tire size

JimC said:

Check the tire manufacturer's rim width recommendation. A WM-2 for a 100/90-19 is undersized. http://www.avon-tyres.co.uk/node/129

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Correct, Jim. 3.8 mm per side. Almost enough to give a crap about. :mrgreen:

Once again Jim you have saved me from myself by emphasizing the mundane. Don't forget to turn that oil valve on.

I offer you the last word.
Take it away.

Sorry ying, hope you get the right tires for your needs.

out

Evidently the tire manufacture gives a crap.

JimC said:

Evidently the tire manufacture gives a crap.

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Thank you, Jim. Once again you have save me from myself by emphasizing the mundane. Don't foget to turn on that oil valve.

I offer you the last word, JimC.

Take it away.............



Sorry ying, hope you get the right tires that meet you needs.

Peace out

Geeze Louise, thank goodness I don't know no better so got away with a couple of different style/brands 110/80 fronts on Ms Peels factory steel WM2. I found it so stupidly bad and against the wisdom of legally advised vendors and seasoned experts grain - that it allowed me the best off road and on pavement handling I've ever experienced in my life. My 2nd Combat also came with 110/WM2 and even with its old hard tire I'm not sure if I'm more pissed off at the new 100 lack of brake bite or me being swayed by the prior tire disscuusions that a 110 was too much to bare. If the 110 tire/WM2 rim front combo could get any better * I sure couldn't make any use of its improvement doing anything harsher to detect improvement...
but then again I do not ride that hard nor encounter anything unusual so likely anything that hold air a day would do me to the max.

A fool, like me, don't never learn from mistakes so i fitted a 130/80 to WM3 on Peel's hinnie.
One thing I've noticed is makes it more bother to get full edge mileage out as just hardly seems to ever run off it normal traction sense of peaked to ice skate like center slicer. I saw how them leaned over 125's got passed so easy by the really hot wide tire twins so I'm hopeless to teach anything the easy way.

Show us stupid ones some evidence how miss guided we are to miss out on the better way to go. Ugh can get so bad its like trying to polish turds

Here is a couple of pics of current tyes. I take the front out to about 1/4" off the edge riding with sports bikes, rear gets most of the tread used, still a bit left on the edges, but local laws don't allow for this muck lack of tread.
Doing a track day Friday so reason I was asking for feed back on the 100/90 90/90 issue on the VM2 19's


Regards Mike

Oh yes indeedy Brooking that shows some thrilling scrub loads put down close to the edge. Don't the cop have to catch ya 1st before they can ticket a balding tire? Nothing beats trail and error and As you are hot to trot - what's the price of a couple tires and changes on same track and state of mood to let us know your sense of it. Most costly to switch rim sizes too, but then how else can ya know for sure. Take track tire shot too please.

Ya know what they used to say about Austin Mini Coppers at Leamans.
If God had meant them to go around so fast he'd given em bigger wheels and tires.

Will do on the track pics and will post video if all goes well. Law here will ping you when you stop for intersections and lights, try to avoid , but not possible where i live
$175 NZD for TT fitted and balanced about $260 NZD for the Avon venom fitted and balanced.
Regards Mike

Aw shoot, can't get away with much in dense populations and traffic lights, so I moved way out of town. Don't trust new tires till warmed and scrubbed off new surface. I'd go out on slightly low aired tires to warm and help scrub but mainly to get skill sense of fork wobble iso's weave onset avoidance and recovery by fairly slow zig zags, then air up on hard side for best steering ease and air balance, then lean more and more till fouling limits on each side engrained, then just short of fouling go in hotter and hotter til the rear skips out a bit or gets squirrely, don't worry pavement re-grips about instantly on let off so nothing much happens but wisdom of limits of far lean and extra power. Then the dangerous part begins for me/you/everyone, put more and more turn force on forks, till the bars tend to slap or the front tire skips or slides some. None of this is done at full power or speed, just on purpose making sort of errors on purpose till subconscious sense in the bone fear builds up automatically to compensate or avoid. Then the fun part begins with a bit less lean for even more power to plant mass back on rear patch to relieve the front tire load dependance. Again and Again till you know what ya can and can't get away with on each particular turn and chicane. I start this sort of practice in parking lot or pit clearing, leaning over more and more slowly til pegs making noise and keep doing it till sense of solid stability sets in, then no fear of how fast I fling a lean over this way and that just worry about going in too fast to control Hinge fish flop off deck danger. This extremes of lean power and steering are not needed to go around most sections of tracks fast as bike can, so gets more relaxing thrilling knowing you are in safe zone even though flying around like crazy.

Do enough of this and may notice a bit of hi side action helping you lift back up after apexes, play with that new sense so you work up to slight over control inputs that help bike fall over then spring back up on its own more than pilot effort.
If ya do the low air work out, let us know how similar or not it is to controlling/avoiding the Hinge at hi speed limits on full air.

