Last week I accidentally replied a new posting about putting speed rated car tires on motorcycles. Little did I know that by answering I accidentally crossed over and stepped into a Dark Side Dung Pile…. Who in their right mind would try to persuade uninformed people to try something as ridiculous as putting car tires on Motorcycles?
I was caught a little off guard when my reply was quoted and responded with very negative comments. I usually let that stuff just roll off but chose to reply the negativity with sound principles which resulted in more negativity and comments like “You are in the Darkside Forum and this is no place for your comments not supporting our crack pipe ideas.” Being the sound engineer I am, I decided to research just why these zealots were so passionate about a Fad that I thought could get someone killed.
What I found was the Darkies have spent at least the last 2 years trying to defend their uneducated attempt for saving money on motorcycle tires by purchasing car tires. The thread I replied was aout a guy looking for high speed rated car tires for his touring motorcycle. I run what I consider to be good Dunlop motorcycle tires on both my Harley’s, H rated out of the box, rated for 130 MPH. My personal car requires W rated tires good for 168 MPH and the last time I bought new tires I paid more than 2 (X) the price of a good Dunlop. Maybe their passion isn’t so much about price so I did a little more research…
What I found is Rider magazine had similar questions; What would make a knowledgeable person try something crazy like replacing their perfectly good motorcycle tires with car tires? Aren’t motorcycle tires designed and built for the stresses of a 2 wheel motorcycle with the understanding the contact patch is critical for traction in straightaways as well as curves?

http://www.ridermagazine.com/browse-...torcycles.htm/

My understanding of this industry experts opinion seems to align very well with my opinion. But it is just an opinion and I am not a tire expert, so I looked a little further for an expert. If not a tire expert, somebody that understands this Fad and has documented his research.

http://www.goldwingfacts.com/forums/...-rim-tire.html

I think this guy is as close to an expert as I will find and I agree with the data he presents and his methodical approach to explain why we should not put car tires on motorcycles.
Bottom Line for ME is everything I read from anybody I respect would suggest car tires do not fit motorcycle rims, are not designed to bead lock, have thinner side walls and treads, and the flat tread does not provide a constant contact patch while leaning in a curve, therefore they are not properly designed for the application and not worth the risk to try. And I wouldn’t even recommend my worst enemy try this. Maybe I am wrong but maybe I am dead right and I am not ready to suggest anyone try it.

 

There is a 'dark side' following on HDF, even a dedicated section, so brace yourself! Thanks for the reading material. I've seen the Rider one before, which is a good read, I'll go into a darkened room to read the GW one!

 

Actually it seems this fad started with GW or metric riders and the GW read was exactly opposite what I expected. A technical analysis without opinion, using data to communicate why anyone trying this is not only putting their lives, but the lives of those around them at risk.

Yes I have already experienced the highly animated opinions of the darkside team when I accidentally commented a new post a few days ago. A lot of negative comments and no supporting data.

 

Do you know where I can get a car tire to fit my 2012 CVO SG?

Can you point me to a news report or verifiable anecdote about a crash where use of a car tire caused or worsened the crash?

For thousands of years the Earth was flat. People were hanged or burned at the stake for spouting that the Earth was indeed round.

If I could find an 18 inch tire that wold fit my CVO I'd run it. I've run car tires before and liked it. It's not about saving a few bucks.

Anyway...

 

You will probably get a answer in the dark side forum..look in the this n that section

 

Actually, yes I can. A rider I've met at a motocampers campout crashed right after he installed a car tire on his Ultra. He was towing a pop-up camper. PM me if you want his contact information.

Read this thread:
https://www.hdforums.com/forum/hacke...-the-bike.html


I know of a few instances of people having issues using a car tire on a motorcycle when towing a trailer. I think part of the issue is that a car tire has a softer sidewall than a motorcycle tire. That's why a number of the people using car tires on a motorcycle will use a run-flat car tire, since those tires have a stiffer sidewall. I also tow a pop-up camper and will never run a car tire after reading these reports. Besides, I have a No Mar tire machine and I'm able to change my own tires.

 

you will be surprised at how many darksiders are out there, i will be one of them and i have installed car tires on valkerie hondas.
one of the biggest arguments is "oh!! the sidewalls are strong enough!!!"
poppy-****!!!
stop and think how does a multi-thousand pound car turn??? well, the front tires PUSH the front over!! so what is a 500# mc??
if you youtube it, there are vid's that actually show the tire on the road in curves way past the posted and the tire never rides the sidewall. would i run a knee-slider, nope but for street, i see no issues. in the beginning, car tire were used but as the industry grew, so did the specialty market and their hype.
personally i like the old english tire, had more feel of the road and sure it required some rider input but is totally controllable. i hate the ball bearing tires, i have smoked them is a little a 3k miles, riding on a 2" patch vs 5", i'll take the later, ball bearing tire, i can break traction at 70mph and on a wet road, even worse.
one cravat is if your rim has a safety bead, don't even try it, they will not go on.

https://www.universaltire.com/175r16...axi-black.html

here is one, i will be using an austone. the darksider web page lists others and machine fitment.

http://darkside.nwff.info/

 

They're made for London taxi cabs, which rarely go outside the city limits! Some of the tyres for them have very low speed limits, so be aware.

 

Could the reason be a combination of the trailer and the driver? 1 crash I saw in Raleigh NC, the guy was pulling a trailer and wasn't able to control the bike with a bike tire on the Interstate.
Not saying it was but couldn't it be?
I can't use one on mine but have rode a Goldwing with one and other than slow speed maneuvers, I couldn't tell the difference.

There will always be both sides to this debate and Darksiders will keep using car tires.

Be safe out there.

 

if you look at the so called taxi tire, not what you think. the tire is from austraila and if you look at the spec's, it is not a run-around-town tire. sure, its name is probably from all the taxi's that uses that size but an eagle tire doesn't mean eagles carry then on their talons.