re: Model 30 Tyres

Post by Taid »

There is a formula used by owners of older caravans, originally fitted with cross-ply tyres, to work out the correct tyre pressure for the radials they now fit ..

on the sidewall it gives the maximum load and the pressure for that load.

if you take the actual load divided by the maximum load and multiply this value by the pressure given, the result the pressure for the actual load .. or so I am led to believe ..
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Now sold ... 1956 AJS 16MS Bitsa .. HSU 414 .. rebuilt/re-registered 1987
56G80S
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Re: Model 30 Tyres

Post by 56G80S »

OK, what I remember (!) was that it involved the practical step of measuring the contact patch when seated on the machine using some process of colourant and white card and comparing it with an "ideal" contact patch shape or somesuch thing. Wish I could remember. I think that the idea was that it would remove the variables and allow the exact optimum to be found for you and whatever load you were carrying rather than attempting complex calculations.

Johnny B
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