Since I built my outfit 26 years ago, I've been using 145x15 and, latterly, 145/65x15 'car' tyres on the front wheel.

I had bought a new Falken 145/65x15 tyre to replace a worn Michelin (32K miles). The wet weather rating for the Falken was 'A' which was the reason for choosing that tyre. 

However, last week I came to fit the new tyre, but after struggling for a couple of hours, I could not get the tyre to seat on the rim. In desperation, I took the wheel to a tyre depot and even they could not do the job; they even risked 100 PSI without success.

So, what to do? I could have refitted the Michelin, which was still legal, go and find a new Michelin (I know their tyres fit my rims), or change to a motorcycle rear tyre as a front fitment. Several sidecar friends have found that a rounded front tyre is far less prone to following road grooves or 'whitelining', than a flat treaded car tyre.

Well I chose the bike tyre option and went for an Avon Venom 140/90x15.

Since last Friday I've covered over 500 miles and the difference is astounding, the rounded tread does not follow any grooved road surfaces, no twitches or wiggles at all. I was actively looking for poor roads just to enjoy the solid feel of the steering. It didn't even 'roll' in, what I call lorry grooves, those indentations in the tarmac caused by heavy vehicles.

I must admit to having been sceptical of the claims of using a round profile front tyre, but now I have experienced it, I won't be going back to car tyres, although I don't expect to get 32000 miles out of the Venom!

Paul.

A very close friend currently runs a BMW R1100 outfit but his previous one was a K1100LT with a completely home-built and home-designed chassis, including the leading link front end and a fifteen-inch Smart car wheel on the rear

http://advrider.com/forums/showthread.php?t=294734&highlight=adge&page=261

-about halfway down the page. He's been driving chairs on-and-off for the thirty-odd years I've known him and swears he'll never use a car-type front tyre for all the reasons you've just enumerated above.

Your comments are very interesting Paul.
A friend here has an K100/Vetter hack with the original front wheel (car wheel on the back) and a K1/EZS with Earls forks and car wheels.
He made exactly the same comment about the handling between the 2 bikes. He found that the rig with the car wheel feel very wiggly when you ride over 100k.
I originally thought that it was due to the difference of geometry between the forks or maybe a worn steering damper.
 I am wondering if you would obtain the same result by installing a bigger car wheel and tire in the front.

I am using 15/135 on the front. Maybe I should try to go back to the original narrower 15/125 originally fitted by EML.

I've had 145/65 Bridgestone and Continental fronts. I like the bigger contact patch for the greater grip and better brake performance, but there was always a bit of a wiggle.  145/80 Hankook was very vague.  All of them were a very tight fit and hard to seat the bead.

 Now running a 130/90-15 Bridgestone Exedra.  Very stable, lighter steering but too much throttle will just make it slip across the road if I push it (not that much grip).  It'll do for the moment butwill probably go to a Metzeler or similar instead.

Al

I'm no chair expert but I think your problem with the Bridgestone may be that they are dual carcass construction i.e. the bit in the middle is a lot harder than the shoulders.

CF, I don't think going to a 125 x 15 would have any advantage, it's still a car tyre with a flat tread and squidgy side walls. There seems to be quite a few 15" bike tyres available, as used with these super-scooters, so if a change were contemplated, I would source one of those.
 
So far, and it's still early days, I'm impressed with the grip from the Avon, in the wet it was much harder to make it 'break away' than my previous Michelin 145/65 15. I am presently running at quite a low pressure, 26 PSI, and I think that helps.

But, as we've said before, sidecarists all have their own ideas and what works for one outfit can be hopeless on another; that's why we love them. :geek:




Paul.

Thanks Paul.

I never looked at these "super scooter's tires" before. I am curious to see how many miles you can put on these.
I still have a complete spare set of 15" car tires (I bought 2 sets because it was almost impossible to find them here in Canada), but the scooters one will be a nice option for the future.

CF

I like a narrow car tire on the front with lower tire pressure for on and off road. I've put 10's of thousands of miles and many different combinations at that seems to be the best.

Now that my Bridgestone Exedra has broken in or whatever, it's fine even in the wet.  I can't make it break loose now.  Definitely bike tyres on the front from now on.

Al

Yes, Al, I'm finding that I'm getting much better wet weather grip as well. Still well impressed.

 I suppose that bike tyres need to be grippier than car tyres and that may have something to do with why they don't last that long!

Paul.

Hello Paul,

I'm also running a scooter tire on the front of my sidecar combo, Yes it is an improvement. But the picture of your front wheel looks very interesting. I'm sure BMW never manufactured a 15" front wheel. I do not see any welds or fasteners. Can you help me understand how this wheel is made?

Halflive, it's a Wasp 15" wheel. They made them for sidecars using the BMW Y spoke pattern for their castings. 
Sadly, no longer available.

Paul.

On a side note, The maximum width of tires for my front fork is 135.
I was looking at the picture of your fork and understood why.
On your sidecar, the supports for the brake calipers are mounted inside the fork.


On the EML, the mounting for the calipers are on the outside and the fork is very tight around the tire. There is a maximum of 10mm space between the disk and the lower part of the fork.


Today I was looking at installing a Sigma bike speedo and after removing the support for the brake caliper, I found that the perfect place for the sensor. It will be the rods attaching the mud guard to the fork and the magnets can go on the lower part of the brake rotor.
The space between the sensor and the magnet will be perfect without any modification. Why was I looking at a difficult problem when the solution was obvious?

Thanks Paul.
Pity these wheels are not widely available, finding them won't be easy. I'll go for an other option, but keep an eye on Ebay.co.uk. It looks like Wasp used a cut down wheel for the mould, nice job.