With my Avon finally getting down to the wear marks, it was time to put that pile of parts together and accommodate the new PR4GT.
I am 'amping up' to do the conversion, possibly over winter or at least by next season. Once you had the parts all gathered, how long of a job was that, please?
Great looking bike.
I also want to do the conversion over winter.
Quote from: Charlie-brm on October 11, 2019, 11:30:33 AM
I am 'amping up' to do the conversion, possibly over winter or at least by next season. Once you had the parts all gathered, how long of a job was that, please?
If you are talking pure assembly of all the wheel parts, ready to go, maybe 20 min.
In my case, this was all done kinda piecemeal. The wheel assembly was acquired 5-6 years ago. The Caliper and wheel needed rebuild and refurbish. Needed a custom brake line (obcessed about the length). Painted the wheel twice because I didn't like graphite. Obcessed about tire clearance (180/55 17 is a non issue). Had the tire mounted at the local bike shop. Obsessed about how long a bolt I needed to replace the lower foot peg bolt for the torque arm mount. Completely pulled out the swingarm and shock to lube everything (never done it before... to anything). Then a bunch of little OCD stuff to boot. Had fun though.
GSXR wheel?
Have you read Ron Oort's post about shearing off the torque arm bolt?
I like the color of your wheel. Something similar to what will eventually happen to mine.
Joe
Quote from: Tuned forks on October 11, 2019, 11:09:17 PM
GSXR wheel?
Have you read Ron Oort's post about shearing off the torque arm bolt?
I like the color of your wheel. Something similar to what will eventually happen to mine.
Yes, a 91 1100. Will have to look that up. Not too worried. I used the stock zuk bolt for the caliper and a hardened one for the forward mount. Can't imagine the failure is the norm, rather than an exception.
Joe
A post from roortcloud in the West Coast Rally thread. I think he may have started his own thread with pics too. Don't remember.
WARNING!!
To anyone who replaced the right foot peg mount bolt with a longer one and attached the rear brake torque arm to it.
Mine just failed going home from the WCR. Sheared off at
the frame and spun the caliper around the axle.
Luckily it happened at very slow speed at a freeway exit stop sign.
The bolt I used was a grade 8 socket head cap screw that I obviously thought would hold up.
Anyone with this modification beware!!!
Ron Oort
Joe
Quote from: Tuned forks on October 12, 2019, 11:36:01 AM
A post from roortcloud in the West Coast Rally thread. I think he may have started his own thread with pics too. Don't remember.
WARNING!!
To anyone who replaced the right foot peg mount bolt with a longer one and attached the rear brake torque arm to it.
Mine just failed going home from the WCR. Sheared off at
the frame and spun the caliper around the axle.
Luckily it happened at very slow speed at a freeway exit stop sign.
The bolt I used was a grade 8 socket head cap screw that I obviously thought would hold up.
Anyone with this modification beware!!!
Ron Oort
Joe
Well of course this would come to light right as I finish the mod. I mean, I just paid off a cc so my Jeep transmission could need a rebuild 3 weeks later. Life. Live it.
It's gotta be a fluke. Otherwise, why wouldn't either the original aluminum swingarm mount bracket or a new welded one not crack before shearing a steel bolt? Seems a little counter-intuitive, at least, when looking at the meat of the old mount point.
Every time you hit a bump with your setup, the torque arm is trying to move the caliper to compensate for the changed geometry of what is now a triangle with one fixed point (the footpeg mount). Caliper's not going to move without a fight so there's loading on the bolt and sooner or later the bolt's going to lose the battle.
Quote from: woodcreekpete on October 12, 2019, 02:54:58 PM
Every time you hit a bump with your setup, the torque arm is trying to move the caliper to compensate for the changed geometry of what is now a triangle with one fixed point (the footpeg mount). Caliper's not going to move without a fight so there's loading on the bolt and sooner or later the bolt's going to lose the battle.
This is 100% correct.
Please, for safety sake, do not mount the Torque arm to the footpeg mount.
It must be mounted to the Swingarm.
