rear shock help

[Merlin]

Brian, go back and reread my post, the point was you said the laid down mount made no difference, I begged to differ by reason of if it were strictly a "travel issue" why would the manufacturers of 4-5 inch travel sportbikes go to all the trouble of the elaborate linkage? The fact is even a poor design forward mount or laydown with 4 inches of travel will still produce more traction that will equal better performance, hence the Maico example. Not opinion, fact.

Quote: Thomas Jefferson, We are all born ignorant, some work to remain that way.
 Quote:Merlin, "it is impossible to teach those that wish not to be taught".

[Merlin]

quote:Originally posted by john durrill

Merlin,
 CZ hop? Always wondered about that and thought we could get my 74 TNT 175 working better if we had moved the top mount forward some.
John D.

 John, part of this classic trait is two fold. First, most people (myself included) read and believed more damping was better, it was if you did not over do it. Most of us made the mistake of turning up the damping too much on our Koni's (Curnutt and Girlings had fixed damping thus no problem), what it caused was "packing" that is the suspension would travel 50% and only return 1/2 the distance hit the same size bump again with only 75% of the travel available so 50% of 75%= less than a 1/3 after rebound and so on until the suspension stayed compressed causing the infamous "hop". The second was CZ made a rear section frame change when they "revised" the twinpipe design to the sidepipe/yellow tank design. What they did was take the rear tubes that on the twinpipe went from the swingarm pivot straight up to the seat/tank junction to the swept forward to a 1/3 of the way up under the tank design. The latter design allowed the rear section to flex helping cause the "hop" unless the suspension was perfect, even then the upper limit of the design was low. The next version of the CZ( pre Falta short travel red frame type) reverted back to the twinpipe rear frame design, problem solved.

Quote: Thomas Jefferson, We are all born ignorant, some work to remain that way.
 Quote:Merlin, "it is impossible to teach those that wish not to be taught".

[john durrill]

Brian,
 This is not a fact LOL but the lay down did work better on Hodakas back in the day over moving the shock forward on the swing arm. That was my impression from riding bikes done both ways. I think that was one reason in 72 when the Wombat came out it worked so well on the trails.
My bike does seem to work better with the shocks layed down even when i am not using 1/2 the travel that is their.
 I think Merlin must be right. You may also be correct. The reason i think that is there are a lot of things that contribute to how well the shock works. Things like how big is the oil reservoir , leverage loads , etc. So it may be one of those design deals where its a trade off to use one over the other. Dictated buy how the rest of the pieces and parts of the bike fit together and affect each other as an assembled tool
 I would think if the shocks were built by someone like Works to be used in the canted position any design changes needed to optimize the shocks performance are their.
Same thing with the mount setup you were talking about. I dont "know "
 But i bet there are design trade offs that are taken into account for each setup.
 I do Know a lot of bikes used the canting setup and had very good bikes that handled well.
 
John " still in the dark about a lot of things " D.

[tomale]

John that has been my experience as well, A couple of years ago, several of us were talking with the late Jim Pomeroy and he was talking about his least favorite Bultaco.. strangly it was the Pomeroy replica. The reason was the shocks were nearly straight up and down... It was as if the only change to the bike was forward mounting of the shocks on the swingarm. He said it tended to hop on down hill bumps and high speed braking into tight corners... Which is why it makes me wonder why the rear suspension on modern bikes works as well as it does. Maybe it is because of a superior shock technology rather than superior shock position.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)
72'sixday (project bike)

[john durrill]

Merlin,
 Thank you. I will print your reply and put in a ring binder I keep.
 Months or a year or 2 from now i will need that very good information and have it on hand.
 My memory is not worth two hoots anymore i am afraid
 chuckle chuckle!!!
 John D.

[brian kirby]

OK, I guess looking back my statement was a bit too emphatic. Merlin and John are right shock position does effect the suspension, but I stand by my statement that it is a minor issue not to be fretted over. You are not going to win or lose because of how your shocks are mounted on a bike limited to 4" of travel. More important is the shocks you get are of high quality and set up properly for your application, and the rest of the bike is also prepped properly.

Brian

'73 Berkshire Team  d-Con
//www.d-conproducts.com America's #1 Rodent Control Brand

[Jerry Chafton]

Brian, I agree with you that it's not a win/lose situation with just 4 inches of travel. I rode 360 CZ in 70-71 (orange tank single chrome pipe)and there was never a better hole shot MX bike built but the Penton outperformed in every event except MX. I really enjoy getting all this feedback from you guys.
Like John my memory from 35 years ago is a little faded but I remember one thing for sure, the older I get the faster I was. ha ha