Have a 2000 Valk with a Motorvation F2 Hack. Wonderful rig.
Built it a couple years ago, pulling the hack from GL1200 after it left us stranded when it blew a head gasket on the I90 turnoff for the Badlands a few years ago... but that's another story...
Anyhow, we ride far and fast; just completed a 4500 mile trip from Tucson to Minny Soda - the Valk (fully loaded with wife, canine, tools, gear, etc) will easily keep up with traffic at 75-80.
Problem is, my alignment does not remain constant. I had to purchase a new car tire for the hack when I noticed extreme wear on inside edge just b4 we were leaving. Then in Minny Soda I had to pull the tire and "flip" it on the rim, so that the almost unused portion of the tread would get us home.
Basically, over time (maybe 5000 miles on it since built) the rig seems to want to collapse in on itself. I.e., the bike cants right, and the sidecar frame cants left. Thereby wearing out the inside of the hack tire and abnormally wearing on the "right" side of the bike rear car tire. It used to wear dead straight across.
We also have a 3 mile long badly graded driveway; lots of ripples, rocks, and potholes. The bike generally responds better riding this at speed, (maybe 40-45); but maybe the forces applied doing this (and taking high speed hits by concrete bridges connectors, potholes, etc) just out-powers the mounting clamps holding power?
An inspection today of the mounting points does not show anything bent, broke, etc. All hardware bolted really, really tight - hard to loosen without a 1/2" socket and 18" breaker bar. It's like... each force over a certain amount the rig absorbs maybe moves things incrementally; until the increments add up.
Had this problem on the GL1200 rig as well. On one trip I ended up having to pull the hack body and re-align the rig in the Mother-In-Laws garage - after purchasing 10' long straight edges at a local Menards...
I do use the linear ram for levelling out the rig; big difference when empty of fully loaded going on a trip. But the ram locks in place, and even if it did move, it's adjustment (hack "up" or "down") could not cause the type of alignment issues I'm seeing.
So. Anybody else experienced this with the 4-point mounting of the Motorvation F2? Any solutions? I have a call into Gary at Motorvation; but my time off does not seem to coincide with their hours of operation. And their mailbox is full... I'll give him a call Monday and post back what he says.
Took some pics this am and compared to what I took during the build. The "pivot" mounts are apparently doing just that...
From the pic of the front of the rig, you can see the lower mounts (front and rear) are almost dead level.
From the pics this am of the lower mounts, they have definitely pivoted, allowing the rig to fold in on itself...
I checked again - all the mounts are dead tight. Just how the heck do I solve this?
About all I can come up with is to fab a vertical mount from the outboard end of what is pivoting, and tie it to the outboard end of the top mounts. Basically, make an "A Frame" from the hack frame mount of the strut to the to the other end of the strut, then down to the pivot. This would make it imossible for the "pivot" to drop - unless it were to also deflect the outer ends of the top mounts - that would not be good...
Click on the attachment link at the bottom for a full size pic to see the mounts closer - they are almost dead level.
Seems I can't edit a post by adding a pic.
So, attached is a pic of the mounting points for the Valk/Motorvation: I have drawn in some red lines to show what I am thinking about adding.
Surely someone has been down this road before?
Pago, I was just going to suggest that, once the rig is re-aligned, add some "witness marks" on the pivot mounts to observe which one(s) are moving, and when & how much. I defer to our members with fabrication skills to suggest how to minimize the movement.
Lee
MB5+TW200+CRF250L+GTV300+INT650
XL883R w/Texas Ranger Sidecar
Zuma 50F + Burgman w/Texas Sidecar<Mrs. SwampFox
I'm thinking it's the wind resistance from that air horn! Wooo Dogie! I bet TRAINS get out of YOUR way when you lean on that thing!
As for finding the problem joint(s) I agree to the witness marks. Also, I see that several joints are put together with the bolt horizontal. In my mind, this orientation allows the joint to act like a hinge with respect to any downward forces. Maybe that's proper. Hopefully an actual expert will be along soon.
That lower front brace looks like its long lever forces it to turn inside the brace! Perhaps a second rest point to the front part of the s/c frame could help a lot. (according to my motto. What cannot get adjusted, cannot get misadjusted)
A witness mark with a center point at the split might help to identify eventual movement.
