[xdonniedarkox]

Wow, amazing Dan. I'm having some suspension quandries and that read was perfect. Thank you for taking the time to write that:thumbup

 

[JohnnyRoastBeef]

This is just what the doctor ordered! I have been trying to gather info to set-up my stock susp. and you provided everything here.

 

[Devil1]

Very nice Dan.

 

[marcaztls]

Just to add mine to the countless list of thanks and appreciations you're bound to get for this thread before the questions start Dan, but seriously, thanks I know you've been working on this for ages but it looks well worth the effort indeed already.

Really look forward to sitting down and digesting this properly. Now hopefully I will finally begin to get my head around suspension and it's intricacies :thumbup

 

[marcaztls]

Okay, first question from me :lol

Assuming that once sag and rebound are set per your intructions, can they be considered 'set in stone' for the average rider who is just learning their way with suspension adjustments until they graduate to a better understanding?

I mean that until a good feel is achieved using compression damping there's no need to alter the sag and/or rebound at that stage correct? Until ultimately fine tuning suspension, sag and rebound setting per your instructions are very good starting points as far as I know and maybe this needs confirming for anyone 'wondering'.

If anyone would like I'll make a small video soon showing exactly what Dan means by the 'settling' on the rebound stroke once set as his instructions. It's exactly the same method I was shown by Doohan's ex suspension guy once and once you've seen it visually, it makes great sense

 

[GPD270]

Great write up Dan.

 

[im2fast2furious]

Great write up Dan, very helpful, its one to print out and put up on the garage wall:thumbup
If you get a chance you might give an explanation on how best to set up low medium and high speed compressionm on a shock. I have never set one up before and a brief explanation would be great if you have any experience with these type of shocks.

 

[turd1]

Great write up Dan, very helpful, its one to print out and put up on the garage wall:thumbup
If you get a chance you might give an explanation on how best to set up low medium and high speed compressionm on a shock. I have never set one up before and a brief explanation would be great if you have any experience with these type of shocks.

what brand rear shock has low-med-high compression adjustments?:dunno

 

[turd1]

Okay, first question from me :lol

Assuming that once sag and rebound are set per your intructions, can they be considered 'set in stone' for the average rider who is just learning their way with suspension adjustments until they graduate to a better understanding?

I mean that until a good feel is achieved using compression damping there's no need to alter the sag and/or rebound at that stage correct? Until ultimately fine tuning suspension, sag and rebound setting per your instructions are very good starting points as far as I know and maybe this needs confirming for anyone 'wondering'.

If anyone would like I'll make a small video soon showing exactly what Dan means by the 'settling' on the rebound stroke once set as his instructions. It's exactly the same method I was shown by Doohan's ex suspension guy once and once you've seen it visually, it makes great sense

get titanium nitrided ohlins forks and the stiction is minimal compared to run of the mill forks.:lol:flex::sing:

 

[DanQ]

Okay, first question from me :lol

Assuming that once sag and rebound are set per your intructions, can they be considered 'set in stone' for the average rider who is just learning their way with suspension adjustments until they graduate to a better understanding?

I mean that until a good feel is achieved using compression damping there's no need to alter the sag and/or rebound at that stage correct? Until ultimately fine tuning suspension, sag and rebound setting per your instructions are very good starting points as far as I know and maybe this needs confirming for anyone 'wondering'.

If anyone would like I'll make a small video soon showing exactly what Dan means by the 'settling' on the rebound stroke once set as his instructions. It's exactly the same method I was shown by Doohan's ex suspension guy once and once you've seen it visually, it makes great sense

Excellent question!

Because of the way we change our position on the motorcycle, gain or lose weight, change our riding gear, and even as the components age, changes may be needed through time. The bigger of these is due to our riding style and preferences. As time goes by and we start with a good known starting point we will want to make small, subtle changes to the front/rear bias etc.

Small changes in the sag can allow us quicker turn in by decreasing the rear sag slightly, or increasing the front, thus changing the geometry a bit. Likewise, if we have a quick enough turn in but the bike becomes twitchy at speed or under hard acceleration we can increase the rear sag or decrease the front for more stability.

