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  1. #1

    Default To stretch or not to stretch...

    That is the question.

    1980 GS850L with almost nothing untouched. I’m going for a certain look using some rake and a lot of lowering but since I’ll be cutting out the triple backbone and doing a proper hardtail, my question is, does it need to be stretched. I’d like to avoid it because the driveshaft then has to be lengthened but I’ll do it if it needs to be stretched for the right look.

    I think the bigger GS bikes are long enough as is but I don’t want to get too far before I realize it’s too short and looks dumb.

    With just lowering and some dismantling and handlebars I’m not actually gonna use, it looks like this:

    multi image uploader

    Any opinions? And I guess Uncle Sam is the look I’m going for:
    Last edited by GSBobber1980; 07-11-2019 at 9:05 PM.

  2. #2
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    you can't make apple pie out of lychee

  3. #3
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    I'd pull the cover off the driveshaft and lengthen it. Naked shafts in a real hardtail look way cooler than hack jobs with the swing arm still in place.
    Click image for larger version. 

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    Dusty

  4. #4

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    Quote Originally Posted by Natehate View Post
    you can't make apple pie out of lychee
    This’ll probably be a short thread but at least you’ll have the stupidest, most useless post in it.
    Last edited by GSBobber1980; 07-12-2019 at 7:00 AM.

  5. #5

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    Quote Originally Posted by DustyDave View Post
    I'd pull the cover off the driveshaft and lengthen it. Naked shafts in a real hardtail look way cooler than hack jobs with the swing arm still in place.
    Click image for larger version. 

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    Dusty
    I assumed the fact that I wrote I’ll be doing “a proper hardtail” was enough information to show the swingarm wasn’t being used, no?

  6. #6

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    Obviously I can’t force anyone to post with constructive advice but Im simply asking if my frame needs to be stretched to match the overal shape or silhouette of my inspiration, the Uncle Sam bike.

    In the pictures I posted of mine (in the early stages), even though they are not fully side-on shots, it appears to me that the wheelbase is long enough and with some added rake and some lengthening of the fork tubes, I’ll have the basic shape I want. I also believe the backbone, which again, will be a single backbone, is pointed in the same direction, that is to say, both bikes pictured have the backbone pointed to the same spot on the rear tire.

    Just asking for some else’s opinion with an eye for proportion. I know for a fact there’s smart guys here. Hopefully a few will post.

    Thanks in advance guys.
    Last edited by GSBobber1980; 07-12-2019 at 8:42 AM.

  7. #7
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    Observe the geometry of transverse four (not Harleys, they aren't transverse fours and will not correctly convey finished proportions in relation to YOUR engine!) which look like what you want then do likewise.

    There are plenty of pics of vintage Japanese choppers to study. You can also visit swap meets etc and directly measure wheelbase, stretch etc.

  8. #8

    Default

    Thank you.

    I certainly do understand the visual differences between the two engines. There are hundreds of transverse 4’s made into choppers especially CB’s. It’s just that almost all of them seem to be more radical than what I have planned.

    And I certainly understand that this will never be the 60’s Shovelhead that I want but I’m confident I can turn this (free and titled) bike into something cool.

  9. #9

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    This is probably a more accurate example of the basic overall proportions I’m looking for. Obviously this shares the basic engine architecture with my Suzuki:


  10. #10
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    to be honest fella, you would be better off getting a full hard tail frame, the dimensions length. rake, length you want from the get go,... you will be sorry in the long run with an altered factory frame plus the work you sound like you want to do front and rear will be as expensive as a whole new frame,..... another way if you plain don't want a full new frame would be to stretcg the front out a couple of inchesbut leave the rear without any stretch or extension

  11. #11

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    At the very least you'll need to drop the rear of your frame to give it the illusion of being longer than it actually is which also has the added benefit of changing your steering rake a little. However that could alter your drive shaft angle to the extent that your u-joint may wear prematurely... something a lot of people don't account for when lifting their trucks and wonder why they have such a high u-joint failure rate.

  12. #12

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    The cost wonít be much of an issue. What I mean is that Iíll use a universal hardtail kit and the welding will be basically free. The rake will be free and the lengthening of the forks will be from forks thatíll cost me roughly $150 plus a used spoked front wheel.

    Iíll take the rest into consideration though. Thank you guys.
    Last edited by GSBobber1980; 07-12-2019 at 3:23 PM.

