Car tire on a trike?

My wife has a 2011 Silverwing with a Tow-Pac "trike" kit. I get that this is a misnomer since it now has 4 wheels, but the question is: has anyone with a similar setup used a car tire on the rear (middle) tire and if so, which one?
Tire Rack offers a 165-70-13 in a brand that I've never heard of. Stock size is 150-70-13 and worn thin at 4,000 miles. There appears to be plenty of clearance for the larger width, but I'd appreciate thoughts.

https://www.tirerack.com/tires/TireSearchResults.jsp?width=165%2F&ratio=70&diameter=13&startIndex=0&search=true&pagelen=20&pagenum=1&pagemark=1&RunFlat=All

Putting a car tire on a motorcycle is called "darksiding". Use the search function on this site or google Darkside motorcycle tire and get ready to read the pro/con debates on this practice.

think overall gearing---trike/sidecar probably need 20% reduction of overall gearing---bigger car tire does not do that and MC bead and car tire bead are different, too.

I understand "the darkside" controversy on two wheels, and I did put "darkside" in the search and came up empty. Since this "trike" does not lean into corners, the main safety issue isn't really relevant. There's plenty of owners of other models that swear by them, but it's something I just would not entertain on two wheels. The tire bead issue may be, depending on the wheel design.
So the question remains: has anyone with a similar setup used a car tire on the rear (middle) tire and if so, which one?

There are a few options in a 155/70/13 car tire. It's close.  Width of car tire bead is thicker.  Motorcycle wheel thinner and never really fully seated on rim but it does seal.   Many have used car tires and never had a issue with sealing.  Clean the rim and it will seal.  

Achilles 122 a inexpensive tire. 155/70/13.  

I think it might affect the steering with a darkside tire on the front wheel, the fork has a pretty noticeable rake which might put the tire on the edge of the tread on the road in a turn. Even though the bike doesn't bank in the turn the front tire really does when you turn a bike.

I have a couple of friends say that steering is heavy after triking a bike. They kept the original bike tire on the front. So I'd suspect it the square cross section of a hard edged tire is the suspect. Both the guys eventually went back to a bike tire in frontl.

VABird wrote:

and I did put "darkside" in the search and came up empty.

This is very odd; I've just typed 'darkside' in the Search box and it's come up with 445 hits.
I wonder what went wrong.

exavid wrote:

I think it might affect the steering with a darkside tire on the front wheel, the fork has a pretty noticeable rake which might put the tire on the edge of the tread on the road in a turn. Even though the bike doesn't bank in the turn the front tire really does when you turn a bike........

Really didn't intend to go dark on the front, but thanks for the tip.

And thanks to all. I'll probably try the Achilles. At 1/2 the price and 8-10 times the wear, it's worth a try.

it might be worth checking out some of the sidecar forums, those folks use car tyres all the time so will have advice to give.
In your case you have less to worry about, even if the tyre does fail you will have two other outrigger wheels to keep you upright while roll to an embarrassing, but safe, stop :-)

I've a car tire on the back of my Guzzi outfit. Front is a square sidecar tire. A car tire not he front would be too much for it. The back certainly slides around on a wet road.
Both are tubed.
With the 'flat' thread, the back always looks as if it's very soft.

A friend of mine who has a triked Goldwing had to change the fork rake to reduce the heavy steering effort. He had auto tires on the back and a standard motorcycle tire on the front.

My current ride is a Grinnall conversion on a BMW R1200 C . It has a replacement top yoke (triple tree ?) in order to change the steering characteristics. I have car tyres on the back wheels and a motorcycle tyre on the front wheel.

bikerboy wrote:

My current ride is a Grinnall conversion on a BMW R1200 C .  It has a replacement top yoke (triple tree ?) in order to change the steering characteristics. I have car tyres on the back wheels and a motorcycle tyre on the front wheel.

I've looked at the front of a BMW with a view to sidecar work. The change needs to alter the position of the front contact patch with respect to the steering axis - the trail. On BMW outfits, usually this is done by replacing the bottom yoke and steering bearing housing, moving the fork out a little but leaving the bearing in its original location and the A-arm stock. This is effectively the same method as you have used.

It can be done the other way by shortening the A-arm and steepening the steering angle but leaving the offset the same but it's a lot more work and not as easily reversible.

British manufacturers in the fifties usually supplied alternative yokes for sidecar work. Usually just the bottom yoke. The Earles-forked BMWs of the 1960s have alternate locations for the front swing arm for solo and sidecar use.

With the steering lightened thus, a sidecar rig usually needs a steering damper (though my Guzzi is grand without one) but is more manageable with a fatter, squarer tire and the much larger steering deflections needed with three wheels.