When we do make changes we have to review all the settings to ensure that they have not been changed by the changes made to other settings, as well as verify the overall balance of the machine has not been altered.

Overall as we tune our suspension one of the most important tools for us to use is a method of recording the information such as the data sheets on Dave Moss' website, or a good notebook. The Tuning Guide page on Catalyst Reaction's website has real good examples of the data to record.

I haven't considered linking video, but I do think it's an outstanding idea. I have a set of Kayabas I'm going to be rebuilding with Race Tech 20mm parts (Hi Frequency Rebound valve, Gen II Compression valve, and 1.0 kg/mm springs). I may have to try shooting some video clips to show the rebound stroke and adjustment. As I was going through the materials I took in, it made most sense watching Dave Moss actually do it on the "Introduction to Motorcycle Suspension with Dave Moss."

 

[DanQ]

Great write up Dan, very helpful, its one to print out and put up on the garage wall:thumbup
If you get a chance you might give an explanation on how best to set up low medium and high speed compression on a shock. I have never set one up before and a brief explanation would be great if you have any experience with these type of shocks.

I've only heard of high and low speed compression damping. And it's most notable that the high speed compression damping is used to to control the high speed shaft or fork movement, not necessarily the motorcycle speed. This will come in handy adjusting for ridged or sharp edge bumps on the track (such as a pavement joint you hit every lap).

The major adjustment on this type of shock absorber or fork will still be made to the normal, or low speed compression damping.

 

[Redgecko]

Thanks for the work putting this together Dan, I am determined to try and work on a better setup this coming riding season and this will make an excellent reference.

 

[sss r1]

thanks for your work dan! as i promised i had some questions on my mind for a long time , so now i have a place to ask

ok , my first question is about the rebound damping .
i always wondered if rebound damping setting can actually help to keep the wheels on the road ,or is it a myth, i'll explain

lets say u are riding at high speed and there is a single bump on the road (i made a pic lol)
once u hit the bump , the front suspension will compress and absorb the energy of the bump .
now , the question is , when the front wheel is now over the bump (left side of pic) and u are riding at high speed , can the fork really expend that fast and keep the wheel on the ground in the area marked red on the pic?
my logic tell me that the fork expansion should be as fast as a bullet to actually do that ...:drunk:
or , maybe the wheel is actually howering above that area and comes down later. and this is probably happens so fast that we dont feel it .

or...
maybe the energy absorbed by the shock when its being compressed ,can be reliesed as fast as it was absorbed ,somehow :lol.

 

[xdonniedarkox]

Again thanks Dan and a Sticky... nice one.
Printed out for the garage and some work.


:thumbup!

 

[DanQ]

thanks for your work dan! as i promised i had some questions on my mind for a long time , so now i have a place to ask

ok , my first question is about the rebound damping .
i always wondered if rebound damping setting can actually help to keep the wheels on the road ,or is it a myth, i'll explain

lets say u are riding at high speed and there is a single bump on the road (i made a pic lol)
once u hit the bump , the front suspension will compress and absorb the energy of the bump .
now , the question is , when the front wheel is now over the bump (left side of pic) and u are riding at high speed , can the fork really expend that fast and keep the wheel on the ground in the area marked red on the pic?
my logic tell me that the fork expansion should be as fast as a bullet to actually do that ...:drunk:
or , maybe the wheel is actually howering above that area and comes down later. and this is probably happens so fast that we dont feel it .

or...
maybe the energy absorbed by the shock when its being compressed ,can be reliesed as fast as it was absorbed ,somehow :lol.

That is ABSOLUTELY one of the reasons many say rebound damping is so important. The rebound stroke is what is allowing the tire to go back down and stay in contact with the road. When we are "bouncing" the suspension to find a starting point, we see it as the suspensions upstroke. But that same force is what is moving the wheel back down to stay in contact with the road surface.

