Frame Bracing.

[posplayr]

WTF what caused that ???

well it would seem what ever it was, that OSS E would brace the rear of the motor preventing it from back sliding.

Pos

 

[Dreef1999]

Seriously. Bracing for that front damage would be a waste.

I think that one qualifies as "User Error" and shouldn't be designed for.

 

[redsoxvw]

I agree, but just to clarify.... I bought the bike like that LOL, Knock on wood I havent hit nothing yet

Seriously. Bracing for that front damage would be a waste.

I think that one qualifies as "User Error" and shouldn't be designed for.

 

[tkent02]

I agree, but just to clarify.... I bought the bike like that LOL, Knock on wood I havent hit nothing yet

OK, "Buyer Error" then.

 

[Ausben]

Caused by.......

Caused by.......

is there anything that can be done to stop the front frame tubes from buckeling?

(thanks redsoxvw for the pic sorry about your frame)

I have seen this a few times and it seems like a common issue, not sure what causes it exactly hard landing wheelies? or front end impacts? or just hard front breaking? But should any bracing, reinforcing or gussets be considered to help keep these front tubes from bending?

This same thing happened to my gs after T-boning a car. The engineer straightening my frame said the suzukis quite often buckle here and he cant always get the buckle out. but the frame can be set straight again with a slight buckle remaining. BTW the Guy straightening my frame does it for a living and is well regarded by people in the motorcycle idustry in Australia (Q.)(Dave Kellet Slacks creek Brisbane.)

 

[posplayr]

Those front legs are interesting but if that is "crash damage" then this is not the topic.

Tone if you are still out there what do you recommend as far as precautions to prevent frame distortion during the bracing phase.

Salty, has suggested MIG/TIG (??) welding v.s. Oxy to reduce heat and potential distortion. Should an engine be kept in place to perform the welding or is a jig necessary?

Or just proper procedure by a skilled welder? I have a very skilled guy here locally willing to do the work. just wonder if I need t o have an engine mounted which would be a bit more of a paint than carrying a bare frame to him.

I'm thinking OSS C,D, and E braces.

Jim

 

[jwhelan65]

This same thing happened to my gs after T-boning a car. The engineer straightening my frame said the suzukis quite often buckle here and he cant always get the buckle out. but the frame can be set straight again with a slight buckle remaining. BTW the Guy straightening my frame does it for a living and is well regarded by people in the motorcycle idustry in Australia (Q.)(Dave Kellet Slacks creek Brisbane.)

The forks actually look a little bowed, looks like a front impact possibly in which case would be driver error not frame error.

 

[jwhelan65]

Whence i get back from my WV trip at the end of the month, I shall be prepping an 82 1100 frame for said brace work. Tone, you suggest C D and E being the MOST important and necessary additions. Any suggestion on exactly how to affix C, spacing and whatnot? You say boxed steel tube as the material? Any info would be helpfull. I am not doing the bracing, the young man that IS is an excellent welder, but this would be something he was doing without exactly understanding the WHY or WHAT necessarily. Would one want to use a jig in order to keep from tweaking the frame?

Josh,

Let me know what you do, I am getting ready to powder coat the 1100e frame, so it might be a good time to consider it.

 

[zathros]

I can't imagine the heat generated by that much Mig welding would be healthy. I have built a few recumbent trikes (3 wheel bicycles) and found that Mig welding definitely can "soften" metal way too much. I prefer Tig. It takes a lot longer but you can really control the heat better. The picture shown looks like an excellent weld job, but I would be worried about the long beads and stress cracks. The forum member "Tone" seems to have great knowledge on this and I wonder what he would recomend for welding like that. I myself have a Tig and MIg welder. The Mig is definately quick and dirty but the Tig really does better work. Also, I would hope that anyone doing this has a tubing notcher because if you try and fill gaps with weld you will end up with junk.

Also, what combination gas: i.e. argon etc. would one use? Is there crystallization on the inside of these tubes? Would they have to have argon flowing thru them? Just wondered.

 

[posplayr]

zathros

zathros

I might have mis quoted Salty, so my lack of knowledge is why I'm asking; but mainly about the requirement for a jig.

 

[tone]

Ok guys here goes i'll try to answer a few of the questions asked here & a couple that have popped up via pm at the same time i'll also pm folk seperately with more detail as required

Firstly the pic of the badly bent frame ...... imo thats from accident damage not from any particular weakness in the frame itself, from the pics i'd say it would not straighten simply by pulling it on a jig......again only my opinion but that would need the front tubes replacing as well as the headstock pulling (not as difficult as its sounds if you have the right kit)

Welding.... personally i use mig as thats what i have to hand & what i'm pretty good with, i would prefer to tig or bronze weld my frames if i'm honest but finances (& skill) dont allow that, i always drill an air hole in any new tube for gasses to escape

