18 inch vs 19 inch rear wheel

I am thinking about getting it my 1970 Norton Mercury on the road. It is basically a single carb 650 SS Dominator. It has 19 inch wheels front and rear. Apparently all the Dominators came with that wheel size, except the Atlas which has an 18 inch rear wheel. I wonder why Norton changed the rear tire size on the Atlas, and how it affects handling? The guy who owned the Mercury before me complained about how it handled, said it fell into corners, and experimented with tires sizes to change the trail and the handling.
Stephen Hill

Stephen Hill said:

The guy who owned the Mercury before me complained about how it handled, said it fell into corners, and experimented with tires sizes to change the trail and the handling.

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So what did he conclude ??

I'd comment that I experimented with front tyres on a Commando, quite some time back.
The difference between having a K81 on the front and the Avon Roadrunner was like chalk and cheese.
And tyres have only improved since then....

Previous owner is an engineer with a fair amount of British bike experience.
He measured the trail and concluded it was wrong, swapped wheels to increase trail, still didn't like how it handled, and sold it to me......

I am just putting the bike on the road so don't have first hand experience of the handling issue.
But it got me wondering whether the 18 inch Atlas vs 19 inch 650SS rear wheel had implications for trail and handling.
Stephen

If I was you, I'd keep the 19" front and rear. It's just an all around better set up. And I've tried both.
The Atlas 18" rear was a US market thing. All the UK model Dominators had 19" rear.
That being said, tire choice will most affect your handling and ride quality. I've settled on Avon Roadrider Universals. 100 / 90 - 19 front and rear.
Save yourself the trouble and headaches. Keep the 19" wheels that are on it now and mount those tires. And Bob's your uncle.

Totally agree with those suggesting that you keep 19" wheels fore and aft.
My late lamented 650SS had standard 19" wheels and with Avon Roadrunners (3.60 front and 4.10 rear) and Koni shocks, well assembled standard forks, it was pretty much the best handling/steering bike that I've ever ridden. I've ridden others that were as good, but they are far more modern.
The only problem might be getting 19" tyres!
cheers
wakeup

There were enough British bikes made with 19" wheels that 19" tires will always be available ?
They may have to order them in though.

I've been impressed with how the prices of some of these new-fangled tires have been climbing though.
$1000+ each for some of the performance car tires - yikes. !
And quite a lot for some of the new oem tires for the current crop of superbikes....
Wowee, how do folks afford it when they only last such a short mileage ??

wilkey113 said:

The Atlas 18" rear was a US market thing.

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This may be so, all UK and other export Atlas came with 18 inch rear wheel out of the factory.
They might have come with a corresponding longer rear shocks to raise the rear for any height lost.