Motorcycle Suspension- Setting Sag
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- sportbikewrench...
Dave Moss of Catalyst Reaction Tuning sets the sag on a 2009 Yamaha YZF-R6. Setting sag properly puts the suspension into it's optimal working range, based on a riders weight.
The suspension for all bikes is purchased and installed. As a manufacturer ideally you want to make 1 of something and sell only that to keep your costs down and profit up. In the suspension world which is why there are industry standards for fork spring length. It is also important to realize that the bike has a price point and every bike has a miss match of fork and shock spring rates so they leave you to fix the problem. Can't make a bike right for everyone.
Dave Moss
Host
@123cyberaug321 Hi Dan,
I may well be coming back a couple of times this year to support some racers that I help via the web. That will turn into a week long stay and working vacation to pay for the trip but it will be nice to be back in Manchester.
SRAD fork sag at 30-35mm and rear shock sag at 25-32mm including free sag. Those bikes were very softly sprung so you may need fork compression to be almost closed to stop initial dive. Where and with what group will you be riding?
Dave Moss
Host
@123cyberaug321 Waiting to get the race schedule from those I support with the NG road racing organization. The dates will appear on my web site schedule page in about a month.
Dave Moss
Host
you don't have to have the hydraulics all the way out to set sag. Set spring tension first, rebound second and compression last
Dear Dave, I am adjusting the suspension on my stock 2004 Honda CBR1000rr. I defined an initial target rider sag based on the amount of travel for forks and shock given by the manufacturer. In my case, the travel is 110mm on the forks and 135mm on the shock (according to the Haynes manual). So my target sag of 1/3 to 1/4 of travel would be (in average) 30mm in the front and 37mm in the back. This seems to contradict the common recommendation of having a lower sag in the rear. Could you please help me out? Thank you!
Hi. My bike is Yamaha Rn09 . The front fork travel is 120mm and rear
65mm. Should I set F:40mm and R:22mm on the road and F:30mm and R:16mm
on the track ?
Hey Dave, thanks for your reply.
Excellent news your thinking of coming to UK, what tracks would you intend on working at? Would be great to come and meet you and have the bike set up properly.
Brands Hatch is the closest track to me so would be looking to go there most, starting in the novice then hopefully moving up to intermediates.
I've done one track day at brands last year booked with club MSV.
hoping to do as many days as I can this year, been bitten by the bug!
cheers.
@Dave Moss, Hello.. nice video. I have a 99 Hayabusa and just changed out the front fork springs with Wilber's. I noticed that I have front end wobble. I also would like to adjust SAG as this was/has not been done properly. I weigh roughly 215 without gear. The bike is also lowered and has touring cases. I know, this is not your typical busa but I still need it setup right. So, any ideas as to where I should be on measurements(front and rear)? Any advice would be appreciated. Thanks!
For Kawasaki 2005 ZX-12R stock front springs at 0.86kg/mm. With such a heavy bike - wet 248kg and stock preload settings, front sag would be around 50mm even for their specified in the manual 68kg test rider. With Ohlins fork springs for zx-12r (~0.97kg/mm) and ALL PRELOAD ADDED, front sag will be about 42mm to 44mm for 80kg rider. Mechanical bottom out is 14mm from axel casting. 120mm travel. Is there any reason why Kawasaki would build a bike with 50mm front sag?
any chance you guys could make one of these videos for a 99 zx6r or somthing in that era so we could see what a bad setup looks like and what you would do to correct it. just to help show what uneven setups look like and show the progress of fixing it for those of us with older bikes.
Can we also use a chock to set sag or should we always find a third person? Also is the numbers you say front and back a good starting sag point for all sport bikes? Finally all your vids show inverted forks. Can u just measure silver part on conventional as well? Thabks for ur great info.
So when adjusting the springs we should have rebound and compression fully out and then set rebound and lastly hi and low speed compression? Would this be in the correct order to setting up the suspension as good as possible?
