Author Topic: Fidding a 18" x 4.5" Rear Moto Wheel Widda Car Tior  (Read 34939 times)

Offline cat0020

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Fidding a 18" x 4.5" Rear Moto Wheel Widda Car Tior
« on: March 15, 2014, 09:31:16 AM »
This is probably going to open a big debate.

I've ridden a car tire mounted on the rear wheel of a Suzuki Burgman 650 for over 14k miles without troubles.


Now I want to put a car tire on a K75S, since most if not all of my riding will be on highways cruising at speed. 

Any K-bike owners ever tried to put a car tire on the rear wheel?

Which make/model car tire have you used?

Any pictures of your car tire mounted?

Offline Scott_

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Re: Going "Darkside"..
« Reply #1 on: March 15, 2014, 10:20:22 AM »
Well, you are probably right about opening up for an interesting debate.......Liability and Litigation are the 1st 2 things that come to my mind when you start thinking of a modification like this.
Not unlike mcycle dealers that won't patch a bike tire because they don't want the liability if it fails at speed and causes a crash.
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1997 K1100LT 0302488
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Offline MEL

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Re: Going "Darkside"..
« Reply #2 on: March 15, 2014, 10:47:54 AM »
Wouldnt even consider it.....
Imagine that.
1995 k1100LT

Offline cat0020

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Re: Going "Darkside"..
« Reply #3 on: March 15, 2014, 11:02:47 AM »
Not long ago, no one would consider earth is round.. or that planes can fly.. plenty of car tires have been mounted on motorized 2-wheel vehicles and millions of miles have been ridden on them. No indication that incidents are more likely riding with car tires mounted on the rear wheel.
As someone who has experience riding with a car tire mounted on the rear wheel, I can say that it is safer in most applications when operator knows how to ride, just as any tire, moto specific or not. Just as any new tire mounted on a vehicle, moto or car specific, learning curve of vehicle handling is to be expected.

IMO, liability is for those who depend on manufactures rather than riding skills.

If anyone is interested in my experience of riding with a car tire mounted on the rear wheel, I'm happy to share.
But to debate about this topic without actual experience is like telling someone the riding a motorcycle is dangerous shouldn't be attempted while never ridden a bike themselves.


Offline TimTyler

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Re: Going "Darkside"..
« Reply #4 on: March 15, 2014, 11:10:08 AM »
... a car tire mounted on the rear wheel, I can say that it is safer in most applications...

Really? What information do you have that shows that a car tire on a motorcycle is safer than a motorcycle tire on a motorcycle?

Do the insurance companies have access to your data and experience?

Offline Scott_

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Re: Going "Darkside"..
« Reply #5 on: March 15, 2014, 11:38:43 AM »
I've not been to a "major" bike rally like Datona Beach or Sturgis, but the only 'car tire' installations on mcycles I've seen have been on trykes, where you won't have the 'leaning' effect on the tire edges.
Short of a custom built bike that may have a super wide rear to fit a car tire, but still a bike you probably won't see in the highway unless it's on a trailer........
  • My Garage
Ride safe.


1997 K1100LT 0302488
1995 K1100LT 0302044
Garmin StreetPilot 2820
Garmin Zumo 550
"One who does not ask questions is ashamed to learn" Danish proverb

Offline cat0020

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Re: Going "Darkside"..
« Reply #6 on: March 15, 2014, 02:38:31 PM »
... a car tire mounted on the rear wheel, I can say that it is safer in most applications...

Really? What information do you have that shows that a car tire on a motorcycle is safer than a motorcycle tire on a motorcycle?

Do the insurance companies have access to your data and experience?

14k miles ridden on car tire mounted on a Burgman 650 myself, 45% 2-up riding, never an issue, not even a flat.. that enough info for me to believe it personally... until you do it yourself.. I can not change your mind otherwise. 

Plenty of videos on Youtube with car tires mounted on Goldwings, Triumph Tiger, Rocket IIIs, leaned at steep angles in corners, just a search away.

Insurance company only care if the bills get paid on time. 

Offline Chaos

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Re: Going "Darkside"..
« Reply #7 on: March 15, 2014, 03:50:40 PM »
this came up once on BMWMOA's forum.  First reaction from most people is same as screen doors on a submarine.  But the people who have done it get impressive mileage and not all the bad dynamics you'd expect.  One downside is rear wheel bearing wear on Wings, if I remember correctly.  Sidecars it's a given they work better.  Since most of us, (well, not us but the Wing and noise and chrome crowd) never push our tires past 6/10th having optimized rubber does not matter so much.
  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
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Offline cat0020

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Re: Going "Darkside"..
« Reply #8 on: March 15, 2014, 04:52:29 PM »
Here are some videos:






Offline Motorhobo

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Re: Going "Darkside"..
« Reply #9 on: March 15, 2014, 05:47:46 PM »
I'd be interested to know if there's a car tire that would fit a K75 for sidecar purposes. I had heard that there was one that fit but it was no longer in producton. This was back in 2009. If there's one now I'd sure like to know about it. It's depressing to buy a moto tire for big $$ and have it wear flat after a few thousand miles.
1994/1995 K75 ABS Frankenbike: original engine 130k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 184k miles
1994 K75 since 2013, 76,000 mi (11k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B'

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline drut

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Re: Going "Darkside"..
« Reply #10 on: March 15, 2014, 06:04:58 PM »
Hadn't seen the videos before(thanks:enjoyed watching them) but first bikes I owned in the 60's had Avon SM rear tires with profile very similar to car tires and no handling issues.Guess finding right car tire for grip etc. might be a matter of luck!