The SW is not the nicest in the wet and I've had some front-wheel adventures - on roundabouts in particular - and I've often thought about adding an extra wheel in the form of a sidecar.

VABird wrote:

exavid wrote:

I think it might affect the steering with a darkside tire on the front wheel, the fork has a pretty noticeable rake which might put the tire on the edge of the tread on the road in a turn. Even though the bike doesn't bank in the turn the front tire really does when you turn a bike........

Really didn't intend to go dark on the front, but thanks for the tip.

And thanks to all. I'll probably try the Achilles. At 1/2 the price and 8-10 times the wear, it's worth a try.

I don't think you could fit a car tire on front of a Silverwing 600... But, if you were
to double darkside (that is a MC rear tire up front with a car tire on the rear) a
140/70-14 might fit on the front, but there might be clearance issues for the front
fender with a wide tire like that.

For the rear, a 165/65R13 car tire is as about as close to the stock scooter tire in
overall diameter as you are ever going to find. I used such a tire on a Silverwing  
600 I once owned so as to not have issues with the ABS brakes... Never did have
any problems with the ABS. Apparently the car tire was close enough in diameter
so that it never found fault. The brakes worked as they should and ABS activated
with testing on wet pavement as well as with loose sand on pavement.

Not so sure about the 8-10 times the wear. More like 3 to 6 times the wear. That
is more like what I got from using a car tire on my Honda Reflex... Still, that is a
lot longer than a stock rear tire.

Oh, and there is this you could look at for info. Still relevant... (mostly) after about
5 years from original posting. But some of the links in that item are dead ends
because some of those pages have been deleted, have been moved or for whatever
other reasons just no longer exist... Sorry, but not anything I can do about that.

https://mcdarksiders.forumotion.com/t7188-for-maxi-scooters-the-darkside-according-to-bandito2-part-1-2

_______________________________________________
Mike B. (AKA bandito2, bandito_two OR Scooter_Jedi ...take your pick)
Rochester Hills Michigan Dark Side Rider
4 Honda Reflex scooters & a Big Ruckus
Originator of the "Darkside" Honda Reflex.
"Yeah dude, that IS a car tire there on the back of my scooter."
Sometimes I'm so far outside of the box, the Hubble telescope can't find me

Thanks to all for your input.
I'll look into the 165/65.

The SW has alot of flex in the frame.  If you go flat on the back and motorcycle tire on the front you will be torqueing the frame a lot.  On a trike or side car set up that runs flat then turning it would be ok.

Murf wrote:

The SW has alot of flex in the frame.  If you go flat on the back and motorcycle tire on the front you will be torqueing the frame a lot.  On a trike or side car set up that runs flat then turning it would be ok.

Torqueing the frame will happen to a much greater degree with a side car set up than
being set up in single track.

A car tire is not a rigid flat thing that would "torque the frame" to any discernable degree
more than a stock bike rear tire with some of the tread face on the center line worn down.
A bike rear tire will wear down giving it that slightly squarish shape when approaching the
time when needing tire change due to wear. A car tire on the rear of a bike will feel similar
to a worn rear bike tire... and would have about as much torqueing effect on the frame.

The sidewall of a car tire squishes down somewhat in a lean allowing enough tread to still
lie flat to the road even as the rest of the tread face is lifted off pavement. There is hardly
enough lateral force being directed to the frame from the rear tire in a leaning turn to even
begin having concern about how much it might be twisting on the frame... most of the force
is carried to the frame through the centerline of the wheel along its plane of loading which
is held in alignment to the main load bearing plane of the frame structure by way of rigidly
fixed points on the axle and swingarms.

With a sidecar rig, much more lateral force occurs in turns that exert a twisting moment
along a plane not in line with the frame.  Car axles, wheel bearings and frames are built to
take load force from the side from "flat" turns. (since car wheels don't lean in turns to the
degree that bike wheels can lean) A bike in single track form can lean in turns keeping load
force along in line with the frame instead of crossways through it.

_______________________________________________
Mike B. (AKA bandito2, bandito_two OR Scooter_Jedi ...take your pick)
Rochester Hills Michigan Dark Side Rider
4 Honda Reflex scooters & a Big Ruckus
Originator of the "Darkside" Honda Reflex.
"Yeah dude, that IS a car tire there on the back of my scooter."
Sometimes I'm so far outside of the box, the Hubble telescope can't find me

Yup ^^^ what Mike B. AKA bandito2, bandito_two OR Scooter_Jedi ... said ^^^

On my 08 SWing Trike the two back tires are basically car tires. They are 14" and about 6" wide and flat. But then it's now a trike and rides flat without any leaning into the turns. I had it turned into a trike a couple of years ago and have no regrets. But on a two wheeler I'd stick with regular motorcycle tires.