Author Topic: 500F Seat hoop  (Read 418 times)

Offline apacheav8tor

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500F Seat hoop
« on: July 24, 2017, 08:29:49 PM »
Ok, how in the heck do you make a seat hoop for a square frame?  Chopped the rear and that is as far as I've gotten. Any help would be great.

Offline JohnnyB

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Something happens at around 92 miles an hour - thunder-headers drown out all sound, engine vibrations travels at a heart's rate, field of vision funnels into the immediate and suddenly you're not on the road, you're in it.

Offline apacheav8tor

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Re: 500F Seat hoop
« Reply #2 on: July 26, 2017, 01:51:33 PM »
I've found many on Ebay but the 500F has square tubing.  How do you fit a round loop onto the square tubing and make it look right?

Offline JohnnyB

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Re: 500F Seat hoop
« Reply #3 on: July 26, 2017, 03:13:33 PM »
My english vocabulary is not so good so it's dificult for me to explain.....
But, post some picture of where you cut the frame and maybe i'll manage to help you, or someone else  :cheers:
Something happens at around 92 miles an hour - thunder-headers drown out all sound, engine vibrations travels at a heart's rate, field of vision funnels into the immediate and suddenly you're not on the road, you're in it.

Offline apacheav8tor

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Re: 500F Seat hoop
« Reply #4 on: July 26, 2017, 06:24:26 PM »
Johnny, thanks for the help.  I ordered one off of ebay.  It is 7/8 round and mine is 3/4 square.  I will fabricate something.  Any ideas?  Sorry having issues with pics. 

Offline moto

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Re: 500F Seat hoop
« Reply #5 on: July 27, 2017, 02:24:26 PM »
I would suggest either bend some box section steel, or have the top and bottom profiles laser cut and make your own box section hoop  8)

Rolling and bending box section is a challenge, it tends to fold up on itself, ive had it on good advice that you can pack the box section full of sand, weld ends on it and then roll it to help it keep its profile, although i haven't tried that!

I went down the route of cutting the back end off and fabbing an completely new subframe.


Offline The Buddha

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Re: 500F Seat hoop
« Reply #6 on: July 28, 2017, 01:15:15 AM »
Its always going to look cobbled together. In fact that's the whole idea.
You remove the airbox, and it looks like it was hammered together in someone's backyard. Probably while they were hammered.
You might as well put decals on it saying "I was so drunk one day man ....... and the bike turned out great"

So square tube ? round tube ? just make it a rube.

Cool.
Buddha.
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Offline Biga800

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Re: 500F Seat hoop
« Reply #7 on: August 10, 2017, 10:49:23 AM »
I know a little late to this thread ! but hope the input can help someone else down the track, when I went to do mine I went to a local shop here that specialises in rolling and bending tube/frame - long story short they filled the square with sand to make sure it didn't collapse and then put it through a series of vertical rollers which progressively bent the tube around, there are a few clips online of people using presses and rollers homejobbed together and then they run the tube back and worth slowly pressing harder until it is 'rolled' round -

Best recommendation - find a local bending shop, a good machine place should be able to recommend someone and it shouldn't be that expensive, the problem is finding someone who can roll it so small and tight, on my build I had the same issue and the local shop couldn't get the curve tight enough so had to cut and shut it anyway :S

ahhh the 'Fun' of DIY projects ...  :-X :-X

Offline gregjet

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Re: 500F Seat hoop
« Reply #8 on: August 31, 2017, 09:14:35 PM »
You could try turning a square crossection bar that fits inside the square frame and turn the other end down to make a plug to fit inside the round hoop ends. Taper it between the square and the round. Braze or weld it on. Should look ok