pglaves
#13338
You need a decent rush of air. Take it to a place with a good compressor. Even a Kwik Trip at $1.00 will do it much better than a little compressor.
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R100RS tire sizes
- Thread starter plehman
- Start date
You need a decent rush of air. Take it to a place with a good compressor. Even a Kwik Trip at $1.00 will do it much better than a little compressor.
beemerphile
New member
You can get a rush of air from a small compressor by using a storage tank. Small portable ones are available and there used to be valve kits that would make one from an old freon tank. Also to help with the air rush, instead of the normal air chuck, buy a clamp-on chuck and use an inline ball valve to start the action. Be sure to turn the ball valve off and remove the chuck after the second pop or the third pop could hurt you. I use a three way ball valve to vent the tire as soon as I turn the air off.
beemerphile
New member
There is a witness line molded into the sidewall close to where the sidewall meets the rim. Make sure that the line is fully visible and about the same distance above the rim all the way around on both sides. That is your assurance that it is fully seated. Sliding into position is not as satisfying as popping into position. Sometimes the tire looks properly seated at a glance but is not.
happy wanderer
Day Dreaming ...
JamesA is correct. I found this out last summer prepping my Brother in Law's 92RS for our run to PA from the Wet Coast. Not only are his rims designed for tubeless tires they are also the same size! 18 inches. I had to look twice at the rims and tires as I had no idea this change had happened. Also, the front tubes on his bike are larger than my 82 RS. Those Mono Levers are a different beast in many ways.
I found the Michelin Pilot Activ on my RS are a great improvement to handling and they wear really well. Many have complained here about how hard they are to mount but with pre warmed tires, the right tire lube (I use RuGlyde) and the right technigue (long tire irons, tiny bites at a time + patience) they are no problem. As Tom Cutter has said many times, it's all about technique.
R100RS tires
I am currently using Bridgestone Spitfires on my '81 RS and like them a lot. But they may have been discontinued. Have used Metzler's on my '84 RT in the past with good results, but they have stiffer sidewalls than some other brands and tend to ride a little "harder". Will probably switch to Avon AM26 Roadrider when it is time for new tires. For tubes go with natural rubber tubes. They leak air a little bit more than synthetic tubes, but do not tear when punctured so don't lose air in a rush. Stay with the inch size tires.
My thinking has always been that when I am depending on 2 small contact patches on the road for traction, I want to be as safe as I can. Trying to make a square peg fit in a round hole (tubeless tires on a tube wheel) or going cheap does not make sense to me.
Just my 2 cents worth.
Sam Creasman
'72 R75/5
'81 R100RS
I am currently using Bridgestone Spitfires on my '81 RS and like them a lot. But they may have been discontinued. Have used Metzler's on my '84 RT in the past with good results, but they have stiffer sidewalls than some other brands and tend to ride a little "harder". Will probably switch to Avon AM26 Roadrider when it is time for new tires. For tubes go with natural rubber tubes. They leak air a little bit more than synthetic tubes, but do not tear when punctured so don't lose air in a rush. Stay with the inch size tires.
My thinking has always been that when I am depending on 2 small contact patches on the road for traction, I want to be as safe as I can. Trying to make a square peg fit in a round hole (tubeless tires on a tube wheel) or going cheap does not make sense to me.
Just my 2 cents worth.
Sam Creasman
'72 R75/5
'81 R100RS
If you use those Avon Road Riders, which are very good IMHO, with tubes, check the inside of the tire for a tag or rough spot. I've read about this tag on this forum. After I got some Road Riders mounted on my 1978 R80 about 25 miles later on the way home I got a slow leak/flat. I had my old tube and put it in, it was one of those thick Metzler tubes. It has held air since. I just got a new Road Rider for the rear in the mail and checked the inside of the tire and it is smooth, so who knows?
Those Road Riders don't have any steel belts in the casing. I've had them on my R-80 and my K75RT and I like them very much, but that said almost all modern tires these days are very good.
Those Road Riders don't have any steel belts in the casing. I've had them on my R-80 and my K75RT and I like them very much, but that said almost all modern tires these days are very good.
robbie9999
New member
Aftermarket tires
I am just trying to figure out what white wall tire I can place on the back and front that will give me a linear stance look, I am not trying to go wider by any means just play with the heights half inch or inch height wise
There is no reference to side wall height or measurements ? Again don’t want to go wider
Again thank you for the positive and negative feedback, I know that building a cafe racer out of a classic bike is not highly applauded here but your ver imformative
I am just trying to figure out what white wall tire I can place on the back and front that will give me a linear stance look, I am not trying to go wider by any means just play with the heights half inch or inch height wise
There is no reference to side wall height or measurements ? Again don’t want to go wider
Again thank you for the positive and negative feedback, I know that building a cafe racer out of a classic bike is not highly applauded here but your ver imformative
robbie9999
New member
Conversion please ?
