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Discussion Starter #1
I have a sidecar on my 2003 V92C Classic Cruiser. Due to fast tire wear because of the hack, I want to put an automotive-type tire on the rear for extended mileage and better traction. Because the bike no longer leans over like a traditional motorcycle, all the wear is in a 1.5" band in the center. Seems like a car tire's wider contact patch would be better all-around for my needs.

After hours of searching online, the only available tires I've located that are in the same ballpark size-wise are a Dunlop and Bridgestone in the 175/60 R16 size. This equates to about .6" wider tire than the stock 160/80B16 size.

My question is has anyone tried to mount a tire this size and if so were there any clearance/fitment issue encountered.
 

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One way you can tell is to use some kids playdoh. Take a bit and roll up a log and put it on the tire with the bike up on a jack. Then, with the playdoh in place, turn the tire to where it will hit whatever it is you're concerned about. Turn the tire back and take a measurement to see if the tire you want to use will fit.

Also; take a measurement of the tire you want to use. The same brand and model can actually be different from tire to tire. Not by a lot usually but certainly by up to a .5".

Bear in mind that when a tire spins it doesn't grow wider but it does grow taller due to the centrifugal force. So if it's the top of the fender you might be concerned about you might position the tire with the playdoh at the top, lower the bike, and sit on it...maybe even get someone else who's heavy to sit on the back and bounce a bit to see if it marks the playdoh remembering the tire grows at high speed.
 

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I recall that a year or so back on another site, there was quite a bit of discussion among V92SC owners regarding "darksiding" (i.e., using a car tire). As I remember, the rear subframe had to be widened slightly - one way was to use a scissors jack (carefully!) to spread it out.

Of course, they were using 17" tires, since the 17" sportbike tires used on the SC had very short tread life... Still, it might be worth looking into.

Of course, when using a car tire, the thing to remember is YOYO (you're on your own), since most places won't even think of mounting a car tire on a bike rim.
 

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Discussion Starter #4 (Edited)
I actually ordered a 175/60R-16 Dunlop SP Winter Sport 3D RunOnFlat tire that should be here tomorrow.

After checking clearance of the swingarm, there's more than plenty on the lefthand side - over 1.5" - but on the righthand side there's about .75" due to the mountings for the belt drive guard, which I've decided I can easily live without since with the sidecar and saddlebags you can't even see the thing anyhow.

The 175 should be approximately .6" wider overall (.3" on each side) so I'm expecting it to fit okay, but the sidewall could bulge out more than on the motorcycle tire, so we'll see.

Worst case scenario I'd have to remove the guard and grind off the mounting tabs for it, but that's a small price to pay for not having to worry about a tire for a couple of years. Besides, the belt drive isn't slinging off chain lube, etc. like a chain-drive bike.

I'll post up after we get the thing mounted and fitted on the bike. I'm planning to mount myself on my HF tire changer which has done almost 150 MC tires over the past four-plus years. If not, the bike shop a half-mile down the road has a really nice hydraulic machine with computer balancer.

My understanding is that the 15" MC rims are a problem with 15" automotive tires, but the 16" size is supposed to mount up pretty easy. Again, I'll know in a day or two.

Stay tuned...

Pix of my rig:
 

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Discussion Starter #5
Mounted up tire today...

The tire arrived yesterday afternoon in the big brown truck. When I saw it my first thought was: "Damn, that's never going to fit!" It looked two feet wide!

This morning I jacked up the Victory and put a big block of wood beneath the lowest sidecar strut to give me some room, removed the mufflers and extracted the wheel and worn out tire. After breaking the bead and removing the tire from the wheel on my HF tire changer, I quickly realized that due to the extension of the drive belt pulley/sprocket thingy the HF machine would not be of any use in trying to muscle this tire on.

The problem was that the new Dunlop - which is also a run-on-flat tire - has sidewalls so stiff that when I sat on the tire it hardly bulged out at all. And it's made for a 4- or 5-inch rim. The Victory's cast rims are 3" wide.

So it loaded up the rim and tire and drove to the local bike place a mile down the road. They have a fancy hydraulic mounting machine and computer balancer which made short work of the mounting. Ten minutes after I got there, I had a mounted and balanced tire with new valve stem for $20 (gladly paid). And when the beads were squeezed together to fit the smaller rim, the sidewalls all but disappeared, making the tire just a few millimeters wider than the stocker.

Re-installing it took some time by myself because, due to the sidecar, you now have to put the axle in from the lefthand side and it complicated the procedure, requiring three hands while I only had two. But after a half hour I figured out a way to put a block of wood beneath it whilst I started the axle, etc., etc. and it was on.

Unfortunately, the new tire's profile is smaller, effectively lowering the bike almost one inch. That'll probably mean some tweaks to the sidecar alignment, but I'll ride it tomorrow and see how it does.

I'm hoping to get 25K miles or more from this tire, so maybe this job will only be an annual or every-other-year task. We'll see. I measured the tread depth in the center of the tire (9mm) and will be checking it at each oil change to see how it's wearing. Looks like it will be a good match for the hack though, keeping at least 4-5 times as much rubber touching the road at all times as the MC tires I"ve been using.

I think I'm gonna like The Darkside!