I did it on the Ural, and til now it is stable. On Jawa there was no way to get it ever right myself, only the Importer Fernando was able to twist and tweek it well. While the MZ quality was a story of itself...possibly Jawa employees smuggled too much Slivovitz to neighbour Zschopau for to weaken their competitors.
Good luck.
Sven
Sven
I know I'm still new to all this but I see a couple things in your pictures that I don't understand
1) your rear lower mount knuckles are at an angle and the nut is tightened to the sub frame and there is no nut at the clevis
2) you front lower mount has the nuts on each side of the adjusting arm and not against the clevis
with this what stops them from moving
I have a Motorvation on a 1500 Goldwing
on my rear lower I turned the arm until it made the connection level then tightened the outside nut until it locked the arm against the clevis
on the front I did the same thing, this way there is NO WAY my mounts can pivot or move due to the threads on the clevis knuckles not being locked tight
here are a couple pictures
Thanks for the comments guys.
Swampfox - While the witness marks are a great idea - and I have used them before, I am positive the movement is at the clevis pin by looking at the pics.
Old School is cool - Indeed, it prolly is the air horn resistance! That said, I do think your assessment of the clevis pin orientation acting like a hinge is correct. For whatever reason, when I put it together I did same as the last install on the GL1200 - thinking that movement for/aft was more important to control than up/down. Not the first time I've been wrong...
Peter Pan - I like your quote: What cannot get adjusted, cannot get misadjusted; words to live by. Don't know what you mean by "turned inside the brace"; but it's the clevis bolt that has un-successfully resisted the downward force. It was level b4 - and now it ain't.
AJ1200 - The rear lower mounts were not at an angle when I started - per the original pic they were both level - the clevis has apparently rotated. There is no nut locked to the clevis, but the threads are in with red locktight - and I installed it with the clevis dead vertical - which it still is.
As far as the front mount, the nut adjacent to the arm is locked dead tight to the other nut. At any rate, visually I am pretty sure that the assembly is just rotating around the clevis bolt. Interestingly enough, your rear mount clevis is oriented in the vertical as well - yet apparently with enough holding power to maintain the joint - or maybe with less forces involved.
Looks like when I re-align this weekend I'll change the clevises 90 degrees - and hopefully it will line up - and stay tight... wonder what the odds are of bending a clevis if I rotate them 90 degrees? what a pita...
Thanks again all.
Maybe rotate them 45* as a compromise to both vertical and horizontal forces.
Sorry myself I had to look up first the word clevis. = Gabelkopf
Brace = Fist
That lower front lever is so long that over time the 2 screws (yellow arrows) will not hold and the arm will turn upwards and the frame will sack down. Once well alligned you could make a rest that could hold the arm level (green/obviously should go below the upper arm/ MS-paint doesn't permit me to correct)
You will be amazed how much force is acting on the sidecar mounts and s/c wheel base. On my MZ with only 3 mounts I was forced to bend back all mounts and the s/c wheel scissor every 3-5 month with a 6ft long pry bar.
Many years in industrial maintenance have told me to use red and green Locktite only where I will be able to use a torch on huge screws to undo them. (640 is only for bearing nests) on most screws I stick to 242/243 blue Locktite or simply use assembly paste=anti sieze (Chesterton 710 copper+785 zink). (Learned that lesson on a match sewer... about 800 out of 1200 M5 Allan screws broke their heads off)
Both lower clevis are supposed to stay vertical for to keep the hinge action for adjustment and keep the orientation for mayor resistance. If you turn them to horizontal they may actually shear off the eye bolt base. The upper ones need to be turned for to permit alignment.
Good luck.
Sven
Thanks again all for comments.
Was able to reach Gary at Motorvation this week. His main comment was that the angle of the upper mounts to the hack frame would be better at a less steep angle. Which I believe is good advice.
But as with a lot of good advice (buy low, sell high comes to mind...) it can be difficult to implement.
I am already at the default track Motorvation recommends (60", outside to outside), and very close to the hack frame elevation of 9" at the rear. I am actually about 9.25, but it looks like I have lost about an inch in height due to the rig collapsing.
