Jr. Dragster wheels tires for Sidecar

[Carl Johansson]

a low speed low cc bike -  anyone looked at those 12" X 1 1/2" wheels and tires they use on the JR dragsters -  I can't seem to find the speed rating on the tires -  but I know those JR drags go 80 mph on 5 hp motors!

Carl Johansson

[JackD]

Part of tire life is a combination of weight and the duraton it is subjected to.
How much does the front end of a JR Dragster weigh and how much time does it spend at 80mph on what kind of surface ?

[1212FBGS]

scta and bni rules say 15" min on rims unless its a liner or sidecar

[Carl Johansson]

Part of tire life is a combination of weight and the duraton it is subjected to.
How much does the front end of a JR Dragster weigh and how much time does it spend at 80mph on what kind of surface ?

I don't know -  but I'm sure it's more weight than would be on my sidecar,  but the duration -  you have a point there -  I'm assuming that these tires need a speed rating -  so I'm trying to figure out what that rating is!    My thought is ah H rated tire is an H rated tire -  or a Z rated is a Z rated -  the rating is what is inspected -  correct?

[Carl Johansson]

scta and bni rules say 15" min on rims unless its a liner or sidecar

Hense the title - ... wheels for a sidecar!

[bak189]

Yes, they go by the rating.......unless it states for "Racing Use Only"

[JackD]

Non rated bicycle tires are in common use on the front of JR Dragsters.
There are special racing tires made for the front at a much higher cost and most of that design is for reduced rolling friction rather that increased speed capability.

[Nortonist 592]

Hey Bak,  Can you elaborate on your above statement?  They go by rating unless it states for racing purposes only.

[bak189]

Regarding,  "racing only" tires.......I have
Dunlap Vintage racing tires on one of my BSA's .(solo bike,not sidecar)....they have no speed-rating on them it only say "racing" on them.
In addition the Dunlap sidecar racing tires (16 inch wheel) on one of my roadracing sidecars, have the "racing
only" on them.
Some Hoosier tires (13 inch wheel) that we use on roadracing sidecars state: "not for highway use"...............................................................................

[Nortonist 592]

And these pass muster with the tech guys?  I'm just curious as it appeared that it was a case of no speed rating, no race.

[bak189]

According to the SCTA/BNI 2006
Rule Book...............................................
"Production tires with a speed rating of ZR OR SPECIAL TIRES
FOR RACING AS DESIGNATED BY THE MANUFACTURER"
If it states racing on the side of the tire, I would think it would pass SCTA/BNI Tech.

[bak189]

Regarding tires for bikes that have 18 inch wheels (Vintage)
here is the web-site for tires that
state "racing only" on the side-wall
.........rcbtires.com...................................
no speed rating.....but they are racing tires.

[Loose Goose-Terry#1]

  Could you use go-kart tires that are in common use on enduro karts? The tires are not rated and they are for racing application only. The kart that I used to race was clocked at 147.682 mph at Road Atlanta subject to extreme side loads and hard breaking. The races lasted an hour. I never had a tire failure.

[beebe]

So you guys are running 16-18" wheels on the sidecar?

Is there any advantage in going to a smaller wheel other than aerodynamic considerations? Are there small, speed rated tires available? I was looking for 10" or so, but the speed ratings are low.

In the SCTA 06 rule book it looks like the photo of the guy in the BMW sidecar has a tiny wheel.

[bak189]

Since the mid-1980's we have been running a 5 inch wheel on the sidecar using a Goodyear tire.
This tire and wheel has and is being used on the front of Top Fuel Dragsters that go 300mph.
On the "bike" part of the sidecar outfit we run 16 inch front wheel and 15 inch rear wheel.