I'm a wee bit confused about what tyre sizes I can fit to my '79 R80/7. For normal road use I use Michelin Macadam 50's. The Macadams were fitted to the bike when I bought it and I have no reason to change them for everyday use.

Now I am thinking of going a wee bit further afield and exploring some (not too demanding) tracks and trails. Having done some really mad offroad stuff in the sixties on old army Triumphs and BSA's ( basic road bikes with a solo saddle), I know that any solidly built road bike can hack a few potholes and gravel. I have therefore resisted the urge to buy a 'proper' RTW type bike (whatever that is?) and stick with the trusty airhead which I know is easily tough enough to put up with a few bumps and knocks.. The choice of bike is easy but now I'm stuck with the problem of getting suitable dual purpose tyres to fit the rims. I've read all the stuff about ' which tyre' and I'm quite up to speed on what's on the market.
The problem is, when I select my rim or tyre size (or my bike type) in the suppliers search engine, all I get is the standard ( recommended) range of road tyres for my bike. If I search for tyre type , I can see loads of great dual purpose and dirt tyres but not a set to match my bike or rim sizes. Sometimes I can find a front, sometimes a rear but never a matching pair. My knowledge of tyre sizing is obviously limited to vintage cross ply so I will throw the problem at this forum and see what turns up. Here is the low down.

Present tyres are Michelin Macadam 50's
3.25 x 19 Front. 4.00 x 18 Rear.

Wheels are alloy, rim sizes:-
185B x 19 Front. 215B x 18 Rear.

I NEED: A (preferably matched) set of tyres which will be suitable for mostly paved roads with occasional dirt, pothole, gravel and dodgy east European ( or even Russian) roads, farm tracks and camping trails. I intend to avoid sand and mud, ditches, rocks, corn fields, forests, watery stuff and anything which will cause my teeth ( and the bike) to rattle badly and which will make me fall on my ass too often..I probably won't exceed about 90 (ish) mph and I prefer to use inner tubes regardless of tyre type.!! I usually travel solo and I travel light but with standard Krauser touring panniers. I'm a canny rider and a canny Scot so I expect to see some miles for my pennies so soft sticky stuff doesn't tickle my sporran (so to speak!). Good mileage IS desireable but not at the expense of my life..!

I've read with interest the reports of such tyres as the TK80, Tourance, Distanzia and similar but can't really make any serious choice until I find out which of these are available to me. So...

First question. What alternate tyre sizes will fit my rims ( and the bike)?

Second question. What Tyres do other R80 owners use in rough terrain?
(R100 and other airheads too but not GS or G/S)

Third question. Think of a question I should have asked and answer it for me please. (That's not really a question..but you get the drift)

Could somebody explain the tyre size and rim size thing to me in simple terms? The way I understand it, some modern tyres seem to be only available in certain sizes not compatible with mine. I need a 185x19 front but some tyres are only available in 90/100x19. I need a 4.00x18 rear but many otherwise suitable tyres are not even listed in that size. What's a 120/80x18?. Will it fit a 215x18 rim? Duh!. I need help...

Hope you can help. I don't want to be stuck on Tarmac all my life.

Thanks in advance.
Ian.

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