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Offline wmax351

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Re: Going "Darkside"..
« Reply #11 on: March 15, 2014, 06:32:12 PM »
You definitely lose some handling, but I don't think the car tire is too big a deal. Might be better for crappy weather/road surfaces. I'd mount one if I was planning on going to Alaska.
  • Ann Arbor, MI
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Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline K75RT Keith

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Re: Going "Darkside"..
« Reply #12 on: March 16, 2014, 12:46:38 PM »
For liability issues it would be wise NOT to make any recommendations on use of an automotive tire on a motorcycle.
You can't help someone who doesn't want to hear the answer.

1990 K75RT

Offline cat0020

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Re: Going "Darkside"..
« Reply #13 on: March 16, 2014, 01:50:09 PM »
For liability issues it would be wise NOT to make any recommendations on use of an automotive tire on a motorcycle.

How many motorcycle fatalities involving car tire usage do you know of? or does anyone know of?
Please provide some evidence or actual stats that got published.

OTOH, I'm sure most of us know of plenty motorcycle fatalities that use moto specific tires.

Offline mjydrafter

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Re: Going "Darkside"..
« Reply #14 on: March 16, 2014, 03:52:07 PM »
Have you found a tire that will work?  The k75 has some narrow rims.  So you would be looking at a really narrow tall car tire with an 18" rim.  They may be out there but I have a feeling they will be big $.

Then I think clearance will be the next big hurdle, I haven't really looked but I don't think there is a ton of extra room.

 :dunno
1986 BMW K75c
1974 Suzuki TC-185 (the little 10 speed)

Offline cat0020

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Re: Going "Darkside"..
« Reply #15 on: March 16, 2014, 04:36:23 PM »
Here's a thread on ADVRider about car tire mounted on a K75, but with sidecar mounted, too.

Car tire/ Darkside options for BMW K75T

Looks like they used a fabricated spacer to allow usage of a car wheel and more room between car wheel and swingarm.







Currently my K75S has 130/90-17 tire mounted on the rear wheel, yes, 17" not 18" wheel.

Probably I can fit a 145/60-17 car tire onto the OEM K75 rear wheel without clearance issues.. problem is finding one in that size.


Offline Opus

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Re: Going "Darkside"..
« Reply #16 on: March 16, 2014, 05:26:58 PM »
The "LIABILITY" is in the "RECOMMENDATION".
If I "RECOMMEND" you try/use a product for something that it is not designed for and you are injured or killed.
I could be "LIABLE" for the damages in a Court Of Law.

As for using a Car tire on a Bike that is something you should research very well before you try it out.
Scooters, Sport, Sport Touring, Cruisers, & Touring bikes all handle differently and what works on one may not work as well on the other.
For my 88 K100LT I would not use a car tire because of the way I ride.

Good Luck....
Toney

1988 BMW K100LT (Current Project Bike)
1982 Honda GW 1100 I (Sold and will be missed)
1975 Honda CB550F [MOD] (Sold)
196x Sears Allstate 250 (Traded in for CB550F)

Offline K75RT Keith

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Re: Going "Darkside"..
« Reply #17 on: March 16, 2014, 11:19:33 PM »
CAT0020,  frankly, I personally don't give a whit what you do.
Please do whatever YOU belive to be in your best interest.
But, by you posting here asking for recommendations and/or approval puts respondents
in a position of being liable if you are injured or killed. 

Again, please do whatever you feel is in your best interest. I wish you all the best
You can't help someone who doesn't want to hear the answer.

1990 K75RT

Offline Grim

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Re: Going "Darkside"..
« Reply #18 on: March 16, 2014, 11:37:23 PM »
Here's a thread on ADVRider about car tire mounted on a K75, but with sidecar mounted, too.

Car tire/ Darkside options for BMW K75T

Looks like they used a fabricated spacer to allow usage of a car wheel and more room between car wheel and swingarm.







Currently my K75S has 130/90-17 tire mounted on the rear wheel, yes, 17" not 18" wheel.

Probably I can fit a 145/60-17 car tire onto the OEM K75 rear wheel without clearance issues.. problem is finding one in that size.

Well you are overlooking something here that's very important. With a side hack the back wheel being offset to clear the swing arm is not going to present as much of a handing problem as it being offset on two wheel machine that needs to lean to turn. The handling would be spooky I'd bet.