Distortion during welding...... as i said ive done quite a few frames over the years some i've done on my jig & some ive done on the floor of the shed, quite a few of those shed floor jobs have later been on the jig to be checked & none have been twisted out of alignment
The main reason for this is i always fit either a swingarm or an acurately measured piece of tube between the swingarm pivot points & bolt it up as if it was a swingarm, if you dont do this then fit brace D the frame wont squeeze in a little to the arm as it does on a stock bike & you have problems
I always like to fit some bolted together (but empty) bottom engine cases when doing any sort of frame work to help prevent twisting but as its not always possible a simple engine sized jig made from 1" box is as good & also helps to transfer any heat away from engine mounts etc you can also use heat sinks but ive never needed to on a simple bracing job
Another trick to help prevent distortion is to space or alternate your welds for example on the horizontal bottom part of brace D i would weld the back half of both ends of the tube first then let it cool before working on the other half (again at both ends) this means the heat generated thats is trying to bend the tube out of shape on one end is ofsett by the same amount of heat doing the same at the other end, you will be hopping from one side of the frame to the other admittedly but you wont be able to mig all the way around any of these tubes in 1 hit anyway so every little trick helps :lol:

Brace C the most important one imo ..... for this brace i tend to use a piece of either 2.5" or 3" x1" thin walled box erw (1.8mm wall thickness if memory serves me well) the shape gives it its strenth in the required plane ! fitting this one can be tricky as because of where the rearmost part of the stock tubes bend down they also bend out, this makes the brace angled slightly from the vertical, i advise cutting the brace & tack welding it on then test fitting the tank before fully welding it
Once happy i tack it securely in a good few places then carefully weld the inside by the do an inch leave an inch method on the inside before letting it cool then going back & doing the bits you've missed + the ends & letting it cool before welding the outside in one continuous run, again with this i would be working on both sides at once as mentioned above

I hope thats all of some use to you all
thanks tone

 

[zathros]

@Tone, If you lived in Connecticut I'd gladly let you use my Tig welder just for the learning experience (on my part). Using empty cases as heat sinks "quite right", and "brilliant" as you guys say. Thanks for a informative lesson. I use similar techniques in building recumbent bicycles and tadpole trikes for myself. Heat build up really can cause metal fatigue. I would advise anyone against using stainless steel tubing as it will crystallize inside unless the tubing is filled with an inert gas.

 

[tone]

Hey zathros if i lived in your part of the world i'd take you up on that offer mate as i really do need a lot more time with a tig the only problem i could see is getting me off it lol the bonus would be that you'd probably end up with a nice jig & a few highly modded frames

Thanks for the kind comments

 

[zathros]

I spent 2 and 1/2 months in Salford, outside of Manchester, U.K. in my youth. I have a soft spot for you Brits. I miss the Fish n' chips, and trifles. I do own a MG Midget (1973). I have a very small machine shop, just a milling machine, 9" back gear Southbend lathe and Mig and Tig welder. I have some very close friends and we share out expertise with eachother. I have a feeling you would fit right in. Cheers mate.

 

[tkent02]

Hey zathros if i lived in your part of the world i'd take you up on that offer mate as i really do need a lot more time with a tig the only problem i could see is getting me off it lol the bonus would be that you'd probably end up with a nice jig & a few highly modded frames

Thanks for the kind comments

We should all pitch in for an airline ticket, give you an old GS to get around the country on, and let you fix up all of our frames for us. I have three for you to do.

 

[Colorado85gs550]

We should all pitch in for an airline ticket, give you an old GS to get around the country on, and let you fix up all of our frames for us. I have three for you to do.

we could set him up with a mobile welder on a trailer that he can pull behind him with a swing-out bench, mounted saw, and tube bender....oh, and don't forget the small Honda 2000w generator to power everything!!!!

We just buy the tubing ahead of time and he rides and like Superman and saves the day

 

[justin caise]

Fashinaetin!
Very timely too - long weekend coming I was gonna finish up my 7/10 bracing but due to misinformation (or misunderstanding information) from a long ago post - I had it all wrong. Cept for the 1" thin wall material used.
Looks like I've got more work (play) ahead of me. And thousands of questions of course - oh here's one now.

I'd like to preserve the coil mounting location which is disturbed by the install of tubes at A (headstock brace) hows about using a triangular plate with the flat facing front instead of the two tubes? Just a thought. Of course that may be the cable tunnel I'm messing with... Sorry, tired and far from the shop.

And I swear this is absolutely the last thread I'm going to subscribe to. Really, I swear it.
JC

 

[tone]

Hi JC
As i've said i rarely fit the headstock bracing (A) on these frames as i'm not convinced its needed & can decern no diferance in the frames stiffness by doing it, if i'm forced i fit brace B alone (Z900 & Z1000 kwacks are a different story :lol: )

Having said that i do see the problem & agree a nicely shaped steel plate would do the job just as well in terms of stiffness (if you really think you need it) the problem with steel plate in this area is that you will need to cut some of it away for routing cables etc through & it may be in the way of the front tank mounts

Hope this helps
tone

 

[jed.only]

what if i wanted to remove the entire rear section of the frame, leaving only the headstock and engine hoop? i want to build a custom subframe, a bolt-on one. i plan to chop the rear section off and weld half-tube pieces over the holes. then, weld tabs about 3" long longitudinal to the vertical portions of the engine hoop and have holes for bolting up a subframe im building.


the reason why i ask, is that Tone suggests brace "D" is one of the most important. i agree with E and C, but in my head, i wont have anything to run "D" to.

keep in mind, this is only a street bike, no track and no super aggressive riding.

 

[posplayr]

JED,
I added some freebody diagrams here; maybe this would help answer your question

http://www.thegsresources.com/_forum/showpost.php?p=1013240&postcount=4

Pos