  13. #13
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    Check out frame mods on this GS:
    Click image for larger version. 

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    Last edited by TriNortchopz; 07-12-2019 at 11:57 PM.

  14. #14

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    That’s pretty radical. It’s also inspirational due to it being both a shaft drive and a transverse 4. I’d love to know more about it if you have a link.

    I’m not planning on mounting the hardtail to the final drive section like this guy however.

    Thanks!
    Last edited by GSBobber1980; 07-13-2019 at 1:50 AM.

  15. #15
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    Click image for larger version. 

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    check the couple of links I just dropped in vwlord's gs thread...

  16. #16

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    Will do, thanks!

  17. #17
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    Frames and parts for CB750 and related H*ndas, as well as Kawasaki KZ series used to be common in late 70s and thru most of the 1980s. Jammer cycle products had some cool catalogs and some bikes featured. Same with other period suppliers. However very little for Suzukis, which is why you dont see a lot of pix or other examples. Its not that its not viable as a bike, its just you might as well accept it. But I bet you could find a old CB or KZ nicel chopped frame already setup with proper rake, trail and ride height and then figure out either convert to chain or how to deal with the shaft.

    I realize you want a raked and stretched ride, and thats possible, But to figure out how to do it right, it comes down to established engineering. Raked trees? Drop? Stretch? Trail? Get it wrong and it be either highly unpleasant to ride or down right lethal. There is many online tutorials on how to figure out proper rake and trail, But heres a good one to start.
    See: https://www.chopperhandbook.com/rake.htm

    High speed wobblies or tank slappers are no fun.

    My input is, either be a genius and extremely talented builder/fab guy to successfully rake and stretch a bike like that, In which case instead of asking here, you would instead be telling US how its done.
    -or B-
    Get the rake, trail,stretch etc and setup frame by buying a pro built aftermarket chop frame
    -or C-
    Run it as a hard tailed bobber with the stock rake and wheelbase Which is what I am suggesting here. Not that I am not in favor of raked out custom choppers, but being realistic, I think Option C is your best bet.

    Many variables can drive the decision on where you go from here. Both personal for you as well as finances/resources and what kind of riding you wish to do with it.

    A friend locally built this many years ago to illustrate ANYONE can build a cool scoot for not a lot of money. He did this for UNDER $1000 and tried to illustrate that anyone (Properly motivated) can build a nice ride. He leaves it up because its a big traffic generator to his website for his business. (Motorcycle shop and parts sales) But while I am at it, last I heard he was looking to sell the business. Yes, you too can live the life of fame and notoriety and be a motorcycle shop owner. (I told him when he started, Starting a shop is great way to ruin a perfectly good hobby)
    There was a page by page "How to" in building it. Might still find it somewhere or elsewhere on his site. But Econ 101, How to build a cool "Cheaper Chopper" See: http://cyclepsycho.com/yamachopper/cheaperchopper.html
    Last edited by Dougtheinternetannoyance123; 07-15-2019 at 5:31 PM.

  18. #18
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    Quote Originally Posted by GSBobber1980 View Post
    I assumed the fact that I wrote I’ll be doing “a proper hardtail” was enough information to show the swingarm wasn’t being used, no?
    Dam you're sensitive I thought I was agreeing with you.
    Dusty

  19. #19

    Default

    Quote Originally Posted by DustyDave View Post
    Dam you're sensitive I thought I was agreeing with you.
    Dusty
    Sensitive? I’d seen your post about the swingarm still being in place. It looked as if you thought that was my plan. Just clarifying is all.

  20. #20

    Default

    In response to Dougtheinternetannoyance123:

    Thank you for that post. That’s a great looking bike you posted. I think whatever rake I achieve will be a couple degrees you get when lowering the rear. And even that won’t be a true rake in relation to the frame. I’ve worked out using ‘82 XL500 forks which will give me some added length and use of a 21” spoked wheel.

    The more I look at the bike, I think stock length will be just right. I can use the swingarm to get the axle plates in the proper location and attach the upper hardtail members to them and the backbone at the same time. From there I’ll weld in the lower hardtail members after cutting away the rear factory frame along with the entire swingarm setup.

    I think meticulous measurements and a laser will help. Plus temporarily tacking the frame to my jig will help keep it square. After enough tacking, I’ll bring it to get MIG’ed by a professional and I’ll do the final assembly at home.

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