I had a first hand sampling of this during a track day at Barber Motorsports this past autumn. I was taking sections of the track more cautiously than others (first time being at that track) and came out wider than I had after Turn 8. When getting on the gas hard, the rear of the machine started to bounce so bad I could actually HEAR the motor spinning the tire to the point I thought I was bouncing off the limiter. W8nonu even heard it from off track. After getting off the track and talking to control riders, Plimmer, and GPD270, they all confirmed that was a good line to take, but most stayed off it because of the road surface. I was about to adjust the high speed compression damping thinking that was what was causing it, but looking in the troubleshooting section of Andrew Trevitt's book (I really do bring it with me everywhere) I realized I needed less rebound damping.

The next session after removing two clicks of rebound I was able to hammer that section of track without having the tire lose grip, and was carrying much greater speeds into the next couple of corners.

So long story short, it's not a myth. It's the reason most tuners regard rebound damping so highly.

Thank you for the question and helping to illustrate this point! :thumbup

 

[im2fast2furious]

what brand rear shock has low-med-high compression adjustments?:dunno

Its a Maxton GP7 shock. Got it there a month ago I haven't used it yet but they are meant to be really good.
Now its already been set up in the factory for me so I shouldnt need to adjust it much, but in case I do Im scratching my head a bit trying to understand how to adjust it. Adjusting high and low can be difficult enough but throw an other setting in there and I don't know.

 

[turd1]

thanks for your work dan! as i promised i had some questions on my mind for a long time , so now i have a place to ask

ok , my first question is about the rebound damping .
i always wondered if rebound damping setting can actually help to keep the wheels on the road ,or is it a myth, i'll explain

lets say u are riding at high speed and there is a single bump on the road (i made a pic lol)
once u hit the bump , the front suspension will compress and absorb the energy of the bump .
now , the question is , when the front wheel is now over the bump (left side of pic) and u are riding at high speed , can the fork really expend that fast and keep the wheel on the ground in the area marked red on the pic?
my logic tell me that the fork expansion should be as fast as a bullet to actually do that ...:drunk:
or , maybe the wheel is actually howering above that area and comes down later. and this is probably happens so fast that we dont feel it .

or...
maybe the energy absorbed by the shock when its being compressed ,can be reliesed as fast as it was absorbed ,somehow :lol.

remember that the tyre itself absorbs and releases energy too. so tyre profile/size/construction/pressure also factors in.
the actual bump size and shape will also be a factor.
speed of travel over the bump is a factor.
speed of compression on bump entry is a factor.
speed of rebound is a factor.
next bump or wallow coming up is a factor.

i guess you are wondering where all this is leading?:lol
well my point is......setting up suspension is always a compromise for the particular job you have set it up for.
this is true for ANY situation you ask of it...e.g different roads/condition/speed of riding/oil weight/airgap/spring type(progressive or linear) etc etc.

this is also the reason pro's setup suspension on their bikes which is unique to every different track, and even different conditions on the same track that they go to.

the trick for us mortals is to find the 'compromise' to suit the wider range of tasks we ask from our 'streetbike' suspension.
there will always be certain circumstances where our suspension is at the wrong end of that compromise and it wont 'feel' very good.:thumbup

 

[turd1]

Its a Maxton GP7 shock. Got it there a month ago I haven't used it yet but they are meant to be really good.
Now its already been set up in the factory for me so I shouldnt need to adjust it much, but in case I do Im scratching my head a bit trying to understand how to adjust it. Adjusting high and low can be difficult enough but throw an other setting in there and I don't know.

nice:thumbup, i hadn't heard of that model shock before. have you got a pic of the shock and it's adjusters?:hellobye

 

[DanQ]

I'm reading about it here.

 

[sss r1]

dan,
in my example , if we will assume that the slope of that bump is 45 degrees ,and , u are riding 100 mph over it ...
if the tire is actually contacts the red area (45 deg slope) , that means that the fork expends at a speed of 100mph , how can that be possible? even without oil and seals ,i think there is no way the fork can expend at 100mph (45 degrees angle , so that means up/down movement equals left/right movement , which is a bike going at 100mph).

blu ,
thats a good point , if the bump is small enough it will be absorbed by the tire.