I'm pretty sure the torque arm isn't mounted on the swing arm on the early gsxr's, like on the FJ it looks too long to mount there, the torque arm I have is about two foot long. The whole setup is designed to move when riding, the caliper is free to move on the axle when the wheel is tight, there's a bush on the end of the caliper where the torque arm mounts to it so it's free to move up and down, plus there's a rose mounted bush on the other end of the arm where it mounts to the foot peg bolt that allows up, down and sideways movement there. I think the problem is the foot peg bolt is only supported one side and the stresses on the bolt can bend or sheer it off. If the arm was mounted between two tabs on the frame then the bolt would be supported both sides of the torque arm and be a lot stronger.
An FJ owner in England came up with the idea of fitting a caliper off a Gsx600f, this caliper sits upright like the FJ and the torque arm mount is to the front so gets mounted to the original tab on the swingarm, just have to make a torque arm to suit, or possibly modify the standard arm to fit.
:Facepalm:
Is this happening on all the gsxr mods that linked to footpeg and have put on thousands of miles since? Because the only aluminum welder I knew just died three months ago.
Got an idea. I am nowhere near the bike right now, but I wonder if I could install a long bolt on the top peg mount too and bracket the two bolts together. It should increase overall strength if there are no clearance issues. Will update later in the week.
It should not be too hard to find a machine shop which can manufacture a new torque arm in the shape of a "Z".
That way, the original mount on the swingarm can be used.
The torque arm can be strengthened with some gussets if required.
If you desire to place a mount on the bottom of the swingarm, I would prefer a clamp type mount as opposed to welding a tab on.
I am in the fortunate position of being able to manufacture my own mounts.
(http://fjowners.com/gallery/11/6034_12_10_19_6_21_37.jpeg)
(http://fjowners.com/gallery/11/6034_12_10_19_6_18_05.jpeg)
Gavin
I read that about the GSX600F caliper mount as well Tony, thinking I may still look into that for the '93, as I myself am not totally happy with the footpeg bolt arrangement we have for the torque arm presently. Before the '93 makes the trip to Dartmouth in March, I will hopefully have something different in place.
Gavin, that custom made caliper bracket looks great, from the look of your photo you have welded that onto the swingarm?
All this makes me happy I opted for the 5" x 17" Thundercat wheel swap option - used the original caliper and torque arm - only needed to machine 8mm off the caliper mount bracket to get the wheel aligned.......verrrry simple !!
Hi yeah that was Me that used the rear caliper from a 88 GSX600F , I used it because the bolt that went thru the footrest that held the underslung gsxr caliper torque arm kept breaking ,the last time was when I was at a bike rally and had to use some wire to hold the torque arm in place , and rode home on the sunday after the rally only using the front brakes, it was 120miles from home so I took it easy , anyhoo I used the underslung caliper mount spun round so it was @ the top and sourced a gsx600f caliper and bolted it onto the mount I used a rose jointed arm that I had lying about that jus needed a few turns on the eyes to line up with the FJ caliper mounts which are on the swing arm,Ive done about 3000 miles since fitting the caliper and have had no issues at all,I was so paranoid about the bolt snapping again that at one point I was gonna refit the fj caliper and 16'' wheel back on it was getting no fun riding the bike and wondering if the nxt time I braked the bolt would snap and lock up the wheel or worse ..glad I didnt and fitted the gsx600f caliper n kept the 17'' rear wheel..things is now Ive been thinking of fitting a thunderace rear wheel and caliper :Facepalm:
Quote from: X-Ray on October 13, 2019, 06:15:34 AM
Gavin, that custom made caliper bracket looks great, from the look of your photo you have welded that onto the swingarm?
The mount is manufactured from 6061T6 Aluminium. It is held in by the axle. No Welding. The lip shown in the top photo sits on the top of the swingarm and stops the caliper from rotating.
This caliper is from an XJR1300 and it is fantastic.
If possible, could someone post a photo of the GSXR caliper and mount by themselves.
There must be an easy solution to the mounting problems.
