"Posh Racing Project" rear shocks

[Nessism]

Are there any safety standards for shock absorbers (ISO, SAE, ANSI, etc.)? Seems like there should be something applicable. Doing a simple pull test on one sample shock may not tell you a whole lot.

Personally, I'd take the shocks to some known expert in the field and have them dissassemble them and give you an informed analysis based on their experience.

[makenzie71]

I don't know that there are any safety standards, but I do tihnk they're technically supposed to be DOT approved...but I can't attest to that because I know the Bitubo on TLS, the foxes on my old GS, the Showas on my current GS, the Works on my old EX500, etc...none had DOT stamps.

There's been a number of people PM me here alone that they have testing facilities near them that tehy have used. I'm hoping to find a set that's seen some road use to send off to one of these places for a full work up. I'll be disassembling one myself eventually to measure seals and such and check into possible rebuild and upgrade capabilities.

[Mysuzyq]

I'm not sure you were a member here when we were attempting a group buy on 'Vipex' piggy back shocks, also being 'custom built to our specs' in China. Apart from the slick marketing line from the guy who pitched them here, they looked suspiciously similar in hindsight, to these generic items appearing on ebay. Unfortunately, things didn't work out as planned so we cannot comment on the quality, but a similar killer (no pun intended)deal did work out for the members on the CB1100 site, so it's probably worthwhile asking for input. IIRC, those were offered to us as a group for around $200.

Tony.

[makenzie71]

I plan to hit up the CB1100 site to see what they think...haven't been on there in a while. I'll have to look into what they were offering for $200...the shocks I saw offered were twince that. Looked cool, and probably worked better, but still...

[salty_monk]

If there was enough of us with money up-front I suspect I could work out a group buy to our spec in China....

[makenzie71]

That'd be spiffy, if they could provide unaffiliated testing to back their products. I would love to have the shocks Lionel offers, but with rebound adjustability and an inch longer.

[makenzie71]

What other forums out there might be interested in seeing whether these shocks live or die? I've got one set of shocks setup, but I really need to find second set...I've got a few donations to help cover the second set, and I've had offers to help with testing. The more people in on it, though, the better.

[makenzie71]

Well, the first set of shocks are now stateside. The seller is located in France, but the shocks hit customs in San Fransisco. Definitely shipped directly from Asia.

[makenzie71]

Very quick delivery. Mailed from Shang'hai on March 31, delivered to my door April 3rd.

First, I need to make sure that it's noted that Lionel is VERY helpful here, and he's been generous. Not only did he send a set of shocks to be put through the paces, he sent the "dual springs" ones that he sells for more money. He's got a pretty high opinion of them.

(pics tonight or in the a.m.)

The good:

The shocks look very good. The machine work is clean. The paint and anodizing are very smooth. Longevity of the finish can't be vouched for, but first impressions are very good.

Preload is easily set.

They DO have oil in them (or it sure sounds like there is).

The low:

No bolts are included for the clevite or adapter.

One of the clevites had burrs around the bolt hole.

The adapter seems a little shoddy. I don't trust it fully. I'll be machining a new clevite adapter from stainless I believe.

GS specific notes:

The clevite is 2mm too narrow for the bushings in the swingarm on the 1981 GS750, but the "Posh" adapter and the shock clevite are both cut the same so it may be just a matter of different bikes.

They're too short for the the 1981 GS750. I had to use the "Posh" adapters.

All in all, they look good, and the preload was easy to set. The rear is pretty firm, though, but I haven't had a chance to road-test.

[makenzie71]

The Shocks Project

[hp1000s]

[QUOTE=makenzie71;984854]Very quick delivery. Mailed from Shang'hai on March 31,
The adapter seems a little shoddy. I don't trust it fully. I'll be machining a new clevite adapter from stainless I believe.

Having been a tool-&-die maker for years(and a wanna' be engineer), both the lower clevis and adapter pieces scare me just a little; the radius in the inside corners is very small, considering the thin-ness of the sides...especially the adapter, since it takes completely different side-loadings...just looks like a stress riser to me. Plus, higher quality aluminum alloys typically don't have a tendancy to burr as much, even with a duller drill bit. My .02
Hugh

P.S. Thanks for the great pics and info! If the shocks will actually dampen, then it'd still be worth machining proper one-piece clevis' for them.

[makenzie71]

I think that the adapter is a poor idea and should be abandoned...if you need it to stretch the gap then these shocks should be avoided. It's not a very good alloy...it's very light, but I suspect that it is safe for a tempory piece.

I'll be pulling my swingarm, though, and installing another that I've added bracing to. I'll either raise the mounts some on the swingarm or move them further up the spars...which brings me a question:

Will moving the mounts closer to the pivot bolt increase or reduce the amount of force needed to compress the shocks?

See, now, I know the longer the lever, the less force is required...but I don't know how it applies when you're looking at angles other than applying force perpindicular to the ground. Geometry is hard to write out in text, with no pictures, but I'm going to try.

Upper shock mount is A
Pivot bolt is B
Lower shock mount is C

Say right now it's all 60/60/60 (Angle ABC is 60*, BCA is 60*, and CAB is 60*), with the wheel axle being 2" beyond point C on line BC.

How would it change things if we went to something like 50/60/70 with the axle being 4" beyond point C on line BC? Is that going to reduce or increase the amount of force needed to compress the shock, or would be about the same?

Ultimately, if I want the shocks to firm up the rear, the best way would be to move the upper shock mount further from the pivot, but I would like to avoid moving the shock mounts if I could.

[pontiacstogo]

I think that the adapter is a poor idea and should be abandoned...if you need it to stretch the gap then these shocks should be avoided. It's not a very good alloy...it's very light, but I suspect that it is safe for a tempory piece.

That's weird - I felt the opposite way. The alloy on the 'Posh' extenders is incredibly hard. Take a dremel or a file to it and you'll see what I mean.

When I pictured the 70mph crash that would turn me into the sausage creature I always pictured the shocks giving and not the extenders.

Or are you talking about the screw in portion for the clevis mounts?

[makenzie71]

The posh adapter isn't as poor as the chinese adapter...but I couldn't go so far as to say it's actually a posh piece. It's everything together that bothers me, not the adapter alone.

[voivod]

have been watching these shocks on ebay for quite a while . But noone has heard of them. Thanks for giving us the review as I do think I will get some .
ps can I ask what weight you are? (not being rude ...honest) As am only just 12 stone about 168lbs . So wondered if the springs were set up for a oriental weight ,not western. If I remember the original bikes in the 60/70's had this problem as were set up for japan