Photos:

During the re-install of the wheel in my garage:


Closeup of the tire tread:


All mounted up and ready for test ride:
 

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Discussion Starter #7
Looks good on there! Imagine the mileage you could get out of the side hack tire if you could find a CT to fit it.

Maybe you could fine one at Coker Tire.
Thanks Bob!

I just put a new tire on the hack; the old one lasted at least 12K, and it's a $60 IRC, so that's not been an issue.

The rear MC tires on the tug were going fast as a dose of salts thru a widow woman... Elite III = about 5K; last one was a like-new Elite II pulloff (not worn, just old) it only went 2,200 miles.
 

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Looks like it will do the job and then some!

With the run-flat ability & stiff sidewalls, it will be interesting to see what tire pressure you find works best...
 

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Discussion Starter #9
Looks like it will do the job and then some!

With the run-flat ability & stiff sidewalls, it will be interesting to see what tire pressure you find works best...
As a starting point, I've put 32 psi in cold. Tomorrow I'm gonna ride it up the interstate in the high-nineties heat and check it hot to see where it's running at operating temps.

It's actually a winter tire in a size used by Mini Coopers (in the reviews I found) so I'm thinking the pressure will be a bit lower than a standard car tire and much lower than a typical street MC tire.

Will post up what works best and also be monitoring wear.
 

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Discussion Starter #10
Test Ride...

I just got back from a little 50-mile loop to test drive the new Dunlop rear tire. Don't think I'm gonna need to change a thing. The bike actually handles better than before so maybe the lower profile tire helped a bit (it's about the same height as the sidecar wheel/tire).

Being a bit smaller diameter it also had the welcome effect of a bit lower gearing, which comes with the unwelcome effect of throwing the speedo off by about 3 mph (by my GPS). The Victory was to this point the only bike I've owned that the speedo was dead on with the GPS! Now at an indicated 60 mph the GPS shows 57-57.5. But I'll take the lower gearing as the V92C was geared a bit tall for a hack IMO.

I checked the pressure at 32 psi last evening with cold tire and it was exactly the same when I left this morning. Upon returning, with the tire warmed up, the pressure went up to 35 psi.

At those pressures the ride is a good bit softer and squisher than with the MC tires running 40 psi. It seems the additional contact patch is also doing some good as the bike didn't want to weave as much under acceleration. Unless there's a problem that crops up I think I'll leave everything as is.

Pix from this morning:


 

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Very nice rig. Is it supposed to lean to the right a bit like that? Seems like it would wear out the tire on the right side sooner than the left.

I've been considering this tire as well since I'm definitely going with a CT on my next tire change. Sooner maybe.

I appreciate you documenting your findings. If you ever pull the side hack and go 2-wheelin' I'd really like to hear what your findings are on that as well.
 

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Discussion Starter #12
Very nice rig. Is it supposed to lean to the right a bit like that? Seems like it would wear out the tire on the right side sooner than the left.

I've been considering this tire as well since I'm definitely going with a CT on my next tire change. Sooner maybe.

I appreciate you documenting your findings. If you ever pull the side hack and go 2-wheelin' I'd really like to hear what your findings are on that as well.
It's actually not leaning to the right, it's just the lay of the gravel road I'm on in the photo. In fact, the setup for a sidecar requires a bit of "lean out" and so it's leaning out slightly to the left when on level ground, though this photo doesn't show it.

My only concern with this tire, it being a "winter" tire, is that it may not wear as well as an all-season type, but I don't really know 'cause in Alabama we never see winter tires.

FWIW, I wouldn't run a car tire on any two-wheeled bike. The only reason I'm doing it here is that the hack never leans over. The sidewalls of an automotive tire just isn't designed for that, IMO.
 

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It's an illusion then!

Fair enough on your opinion for 2-wheelin' darksiders. I've ridden darkside (CT) before and found it to be better than a MT in most situations I ride in. If I lived in the mountains where I rode twisties a lot or somewhere where the roads were just terrible and uneven; I'd stick with the MT. Then again; I'd also stick with something much lighter than a touring bike. I've yet to see any documented cases where the CT couldn't handle the stresses of being on a bike but there's always a first time.

I live in the desert though and most touring bikes see only a fraction of twisty roads vs straight or country roads. It's kind of a no-brainer for me to go to a CT knowing what I know about them. The 25k+ mileage per tire is the icing on the cake. I'll probably end up a double darksider when I need to change out the front tire and put a rear MT on the front for better mileage unless I feel a significant reduction in handling, which from what I've read from those who have done it, isn't an issue.

YMMV, FWWIW, IMHO...thumb up cheers

Btw; do your dogs ride with you often? I'm jealous. My two don't even like going in the car...
 

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Discussion Starter #14
Btw; do your dogs ride with you often? I'm jealous. My two don't even like going in the car...
Most of the 9K miles I've put on the hack since buying it last November have been with the pups. We camp usually a couple of times a month somewhere. They love it!

 

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Discussion Starter #16
Very cool! I like the temporary dog run you have set up. Is that to keep them from chasing down the local critters?
I always do that. Sometimes we're in busy campgrounds with lots of people, other times hardly see another person. But they're used to being on the dog run and it avoids issues with other campers.

At night I have a cheap Wallyworld "pup" tent (I think it's their cheapest one) that they sleep in. And for the same reasons as the run - they know it's where they are supposed to go at night. Also, less chance of problems if a stray skunk or raccoon wanders through.
 
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