Wednesday, October 17, 2012

The Dark Side

Hi, it's been a while, I know.  I'm having severe withdrawals from blogging.  On the other hand, I've been experiencing a fantastic ride the past few months.  I solemnly promise to share what's been going on soon.  I also miss reading everybody else's blogs.  To quote some guy with a corncob pipe, "I shall return".

In the meantime I want to ask a favor. 

I'm tasked with ruling on whether or not motorcycles with car tires mounted on them will be allowed in our classes.  I want the decision to be evidence based.  It seems a good way to make a wise decision that reflects reality.

There is no end to the arguments on the forums.  The problem is that everything has a nebulous base.  On the one end are people who have put car tires on their bikes and point to the fact that they haven't crashed, yet.  It's a good start but it's not definitive proof of the safety of the practice.  I know a lot of riders who haven't crashed yet, either, but I know they're not safe riders.  They just haven't been really tested so far. 

On the other end are people who claim that if bikes were supposed to have car tires then they'd have steering wheels, too. 

What I seek are published studies.  Does anybody know of any actual research that's been published on the matter?

Secondly, I'm seeking information on rims.  One of the big arguments for not running a car tire on a motorcycle rim is that the beading system isn't compatible.  Are there rims that ARE compatible with car tires that will mount on a motorcycle?

Input would be most appreciated. 

Miles and smiles,

Dan

18 comments:

Charlie6 said...

Hi Dan

I've not ridden a motorcycle with a car tire in the rear without a sidecar and not aware of any formal studies about the safety of such.

Methinks you probably won't find any as no one wants to lay themselves open to liability claims should they come out in favor of it.

You also probably know most moto dealers will refuse to mount car tires onto motorcycle wheels, again they cite liability issues.

To answer one of your questions though, a Suzuki V-Strom's stock rear wheel holds a car tire just fine...I can send you the specific tire brand/size if you wish.

Most folks put on car tires as they last much longer than regular moto tires. Sidecar owners use them for this reason and because you really can't lean a sidecar during normal operation so a car tire is fine. In fact, over in Europe where they take sidecaring much more seriously, it's car tires all around on their sidecar rigs.

Hope you find the answers you need to make a decision.

Cheers

Dom

Redleg's Rides
 
Colorado Motorcycle Travel Examiner 

Trobairitz said...

Dan - I have no input whatsoever on the subject at hand, but wanted to say that the bloggers miss you too. We shall be patient though as we know how busy you are.

Cheers!
-B

RichardM said...

I haven't heard of a scientific study but all of the concerns about liability and tire design are hard to ignore. You may have seen these two articles already but the first deals with a very similar situation as you find yourself in.

http://www.ridermagazine.com/browse-by-type/tires/tales-from-the-dark-side-putting-car-tires-on-motorcycles.htm

http://www.motorcyclejustice.com/law/Reader%20Questions/14may2011.html

bluekat said...

I once saw a vid of a car tire on a bike. Kinda freaky watching it in the corners. Liability issues could be a headache.

Something along this line...
http://www.youtube.com/watch?v=gZKhoFbL7Fo

So, how's Elvira doin'? :)

karinajean said...

hi friend!

I also don't know of any studies and have no personal experience.

however I did do several group rides with a rusty rider who had a big bike with a car tire on the wheel. it was terrifying to watch him around corners - there was no room for him to lean over -- it was all flat center of the tire and then sidewall. no transition to roll onto. it was like watching someone try to go around corners on a rectangular box.

Geoff James said...

Dan,
I've approached one of my riding partners who is the senior engineer for the government dept responsible for vehicle issues in NZ. He says that as far as he is aware, there have been no formal studies. He also sits on joint committees with Australia.

However, he goes on to say that with the exception of sidecar rigs, they would not be allowed in NZ because car tyre construction(and profile I guess) is not compatible with the forces generated by a solo motorcycle when cornering.

Hope this is of some background use.

Bryce said...