Quote from: scotiafj on October 13, 2019, 04:57:39 PM
Hi yeah that was Me that used the rear caliper from a 88 GSX600F , I used it because the bolt that went thru the footrest that held the underslung gsxr caliper torque arm kept breaking ,the last time was when I was at a bike rally and had to use some wire to hold the torque arm in place , and rode home on the sunday after the rally only using the front brakes, it was 120miles from home so I took it easy , anyhoo I used the underslung caliper mount spun round so it was @ the top and sourced a gsx600f caliper and bolted it onto the mount I used a rose jointed arm that I had lying about that jus needed a few turns on the eyes to line up with the FJ caliper mounts which are on the swing arm,Ive done about 3000 miles since fitting the caliper and have had no issues at all,I was so paranoid about the bolt snapping again that at one point I was gonna refit the fj caliper and 16'' wheel back on it was getting no fun riding the bike and wondering if the nxt time I braked the bolt would snap and lock up the wheel or worse ..glad I didnt and fitted the gsx600f caliper n kept the 17'' rear wheel..things is now Ive been thinking of fitting a thunderace rear wheel and caliper :Facepalm:
Were any of these broken bolts a 12.9 class?
Here is what I did on my GSXR rear swap. I made a simple bracket out of stainless steel. I got all the bits assembled on the bike to see the correct position to mount the bracket and marked the positions. Then drilled the 2 holes and used riv-nuts. Many thousands of miles with no issues.
(http://fjowners.com/gallery/8/medium_104_05_04_15_6_45_21_0.jpeg)
(http://fjowners.com/gallery/8/medium_104_05_04_15_6_45_24_1.jpeg)
(http://fjowners.com/gallery/8/medium_104_26_03_15_3_56_43_4.jpeg)
Out of curiosity Monkey, are those unhardened stainless steel allen head bolts? I've experienced a lot of soft SS hardware. Did you also use Loctite or anti-seize?
Joe
Quote from: MACHV on October 13, 2019, 09:51:02 PM
Quote from: scotiafj on October 13, 2019, 04:57:39 PM
Hi yeah that was Me that used the rear caliper from a 88 GSX600F , I used it because the bolt that went thru the footrest that held the underslung gsxr caliper torque arm kept breaking ,the last time was when I was at a bike rally and had to use some wire to hold the torque arm in place , and rode home on the sunday after the rally only using the front brakes, it was 120miles from home so I took it easy , anyhoo I used the underslung caliper mount spun round so it was @ the top and sourced a gsx600f caliper and bolted it onto the mount I used a rose jointed arm that I had lying about that jus needed a few turns on the eyes to line up with the FJ caliper mounts which are on the swing arm,Ive done about 3000 miles since fitting the caliper and have had no issues at all,I was so paranoid about the bolt snapping again that at one point I was gonna refit the fj caliper and 16'' wheel back on it was getting no fun riding the bike and wondering if the nxt time I braked the bolt would snap and lock up the wheel or worse ..glad I didnt and fitted the gsx600f caliper n kept the 17'' rear wheel..things is now Ive been thinking of fitting a thunderace rear wheel and caliper :Facepalm:
Were any of these broken bolts a 12.9 class?
Yes they were 12.9
I just ordered an '88 GSX600F rear caliper from ebay to try on the '93. If it mounts up ok and gives some more feel/bite than the weak GSRX caliper currently fitted, it will be a win. :good2:
Quote from: FJmonkey on October 13, 2019, 10:53:37 PM
Here is what I did on my GSXR rear swap. I made a simple bracket out of stainless steel. I got all the bits assembled on the bike to see the correct position to mount the bracket and marked the positions. Then drilled the 2 holes and used riv-nuts. Many thousands of miles with no issues.
(http://fjowners.com/gallery/8/medium_104_05_04_15_6_45_21_0.jpeg)
(http://fjowners.com/gallery/8/medium_104_05_04_15_6_45_24_1.jpeg)
(http://fjowners.com/gallery/8/medium_104_26_03_15_3_56_43_4.jpeg)
Excellent solution. I just wrestled this whole thing back together though. I need some serious mental downtime before I pull it all back apart to do this though.
Quote from: Tuned forks on October 13, 2019, 11:38:44 PM
Out of curiosity Monkey, are those unhardened stainless steel allen head bolts? I've experienced a lot of soft SS hardware. Did you also use Loctite or anti-seize?
Joe
Joe, I did not get any special hardness so I really don't know. The bolts are in shear and will have way more strength that the torque arm can put on it. I did use a medium strength thread lock.
