$14.00 VF500 F rear suspension fix. Input please.

Hi All,
Several days ago I posted looking for help in getting my 1986 VF500 F low budget project bike roadworthy by my low standards of what constitutes "roadworthy". Since that post has had only 37 views and no responses I'm posting again with my tentative solution to see what folks think of my plan. First, for those who did not read it let me repeat my prior post here, after which I'll describe what I think will work, again, to my low standards of "roadworthy":

Hi everybody,
I have made excellent progress on my "low buck, get it on the road" project but need more help. To briefly summarize what has been done to date: I bought a non running, but all there, '86 VF500 F back in Februrary and have gpten it running great at this point by: replacing the battery, replacing the starter relay, replacing the spark plugs, 1 coil, 2 plug wires, replacing 1 CDI box, cleaning the carbs, setting the valve clearances, rebuilding the clutch slave cylinder, replacing the drive chain, fork seals and all brake pads. The grand total in the bike so far including the $400 purchase price is $720, which includes oil, an oil filter and a $65 E Bay belly pan (for later when I put the plastic back on). Most of the parts were bought through E Bay which has kept the costs in line so far. The most valuable thing in making the project workable though, is the information I've gotten from this web site and its members. I definitely could not have gotten to this stage without your help, so thanks a lot for everything!
So, now the bike is running great and the budget not exceeded... but the rear shock is trash. I left a message with Jamie Daughtry today and he called back and left a friendly and detailed message on my phone saying that based on its symptoms, the shock was toast and not rebuildable. He also said there was no salvage yard shock that could be readily made to work on my bike.
It could be that down the road I'll be ready to put more serious money into the bike, but right now budget issues prevail. Until I've ridden it for a few months and put at least 1000 miles on it I can't justify putting much money into it since I'm not sure if I will want to hang onto it for years, although it is VERY impressive so far.
Anyway, remembering that I'm a guy who says, " you can tell poor workmanship by the wrinkles in the duct tape", does anyone know of a cheap way of getting a shock which is adequately workable, not great, not as good as new stock, but just livable; I don't need a remote resivoir or air adjustability. I'm an old guy who cruises mostly country roads in semi-rural Florida and the stock freshened up VF500 F front suspension feels like heaven compared to my '68 Bonneville.
I have a friend who is a machinist and could mill up an adaptor and also am not adverse to cobbling up something with welding and steel stock if that will work. I vaguely remember a post that suggested that an '87-'90 Hurricane 600 shock could be fairly easily adapted, but gave no details.
So, all input will be greatly appreciated as would be the sale of an adequately working stock VF500 F shock if you have upgraded to one of Jamie's and have a working old one on hand.

So, since my first post above, I've done a lot of homework on shocks and have come up with what I think will be an adequate fix given the low standards described in my original post. And yes, I'm clear that it will be far from optimum and probably not as good as a stock good condition VF500 F shock, but remember that the shock I'm actually riding around on now is totally shot.
What I plan to do is get a good condition VTR 1000 shock from a local salvage yard which has one on hand for $14.00, cut the bottom eye off, drill and tap into the solid material above the eye and bolt the VF500 F lower clevis to it. There is plenty of material above the eye on the VTR (which is long) to drill into and all I need to do is cut the eye off at a location such that when I bolt the sawed off VF500 F lower clevis to the stub it maintains the 364MM eye to eye length of the 500. While I'm pretty sure the linkage ratios and progression rates are different between the two bikes, that procedure will give me the stock rear ride height and hopefully a ballpark spring and damping combination. No welding , no machining and $14.00 out the door! I would greatly appreciate any helpful input. I realize this is backyard engineering to the max but am just looking for a rear suspension that deflects on bumps and is damped. If I'm fortunate and it works quite well but has a too weak or strong spring, that should be correctable at low cost. Your constructive thoughts please...

 

Plus 10 what Tink said.
John

 

Tink summed it up well I'd say. I get staying under a budget but don't do so by compromising safety. If you're patient and/or know how to perform internet searches that turn up good results, I'm sure you can find a good replacement for a decent price.

 

Not very familiar with the shock you're talking about but that big chunk of metal at the bottom generally has the rebound adjuster in it which means the fluid circulates through it. Cut into it and you have a heavy spring mount with no dampening properties.

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Hi Guys,
Thanks a million for the input so far. It is clear that my idea for using the VTR 1000 shock is a major loser. Also as Commrad points out above, the base is not solid aluminum as I had inferred from the E Bay photos and so it could not have been drilled and tapped. I was seduced by the fact that it is exactly the same length as the VF500F stocker.
I found a web site that lists eye to eye specs for many many monoshock sport bikes and there are very, very few that are in the ballpark of the long (346 MM) VF 500 F. I was really excited about the 2003-4 ZX 6R Kawi shock since it was 340MM with about the right bike weight, but it has an adjuster that extends slightly above the top eye and there is zero room above the eye on the 500 frame. I checked out several other possibilities and none in the 330-350MM will physically fit the upper frame clevis and clear the frame. So, recognizing that I would need to go with a shorter shock and lengthen it in a similar fashion to Jamie D's F4i modified shock I looked some more.
What I am now is thinking that a Honda CBR F2 shock (292MM) which will clear the frame fine up top since it has no external resivoir, lengthened to 345MM eye to eye with .125 or .1875 steel strap, bolted through the F2 eye with sturdy tabs on the sides just above the shock eye to prevent it from pivoting on the through bolt might work. It looks like that to prevent pivoting, Jamie mills a slot in the shock body and indexes this with a tab on the extension pieces which is much more elegant, but expensive. I could mock it up out of masonite, using hot glue to hold it together and if it seems workable duplicate it in steel. Maybe later today after completing some "Honey dos" I can mock it up and post a photo since I'm not sure I've explained it adequately.
So, it looks like the budget is now up to $35 for a good used F2 shock and $10 for welding up tabs on the sides of steel adapter pieces that I've cut and drilled. That is still quite affordable. Any more input for how I can accomplish the goal of adequately "roadwrothy" would be appreciated, especially a photo or photos from Tink on his adapter solution and shock suggestions.
Thanks Again
Jay

