Skip to content

USCA Sidecar Forum

For some extra information about navigating the forum you can go to Forum Tips

Please or Register to create posts and topics.

Looking at going to the Dark Side for tires

(Still new to the forum) I have a 2001 Yamaha FZ1 sport bike with a Hanagan sidecar attached. Been riding it for years on motorcycle tires but I'm curious about converting it to car tires. The bike comes from the factory with 17 inch rims. The standard sport bike style tires are 180 x 55 x 17 ZR for the rear and 120 x 70 x 17 ZR in the front. 

My curiosity stems from the thoughts of making the wear last longer and traction or grip better. On the other side, some of my worries include:

  • steering difficulty with a wider flat tire on the front at low speeds
  • availability of "Z" rated car ties to fit the stock bike rims and fenders
  • sealing the bead of a car tire on a motorcycle rim
  • change of driving dynamics and adjustments needed to the sidecar

Any help would be greatly appreciated....

Ben / DRUMS01

Uploaded files:
  • IMG_2236.JPG
CCjon and FlyinMonkeys have reacted to this post.

Hey, Ben!  Allow me to use this thread to say "Welcome to the forum!"  I've been unplugged the last couple of weeks while out hacking to Colorado and back so I just saw you thread this morning.

First, your concern about steering difficulty with a car tire up front.  Yes maybe a little, but the bigger problem is the tire's tendency to "hunt" while driving down the road, especially any road that's got a lot of wear.  A moto tire will track straight and not require constant correction.  My recommendation would be to stick with a moto tire up front.

But do you really need a "Z" rated tire?  Z-rated tires are designed to handle sustained speeds ABOVE 149 mph.  Well, those are racing tires and you will NOT get good longevity from them.  I suggest you switch to a regular old 120/70-17 tire.  For longevity you can't beat the Metzeler ME888 Marathon Ultra.  It's a heavy duty bias ply carcass that will resist lateral deformation during high speed cornering, while also protecting your rim from potholes.  It's also V-rated, which means it's considered safe UP TO 149 mph (if anybody really goes that fast!) and can go all day at 100 mph if that's your thing.

On the rear, there's every reason to switch to a car tire.  There will be no problem with a car tire bead mating up with the moto bead on your bike.  The diameter of the tire bead is fixed by steel wires inside the bead, but those wires are encased in rubber which has enough "give" to conform itself to the slight differences in the shape of the bead.  Many thousands of darkside riders use 17" rears with no problem. 

The bigger issue is finding a tire that will have clearance inside your chain and swingarms.  Now, you already know that a 180mm tire fits.  Try to get down there to see how big a gap there is between your sidewall and the chain/swingarms.  If you have a 15mm gap on both sides then that means you can mont a 205/50-17 car tire.  This tire is almost exactly the same diameter as your 180/55-17 so there will be no change in your sidecar setup.  What's nice about the 205/50-17 is that there are hundreds of different car tires made in this size.  Including the Bridgestone Driveguard RunFlat which is what I use on my Goldwing rig.  Nice to have the peace of mind of a run-flat tire so you can limp in with a puncture if that happens.

If a 205 won't fit, well then now you're pretty limited because there are very few 195 or 185 car tires available.

Take a look then post up what you find.

CCjon, Thane Lewis and FlyinMonkeys have reacted to this post.
CCjonThane LewisFlyinMonkeys