Tyres for a 99 De Luxe

http://www.avon-tyres.co.uk/motorcycle/roadrider

Avon list a few universal sizes in 18" and 19" dia. Unless the tyres you're using are the ones fitted by Norton when the bike was new, you shouldn't be having slides. Worth while checking the wheel/frame alignment.

Roadriders are indeed great tyres. At the moment I have Avon Speedmaster ribbed 3.00x19 on thefront, SM MkII 3.50x19 on the back and they perform admirably. I am not known fortrepidacious cornering...

What are your current tyres? The only tyres which have frightened me are Dunlop K70s which when fitted on the back have caused some horrible slides.

I have a Roadrider 100/90-19 fitted to the rear of my swinging arm ES2 and have just measured it at 105mm wide. There are no clearance problems and I think a 90/90 tyre on the rear would be a bit narrow.

The 100/90-19 is equivalent to the old style 3.50 and 90/90-19 equivalent to 3.25-19. It would have used a 3.50 when new.

They are good tyres The Avon SM is archaic in comparison. It does look the part more than the Roadrider but if you're going to ride the bike rather than look at it the Roadrider is a better and safer choice.

Ian

I have a 90/90-19 AM26 on a front WM2 (It shouldn't make a difference if it is an original rim or alloy) and it measures 93.2mm - Unfortunately, they don't seem to list a 90/90-19 for rear fitment. Maybe Avon could advise if the front type is acceptable on a relatively low-powered machine.

An internet search hasn't shown any 90/90-19 rear fitments...it might mean sticking with a 3.50 if the bodywork is that restrictive but even the Dunlop K70 and the Avon SM are now made in modern compounds so will be an improvement.

If you look at the link posted earlier you'd see Avon do a 3.25" x 19" universal, width 3.9" (99mm), same as the 90/90 x 19" front, but 0.3" larger on the radius.

And that's why my 99 Deluxe (though it no longer looks much like one) ended up with the Speedmaster/SM combination whilst my BSA has Roadriders - originally bought for the 99. The BSA has plenty of clearance for the tyres, unlike the 99.

Roadriders are indeed great tyres. At the moment I have Avon Speedmaster ribbed 3.00x19 on thefront, SM MkII 3.50x19 on the back and they perform admirably. I am not known fortrepidacious cornering...

What are your current tyres? The only tyres which have frightened me are Dunlop K70s which when fitted on the back have caused some horrible slides.

Previously robert_tuck wrote:

Thank you David,thats the other piece of the puzzle sorted! , the fronts too tight as well for a 90 90. Looks like I'm back to the old speedmaster/SM combination ,The only good thing in their favour is they seem to last forever but how long does the rubber stay supple? ,The deteriation is so gradual its hard to tell. I would say 10 years ,How often do you change yours Gordon?.

Try a 360x19 tt100 they are front/rear fitment

I change tyres when they wear out or show signs of age. The ones on the 99 are about 5 years old and are low on tread and due for a change.Too many bikes in the shedthese days. When it was just the 99, annual or even 6 month tyre changes were the norm. Richard is right to point out that old-style tyres are now made from modern compounds. You should be pleasantly surprised with the effect a new pair of tyres has on the bike.

In one of the Classic mags, one contributor proudly announced that he had found and fitted a pre-cling rubber tyre to the front of his Norton. I keep checking the obituary columns. Just the thing that MoT tests where intended to prevent. OK, for the pedantic, MoT tests don't check the age of a tyre, but it's hard to imagine a 60 year old tyre doesn't have cracks.

True confessions time. I have briefly tested a Rudge with 60 year old tyres BUT it will get new tyres before it is fully recomissioned and put back on the road.

A rear Roadrider lasts me no more than 4,000 miles - cost is approx. £70 (I fit and balance them myself), so that's 1.75p/mile. In comparison fuel costs approx. £5.00/50miles = 10p/mile.

On average I get through two rears and one front a year, so age is not a factor. Tyres obviously play a big part keeping you out of hospital and are very cheap in my opinion, considering what they do. If I wasn't doing the mileage I'd probably change them every 3 years which is approx. £23/year, so that's 6p/day. Too much to stay safe?

P.S Sorry, times 2 = 12p/day.

Previously David Cooper wrote:

There is a perfectly reasonable theory that says that poorer grip and poorer brakes result in lower speeds and less energetic accidents....

The difference between two motorbikes (one with poor brakes and tyres, the other with good brakes and tyres) travelling at 30mph and performing an emergency stop, in the wet, is, if the one with good brakes and tyres manages to avoid an 'energetic' collision, then the other one probably wont.

I've been using Mitas on my bike, 3.0 HO1 on the front and HO3 on the rear. They have done over 3000 miles and have been excellent. Need to replace the rear over the winter. Having changed the front mudguard I plan to fit HO1's in 325 and 350 - currently available from Wyldes for £86 for the pair including tubes and delivery!

I recall running a rear TT100 with a ribbed front back in the 1970s. From memory, it worked fine. I'd suggest try it and see...

We have been through this question before, Robert. You can fit the excellent 19 inch Avon 90-90 front tyre if you want to. (WM2 Rim) You just need to swap the standard bridge with a stainless Commando bridge and drill the appropriate holes in the new thinner bridge. This is what I did with my 1960 99 (Still waiting for my V5 but maybe tomorrow?)

I can't understand why you can't fit a 100-90 to the rear, went on my 99 no problem on a WM3 stainless rim.

As for your suggested combo: This is what I hope to put on a 1957 model 50. Remember the swinging arm is the same width at the fork but at the pivot is two inches narrower! The tyres are fine as long as you ride steady.