Hey there. I never realized that OddBike hosted this on RU-vid. I'll answer the questions: No, no recent video of this bike: it was basically an "art bike", and was horrible to ride, but the front suspension worked fantastically well. The running components were returned to their donor chassis in 2020, and a custom scrambler was built from it. Thank you! I take "insane" as a high compliment. :) No, in fact, the A-Arm length is how you control the wheel path, and pretty much have to be unequal-length to get a pretty straight wheel path. The more vertical the wheel path, the greater anti-dive it has. The more leaned back (like teleforks) the more pro-dive it has. If the wheel path lengthens the wheelbase, it is actually pro-rise. Tony Foale is who I learned this from. His books are utterly invaluable when designing motorcycles. Спасибо! Быть маньяком - это круто Hitting a curb... I think the rim would bend. On this bike, the A-Arms were constructed of 1" .074-wall tubing, and have solid 3/4" pivots. For comparison, a pre-runner truck uses 1.25" .125-wall tubing for it's suspension components. The truck uses material that is ~4x the stiffness but the truck weighs more than 10x what the bike weighs. But, generally, if I'm hitting a curb, I'm having other problems to worry about.
Put the joint steering ball allover the imaginary lines better the top triangle pins en the chasis and the bottom pins triangle on the chasis Them when the suspension move up or down you have same line on the steering
I'd like to see the Wishbones separated a bit more, the closer they are together (vertically), the more strain they're put under during Braking. Also, Rod Ends aren't designed to take loads in the way the Lower one is set up, with the Suspension loads going through it. Interesting take on Mr Hossack's design though, and nice to hear him getting a credit/mention.
Alan, you turned me on to this video many years ago, but I lost it, so pleased to stumble on to it today! I am just starting work on my dit bike front end, finally!!
No. In a Girder Fork System, the Upright is held by (and moves on) Four Link Arms (two on each side), the Link Arms attach to upper and lower Fittings that Pivot in a conventional Headstock. There are many different design variations, but they basically all work the same way. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-2nA2X_WPM9g.html
@@chrishoesing5455 Sort of Chris. Unsprung Mass would be similar with both Systems, The Upright and everything on it (Wheel, Brakes, etc), and (most of) the Link Arms and Shock.
@@Docv400 sorry I should have said swivel, not pivot. I meant the head tube and bearings. The girder would have slightly less moving mass as the two large bearings wouldn't be a part of it.
By altering the lengths, and the position of the pivot points you can get almost any wheel movement path you would want for whatever the bike will be used for.
You are getting into 4-bar linkages, which can do some pretty cool motions. If the linkages were the same length and parallel (not crossing each other), you will get motion that maintains the same angle/parallel. EG you could make a desk that works for sitting height and can be raised for standing height and it would still be level/not dump everything off it. If they are unequal length linkages, then motion causes angle change. But if you consider what is happening to the rest of the bike geometry, the front end would be diving, so even though relative to the pivot points, it would be parallel, the actual total effect on the bike would be rake angle loss and trailing loss (just like a normal bike). But then you would also have forward to back motion that doesn't exist in regular bikes (well, except by flexing). That would affect wheel base, but could actually be tuned to get rid of the loss of wheel base regular bikes see when the front dives. If you make the top link shorter, the front wheel will swing further out (more rake, more trail, lengthening wheel base and looking more like a chopper). This could counteract some of the effects of front end dive. But overdone, that would cause competing motions when hitting something like a curb or exiting a pothole. The backward force would try to _raise/extend the suspension,_ at the same time that the upward force is trying to lower it. If excessive, that would make the front suspension not even react/move (wham!) or even increase the upward bucking. If you make the top link longer than the lower link, then the opposite effect happens. Hitting a bump/compressing the front would also tuck the wheel back/shorten wheel base. The angle of the pivots on the frame controls where the motion will go. Think about the 1st case with even length links (staying parallel) Now imagine a big circle. if you were having motion approximately tangent to that circle, what angle would you want to start at? The bottom and top have almost no vertical travel (bad for suspension). The sides have a lot of vertical travel and minimal front to back travel.