Quote from: FJmonkey on October 13, 2019, 10:53:37 PM
Here is what I did on my GSXR rear swap. I made a simple bracket out of stainless steel. I got all the bits assembled on the bike to see the correct position to mount the bracket and marked the positions. Then drilled the 2 holes and used riv-nuts. Many thousands of miles with no issues.
(http://fjowners.com/gallery/8/medium_104_05_04_15_6_45_21_0.jpeg)
Did you drill those holes in the bottom of the swingarm, in the horizontal element on the bottom?
Got any photos of how it looks now, after the many thousands of miles?
I notice that the stock swingarm has all the fiddly little bits welded onto the outside of the swingarm extrusion. The only exception I can find is the factory bracket on top of the RH side, which is held in by a small screw threaded into the top about halfway between the rear axle and the lower shock mount. Being on top, this screw is under compression radially; the force of the bike's weight on the rear wheel is trying to bend the swingarm up in back, which tries to smoosh the front and back of that bolt's threads together toward each other. You can do this on things that are in compression, because the aluminum from the swingarm would press in toward the center of the bolt and try to squish the bolt. If this screw were on the bottom, this hole would be in tension, and holes make your stuff weaker in tension even if you fill them with other stuff.
What worries me a bit about your assembly is that you have drilled holes into the aluminum on the bottom, where it is under tension. Drilled holes filled with hardware are okay under compression, but they are not okay under tension; you have effectively reduced the cross section of that horizontal bit by the width of your hole. A 1" wide section of flat-stock under tension with a 1/4" wide hole drilled in it will basically be a 3/4" wide section of flat-stock under tension.
Not only have you done that, but it looks like have drilled two holes offset from each other. If you have a 1" section of flat stock in tension and you drill a pair of 1/4" holes, you really don't want them offset from each other, you want them lined up so that they both only effect the same 1/4" of width; if you offset them so they don't overlap at all along the axis of the stress, you effectively turn your 1" section of flat stock into a 1/2" section of flat stock.
And also, you have drilled those holes in the front part of the swingarm, between the frame mount and the lower shock mount, which is the more-heavily-loaded section of a swingarm on a bike with a monoshock setup like the FJ's. This would be hardly a problem at all on a traditional two-shock suspension, where the shock bottoms mount near the axle, but it is a much bigger deal on a swingarm like the FJ's where the shock mounts between the swingarm pivot and the axle. (Since the distance from the lower shock mount to the swingarm pivot is about 1/3 as far as the distance from the lower shock mount to the axle, the part where your holes are is under about 3 times the stress that they'd be on the back part of the swingarm.)
So what all this means is that you have made your bottom horizontal member of your swingarm effectively smaller in cross-section, by the widths of your holes, in the exact part of your swingarm that should be the most effective at keeping it from bending, in the front part of your swingarm that is subject to the highest bending forces. You have basically turned your box-section swingarm into a c-channel-section swingarm, with the open end of the "c" facing down.
I mean, it *could* be fine. But you will definitely want to inspect it visually periodically. You will be looking for evidence that those holes are becoming elongated, or that the sides of the swingarm are buckling.
(http://fjowners.com/gallery/11/7_14_10_19_6_08_08.jpeg)
And if I were you, I would think about sourcing another swingarm (like $45 on ebay?) and taking another pass at your design, maybe either welding a torque arm bracket onto the bottom, or fabbing a completely separate bracket that clamps on around the box swingarm assembly, rather than drilling holes in the part where holes are the most disruptive.
Because you do NOT want to make holes in the bottom of a box-section swingarm. You want the top and bottom elements of a box-section swingarm to be intact, where they can resist the bending load by being in compression and tension respectively. If HAVE to make holes in an assembly like that, you want to make them as close as possible to the center of bending moment. It's like how you want to drill a hole through the center of a floor joist rather than notch the bottom. (If you drill a 1" hole in the center of a 2x8, it's basically just as strong. If you cut an inch out of the bottom, you have basically made a 2x7.)
___
| |
| |
| |<- you really want to make holes here
| |
|__|<- and not here.
Meanwhile, definitely check it often.
Too late to edit:
___
| |
| |
| |<- you really want to make holes here
| |
|__|<- and not here
^
and DEFINITELY
not here.
