Going to the "Darkside" observations

TexasDave · June 15, 2014, 03:13:16 PM

Over the last few years I have observed more motorcycles with car tires on the rear. Most of you know this is known as going to the "Darkside". This is a hotly debated topic with most either very opposed or very happy with their conversions. Most conversions were Harleys and Wings. This makes sense to me if you have a large heavy bike that is made for long trips that doesn't handle well to begin with. These tires will handle larger loads and go many thousands of miles farther than conventional bike tires. It makes no sense to me to put one on a FJ and destroy the good handling characteristics. So I was surprised to see one the other night on a 2008 FJR. I have seen a side car equipped FJR with car tires front and rear which makes sense to me. The rider of this bike said the only mods he did was move the rear brake caliper brace over slightly to clear the tire with no other mods. He was happy and said the steering was heavier in the corners but he had no problem riding the tail of the dragon. Dave

Arnie · June 15, 2014, 08:24:28 PM

Dave,

You didn't ask any question, but in case you want comments.....

Sidecars don't really lean so that makes sense.
For the 'other' conventional motorcycles, I think PT Barnum summed it up well.

He said, "No one ever went broke underestimating the intelligence of the American public"

I agree with his statement, except I think the 'American' qualifier should be removed. it applies much more widely than that. :-)

charleygofast · June 15, 2014, 10:12:03 PM

Automobile tires are not designed to tilt and lean like cycle tires are. Even with a sidecar I don't think its a wise choice, unless its one of those roadrace side cars,and they might be running special tires made for that application...I don't really know. I have owned 2 sidecars in the last 25 years. 73 Moto Guzzi and a 81 Yamaha XS650 and I found wider tires did handle better but with flat profile car tires you wouldn't be able to get the car airborne and fly it safely. theres lots of big cycle tires out there that will work well on FJs , I'm just amazed how people can screw up nice bikes just to have something different or extreme... did that 08 FJ also have ape hangers? Charley

TexasDave · June 15, 2014, 10:30:47 PM

I'm always interested in responses to the posts on this forum---whether its comments, questions or cuss words. One of the great ways to learn from the pool of knowledge here. When I asked why the car tire he replied he was tired of changing them all the time. He has had the 08 FJR since new and logs alot of miles. I know I would not run one on a bike. I agree with Arnie. Dave

andyb · June 16, 2014, 07:54:56 AM

Interestingly, it's one of those topics where frequently the people who have actually done it rather liked it, and those who have not done it speak out immediately.

I've wanted to try it out for awhile, but haven't had appropriate machinery to do it on.

ribbert · June 16, 2014, 08:30:14 AM

Quote from: andyb on June 16, 2014, 07:54:56 AM
Interestingly, it's one of those topics where frequently the people who have actually done it rather liked it, and those who have not done it speak out immediately.

I've wanted to try it out for awhile, but haven't had appropriate machinery to do it on.

I have an appropriate machine for it, it's a car.

Seriously, think about what a pig your bike becomes in corners even when the rear tyre just wears a bit in the centre.

Noel

the fan · June 16, 2014, 02:34:09 PM

When I was running a bike shop we installed a few car tires for customers. I made the customers sign a waver attached to the work order stating that we did so at thier request.

3 of the bikes were big bar hopping cruisers and the fourth was a gold wing.

I rode 2 of the cruisers and the gold wing after the install.

The cruisers were a custom stretched softaiol with a wide tire and a full dresser. With the soft tail it handled really weird especially doing a right/left transition. This was likely because of the really wide tire he put on but I would consider it dangerous at anything over a walking pace. The bagger dresser was better but the car tire was noticeable in turns tight enough to scrape floorboards.

The Gold wing was flat out scary. This was pretty early in the car tire thing, so the pressures were probably a bit off, but with the increased speeds and cornering capabilities of the gold wing it was very noticeable.

Based on my experiences with car tires there is no way I would recommend them for anyriding. They may work in some situations if the rider was very familiar with them, but I feel they would be very unsafe in a panic situation. If your riding involves curves of any type, stick with those round MC tires the engineers had in mind when they designed the bike.

Joe Sull · June 16, 2014, 05:38:02 PM

The more mass of the gyro, the more stable it is.

ribbert · June 16, 2014, 06:51:39 PM

Quote from: Joe Sull on June 16, 2014, 05:38:02 PM
The more mass of the gyro, the more stable it is.

.......and the more resistant it is to changing direction, that is, lean into a turn.

That's one of the reasons BMW's turn in so easily, the longitudinal crankshaft.

Noel

andyb · June 17, 2014, 07:46:18 AM

Wouldn't advise doing it to a sportbike, but a touring bike? A goldwing isn't going to be nimble at the best of times. Or some cruiser that's so lowered that any lean is out of the question anyhow? Would be interesting.

ribbert · June 17, 2014, 08:49:11 AM

Quote from: andyb on June 17, 2014, 07:46:18 AM
Wouldn't advise doing it to a sportbike, but a touring bike? A goldwing isn't going to be nimble at the best of times. Or some cruiser that's so lowered that any lean is out of the question anyhow? Would be interesting.

Andy, I don't understand what would be interesting about trying to turn a corner on a bike with a square tyre. All bikes, even wings and cruisers, have to lean to turn and I can't imagine trying to "lift" a bike onto the edge of the tyre to get it to turn and reducing the contact patch to a knife edge.

The nearest I've come is riding a bike with a chronically squared of rear tyre, it just did not want to turn. A car tyre would be even worse and that would have to make it un rideable.

Noel

Steve_in_Florida · June 17, 2014, 09:27:06 AM

Quote from: ribbert on June 17, 2014, 08:49:11 AM

The nearest I've come is riding a bike with a chronically squared of rear tyre, it just did not want to turn. A car tyre would be even worse and that would have to make it un rideable.

Sure would be useful in the ever-popular "Slow Race", or for the times you forget to put your foot down at stop lights between pubs.

See, there's a mod for every type of riding style!

Steve

the fan · June 17, 2014, 12:38:24 PM

I forgot about this one...

Have to admit it was pretty fun to ride, but didn't turn or stop all that well.

FJ Flyer · June 17, 2014, 01:37:56 PM

There is a small (but growing) contingent of Darksiders on the FJR Forum. The converts profess that there is no downside and you get used to the 'different' handling rather quickly. Most, I think, are LD riders, versus more sporty riders, but I'm not completely sure about that. The question of your insurance company ripping up your policy and walking away from your smoking pile of parts when they find out you were running a car tire comes up often.

I'm not taking the red pill. I'm happy with a bike tire.

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Going to the "Darkside" observations

the fan

the fan