Quote:
Originally Posted by
Petenz (Post 224591)
Why havn't they taken the weakest option and bent sideways...
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Probably, I’d assume, due to the clamping forces of the bolts holding the plates against the bearing collars meaning the whole thing is kept dead square; the two linkage plates are perfectly parallel and the collars/bearings/bolts are perpendicular to them. The whole thing is dead-square. The resultant forces in the linkage plates will be exactly and directly opposed to each other, whether under compression or tension. The plates would only bend outwards (or inwards) should the arrangement become out of square and the forces become off set to one another. For example a worn needle roller bearing, worn collar or a loose bolt could potentially cause outward or inward bending. The main thing though, is that even if they were made of material too thin/weak to start with (which the Projection Components items most certainly aren’t) they would more likely fracture, crack, tear or split under the tension that the system is under 99% of the time, long before they ever had the chance to bend under compression.
Quote:
Originally Posted by
jon660z (Post 224603)
Because they are under tension so effectively are always being pulled straight?? Another thought i had ia that maybe they arnt "bent" as such but "stretched" as the bolt holes are off the centre line of the links. Think of a banana if you pull it from either end it will straighten out. And ita effective length will be longer.
I think im correct in saying that the shorter the links the higher the rear end. Mine are lift links yet they were near as makes no difference the same length as the stock ones when i removed them.
Heavy loading and jumping a 200+kg bike with +110kg rider could have bottomed the shock and the links were pulled straighter by the force?? I used to use a hyperpro progress spring along with the progressive linkage on the Ten would have made it virtually impossible too bottom out. All that pulling force would have been on the links.
Discuss.................
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Banana is a good example and yes, because of the bend, your links have ended up longer and a similar length to OE. The shorter the linkage plates between hole centres the higher the bike by a ratio of 1:3 so 5mm closer hole centres will give approximately a 15mm rise at the rear.
Quote:
Originally Posted by
jon660z (Post 224604)
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Theoretically the effective load is between the centre holes, but it isn’t in reality with the projection links because the holes have no material between them to transmit that force where it would want to go (between the holes centres/dashed line on your drawing/yellow line on mine below). In a normal stock linkage plate this would be the case. The actual force in the Projection Components linkage plate is transmitted along the top edge of the (as orientated in your drawing) – following the red line. This creates a moment arm (blue line): the product of the a force and the distance from a its reference point (hole centre in this case). This moment arm creates torque, and that torque, because the forces are acting in opposing directions, acts in different, opposing directions at each end of the arm, resulting in the bending (or stretching if you like) observed. This torque reaction will apply equally whether the opposing forces are pulling or pushing against each other (topping/bottoming-out); it just means it would bend the other way.
http://i864.photobucket.com/albums/a...psn8xoltze.jpg
In layman’s terms, here’s an example that might help: If you get a four hefty chaps at each end of a traditional style hospital bed like this sort of thing…
http://i864.photobucket.com/albums/a...ps0jj5yysl.jpg
…and they grab the head and tail ends in line with the mattress base frame and pull, or push, the bed will not bend in the middle. If those hefty chaps now hold the bed at the top of the head rails and tail rails and pull, or push, with exactly the same force, the bed will bend in the middle (upwards if pulling, downwards if pushing) because of the moment arm introduced (additional distance from the force’s reference point which is level with the base, the link, or couple between the two bed ends) and its resultant torque.
In a nutshell Jon, all of the above was the result of your shagged OE Sachs shock allowing the suspension to crash into the bump-stop on compression and extension without any control/damping at all. Personally I think the PC links are more than man enough for the job if everything else is in GWO; they just become the weakest link in the chain if something else in that chain craps itself!