And +1 on appreciating your videos. :)
My 2014 z1000 rebound in the rear is so slow it's painful to watch after watching this video. The front rebounded is so quick I can't believe that Kawasaki sells the bike with this setup.
@SportbikeWrench Excellent, thanks for the reply. When you are measuring conventional forks can you still just measure the silver shaft like inverted? So much to learn, thanks again!
@SportbikeWrench I am actually interested in this aswell, got me self a '98 and the suspension is WAY too soft. Hope you guys can help me out with a nice video.
omg...thank you guys...this is exactly what i was looking for....GIve me some chon chon =)...seriously...good work
very good instructional video......
any chance you could do one for an Aprilia RS 125? lol
Great video and not important but funny since when is 589mm + 8 more mm equal to 596mm ???
@buddha65281 usually after replacing the fork springs the front end stands very tall and can create a wobble as the balance of the bike has changed dramatically. Sag in the front should be 30-35mm, in the rear with the bike fully loaded and you in your gear, it should be 30mm.
Dave Moss
Host
@BoomVision if you have a sport chock, that works fine. If you want extended length data, then a second person is needed to top out the front and rear suspension (that can be the rider themselves assisting). Then you can measure top out, static sag, rider sag etc and get all the data.
Dave Moss
Host
@MIGHTYSAMINYOURFACE You would be correct. For your weight, you are in the target range, but the shock is very soft compared to the forks. Make sure you service the fork and shock if they haven't been done recently!
Dave Moss
Host
@omfgthisisshittingme removing hydraulics is a great idea so they are out of the equation. You might also want to measure cold and then again after 50 miles to see what changes in sag numbers. I always do that just to be sure.
Dave Moss
Host
@BoomVision with conventional forks, measure from the lower triple clamp (top or bottom of it) to the dust seal on the lower leg.
Dave Moss
Host
@mercedesCH street settings are 37 to 42mm for the forks, 33-37mm for the shock. Track settings are 35-40mm for the forks and 25-32mm for the shock. This includes free sag as well so the front and rear suspension must be topped out to get the initial reading correct prior to the riding getting on board.
Dave Moss
Host
@BoomVision Thanks and remember that 'right' is relative to what you know. Once you have a base line then start tuning each suspension adjuster individually to get that adjuster set for you, your needs, and your riding style.
Dave Moss
Host
This is all in the owners manual.. why mess with what Yamaha themselves suggest for the street?
@nanahc that's an interesting thought! Let's see what we can figure out in regards to this for a future video.
Dave Moss
Host
If we can get our hands on one we will. We start filming again the second week in January for the suspension work.
Dave Moss
Host
we can change the phrase to ride higher in the stroke for better accuracy.
Dave Moss
Host
whats the correct sag for racetrack front and back?
Great videos. Are most of these adjustments tailored to mostly track riding opposed to street? Or is there not really a difference ? I have an 07 r6, over 10k mikes...i've never taken it to the track and never will. Still riding on suspension settings bike left dealer with. Wondering if i should get it adjusted for the casual street riding i do.
i have a pogo issue with my bike! i have to adjust!
great video, thanks for sharing
5:40 what's really confusing..is to hear an expert saying that you basically make the spring stiffer by increasing preload which is not true. And I know you guys know it, but I hope you can clear this up before riders get confused and spread the word.
I love your videos, greetings from germany :)
Hi Dave,
I've been watching a lot of your videos and learning a great deal, they are by far the best i've seen. Wish you worked in the UK, Keep up the great work!
I'm going to attempt to set up my suspension for novice track riding. What would you say is a ball park figure for front and rear sag for the track?
I'm using a gsxr 600 srad on stock shock and forks and I weigh 11 stone (154lbs)
Any other tips other than whats in this vid for initial set up.
Many thanks
Dan.
Perfect overview of this topic; exactly was I was looking for; clearly, Dave knows what he is talking about....thanks for the information.
what kind of chalk is that?
Thank you for clearing that up for me. Your knowledge is insane (in a good way) from your help I'm finally learning how to set this bike up after five years it's now a totally new bike.