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Thread: Car tires on rear

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  1. #1
    Curmudgeon At Large Bobmws's Avatar
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    Car tires on rear

    New to this forum and newly returned to a hack after 30 years.
    I just put a Hannigan Conde Classic on my BMW K1200RS, and I'm sure tire wear will soon be a concern! Rear rim is 5.5 x 17 and I've seen some numbers for mounting a 205/50-17 (Bridgestone Potenza G 019) that is actually specced for a 5.5 rim width.

    My question is how thick of a spacer can I safely use to gain a bit of clearance on the swingarm?
    I'm assuming it would be best to find lugs bolts that are longer so the threaded depth in the hub is the same.

    Any help would be appreciated, thanks.
    Bob Weis
    '04 K12RS - Hannigan Hack
    www.earplugco.com

  2. #2
    Registered User grafikfeat's Avatar
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    Quote Originally Posted by Bobmws View Post
    ...I just put a Hannigan Conde Classic on my BMW K1200RS...
    What does Hannigan say?

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    I'm running a 2004 K12GT with Hannigan Astro Sport. The GT also uses the 5.5x17 rim, and I did a lot of research after having the rig built and quickly burning through a couple of expensive MC tires. Unfortunately, I didn't find anyone who had mounted anything wider than a 195 tire. Using the tire size calculator at http://www.tacomaworld.com/forum/tirecalc.php your 205 tire would be only about 1% difference in diameter, but I don't think you could safely mount a thick enough spacer to get that tire to clear the swingarm. If you prove otherwise, please let us know!

    In my own case I went with the adapter and car wheel from C Stanley Motorsports (http://freedomsidecars.com/) and am running a 155/80 R15 tire. This also works out to be very close to the OEM diameter, just a tad smaller which works out well on overall gearing. The adapter/wheel package is expensive but I'm putting on a $80 tire every 12-14k instead of a $180 tire every 4-5k, so over the life of the rig I'll come out OK. It's nice to be able to know the rig will be ready anytime for a weekend trip, no worrying about whether or not there's enough tire to go the distance.

    Good luck, and do let us know if you find a way to wedge in that 205 tire without over-spacing the wheel and getting some flex introduced.

    Good luck!

    GTRider
    Last edited by GTRider; 02-04-2012 at 03:13 AM. Reason: spelling
    DGerber
    1983 R80ST -- 1988 K100RS (r.i.p.) -- 1995 R1100RSL (gone, never forgotten) -- 2004 K1200GT w/Hannigan S/C -- 2010 K1300GT

  4. #4
    Registered User grafikfeat's Avatar
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    Quote Originally Posted by Bobmws View Post
    My question is how thick of a spacer can I safely use to gain a bit of clearance on the swingarm?
    Why not use washers to get the distance from the tire wall to shaft, get the measurement and then shop a spacer...

    They're sold everywhere!

  5. #5
    Curmudgeon At Large Bobmws's Avatar
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    GrafikFeat:
    Hannigan doesn't comment on car tires on a stock rim, the ones they use on their HP rigs have a widened rim.
    My stock MC tire measures 7 1/8" wide with 9/16" clearance at the swing arm.
    Tirerack lists the specs for each individual tire and which rim it was mounted on for measurement. The 205/50 has a widest section measurement of 8.3", mounted on a 6.5 wide rim. It is spec'ed for rim 5.5 to 7.5. Mounted on a 1" narrower rim the section width should be a bit less. I think 2 additional 2mm stock spacers will do the trick.
    Realoem lists 5mm longer lugs for one of the bikes so I should be good with retaining thread depth.
    The 195 tires list similar section widths also mounted on a 6.5 rim, but none of them are spec'ed top mount on a 5.5" rim.

    GTRider:

    I'm aware of the car tire adapter ($$$), I'l try this route first and will report back.
    What front tire are you running?
    Bob Weis
    '04 K12RS - Hannigan Hack
    www.earplugco.com

  6. #6
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    Quote Originally Posted by Bobmws View Post
    GrafikFeat:
    Realoem lists 5mm longer lugs for one of the bikes so I should be good with retaining thread depth.
    The 195 tires list similar section widths also mounted on a 6.5 rim, but none of them are spec'ed top mount on a 5.5" rim.
    Ahh, I had not seen the longer bolt availability--that was one of my concerns with stacking additional spacers on the wheel.

    Quote Originally Posted by Bobmws View Post
    GTRider:
    I'm aware of the car tire adapter ($$$), I'l try this route first and will report back.
    What front tire are you running?
    The only thing I've found that gives any kind of reasonable life is the 120/70VB17 Metzeler ME880--the bias belted version. And at that, I'm only getting about 6k from a front tire. If you have found something better please speak up!

    I can't find a car tire in a usable size for the front and don't see a reasonable way to fit a car rim up front on the stock front end. "Unit", from overseas, is not interested in building a LL front end for the telelever brick K bikes either--at least that was their response last time I contacted them.

    Now, if one were to replace the front shock with a strut and remove the OEM fork tubes, then replace them with an appropriately size and properly constructed pair of leading-link fork legs.... well, you get the idea. But that's a project that will have to wait until after I retire and that's a bit down the road yet...

    Best,

    GTRider
    DGerber
    1983 R80ST -- 1988 K100RS (r.i.p.) -- 1995 R1100RSL (gone, never forgotten) -- 2004 K1200GT w/Hannigan S/C -- 2010 K1300GT

  7. #7
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    On my rig I also went with an adapter from Claude Stanley



    Used a 195/50 x 16 tire, on a Mini Cooper rim

    Over on the HSidecar forum there has been topics on car tires on bike rims

    http://hpsidecars.com/


    I don't have the exact #'s in front of me but besides the rim profiles being completely different, bead seat diameters are also different on car and motorcycle wheels. In the case of 17", the motorcycle rim diameter is significantly smaller than a car rim. So a car tire slips easily on to a motorcycle rim but it's wrong because the rim can move around on the bead seat. Basically the tire has to be over inflated to secure it to the rim but there is always the possibility of catastrophic failure.

    Wheel size 15" ________ 16"_________ 17"_________ 18"

    car rim dia 14.968"______15.968"______17.189"______18.189"


    mc rim dia 15.08"______15.978"______17.08"______18.08"

    I know lots of people do it, but I'd be careful.
    Mike Currin
    93 K1100RS / EML Speed 2000 sidecar
    89 Honda GB 500
    67 Triumph 650 Chopper

  8. #8
    Registered User grafikfeat's Avatar
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    Quote Originally Posted by michaelcurrin View Post
    ...I know lots of people do it, but I'd be careful.
    30k plus on a 50k tire on a 15" BMW rim.
    No worries... Even while flying the chair.

  9. #9
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    Quote Originally Posted by michaelcurrin View Post
    On my rig I also went with an adapter from Claude Stanley

    Do you remember how thick the adaptor is?

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