Quote from: Bill_Rockoff on October 14, 2019, 07:05:33 PM
.........I notice that the stock swingarm has all the fiddly little bits welded onto the outside of the swingarm extrusion.....
Bill, you understand the forces at play and I agree with every single thing you said - technically!
However, in practice I doubt the holes would compromise the integrity of the arm in operation. Having said that though, I would be reluctant to do it for other reasons.
I would have a greater concern about the rivnuts in aluminium, I would worry the holes would elongate over time, a process that would speed up exponentially as the play increased. It is the sort of thing I might do on my own bike and monitor but not on someone else's.
I would also want a thicker bracket to minimise the shearing risk by spreading the load over more over more of the bolt, especially the one the arm attaches to.
But hey, Mark may just be a better engineer than both of us. If his shows no sign of wear in the above mentioned areas, it's doing all it needs to do.
If someone were to ask my advice on this topic I would simply say "just weld a tab where it needs to go on the arm and move on to the next job, there's nothing to think about". If your skills or enthusiasm only run to finding some other bolt hole somewhere because it's easy, maybe you shouldn't be friggin' around with your brakes.
Someone in this thread suggested welding was no longer an option as the only welder he knew recently died - find another one, they're hardly rare.
Noel
Quote from: ribbertI doubt the holes would compromise the integrity of the arm in operation.
Those holes are on the bottom of the swingarm. When the swingarm is loaded by a rear wheel holding the bike up plus the shock mount pressing down in the middle, the bottom of the swingarm is in tension. A piece that is in tension is acting like a bunch of strings being pulled tight. Drilling a hole in that part is like cutting some of the strings. All the other "strings" have to take up the load. Putting something like a bolt back in the middle is like putting a bolt back in between the cut ends of your strings - it doesn't help at all.
So your doubt is completely unfounded.
Drilling holes in a part that's in tension absolutely would compromise its integrity. Drilling the holes in the top (like the factory hydraulic hose bracket mounting screw) would have been better, because the top of the swingarm is in compression. Material in compression doesn't act like strings, it acts like a bunch of blocks pressed together. You can drill out some of the aluminum in the middle and replace it with a threaded bolt, and it would be fine in compression. So, one more reason why mounting the caliper on top might be a better solution - you would have the caliper's torque arm on top in compression, mounted to the top of the swingarm in that is also in compression. (Now, if you just drilled a hole and didn't thread a bolt in there, it *would* be weaker in compression.)
Quote from: ribbertI would also want a thicker bracket to minimise the shearing risk by spreading the load over more over more of the bolt, especially the one the arm attaches to.
I think the shear force occurs at the interface between the two parts, which is not affected by their thicknesses. The bolt is the strongest of the materials there; I don't think his mounting plate is going to scythe through the bolt and sever it. And I don't think the shear stress is affected by the thickness of the two elements applying the shear.
Then again, I took that class 35 years ago and I think I got a "C" in it.
Also, as long as it's bolted correctly, there shouldn't be any movement or elongation from forces applied from the torque arm mounting plate. The bolts clamp the plate to the swingarm, and your force is ideally resolved in the friction between the plate and the swingarm which keeps the two parts from moving relative to one another. You aren't depending on the bolt's resistance to shear to prevent movement, you are depending on friction between the two parts. The bolt should be in tension. Otherwise, you're not bolting it tight enough.
Quote from: ribbertBut hey, Mark may just be a better engineer than both of us.
It's pretty likely that both of you earned better grades in engineering school than I did. Also, my area of practice is not structural. But most of my observations here are based not so much on my expertise, as on the idea that "the people who had the expertise(*) aren't doing it that way, there are probably reasons for that." Kind of like how, structurally, "open-web steel joists" are a thing, but "serrated-edge beams" are absolutely not a thing, because cutting the tops and bottoms will make it weaker in bending.
(*)There's nothing wrong with reevaluating someone's expertise, but it helps to understand why they made their design choices before you second-guess them. To paraphrase a guy on a car forum I'm on, "there's nothing wrong with reinventing the wheel, but you have to understand the concept of 'round' first."
(popcorn)
Some good observations and points have been made. I currently don't have a lot of free time to work on the bike. I will inspect what I can with the arm in place, and later I will remove the swingarm (when I replace the rear tire) and inspect the arm, bracket and modification for signs of deformation.
