I believe that enterprising individual would run afoul of the NHTSA and their specifications for motorcycle and motorcycle components. Particularly FMVSS 119 and 120.

 

Its always something.

From the less than overwhelming response from self proclaimed DarkSiders, I take it to mean the bead mismatch isn't enough of a concern to spend the money to correct.

I had a CT mounted on the back of my '42 Flathead for years, back in the late 60s and rode that rigid hard, on every type of bad road imaginable, without ever giving the tire a second thought.

 

What I find a bit disconcerting is that some of the most vocal proponents of dark siding weren't even aware of the bead mismatch. My initial comment about it in this thread was dismissed until someone posted pictures of the spec I was referring to.

I only stumbled upon dark siding a few days ago and this turned up in one of the first articles I read on the subject. The fact that a CT's bead is not designed for a motorcycle wheel is enough to make me not even want to try dark siding.

 

I don't want to speak for anyone else but I have known of the differences for years and I think most knowledgable proponents also know/knew but as mentioned, just don't see it as something to worry about or throw money at. Accumulated, logged, combined mileage would seem to verify that it is not a pressing problem. For most that have tried it, the benefits out weigh any concerns in their eyes.

 

I stumbled upon the dark siding practice by chance. I came at this with an open mind. I tried to understand. I read. I asked questions; but I am completely unconvinced this is anything I would try on my bike.

I respect your right to your opinion and use anything you wish on your bike but I personally need sound engineering behind any decisions I make on important safety related equipment.

None of the science makes any sense to me. The shape of the tire tread area is inappropriate for a single track vehicle. The bead shape of the tire and wheel do not match. The sidewall construction of a CT is not designed to handle the cornering forces of a motorcycle in a lean.

I have seen no good reason to use a car tire other than a lot of unqualified opinions that it "works" for them and I should give it a blind try.

Zero tire and wheel experts or manufactures of any of the equipment involved have endorsed this practice. In fact they state quite the contrary not to use a CT on a motorcycle.

The videos offered demonstrate cornering behavior that visually backs the reasons experts in the field state why a motorcycle tire is designed to be round and a car tire flat.

 

I too have been aware of the differences between a motorcycle tire bead and a car tire bead for a long time. Before I went to the darkside, I studied it quite a bit. One of the resources I used was the GW forum. They talked about it quite a bit, but some of them had 200K miles+ on a car tire.

In all of my research, I have not found one case of a problem because of the difference.

I've only got 25K on a car tire without a problem. To me, the bead difference is a non-issue.

 

The motorcycle tires do have a nice round design when you install them, but when you remove them, whether it is a soft tire in a few thousand miles or a good touring tire in 10+ thousand miles, they are no longer round. They have a flat profile that rounds up on the sides, kind of like a CT. Might as well start that way.

 

Sorry, I find that ridiculous. That is a very hard tire or a very old one or both. I would expect any CT worn out by 100k. And lets just wildly assume 25,000 miles a year. That is an 8 year old tire, also time for a change, especially for tires manufactured over 10 years ago.

And you totally discount the design of MT sidewall.

 

LOL

He was not in any way implying that someone rode a single car tire for 200,000 miles. All he said is that some riders have 200,000 miles on car tires.

Surely you knew that and you were just making a joke...

Right?

 

It's a very personal decision to go DK, Many do it and will do it without adverse effect. I have several friends that do it. I have followed them on Interstate as well on the tail of the Dragon and never saw them flinch ....Again for me it's a personal choice but it does work and you can get 25000-50000 miles on them...For the same price as a M/T One of my friends puts like 25-35000 miles a year on hi Goldwing so it pays off for him.