Dan:
Having ridden sidecars many years prior to solo, and then afterwards for a period, including being a specialty importer to north America of sidecar fittings from the UK; can only advise of what i have seen.
With a solo motorcycle ie two wheels only you ride the machine and swing and sway through the curves.
With a sidecar mounted you drive the
combination as if operating an automobile. All three wheels remain flat on the ground, as also with triked motorcycles.
You "drive a sidecar/trike." You are
basically driving an automobile so best to have non-motorcycle tires in palce.

With a solo machine the added flexibility and the ability to turn the handlebars
means the sidewalls of the motorcycle tire
are flexing all the time and you will in fact use some o fthe tread on the side of the motorcycle tire.

My own suggestion is let the person try,
and if the whole scenario goes tits up, then you'll know.

Bryce Lee

polarbear said...

Would you let a student use a football helmet in place of a motorcycle helmet?...both cover the head....I say no to car tires.. its your range and your rules.. a motorcycle tire is for motorcycles and car tires are for cars.. Lets not confuse things..tell them it is an incompatible rubber issue that could cause problems for other riders..

shutterpilot said...

In the RiderMagazine article RichardM sent along, there's this "official" ruling:
The Motorcycle Industry Council puts it more directly, “Never mount a passenger car tire on a motorcycle rim; the flat profile of a car tire is incompatible with the dynamics of a vehicle that leans as it corners, and the section of the tire in contact with the rim (the ‘bead’) is incompatible with motorcycle rims.”

trophydan said...

I just cannot believe that anyone would do anything so stupid - and that there is even an argument about it!

Er, bikes lean round corners, so you need some kinda rounded profile?

Or have I been wrong for the past 33 years riding?

trophydan said...

I just cannot believe that anyone would do anything so stupid - and that there is even an argument about it!

Er, bikes lean round corners, so you need some kinda rounded profile?

Or have I been wrong for the past 33 years riding?

Ms. said...

Dan - check your email. I'm trying to put you in touch with someone who might have done research like you're interested in when putting together his sidecar... which has been extensively stress tested as both a 2-wheeler & 3-.

"not compatible with the forces generated by a solo motorcycle when cornering"
It's difficult to prove a negative - car tires on motorcycles are not dangerous.
If it's true, proving a positive should be much easier - car tires on motorcycles are dangerous.
Have there been any instances of bead failure attributed to using a car tire on a bike?

"All three wheels remain flat on the ground"
"you really can't lean a sidecar during normal operation"
LOL So getting it on 2 wheels isn't considered normal?
I've tried to tell Karl that...

irondad said...

I appreciate everyone's input. If there is a scientific study nobody has been able to find it. On either side of the equation. Perhaps it's one of those things that seems too obvious to study.

The Rubber Manufacturers Association ( all the tire folks ) has issued a warning that includes the terms "serious injury or death".


I'm meeting with the team next week for a final resolution. I'll keep you posted.

American Scooterist Blog said...

Late to the party but have to remind you of the old Goodyears. People called them Neverwears because although they had the right profile for a leaning vehicle, they were far too hard a compound to be safe in too many conditions. So while some are only looking at profiles, consider also that the hardness of the sidewalls make such tires more dangerous for us.

Harv

American Scooterist Blog said...

Late to the party but have to remind you of the old Goodyears. People called them Neverwears because although they had the right profile for a leaning vehicle, they were far too hard a compound to be safe in too many conditions. So while some are only looking at profiles, consider also that the hardness of the sidewalls make such tires more dangerous for us.

Harv

Conchscooter said...

"soon..."

Suzu Gladi said...

I do not have an answer for you on this one, but wanted to encourage you to keep on telling us about what goes on in your range classes, your ride reports and your how-to articles. They kept me going through last winter and then when I got on the road again in the spring, all the reading paid off in better control and confidence on my bike.

By the way, that's quite the flood in your new picture!

Suzu

irondad said...

Suzu,

Thank you so much for the comment! One always wonders if their blog actually means something to somebody or if it's just another trivial thing in a world awash in writings.

Perhaps I'll fire it up again soon.

Take care,

Dan