Rear tire
18 - 4.00 British inch size
the four is the width
Front tire
19 - 3.25 British inch size
The 3.25 is the width
What is the conversion for these in new tire sizes ? Is this correct
Front 110/80-19
Rear 130/80-18
Width /height to percentage of width/ the size of wheels
Rear tire
18 - 4.00 British inch size
the four is the width
Front tire
19 - 3.25 British inch size
The 3.25 is the width
What is the conversion for these in new tire sizes ? Is this correct
Front 110/80-19
Rear 130/80-18
Width /height to percentage of width/ the size of wheels
Rinty
New member
beemerphile
New member
There is no conversion from inch to metric because the aspect ratios are different. The old inch sizes were 100 aspect, so...
3.25x19 = 83/100-19
4.00c18 = 102/100-18
As an example for the front, the 90/90-19 is closest to the stock width, but is not as tall. The 100/90-29 is about the right width, but wider. Stock height is most important to maintaining the designed in steering geometry, but the wider tire doesn't steer nearly as well. The correct solution is still to use the correct size tires in your choice of brands and aesthetics. If the question is which wrong tire to use for maximum cafe-ness, I'll go do something else.
Asking how wide or how tall a tire "will fit" completely ignores the fact that motorcycle handling is a complex set of dynamics.
pglaves
#13338
This is all true. But it is an imperfect world. And I am not a purist. One eighth inch extra sag in fork springs will alter handling as much as close-but-not-perfect metric tires. So will rear shocks set one notch too soft. Add a fairing? Take a fairing off? Have a passenger? Add a top case? All of these things alter handling a lot more than metric tires. Yes a wider tire may "slow" steering but it is an open question whether that amount of "slow" is too slow.
It is unfortunate that several of the premier tire manufacturers don't offer their better or best tire construction in inch sizes which are now technically obsolete sizes. This is of course due to the declining demand since nobody that I know of specifies inch size tires any more. BMW went metric with the K100 in 1983.
If I were to truly adopt the purist position I would conclude that soon I would have to make my Airhead a museum piece since I couldn't get proper decent tires anymore. We are not there yet, but I suspect soon will be.
beemerphile
New member
I can't disagree. In theory there is no difference between theory and practice, but in practice there is. We may one day have to compromise; and when the time comes, I will; but I see no sense in compromising early. If people (us) riding these old bikes switch to alternatives early, then the volume of the market will go down and the choices will disappear sooner. Those with a classic bent can still get the classic Continental RB2/K112A and Dunlop K70's. The ContiTwins were even "brought back from the dead" using more modern compounds. Reasonably modern bias ply choices include Michelin Pilot Activs and Avon AM26 Roadriders. There is even a radial construction by Continental called the Classic Attack. Continental has been great in continuing to support us. I'm sure it's no longer true, but at one time the head of Continental Tire's motorcycle division rode an R100RS.
I've run metric Bridgestone Spitfires in 90/90-19 and 110/90-18 and they rode ok. It messed with the side and centerstand functionality though. I tried the 100/90F and 120/90R and couldn't get them off fast enough. Handling was horrible. Bigger just doesn't work well for me on the old twin shocks. I tried the fancy Conti radials and didn't like them either. They made the handling too fast for the old chassis. They fell into turns and in the wake of a large truck the bike would get into a weave. A Rubber Cow is a handful to begin with, but a Twitchy Rubber Cow is just too much to take. When I "tire" of fighting Pilot Activs on and off the rims, I'll probably transition to Avon Roadriders. When they disappear, well, maybe Coker Tire will provide some fitments.
pglaves
#13338
Indeed, but oh my God do not ever ride across a steel grate bridge.
Milled pavement is bad enough with those.
kbasa
Well-known member
Conti Classic Attacks are radials for airheads and are transformative on these bikes. I'm running a 120/90R - 18 on the back and a 100/90R-19 on the front.
It has made my airhead feel actually connected to the road for the first time in more than 45 years of riding these things.
Still takes a tube, still needs a rim strip for spokes, but holy cow, it's night and day vs. bias ply tires. When my /2 finally wears out its Avons, I'll be looking to put them on that thing.
It has made my airhead feel actually connected to the road for the first time in more than 45 years of riding these things.
Still takes a tube, still needs a rim strip for spokes, but holy cow, it's night and day vs. bias ply tires. When my /2 finally wears out its Avons, I'll be looking to put them on that thing.