Perhaps I should have chosen my words better. When I said I agree with everything you said, the inference was that I also understood everything you said, no further explanation or example was necessary.
Haha, I also did the course but it was 50 years ago and I have no idea what I got.
When I said I didn't believe it would compromise the integrity of the section, I was saying that such a modification would not exceed or even get near the factor of safety, which would be considerable.
However, on the point of greater strength on the compression side than the tension side, I don't agree. Yes, it is the case on solid tube, as per the several examples you gave, but not on hollow section.
If you apply a load to a hollow section until it deforms, it is the compression side that fails, it buckles and folds in on itself, if the swing arm was solid, it would fail from the underside as you suggested.
And then there's that great theoretical leveller, empirical evidence. There's Marks bike and there's my bike and probably many more. I drilled two holes longitudinally, approx. 10mm in diameter about half way down on the underside of my swing arm (for another purpose, not the brake arm) I doubt there is an FJ here that has done more miles, with heavy loads over worse roads and routinely bottoms out the rear end more than mine. Those holes were drilled over a 100k ago. There is no hint of deforming nor would I expect any.
The safety margin built in to these sort of components is probably something like 5-10 times the calculated maximum load.
We surely must have an engineer here that can weigh in with some professional cred? We need one smart enough to know the answer but not smart enough to stay out of the discussion. :biggrin:
Noel
This is the beginning of a bracket I am working on that will bolt up to both footpeg holes. This is 1- 1/4 inch scrap I had laying around the shop. When done, there will be more meat on the back side (welder has it right now) and the total strength should be substantial enough, and yes, clear everything. The torque arm will ride between the two furthest holes and the bracket will double the sheer plane of any bolt put through there. .... because after the years, the money, the time, I'll be dammed if I am taking the swingarm back off, drilling holes in it or, buying/rebuilding another caliper, wasting a custom brake line, etc.
Pics when done.
Quote from: ribbert on October 16, 2019, 05:50:46 AMWe need one smart enough to know the answer but not smart enough to stay out of the discussion. :biggrin:
Noel
HAH! That's my favorite bit from this site since the last thing I read from Klavdy. I definitely meet the second criterion, don't know about the first.
Someone with a bit more time on their hands could certainly calculate what it would take to bend the swingarm there, in both unaltered box-section and drilled-hole c-channel versions, to determine what it would take to fail the altered swingarm in terms of rear wheel load. If you've really put 100,000 km on yours (and those recent pics look amazing, I'm very envious) heavily loaded to no ill effect, I can bring myself to believe that the holes don't weaken it enough to matter in that type of use.
I had assumed that 1) the aluminum in the swingarm has an equal modulus in both tension and compression, and 2) that the box-section is symmetrical, and that therefore 3) the top and bottom elements would fail at the same time, which would mean that weakening the bottom at all would weaken the entire assembly. Then again, a friend who went on to get a PhD specifically in materials told me 30 years ago "in grad school you learn how to solve the equations when none of the assumptions made in undergrad are true." Very likely, the strength you'd lose drilling a hole in the compression-side would be less-than-fully made up by replacing something in that hole.
MACHV, I don't think your problem with using the footpeg bolt is due to the footpeg bolt being too weak to withstand expected torque-arm force due to braking with the rear caliper. I think your problem has nothing to do with braking forces at all, and everything to do with the fact that the caliper moves with suspension movement, while the footpeg doesn't.
Why would that matter? Both ends of the torque arm pivot and the front is on a ball pivot. If all parts are installed near perfect parallel to the driveline (which they will be), all axiis involved will be in the same direction. I feel the problem is entirely brake force related. The bracket I am making "should" ask the bolt to do "at best" half the work by allowing it to bridge a gap rather than hang in space.
Will go through some rigorous stops in a protected area, followed by close inspection before I feel comfortable.
Additionally, I have to wonder if those who mounted the arm to the center stand bracket have experienced a similar issue. Granted, the bolt there IS larger but if the problem lay in "how" the arm is mounted... should be the same problem in that location.
Jesus christ, just weld the fucking tab on the bottom of the swingarm.