Took a shoot of how narrow the real weight and thrust enduring the patch is on 110x80 fitted to rear 18" WM3 rim. This was from my roll into smooth finish oiled garage floor. Today I flanged Trixie enough to sense the slightly low air allowing some tire wallow, but plenty stable for sane thrills and nicer to make it all the way home w/o sharp textures getting through. Looks about an inch wide to me. After normal tire conserving ride home, no far leans nor spin, just a bit of slip/slide I can't avoid.

So.. I've searched and read, read Mfg.'s data tables, etc. My Bike has WM2's front and rear. Understood that they pull the tire into a much rounder profile than intended. I'm not replacing my rims anytime soon, I enjoy the modern (RoadRider) rubber, but is the retro Dunflop knobby tire a better choice due to profile when fit on a narrow rim?
Front:



Rear: Is this an aftermarket rim? Or could it have come from the factory?

I don't think the WM 2 was the optimum rim width when the Commando was first built. Probably had more to do with what rims Norton had on hand.

FWIW there is a very handy tire size vs. rim width reference at http://www.mtsac.edu/~cliff/storage/gs/ ... _Chart.pdf

and a datasheet for the Avon AM26 Roadrider at http://www.avontyres.com/sites/default/ ... er_web.pdf

ludwig said:

pvisseriii said:

.. please let us know so we can help deny ying the benefits we all enjoy.

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We arent denying ying (!) anything .
Not only is a 100/90 on a WM2 not correct , but it is plain stupid .
Why ?
Because the cheaper alternative of a 90/90 tire front is a far better solution and readily available .

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Now we're getting into personal preference. I have run both 90/90-19 and 100/90-19 AM26 on the front. Don't like the stearing with the smaller profile. Going a wider rim, could foul the front fender stay. Mine has an eighth inch clearance with the stock rim on my '72.

I run a 90/90 on the front of my 1974 850 Roadster - I immediately noticed a "sharpening" or quickening of the steering when i fitted it replacing the 100/90. I like the feel much better, however a bloke I know who has the 100/90 fitted to his similar bike, prefers the feel of his - we both ride extensively in the Adelaide Hills, an area endowed with a lot of beautiful "twisty" roads - the tyre choice is probably a personal preference issue. In the "old" Service Notes of the NOC UK, the narrower tyre was recommended.
Cheers,
Dave

eezeetoo said:

I run a 90/90 on the front of my 1974 850 Roadster - I immediately noticed a "sharpening" or quickening of the steering when i fitted it replacing the 100/90. I like the feel much better, however a bloke I know who has the 100/90 fitted to his similar bike, prefers the feel of his - we both ride extensively in the Adelaide Hills, an area endowed with a lot of beautiful "twisty" roads - the tyre choice is probably a personal preference issue. In the "old" Service Notes of the NOC UK, the narrower tyre was recommended.
Cheers,
Dave

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Service Notes says fit 3.60x19 on front, not 4.10x19. Page 40 under high speed weaving. Hummmm...still personal preference. I agree with the "bloke". That said, back to 100/90-19 on WM2 rims, could be the reason I can only get 3000 miles maximum on an AM26 rear. I'm not about to change the original rims though. Spent too much on the Buchanan polished stainless spokes.

" but is the retro Dunflop knobby tire a better choice " You mean these suckers , Steve ? TT100 / K81 ? ?



Theser a stiffer more rounded caseing than of old . The ' R ' case , American . being R forACE , er Race CASEING . so it doesnt blow up , or out anyway .

Requires differant suspension tune , perhaps . Not a lot of Pnematic springing there .

From Hobots link above " there is a trend toward taller sidewall or section height on the front tire. "

Thes ones aint , appeartobe still available . Gotta check the compound in the old days were 3 ( pre 1970 )

Notable for its SHORT sidewall , promoteing precision , a rough ride , & twithyness . But good for 100 mph I.o.M. Laps .

Hymph . " 300-19 KR76 . 587 . . 3800,00 " http://www.dunloptyres.cz/en02.html

http://www.motopsychos.co.uk/dunlop-fit ... -354-c.asp

KR 76 - > http://racedunlop.com/classic.html

Perhaps you should buy a magnetic based protractor and measure the rake ? The very first commandos had suspect steering geometry which was corrected in later models.

I ran the TT100s on my bike when I first put it together.

I DO NOT recommend these tires if you live anywhere where there are drawbridges or they repair the tarmac cracks with tar (tar snakes). The large groove down the middle of the tire loves following the tar snakes and grabs the steel grating when one passes over a bridge. The bike will dance side to side a bit which can be unsettling, unless you know the exact speed to cross that particular bridge.

The modern tread pattern on the Avon does not do this.

Even the old-style ribbed Speedmaster on the P11 doesn't do this, but it has a rib on the center of the tread rather than a groove.