A65 Tyres

[watts]

I know this's frequently asked and I apologise.

I read the posts here and online I am confused about the sizes.

I have 1970 A65 tyres this has K70 4.00x18 and 3.25x19.

I thought I would go for K81s these but I cannot find the size I read the equivalent size is 4.10x18 and 3.60x19.

Or even Metzler Me11 and M77

I would be grateful for some advice as the sizes seem a bit of a minefield.

Thanks
Matthew

[limeyrob]

The A65 came with 4:00x18 / 3.35x19 K70 when new. Its a long time ago but I bought a new A65 in 1971 and that's what it had.  When they wore out I replaced them with K81 4.10x18 / 3.60x19 and that's what I stayed with. The grip and cornering on the K81 was superior but tyre life was terrible. The compound will have improved a lot since them but the rear tyre contact patch on the K81 is small so the centre wears down.
I recently bought a set of K70 for my Road Rocket - correct Dunlop ones not copies - and was concerned to find they have quite a low speed rating, odd since they were original fitment on the A65. Fine for me as I won't be going fast, but something to look out for.

[DAVE BRADY]

Hi,

I use Avon Road Riders.  Good in the dry and the wet.  They are usually available in imperial and metric profiles.  If these are hard to find then the main brands like Continental and Metzler should be as good.

Dave. 

[neil1964]

Hi,
I use Avon Road Riders.  Good in the dry and the wet.  They are usually available in imperial and metric profiles.  If these are hard to find then the main brands like Continental and Metzler should be as good.
Dave. 

Me too v happy with mine. Front 90/90 x 19, rear 100/90 x 19. I've kept GS size rims (WM 2) front and rear.
My scrambler has Dunlop Traimasters so went to WM2 x 21 front and WM3 x 18 for wider tyre choice.
Beware recent issue with Roadrider supplies.

[watts]

Hello

I think I have found some Roadrider MK1s 110x18 and 90/90x18. I am not sure is the 110 is too big?
Also they are unused but 2016 are they too old?

Thanks
Matthew

[limeyrob]

The "too old" tyre question is a thorny one. There are liability implications if something goes wrong even if the tyres are fine, next year they will be 10 years old.  The trouble is a lot depends on how they have been stored, I'm sure there are 10 year old tyres that are in great shape, but you can't tell.
In the past I've ran old bikes with tyres on for donkeys years an never thought twice about how old the tyres were but now? Despite the extra cost I think I'd go for new tyres.

[neil1964]

The 110/80 x 18 will be fine on a WM3 rim. The 90/90 would be best with WM2 but ok with a WM1.
Age of tyres is a moot point as limeyrob describes.