What Front Tyres?

[ProtoTipo]

Thanks Neil.

So a
205-50-15 is 586mm
215 TB15 is 612mm

I've also got (for 205)
55 ratio at 606mm and
60 ratio at 627mm

So maybe 205-55-15 would still be smaller diameter than a TB Michelin?

[turbonutter]

I get ~607mm for the 205-55-15 which is more or less the same as the tyres you are replacing.. you wount notice 5mm difference ( its less than the diameter change due to tread wear.
Also as you can see from my spreadsheet the actual tyre sizes do not always exactly match the theoretical diameters either.

[StruanR]

Michelin Racing Size Designation	Road legal sizes	Rolling Circumference	Recommended Rims
16/53-13	175/60R13 72V	1640 mm	5 to 6 inches
20/53-13	225/45R13 77V	1635 mm	7 to 8,5 inches
15/60-15	170/65R15 77V	1847 mm	5 to 6 inches
18/60-15	215/55R15 79V	1885 mm	6 to 7.5 inches
23/62-15	270/45R15 86V	1923 mm	8.5 to 10.5 inches
26/61-15	295/40R15 87V	1891 mm	10 to 11.5 inches
29/61-15	335/35R15 93V	1903 mm	11 to 13 inches

Michelin TB15 sizing..

[ChrisCar6]

205 / 50 x 15" on my front

[ProtoTipo]

205 / 50 x 15" on my front

Thanks Chris.