Cheap Replacement for 88-90 Rear Shock

[woodcreekpete]

My life's too short to find any info through the search function so:  Aside from aftermarket types, has anybody found a shock that'll swap into 88-90 models relatively easily and cheaply? Can't afford any of the high zoot types at the moment. 2007 CBR600RR comes pretty close in length but the canister looks like a problem.  Thanks, Pete

[woodcreekpete]

    Well Pete, to answer your own question, there's nothing that's a simple swap in. Priced out a Wilburs and it was worth more than the bike. RPM shock, to my door, would run about $1400. Too rich for me.
Found a site on the net that lists shock lengths for most bikes ever made. Closest I could find with a clevis  was BMW 650. I picked up a 650 Dakar shock for $100.
 Good points: It's a Showa, rebuildable, remote canister and preload adjusters. Rebound and compression
                      damping are adjustable.
                      It's out of a BMW so it must be swanky.
 Not so good: 37mm longer than the stock FJ.
                     Fitting for the canister hose points straight back at the battery box support.
                     Top mount is too narrow and the bolt diameter is too small.
                     Spring is way too soft.
                     Clevis is too narrow for the FJ mount.
  Sitting there, contemplating cutting the b-box mount, shortening the box itself and buying a Lithium battery, it came to me that I could kill 2 birds with one use of the zip cutter. Lopped off the top mount, got Tony the machinist to whip up a new one, rotated the shock 90 degrees, made a jig to align the top mount and got it welded up. So far, so good.
 Again, got Tony to hog out the clevis, leaving not enough material left to be safe. Welded pieces on both sides of the clevis to add some support.
 On to the spring:  Turns out the FJ spring is the same diameter as the BMW. The spring rate, 19.3 is very close to what Racetech recommends - 19.5. About 1 1/2" shorter though. Again, Tony to the rescue with a spacer to make up the difference.
 New dogbones kept the stock height but I might try one's about 1/4" shorter which should raise the back about 3/4".
 Assembled it and test fitted it. Made up a mount for the canister where the air box used to mount. Preload adjuster fits where the shock adjuster used to be.
Mounted on the bike, sag with just the bike weight was about 5mm. With me on it, no preload, sag was 27mm. Bit of a Pogo stick with no oil in it though.
 I know nothing of valving and shim stacks but I'm guessing a shock from a so-called dual purpose bike that's 100 lbs. lighter than the FJ is going to need some tweaking. Gonna leave that to a pro.
 I'm not thinking this is gonna be an earth-shattering improvement but we'll see. I rode a hardtail Triumph for a couple of years so anything with any springing at all is fine with my un-sophisticated ass.
 Been an interesting thing to play with. We'll see how it works out.

[Millietant]

Is $370 USD too high zoot for a brand new quality shock set up for you specifically, that uses all the existing mountings with no changes other than removing the Schonk chain adjuster set-up.

If not, try Hagon - I know Jacob (RevDeal) got one recently on my recommendation - ask him about it.

[woodcreekpete]

 :Definitely a case to be made for that. Cheapest Hagon though,  on eBay, would be around $600 Cdn to my door. Add another $2-250 for remote preload. But, sometimes you get an idea and you have to run with it.
  All in, including a rebuild and some re-valving, this thing'll have cost about $400. Money well spent? I'm not so sure about that but it has been an interesting thing to play with.

[Millietant]

If you call them rather than use eBay, you could save approx $100 CDN on that price, but that's maybe something for the future as you've already laid out the cash on your conversion 

Hope it works out nicely and rewards you for the effort. Nice job!

[Pat Conlon]

Hey Pete, thanks for the options...
FYI I went to the Race Tech website for your 2001-2007 BMW 650 Dakar shock and they list the stock spring rate to be 15.8 KG/mm....or about 884lbs/inch
Scroll down: https://racetech.com/ProductSearch/12/BMW/F650GS%20Dakar/2007

So, you are not that far out of the box on your spring rate. FJ's run 800 to 1100 lbs/in for shock rates.
Your shock is valved for 880 and if you needed to go up to 1,000 lbs/in I would bet that the stock BMW valving in you shock would handle the slightly heavier spring just fine.

Cheers.....btw, can you post the link you found on the shock lengths?
I'll put it in the Files....That info will help folks here.

Pat

[Paul.1478]

Is $370 USD too high zoot for a brand new quality shock set up for you specifically, that uses all the existing mountings with no changes other than removing the Schonk chain adjuster set-up.

If not, try Hagon - I know Jacob (RevDeal) got one recently on my recommendation - ask him about it.

RPM was out of there shocks for a while and i needed something. I went with Hagon. Called them, gave them my payment and in 3 days i had it at my door from the UK. Great services.
Shocks works way better than stock. I cannot compare to anything but stock.

[woodcreekpete]

Pat:   the site for the shock lengths is:
        Motorcycle rear shock lengths/cyclecycle.info
  I'm waiting for the plague to abate before I venture over to the shock guys shop for the seal head kit, oil, and nitro charge. Probably won't be until spring to see how it works out.
Pete
 

[woodcreekpete]

A while back, I responded to a post on the local free ad site - a guy claiming to be a shock rebuild specialist. Loaded up and drove 50 miles into Quebec to get the work done. Red flag #1 should have gone up - the guy's working out of an 8x10 aluminum garden shed. Talking to him, I'm getting an inkling that I know more about the shock than he does.
Fool that I am, I leave it with him. Calls me up the next morning to tell me it's done but, because it was so complicated, it's going to be 50% more expensive.
Again make the trip to his place. He's showing me how good the damping is by pumping the shock. Proceeds to pump all the oil past the seal head. Flag #2 - says it's no big deal, he'll get a new seal at the nearest hydraulic supply place. At this point, I'm wondering what he had actually done to it. He doesn't seem to understand what a seal head is - I'm giving him the benefit of the doubt because English is a second language for him.
Left it with him again but stewed about it all the way home. Phoned him up and told him not to do anything more to it. Went back and picked it up. I think the guy must have been pretty embarrassed - sent me a message that the shock would be outside the door and he was nowhere to be found. At least I didn't have to pay him anything. Over 300 miles worth of gas though.
Decided to take it apart myself which turned out to be pretty simple - cap off, retaining ring off, a shot of compressed air in the hose fitting for the oil reservoir and the internals slid out easily.
Ordered a new seal head kit from an outfit called Stadium in Montreal for about $40 US. Turns out they're out of Europe and build shocks for all kinds of bikes.
Simple to install. Filled up the oil with 3.5 wt and assembled the reservoir and remote preload.
Got the name of another shock guy from one of the bike shops near here. Set up a time to get the nitrogen filled. Turns out he's only 20 miles from my place.
  Talk about night and day - this's guy's shop was like an operating room. Shocks of all kinds in very organized racks (who knew snowmobile shocks needed the rebuild -  revalving treatment). Turns out he's a Racetech dealer too. Really decent guy.
  $10 to fill the nitrogen and he was almost apologetic for charging me that.
Done and installed - we'll see how it works.
 
Lesson learned for now anyways - anybody can claim to be an expert. Feels like I dodged a bullet on this one.

[FJ1200W]

Pat:   the site for the shock lengths is:
        Motorcycle rear shock lengths/cyclecycle.info
  I'm waiting for the plague to abate before I venture over to the shock guys shop for the seal head kit, oil, and nitro charge. Probably won't be until spring to see how it works out.
Pete
 

Thank you - That gives some possible options!