Per Gary, here is a Valk with another hack - but look at the angle of the strut - it is at least 20 degrees more horizontal - thereby applying more force horizontally, as opposed to vertically - which the bolted joint just apparently just cannot keep from rotating. Unfortunately, the easiest way to get this more horizontally would be to increase the track width - from 60" to ??? 62"? 64"? Not sure, but I do know that every inch increase in width makes it handles worse...
Take a look at a closeup of the upper mount as well - it is physically bent at the threads. Not much, maybe 3/32". But again, it was not bent when I built this. The only way for this to bend the threads is for the hack strut to exert force upward.
I again come to the conclusion that either our driveway (at speed), and/or just hard riding and typical road impacts at speed (again, we easily do 75-80 when slabbing it, although our preference is for more secondary roads) conspire to just overwhelm the hardware in it's present configuration.
See pic - interestingly enough, I pulled up some pics of our off-road rig - an XR1200 with a Ural hack. This sees a lot of stresses from trail riding, albeit they slower speeds. Has a track width of only 56", but also has a much better angle for struts. No way for the rear strut to "hinge-in". In fact, the rear hack frame connection loads are just about dead horizontal. The alignment has not changed in maybe 5000 miles over 3 years. But I see no way to duplicate this setup on the Valk without making the track wayyyy wider. Or going to a skinner hack...
Another Valk owner ran a strut from the upper mounts to the hack body, dead horizontal - but as the Motorvation hack body is fiberglass, this ain't gonna solve anything. Even welding on a 2"x2" tower maybe 8" tall to the hack frame, it would bend - prolly easier than the 3/4" threaded clevis. He also recommended a strut between the lower "pivoting" tubes and the top mounts - much like my sketch above. But as I have already bent the upper clevis threads, I'm thinking this may not be sufficient if it was the only change.
So, today I'm going to pull the rig off, make it 2" wider, cut down all the clevis mounts maybe 1" shorter, and replace the bent clevis mount. Will also remove the crash bar (just used to mount freeway pegs) in order to shorten the bent clevis mounts and thereby get the strut more horizontal; this will probably mean in the future that I would have to pull the strut in order to pull the right cylinder head cover - a pita for sure, but then again the only time I pulled the cylinder head covers was to switch to a set I had powdercoated.
Dang. Finally got a rig that is powerful enough to ride hard and fast (ie, capable of keeping up with 95% of freeway traffic), and have to redesign hardware due to the forces it generates...
Any other thoughts on simpler solutions welcome...
Update - Taking a break from breaking the rig down into components in Tucson's 107F temp today (last weekend it rained ALL weekend, today is an oven... sheesh.), I was wondering just how much force it would take to bend the 3/4" threaded steel on the clevis. If I did not screw up the math, looks like about 800 lbs(!!!) with a nominal 3" lever to reach the yield strength of (assumed) mild steel. Dang indeed. Big forces at work here.
Got the body off and the rig levelled easy said than done.
The hack frame was level when I set it up last time. It is now off level by about 3/4".
When I start pulling hardware tomorrow, I am thinking of moving the front top mount to the frame to the forwards hole, about a 6" move. This should help with the leverage of the front top mount - I think.
The THREE upper struts are very vertical with no way to move them out further. The rig measures 7 ft wide from left pannier to SC fender.
Tire wear is more pronounced on the front inside and the rear outside edges. ????? a mystery there. Since I just mounted a new sidecar tire, cannot use that for analysis.
More photos in next post.
CCjon
The front lower mount appears to have dipped slightly. The Rear lower mount appears level but the subframe plate appears bent. Could be the photo or is bent.
Because of the narrow space between the tug and the tub, the three upper struts cannot be placed any further out. They are splayed at angles frontward and rearward.
I see it was suggested to turn both lower clevises horizontal, might try one vertical and the other horizontal thus resisting both sets of forces between the tug and tub. That will change the toe-in.
Am going to try loosening all the bolts, adjust the front lean out slightly, level the front lower mount and retighten everything before making the last 1500 mile run to home. Am still on the road returning from Labrador.