Quote from: ZOA NOM on October 16, 2019, 09:03:14 AM
Jesus christ, just weld the fucking tab on the bottom of the swingarm.
I can't weld aluminum. I don't know who does. In order to get my swingarm out, I have to remove my Penske. To get that out I have to remove the airbox, the carbs the gastank... BS. Suzuki didn't deem it necessary to mount to the swingarm, so now that I see this, I feel better about my solution.
My post wasn't aimed at you. The "engineers" above however... :Facepalm:
As for aluminum welding, take a look at these. (http://www.weldingtipsandtricks.com/durafix-aluminum-welding-rods.html)
Quote from: ZOA NOM on October 16, 2019, 09:29:54 AM
My post wasn't aimed at you. The "engineers" above however... :Facepalm:
As for aluminum welding, take a look at these. (http://www.weldingtipsandtricks.com/durafix-aluminum-welding-rods.html)
Ah. No problem. I skipped over those anyway because I have to work with what's on hand and at the hardware store at this point. Not spending any more $$$ on this conversion, other than the 12 pack I promised to the guy welding the steel for me.
Quote from: MACHV on October 16, 2019, 07:14:13 AM
This is the beginning of a bracket I am working on that will bolt up to both footpeg holes. This is 1- 1/4 inch scrap I had laying around the shop. When done, there will be more meat on the back side (welder has it right now) and the total strength should be substantial enough, and yes, clear everything. The torque arm will ride between the two furthest holes and the bracket will double the sheer plane of any bolt put through there. .... because after the years, the money, the time, I'll be dammed if I am taking the swingarm back off, drilling holes in it or, buying/rebuilding another caliper, wasting a custom brake line, etc.
Pics when done.
Looks like that'll do the job just fine, I might knock up one myself. :good2:
I would buy the guy TWO twelve-packs, and have him weld a tab on the swingarm and cut/weld your mounting arm to length so you can connect to that tab instead.
I don't remember pulling the carbs or airbox to R&R my rear shock, just the tank and the battery box.
It *does* look like Suzuki made theirs work on those early (mid-80s) GSXRs by using a really long caliper arm, kept nearly parallel to the swingarm, and with its forward mount far enough below and in front of the swingarm pivot to mimic its rear mount location relative to the axle - a four-bar linkage. I don't remember those breaking anything, so it must have worked okay. Yours broke something, so I'd put some serious thought into why Suzuki's worked and yours didn't if I were you. You want to make sure it doesn't bind anywhere during the swingarm's motion. Until you figure out what went wrong, I would be worried that a stronger bolt (or a sturdy plate at the front) won't keep you from breaking anything from now on, it would just make sure that something different breaks next time.
For what it's worth, later GSXRs mount the front of that caliper torque arm to a tab welded to the swingarm. The caliper moves with the swingarm that way, and stays stationary relative to the swingarm unless you're in the process of moving the axle to adjust the drive chain. Everybody uses a tab on the swingarm these days; everybody does it that way for a reason.
I understand the appeal of trying to make it work with whatever happens to be on hand. But if you don't have the right things on hand, it's just not going to work.
Shoot, Noel says he hasn't had any trouble with a swingarm full of bolt holes, maybe you could bolt a tab to the swingarm like he did. I'd still go through the side plates with a bolt running left-right, rather than going through a top or bottom plate with hardware running up-down.
Mine hasn't broken. I just finished the modern haven't even test driven it yet only to find out that after years of reading about this thing and finally doing it that bolts were getting broken. And I am not pulling the swing arm back out of the bike until it's time to re grease everything in 15000 miles. I already know this idea Is going to work. I just hope the prototype becomes the finished Products in time for me to actually test ride the thing before it starts snowing around here.
Quote from: MACHV on October 16, 2019, 09:25:23 AM
....In order to get my swingarm out, I have to remove my Penske. To get that out I have to remove the airbox, the carbs the gastank...
No you don't.
Quote from: ZOA NOM on October 16, 2019, 09:03:14 AM
Jesus christ, just weld the fucking tab on the bottom of the swingarm.
Rick, I believe I already said that at the outset (but not so eloquently) -
Quote from: ribbert on October 15, 2019, 08:10:11 AM
...."just weld a tab where it needs to go on the arm and move on to the next job, there's nothing to think about".....