 

So Dr. Jay, what's really going on? Your profile says your a clinical physcologist, university professor, and have a stable of bikes, yet you started this thread like your a charity case looking for help or for someone to give you a shock for your project. I noticed you responded to outis's thread in the 1st & 2nd gen forum that he is getting a vfr500 parts bike and you asked him if you could have the wind screen if it wasn't more than $25 to ship it to Florida, but didn't mention that you desperately need a shock! How about safety first! I'm frugal, but man you take the prize.
John

 

Outboard John and any curious others,
All the background info on me is accurate. So is the fact that as a private practitioner and adjunct professor since 1979 I was self employed, didn't make a pile of money and therefore have minimal investment income. I'm far from starving, but do need to be very careful about spending. I aquired all my bikes except the VF 500 F when I was making more and before I retired in October 2013. By far my greatest source of income currently is a monthly social security check.
I have been married 37 years and when discussing getting the little 500, told my wife it would be a maximally low budget project bike for a guy who, now retired, loves tinkering in his shop. Given this background, am I now entitled to be as frugal as possible? Hell I bought Shell Rotella at Wal Mart for my first oil change on the 500 knowing I would only have it in the bike for the first couple of hundred miles to flush it out before changing to synthetic. Btw I didn't ask the guy parting out the 500 about a shock since I could have no assurance it was any good.

Jay

 

Sorry I got in your face Jay, I guess I got my panties in a bunch when you didn't inquire about a shock (with outis) that you obviously need just to be road worthy and safe. Tinker on but please don't go cutting up that shock.
PS, nothing wrong with T6 Rotilla IMO.
John

 

I fully understand the desire to keep things on the cheap, but have to agree with the other guys. No matter what my project is, there are a few essentials that you can't scrimp on. One of those is suspension. Hopefully I will have that bike in my possession next weekend or the weekend after, at which point I can check out the rear shock on the bike. Judging from how clean the rest of the bike is, and the fact that it's only clocked 24000mi, I can't imagine it's unroadworthy. If you wanted the screen and the shock, I would be more than happy to work out a fair deal. I'm not really out to make money with the bike so much as get the parts I need for free I'd rather see those parts bring another 500 back to life than sit in my back yard anyway. I also just did a search on ebay, and there's a shock on ebay from ohio for 50 bucks if you wanted to go that route; shipping from me might turn out to be pretty pricey.

 

Hi Again,
I am in complete agreement that if I adapt another shock to my 500 that the adapted assembly must be as strong and durable as the original 500 shock. Also, it is clear that my initial thought of using a VTR 1000 shock as I speculated about modifying it would have quite possibly have earned me that coveted Darwin Award had I actually implemented it. (Which is why I sought input here.) I additionally understand that a shock and spring assembly designed for another bike will almost certainly have far from ideal springing and damping rates for a VF500 F. However, my experience with fitting a number of "not designed for the bike" shocks of unknown damping and spring rates on the dual shock Triumphs Nortons and CB550 I ran on both the street and track leads me to believe that there is a wide range of spring and damping rates that would be acceptable to me for easy street riding.
I truly appreciate the time and expert input which forum members have already given on this issue and recognize that this shadetree approach is not the way most would want to deal with it. However, please bear with me and let me know what you think on my latest tentative plan.
As I stated in post 7: What I am now thinking is that a Honda CBR F2 shock (292MM) which will clear the frame fine up top since it has no external resivoir, lengthened to 345MM eye to eye with .125 or .1875 steel strap, bolted through the F2 eye with sturdy tabs on the sides just above the shock eye to prevent it from pivoting on the through bolt might work. It looks like that to prevent pivoting, Jamie D mills a slot in the shock body and indexes this with a tab on the extension pieces which is much more elegant, but expensive and I suspect perhaps no stronger than steel tabs would be.
I have mocked up the adapter I am talking about in the attached photos and would appreciate comments on whether there are any problems apparent with the basic design. I'm sure actually fabricating it may involve spacers on one of the through bolts to make things work, or most likely other currently unknown fitment problems. Also, if you have any ideas about what might be a better candidate donor shock than the Honda F2, I'd appreciate that input
Tink, if, and only if, it is not too much trouble, could you share some details of the swap you did with the shock you lengthened pictured above ; the shock, the bike, whether the transplant worked adequately and what you learned from the experience.
Again, Thanks to all for your time and ideas.

Jay

 

If you put 30wt rotela in get it out NOW! Their 30wt oils aren't wet clutch compatible. If you used t6 it's fine or the 40wt Dino oil.

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Here's a pic of my cbr600f2 fox twin clicker installed. Not cheap or readily available but it's worth every penny. The stock shock does Suck but it can be rebuilt. There are instructions on the net. Check for a vf750/700s sabre. Different shock but instructions are the same.



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