Wheel Size Question?

Discussion in 'Hacks' started by MMMOTORCYCLE, Feb 11, 2009.

  1. MMMOTORCYCLE

    MMMOTORCYCLE Been here awhile

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    I have been drooling over the new Ural Sahara as I am rebuilding my R75/5 and noticed the ural's have 19" wheels all around. My R75/5 has three different wheels and was wondering what effect that may have on my rig? Bike front 19", rear 18" and hack 16". Sidecar is a Velorex 562 by the way....Dauntless sub-frame in the very near future.

    Also, anyone fit a Ural Leading Link on an R75/5?

    Mike
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  2. Uncle Ernie

    Uncle Ernie Long timer

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    Don't know about Ural Earles, but if the whole rig is set up right, i can't imagine the different wheel sizes will matter. There is one size that's hard to get in a sidecar tire, though. I think it's a 3.50 x 19 that's hard to get hold of.
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  3. claude

    claude Sidecar Jockey

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    No real big deal with different wheel sizes as far as handling goes.
    Tires with flat tread, if you want them, are avaible in 4.00x 18 (Metzler Block K) and 3.50x 19 (Avon triple duty ).
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  4. MMMOTORCYCLE

    MMMOTORCYCLE Been here awhile

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    I assumed Ural used 19" all around for simplicity purposes and they are all interchangeable.

    You bring up a good question about tires. I am having a hard time finding same make/model in all three sizes to fit my project. The 19" front seems to be the problem. I have been focused on dual sport tires and that may be what's limiting me. Can I run a 19" rear tire on the front without problems? What actually makes a rear tire a "rear tire"??

    Thanks for the input.

    Mike
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  5. Richard-NL

    Richard-NL Sidecar Fan

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    And for 16 " rims (Velorex, MZ etc) there’s the Heidenau 3.50 x 16 SW (Seitenwagen)

    [​IMG]

    Richard-NL :bmwrider
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  6. claude

    claude Sidecar Jockey

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    [​IMG]
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  7. Uncle Ernie

    Uncle Ernie Long timer

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    Claude, I was wrong- I have 18 inch wheels. Mine are OK, but do you have a recommendation for a 3.50 x 18? That's the one I had a devil of a time finding last time. I ended up finding a Russian tire.

    Also, since we're on tires; How old is too old?
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  8. claude

    claude Sidecar Jockey

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    Uncle Ern,
    I think the block k (4.00 x 18) will work but it will be tight. There is more than a couple of older airheads running them. Dunno if they had to do anything to get clearance though. Worth a shot?
    If it doesn't fit call me and I'll buy it off you if you pay the shipping. Not a huge loss.
    No flat tread 3.50 x 18s around that I know of.
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  9. RedMenace

    RedMenace Adventure Sidecar

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    The Kenda K270 is pretty darn close to a flat tread and I believe comes in that size
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  10. Uncle Ernie

    Uncle Ernie Long timer

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    I'll be- I guess I lucked out finding this Russian rubber. Wish I could remember where I found it. It doesn't hold air long, but it sure has lasted.
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  11. MMMOTORCYCLE

    MMMOTORCYCLE Been here awhile

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    OK-last question and I'll shut up....

    I thought I had this tire thing figured out until I ran across a sizing chart in a Dennis Kirk catalog. They show different size tires for 2 rim sizes...

    SOOOO, I need some input on my tire choices

    BMW front wheel is a 19" 1.85 rim currently running 3.25-19. 3.25" x 25.4mm=82.55mm.

    I found a Kenda K760 Trak Master II in 70/100M-19 and 100/90M-19. So my question is which one? The 70/100 is for a 1.85 rim but will the 70mm wide be too small for the beemer? The 100/90-19 is for a 2.15 rim, will it fit a 1.85 rim?

    Rear wheel is a 18" rim running 4.00-18. 4"x25.4mm=101.6mm. Looking at 100/100-18, but it's for a 2.5 rim?? Will that fit a 1.85 rim?

    Velorex 562 is running a 3.25-16. No clue on the rim side...will a 60/100-16 for a 1.85 rim work or too skinny?

    Thanks in advance for your wisdom:D

    Mike

    UPDATE:
    I decided to try the IRC GP-1's for the bike (2.75-19 front, 3.00-18 rear) and a ChengShin C858 3.00-16 for the hack.
    #11