Noel
Quote from: ZOA NOM on October 16, 2019, 09:29:54 AM
My post wasn't aimed at you. The "engineers" above however...
Thanks Rick, I'm flattered, I'll add it to my CV.
Noel
:drinks:
I just used the rear wheel and sprocket carrier from a Thundercat 600..
So easy to do at home with a grinder and hand tools.
Quote from: FJ12IRL on October 19, 2019, 08:32:50 AM
I just used the rear wheel and sprocket carrier from a Thundercat 600..
So easy to do at home with a grinder and hand tools.
I was also surprised when people were saying here that the GSXR wheel swap was the simplest !!!!!!
But, with the Thundercat we do only get the 5" rear wheel, rather than the 5.5" and that can be an issue for some people.
Just do the complete Thunder Ace rear end swap, swinger and all....
Quote from: MACHV on October 12, 2019, 12:02:33 PM
It's gotta be a fluke.
Otherwise, why wouldn't either the original aluminum swingarm mount bracket or a new welded one not crack before shearing a steel bolt? Seems a little counter-intuitive, at least, when looking at the meat of the old mount point.
Maybe your right, it is a fluke.
Quote from: MACHV on October 16, 2019, 09:25:23 AM
BS. Suzuki didn't deem it necessary to mount to the swingarm, so now that I see this, I feel better about my solution.
If it was good enough for Suzuki, hell it should be good enough for everyone. Just run it, whats the worst that can happen? Maybe you could die (thats bad :negative:)
Quote from: Millietant on October 19, 2019, 03:09:10 PM
.....I was also surprised when people were saying here that the GSXR wheel swap was the simplest !!!!!!
(https://live.staticflickr.com/65535/48928372677_82b627f6cb_o.jpg)
Noel
I still feel my "Z" shape, Off Set Torque Arm idea will work and be simple to manufacture and implement.
Something like this.
(http://fjowners.com/gallery/11/6034_20_10_19_3_59_13.jpeg)
You will need to fabricate and weld some U shaped brackets to the ends of the torque arm for fixing to the existing mounting on top of the swing arm and the caliper.
Use a quality carbon steel for the arm and brackets, not stainless steel.
The gussets will add strength.
Gavin
Quote from: Pat Conlon on October 19, 2019, 05:31:51 PM
Just do the complete Thunder Ace rear end swap, swinger and all....
Oh yes, defo the ultimate option !!!! (But still not the "simplest" :-) :-))
OR:
Take your original caliper bracket and cut it where the line is in the picture. Finished length should be 20mm shorter than original. Bevel out the areas that'll get welded. Clamp it or bolt it to a stiff piece of steel to keep the inner machined faces parallel. This ensures that the caliper will align properly with the rotor. Get someone qualified to weld the shit out of it. Make a new torque arm out of 1/4" steel or aluminum. Might need a bit of offset to line up properly.
That's it - simple, uses original caliper and hose. Cheap - cost me $25 Cdn. I've done 4 or 5 this way with no problems.
What's so hard about a couple spacers? I used washers. The GSXR requires no machining, welding, or fabrication of any kind. Just use the GSXR torque arm and attach it to a new bolt at the backside of the foot peg. Ride, repeat.
Bracket installed. Bolt stress distributed.
Using the scrap on hand, I first made a cardboard model from the box my chain came in, to establish shape and clearance. Went from there. Had a strengthening wall welded (for free) where I wanted. Now the bolt has two sheer planes because it spans a bridge instead of having only one attach point. I refused to take the ass end apart right after putting it all back together and cleaning everything. Plus I was not interested in drilling or welding on the swingarm.
Forgot a pic.
Looks very sturdy. Someone mentioned once that having the bolt in double shear really increases the strength of the connection.
Joe
Quote from: Tuned forks on October 24, 2019, 07:24:39 PM
Looks very sturdy. Someone mentioned once that having the bolt in double shear really increases the strength of the connection.
Joe
Well it made sense, then I studied and confirmed. The former method basically gave the torque arm a whole inch of leverage from where the bolt comes through the frame. Maybe not all the bolts on all the bikes are breaking but, I wasn't going to risk it. Never would have guessed that the above avg bolt might not be enough so...
Thanks to everyone for the input!