Is there a set of dog bones from another bike that are direct swap and offer a 2" lift at the rear?
I'm keen to raise it up a bit and wated to know what others have done..
Cheers
The 1100 has a scissor style shock linkage. There are no dog bones.
If your 1100 has been modified with a later model 1200 swingarm. You can fabricate shorter dog bones for your desired height, or use Soupys adjustable dog bones.
https://www.ebay.com.au/itm/183420326524?hash=item2ab4b4127c:g:Z6QAAOSw-7tg94~a (https://www.ebay.com.au/itm/183420326524?hash=item2ab4b4127c:g:Z6QAAOSw-7tg94~a)
Fred
I installed a Honda F4 shock on my 1100 which increased the rear travel.
https://www.fjowners.com/index.php?topic=6549.15 (https://www.fjowners.com/index.php?topic=6549.15)
Robert, will the new RPM shock be height adjustable for the '84 to '87 FJ's?
Option of a longer eye would be nice.
Not at the moment. The shock designer only has them made up for the 89-90 as of now.
Quote from: Dads_FJ on September 16, 2021, 12:05:09 PM
I installed a Honda F4 shock on my 1100 which increased the rear travel
I also did the Honda F4 conversion on my 84 FJ and it noticeably improved my front wheel grip when cornering and consequently improved front tire wear as well. Probably the least costly way to raise the rear end. I think I paid $60 for the F4 on eBay. There is a very well presented F4 conversion in the modification files section which made it a lot easier :good:
Wouldn't recommend adjustable dog bones. That's not a place for a weak piece.
I would normally agree, but Fred and others have done many thousands of miles on their FJ's with Soupy's adjustable dog bones, without issue. :good2:
I have ~40k on my Soupy's and they are fine.....but I agree with Rick. I don't recommend them.
It's not because they are weak.
It's because you have to set each side "dead nuts even" or you will tweak the linkage bearings in your swing arm. You can not get this type of tolerance by adjusting them on the bike. The threads are too course.
I do the final adjustment on a jig where I can get proper accuracy when I snug down the lock nuts.
When you fabricate your own dog bones out of strap steel, you clamp both pieces together when you drill the holes, so we know those holes are even.
Quote from: ZOA NOM on September 17, 2021, 03:42:39 AM
Wouldn't recommend adjustable dog bones. That's not a place for a weak piece.
"I agree entirely with that, mostly for the reason Pat points out, the near impossibility of adjusting them dead even and the subsequent excessive load, accelerated wear etc and the fact the engineering is all wrong. I could not in good conscience recommend them as a permanent fitting. I have seen them used to find the right length then use that measurement to make fixed ones, after all, who changes them after that anyway.
Not having had a failure does not in itself make it a good design.
Pat, didn't you prematurely wear something out from uneven adjustment?
And then there's this FJ.......
(https://farm5.staticflickr.com/4349/36811629562_f9ecffe181_b.jpg)
...look at the design, you could bet the house where that was going to break."
Yes, I speak from experience. I learned the hard way.
In the picture you posted above, see the 5 difference faces of turnbuckle nut on the Soupy dog bone?
I was worried about my ham fisted uneven adjustment so I stamped each face of the turnbuckle nut with a number. Using a reference point on the frame, I made sure the correct number lined up on each side, before I locked it in.......Still not good enough....A millimeter or two off in the length between links will tweak your needle bearings.
Tim (Axiom R) had a failure of a single Soupy dog bone on his R-1 swingarm conversion.
In that case, yes, a single Soupy was too weak. My double Soupy's are holding up fine (so far)
However....Now that I've said that..... :dash2:
Don't get adjustable dog bones, you don't need them.
What length do you need for your bones?
With the bike on the center stand, disconnect the linkage, put a piece of 3/4" plywood under your back tire and measure for the length of the new dog bones. Clamp them together when you drill the 10mm mounting holes.
Call it a day, keep it simple. I'll bet you a jelly donut you will find the new height perfect.
It will be so much better than the stock height, especially with a 30+ year old sacked out oem shock.
Mainly, they are easy to fabricate so I don't see the value in adjustability.
If I recall, about 115mm length, center - to - center was an ideal length for a nice ride height.
Quote from: Pat Conlon on September 17, 2021, 11:27:19 AM
....A millimeter or two off in the length between links will tweak your needle bearings.
"Pat, I think you're being generous allowing even 1-2mm.
As for that failure in the photo being a single Soupy, that's exactly what a pair becomes when the adjustment is uneven, all the load shifts to just one. Given that failure would be instantaneous, without warning, total and catastrophic, and it's not even a risk that has any reward, I see no point. There are Rose joints with more of a taper that would be stronger, but once again, why bother.
Haha, anyone familiar with this process .....
(https://qph.fs.quoracdn.net/main-qimg-0c46c7f8f1b5c32ddd1186cfdc4177bc.webp)
.....knows that nipping up the locknut
always changes the setting.
As Rick, Pat and others have said, once a length has been determined, adjustability is no longer necessary or even an advantage.
I go one step further than Pat when making linkages, I tack them together until they're finished."
Source: Fjowners Forum
Haha, anyone familiar with this process .....
(https://qph.fs.quoracdn.net/main-qimg-0c46c7f8f1b5c32ddd1186cfdc4177bc.webp)
.....knows that nipping up the locknut always changes the setting.
I remember the first time I had to adjust the valve shims on my cb900f . I was intimidated. As a current owner of Volkswagen's , a 92 Toyota truck, and several cb 750's I still prefer adjusting valve tappets to changing shims.
