Great page on different suspensions
- Thread starter spalkin
- Start date
Help Support Yamaha FJR Motorcycle Forum:
Capt. Bob
Bilge pump. A novel idea.
That Bay County Boy sure gets around. 
wfooshee
O, Woe is me!!
Jus' tryin' to enlighten the unwashed heathen. B)
The main subject of that board, how it started, is the GT games for Playstations. Those folks saved me a lot of thumb stress over the years!
The main subject of that board, how it started, is the GT games for Playstations. Those folks saved me a lot of thumb stress over the years!
wfooshee, I am unwashed and heathen. I didn't know THIS. Der. Thank you.
"At this point I need to express very strongly that you NEVER EVER shift a motorcycle that is not moving, except to get 1st from neutral, and even that is only with the engine running. The reason is that when nothing in the box is turning, the dogs will not engage, yet the shift fork is moved fully into its position. If that is the case, something has to give, and you end up with bent shift forks, subsequently resulting in poor shifts, or actual failure to shift into certain gears. If you're test-riding a bike and you find one gear that engages harder than the others, or slips into a "false neutral" between gears, this might be the problem, and you want to avoid that bike. ."
"At this point I need to express very strongly that you NEVER EVER shift a motorcycle that is not moving, except to get 1st from neutral, and even that is only with the engine running. The reason is that when nothing in the box is turning, the dogs will not engage, yet the shift fork is moved fully into its position. If that is the case, something has to give, and you end up with bent shift forks, subsequently resulting in poor shifts, or actual failure to shift into certain gears. If you're test-riding a bike and you find one gear that engages harder than the others, or slips into a "false neutral" between gears, this might be the problem, and you want to avoid that bike. ."
Last edited by a moderator:
MotorToad
Well-known member
Gah, man, you didn't mention the Gilera strut type front end! (It's basically the same as Cannondale's "lefty" fork, and about as useless.) The fact that BMW invented the telescopic fork or BMW's first "anti-dive" fork, the leading link.
BTW, BMW's "duolever" suspension has been known for decades as the Hossack. (Shame on them for stealing it and changing the name!)
After the Tesi and Hossack, I think my favorite fork is the Motocysz, not just because it has much less unsprung weight but it uses roller bearings instead of plain bearings in the sliders. Linky to very not small picture.
One thing I'd categorize as a correction, though, is that you said it matters if the forks are sprung differently. The loading on the fork bushings is such a tiny tiny fraction of what they're designed to withstand (braking) as to not matter at all. Many bikes have springs in one fork and damping in the other, or compression in one fork and rebound in the other. You probably won't find that done on the MotoGP grid, but I don't think they'd let it loose on the public if it were going to cause wrecks and subsequent lawsuits.
And if you really want the best example in history of how not to make a shaft drive system, Google the Laverda V6 endurance racer.
That's the later version with the longer swingarm and telescoping driveshaft. I'm too lazy to hunt down the early bike where the swingarm was the same length as the driveshaft.
BTW, BMW's "duolever" suspension has been known for decades as the Hossack. (Shame on them for stealing it and changing the name!)
After the Tesi and Hossack, I think my favorite fork is the Motocysz, not just because it has much less unsprung weight but it uses roller bearings instead of plain bearings in the sliders. Linky to very not small picture.
One thing I'd categorize as a correction, though, is that you said it matters if the forks are sprung differently. The loading on the fork bushings is such a tiny tiny fraction of what they're designed to withstand (braking) as to not matter at all. Many bikes have springs in one fork and damping in the other, or compression in one fork and rebound in the other. You probably won't find that done on the MotoGP grid, but I don't think they'd let it loose on the public if it were going to cause wrecks and subsequent lawsuits.
And if you really want the best example in history of how not to make a shaft drive system, Google the Laverda V6 endurance racer.
That's the later version with the longer swingarm and telescoping driveshaft. I'm too lazy to hunt down the early bike where the swingarm was the same length as the driveshaft.
![fjackets Real Lambskin Leather Biker Jacket — Quilted Cafe Racer Zip Up Moto Leather Jackets For Men | [1100085] Johnson Brown, XL](https://m.media-amazon.com/images/I/41I7Pm1f+vL._SL500_.jpg)
wfooshee
O, Woe is me!!
I had almost included that leading link fork, because we saw one at AHRMA last year parked near us. It actually raises the front end under braking! How weird would that be? My pics of it sucked, though, so I dropped it.
The Motocysz is supposed to have some engineered amount of side flex in the forks, is it not? The fork blade makes kind of a vertical leaf spring (allowing the wheel to move laterally) without actually being springy, just a little flexible?
The Motocysz is supposed to have some engineered amount of side flex in the forks, is it not? The fork blade makes kind of a vertical leaf spring (allowing the wheel to move laterally) without actually being springy, just a little flexible?
Last edited by a moderator:
MotorToad
Well-known member
Yeah, the fork "tines" are ovoid so they allow some side flex but not flex under braking. They've been messing around with "tuned flex" as Honda calls it for a long time. Swingarms and frames are pretty easy, but traditional forks have had to be round so it's never really made it that close to the front wheel before.
I've heard that Colin Edwards' ability to tear the second half of the 2002 WSB season apart and win the championship (Bayliss basically won the first half, Colin the second) was because they left a front engine mounting bolt out of the bike making it flex more and handle better. This is completely unverified hearsay, but I think it's entirely possible or maybe a misinterpretation of the actual event.
BTW, I'm pretty sure that's my cigar buddy's LTD in the background.
Last edited by a moderator:
Similar threads
