G/S rear wheel clearance to swingarm??

Discussion in 'Airheads' started by One Less Harley, Apr 2, 2013.

  1. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    I had recently installed a Mefo Explorer 120-90x18 and had issues with the tire rubbing on the swing arm, just a small amount hardly noticeable spinning the wheel. Ian mentioned he runs a Mefo 130-90x18 with no problems. I assume my rear wheel is stock, it the Akront rim. But what I'd like to know is what some other G/S have for clearance from the outer edge of the rim to the swing arm. Ths is the widest portion of the rim. I can just fit an 8mm deep well craftsman socket between the rim and swing arm. this measures 11.14mm.

    So if any of you Old Schoolers would be so kind to get me some measurements...:ear
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  2. Airhead Wrangler

    Airhead Wrangler Long timer

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    Earlier G/Ss have a 2.15x18 rim which will squeeze a tire a little bit narrower. I believe '83 and later have a 2.5x18 rim. Take your wheel to any wheel guy and they should be able to dish it out to the left just enough to give you some breathing room without having to use different spokes. I've fit a 120-90-18 Mefo Explorer on without any rubbing.
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  3. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    It's a 1984 G/S. 2.5" rim, if putting a straight edge on the outer rim on the left side of the rim there is about 1/4 inch space between the straight edge and brake drum.

    If dishing a wheel off to one side will it cause the bike to ride differently, like pulling or in this case pushing to one side???
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  4. Airhead Wrangler

    Airhead Wrangler Long timer

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    The answer would have to be yes, but judging by how wonky a G/S handles as-is with the torque reaction of a longitudinal crank, the "shaft jacking" reaction, and a really flexy frame, I doubt you'd notice anything at all if you just dished 5mm or so out to the left.

    Here's a photo that Roadsacallin took for me to show the amount of dish on his rear wheel which he runs 140s on. He's got an HPN swingarm though, so that buys him a little bit of clearance. He used an Excel 2.5"x18 rim, so it might not look exactly the same with an Akront.

    [​IMG]
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  5. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    Thanks for the photo AW- the rear tire is already out of line with the center of the frame anyway, at least the rear fender as a reference. I'll see where mine lines up.
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  6. Airhead Wrangler

    Airhead Wrangler Long timer

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    I'm pretty sure all airheads' wheel centerlines are offset by 1-1.5 cm or thereabouts from the factory. I'm sure someone will chime in with the exact amount for each different swingarm / final drive combo.
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  7. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    I just checked mine like your photo AW, the straight edge is just inside the lip inder 1/8". That much ofset would give me clearance to fun the 120-90x18 Mefo. My extra rim has the same offset. I'm sure Woody could offer good advise on a change in offset. I just can't afford to even do that right now:cry
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  8. Airhead Wrangler

    Airhead Wrangler Long timer

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    Any wheel builder should be able to do it for you for less than $100. If your spokes and nipples are in decent enough shape and not seized up, it should be a breeze for someone who knows what they're doing.
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  9. bgoodsoil

    bgoodsoil Dare to be Stupid

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    Ah the things we'll buy after graduation....:D
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  10. Spark Plug

    Spark Plug Low on compression

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    If you have a spoke wrench, you can loosen the right side spokes 1 turn and then tighten the left side 1 turn until you get your clearance.

    As long as you make sure you tighten/loosen equal amounts you should be fine. Let the air out of the tube before you start.

    If it makes it easier, put a dot on each spoke with a sharpie facing out. Start at the valve stem and work your way around.
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  11. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    well that's one way to do it. I'm pretty good truing up bicycle rims, never built a wheel though. Could temporarily build a truing stand using the Marc Parn's wheel balancer....The spokes are pretty old so loosening/ tightening could be an issue.

    $100 to balance and shipping both ways...$$$$ I shouldn't spend right now. No one here in BG KY I'd trust. Of course I could learn, just get a spoke torque wrench. Oh well i can put the Mefo back until a later date. Got a K60 110-80x18 on it now. I like the tread of the mefo seems like it should grip a little better than the heidenua. K60's have been my 1st choice thus far, about $200 for the set. Just hard to get the rear.
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  12. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    anyone care to get me that clearance measurement??? I'm still curious.
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  13. Spark Plug

    Spark Plug Low on compression

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    I just went out and a quick measurement showed 12.5mm
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  14. Spark Plug

    Spark Plug Low on compression

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    I'm putting on a set of 606's this weekend, 120 rear. I'll let you know how it goes.
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  15. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    well that 1.5 mm more than mine and that would have been enough to fit the Mefo 120-90x18, still might rub under low pressures though.

    Thanks
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  16. ontic

    ontic

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    Bugger of a spot to measure with the tyre on.
    I squeezed the end of an old set of calipers in between the narrowest point of rim to swing arm and this end of the caliper measured 15.65mm. Lets call it 15.5mm for an easy fit.
    However mine is a 81 year with the older 2.15 Weinmann rim (same as my new spare wheel).

    at .35" narrower than the 3.5" rim, that is almost 9mm narrower- a bit less than 4.5mm for for each side, 11mm to 15.5mm seems about right if they have aimed to centre the rims to the same point.
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  17. hardwaregrrl

    hardwaregrrl ignore list

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    Yep, I'm with Hans. my 606s arent' even close to rubbing. Sorry Richard, hope you get it sorted.
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  18. desmo

    desmo Been here awhile

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    On later models some people use this 2mm shim from a K Bike. :wink:
    36 31 1 451 791 SHIM - 2,000MM $20.51
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  19. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    yeah it's a very difficult spot, that's why I used a socket as a gauge..then measured it's OD, works pretty easy.
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  20. Ras Thurlo

    Ras Thurlo Desert Lion

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    on the earlier 2.15 wheels are the hubs identical to the later 2.50s?

    had bought some unloved 2.15 wheels on fleabay for the hubs on the assumption that they did not change- but worth checking before getting some excel rims
    #20