I use a "go, no-go" version on the backside of the cam lobe rather than trying to get a 90 degree bent feeler under the elephant feet on my Porsche. It makes trackside valve adjustments much quicker and easier access. It allows me to just rotate the engine without worrying too much about TDC for each cylinder, as long as the rocker isn't anywhere on the lobe, the adjustment can be made.
I will add to routinely examine the homemade links. I saw noticeable ovaling on mine after a couple years on the street bike. That's why I went with Soupy's .....
All modifications have their compromises - just be aware of them and deal with them appropriately!
I'd like to fab a pair of "fat" links with serviceable bushing for the street bike. Probably way overkill .... And unknown what their compromises might be!
I didn't know what you were talking about Rick. The only Porsche I've ever worked on was a friend's 914. I had to Google valve adjustment for a 911. I didn't know they have dual overhead cams and no pushrods. The guy in the video used a special dial gauge that screwed on to the valve cover stud then he zeroed the gauge with the rocker pushed against the cam lobe then pushed it down until it touched the valve stem for his measurement.
Just not at all worth it to take any chances on a critical suspension component. I was SOOOO lucky not to be hurt. For me, the obvious test is; "was the part manufactured to be a suspension component?" The Soupy's links were not. They are assembled parts from a hardware supply. NO - you would not expect one to break - I certainly was surprised. But looking back at the situation - Why did I take that chance? Totally unnecessary. AND.... look at the dogbones and links used as stock components; they are solid or billet material 100% of the time.
Heim joints, even used in pairs, allow rotational and torsion forces to arrive in the linkage - this = "ovaling" as mentioned above. My spacers and fittings were heavily worn at the centers.
"Keep checking it for wear" is a foolish approach because you cannot tell from looking at it when it is about to give... observe the clean break on my unit it looked fine minutes before the break.
Adjust your rear height on the shock - like a pro.
OR - buy parts that are manufactured and engineered for the specific job.
JMHO...
tim
I recall Aviation Fred made a pair of bones out of titanium.
Quote from: T Legg on September 18, 2021, 02:57:48 PM
I didn't know what you were talking about Rick. The only Porsche I've ever worked on was a friend's 914. I had to Google valve adjustment for a 911. I didn't know they have dual overhead cams and no pushrods. The guy in the video used a special dial gauge that screwed on to the valve cover stud then he zeroed the gauge with the rocker pushed against the cam lobe then pushed it down until it touched the valve stem for his measurement.
I think you're referring to the Stomski tool video. That's a nice accurate way to do it with the engine on a stand, but it's too tight inside the engine compartment for that method. I like using the "backside" method, which sets the gap using a feeler gauge between the cam and the rocker when the valve is not under tension of the cam lobe. It makes access much easier, and you get to the point where you don't even need the feeler gauge, you can feel the right amount of movement with your fingers. Haven't broken a rocker yet, and I spin her up to 7k. The spec is pretty wide, between .002" - .006", and they should be set on the loose end, because they tighten as the valve seat wears.
Here's how a master Porsche Mechanic does it. Note the wiggle check at the beginning.
https://youtu.be/kbR2T6Ue-Ds
Quote from: ZOA NOM on September 18, 2021, 09:40:51 AM
....It makes trackside valve adjustments much quicker and easier access.....
Why are you adjusting valves at the track?
Quote from: ZOA NOM on September 18, 2021, 09:15:34 PM
..... and you get to the point where you don't even need the feeler gauge, you can feel the right amount of movement with your fingers....
Here's how a master Porsche Mechanic does it.
https://youtu.be/kbR2T6Ue-Ds
...and he calls himself a Porsche Master Tech?, tell him to come back when he can do it without feeler gauges. :biggrin:
Quote from: Pat Conlon on September 18, 2021, 08:26:29 PM
I recall Aviation Fred made a pair of bones out of titanium.
The Titanium dogbones are installed on the Streetfighter project.
Fred
Quote from: ribbert on September 19, 2021, 03:47:53 AM
Quote from: ZOA NOM on September 18, 2021, 09:40:51 AM
....It makes trackside valve adjustments much quicker and easier access.....
Why are you adjusting valves at the track?
Because you may have set them at home when the engine was relatively cooler, and they may be tight. It happens. The point is the access, which is also useful at home.
Quote from: ribbert on September 19, 2021, 04:15:05 AM
Quote from: ZOA NOM on September 18, 2021, 09:15:34 PM
..... and you get to the point where you don't even need the feeler gauge, you can feel the right amount of movement with your fingers....
Here's how a master Porsche Mechanic does it.
https://youtu.be/kbR2T6Ue-Ds
...and he calls himself a Porsche Master Tech?, tell him to come back when he can do it without feeler gauges. :biggrin:
I'm sure he uses the gauges when he's being paid to adjust someone else's valves.
Here is a up close photo of the Titanium dogbones.
Fred
Thanks Fred....No worries about ovaling out those bad boys...
Fred, remind me, where did you find the stock, how much? Was it hard to cut and drill? Any special tools needed?
I've never worked with titanium before....
I've heard titanium can be brittle. I don't know enough about it in this application. My mild steel version would likely bend before breaking, which I would prefer.
You can get Ti here:
https://www.titaniumjoe.com/ (https://www.titaniumjoe.com/)
We use a lot of Ti in helicopters. It has a similar strength to steel but in some applications will show worse fatigue life. It is hard to work with. My airplane landing gear is a 1.125" 6A-4V rod and that is a bear to drill through.
Without loads or analysis hard to tell if it is good or not. As long as Fred is leading the fleet it is probably not that scary of a part. For the relatively small weight savings for those small pieces, steel seems like a good bet.