1995 Morea Green K1100LT

Offline mr_10brook

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Re: Going "Darkside"..
« Reply #19 on: March 17, 2014, 06:49:17 AM »
Here's a thread on ADVRider about car tire mounted on a K75, but with sidecar mounted, too.

Car tire/ Darkside options for BMW K75T

Looks like they used a fabricated spacer to allow usage of a car wheel and more room between car wheel and swingarm.







Currently my K75S has 130/90-17 tire mounted on the rear wheel, yes, 17" not 18" wheel.

Probably I can fit a 145/60-17 car tire onto the OEM K75 rear wheel without clearance issues.. problem is finding one in that size.


One of those pictures had a car wheel adapted to fit the BMW. There used to be a guy in PA that did 15 inch car wheel modifications $$$ for sidecar use.

  The tire size you mentioned, for the OEM rim with a 60 series profile will change your gearing for higher rev's on highway.

Another alternative to a long lasting tire on your K75S would be to put a Metzeler ME 88 Marathon in the 140/80 -17 size which should give you a long lasting tire. I have put a couple thousand miles on one currently and still no detectable wear.

I have also used Dunlop's economy D404 and get 10-12k out of those.

If you find a car tire that fits an OEM rim let us know.
97 K1100LT
94 K1100LT Pine Green (rear ended and totaled)
93 K75S Pearl White
93 K75S Mystic Red
91 K1 Black
79 R100RS (not running)
71 R60/5
66 R90/2 (runs just have not registered for several years)
08 Wee Strom
Other various brands (I have MBD, Multiple Bike Disorder)

Offline cat0020

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Re: Going "Darkside"..
« Reply #20 on: March 17, 2014, 09:35:29 AM »
Well you are overlooking something here that's very important. With a side hack the back wheel being offset to clear the swing arm is not going to present as much of a handing problem as it being offset on two wheel machine that needs to lean to turn. The handling would be spooky I'd bet.

Well, where did you read that I plan to use a car wheel for my application?

I know the front/rear wheel off-set when a spacer is mounted on a car tire may present a problem, but most car wheels are built with an off-set that can also easily compensate for the spacer needed for the application.

Handling difference of riding a car tire mounted on the rear wheel feels no more different than riding with rear luggage on/off to me.
Any change on a moto can affect handling, safety just depend on how well a rider can cope with the change, however spooky it may be.
 

Offline subforry

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Re: Going "Darkside"..
« Reply #21 on: March 17, 2014, 12:59:06 PM »
Interesting, never heard of using a car tire before.  One thing that comes to mind right away is that when the car tire is forced to compress the side wall and bend the tread when cornering and will generate quite a lot of heat.
From the video it looks like the rear tire diameter doesn't decrease as much as a round profile m/c tire.  This means the m/c wont slow down when turned, which will be kind of odd.  Also the contact patch of rear wheel will have a smaller radius than the front, don't know what that will do.
I think the real problem is finding a high performance, high temp rated tire that is small enough in rim and profile.
  • Hermosa Beach, CA, USA
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1990 Suzuki Katana 1100 (GSX1100F) - sold
1996 BMW K1100RS
2009 BMW K1300GT

Offline cat0020

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Re: Going "Darkside"..
« Reply #22 on: March 17, 2014, 04:04:31 PM »
Keep in mind that car tires are designed for vehicle weight 3 to 4 times of a motorcycle; withstand forces generated by vehicle 3 to 4 times as heavy as a motorcycle.
Whatever handling difference by using a car tire vs a moto specific tire is just something to learn for the operator, as for any new tires mounted on a vehicle. 

Offline Opus

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Re: Going "Darkside"..
« Reply #23 on: March 18, 2014, 02:28:02 PM »
@ cat0020
Then Do It!
Start a project post, document your work and post your findings.

I have done some surfing and see that almost all the MC to Car tire/tyre conversions were done to mostly to heavy cruisers and the large touring bikes. There was a few videos of a Triumph Rocket 3 and a FJR 1300 that did the swap over but none using a BMW K bike (other that the ones who added a side car) Oh and a few Scooter videos.

Just remember to document, document, and oh yes, DOCUMENT your work. The Devil is really in the details.....

Good Luck and looking forward to your results.
Toney

1988 BMW K100LT (Current Project Bike)
1982 Honda GW 1100 I (Sold and will be missed)
1975 Honda CB550F [MOD] (Sold)
196x Sears Allstate 250 (Traded in for CB550F)

Offline Turkus

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Going "Darkside"..
« Reply #24 on: March 18, 2014, 06:04:58 PM »
Maybe there's a reason the OEMs DO NOT put car tires on their motos....
Different sidewall construction and cornering ability comes to mind,
not to mention HUGE liability issues from almost everywhere imaginable.
IMHO you are playing Russian Roulette with (at least) TWO rounds in the cylinder

Just because you can do it doesn't make it right.....
You can get more with kind words and a REALLY BIG gun, than with just kind words...trust me

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