Just about to order a new tyre (or tire) for my RT3. Shinko 3.5X19 #241. The o/a diameter is 26.57". Will my standard front guard clear it. I can't foresee any mud ever getting between tyre and guard.
The smaller alternative is 2.75x19 with a o/a dia. of 25.16"
I prefer the look of a chunkier tyre.
cheer
paul

The RT3 is a '73 and has a 21" front wheel. '70-'72 has 19". The fenders are the same. 19" and 21" fit. So if your bike has a 19" front wheel the larger tire should fit.

That’s great, thanks. I thought that the 21” wheels ran a high guard, mounted under the lower triple clamp.

Cheers
Paul

That came on the '74 and later models. Some '68-'73 models had Yamaha MX or aftermarket high front fenders.

Original "19 on whatever year 250 had them is 325. 350 no doubt is wider as the number says. Anything smaller like a 275 will look a bit out of place. If 350 means 3.5 inches just measure how wide it is between where it's liable to rub. i dare say it could be a bit taller 350 to 325 but maybe only wider. Could look a bit like an old style american desert racer front fat tyre. I thought they looked neat. Give a softer ride too. I doubt a 350x19 would be as tall as a "21& just thinking of guard clearance. Could raise it a bit if it doesn't hit the steering damper on full compression but not easy to raise the way its mounted. Is there an exact metric equivalent to 325x19.

Thanks for your info. I assembled my fork lowers and mudguard and I’ll have 4.35” as the narrowest part, somewhere near where the tyre will be. Shinko website gives the overall width as 3.66”, so I’ll go with the 3.50.
You’ll see from the pic, that I’ve still got a bit to do.
Thanks again.

Look forward to a pic of it fitted when you get that far.

Nice paint job!

have ordered the 3.50x19 and the 4.00x18 this morning. Will post a pic.
My next job is assembly of the lower forks. It'll be a new post.

ordered and received my Shinko #241 3.50 x 19" front tyre. Fitted the mudguard support to the forks and was pleased to note that there was no interferance. I'm glad that I went up tp 3.50 rather than drop down to the 2.75.