what is installed preload on a shock spring and how do we measure it?
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- Опубликовано: 23 июл 2011
- home.php#!/da... we use an 06/07 Yamaha R6 shock to demonstrate spring free length installed prelad and then range of preload adjustment this shock allows with its ramp adjuster.
This stuff is a science in its self! I'm hoping if I watch enough of Dave's videos the penny will finally drop. Great video thanks.
Um...science comes from the word Scienta: means to Know. Somehow along the way the Darwinist pretend they the creator of curiosity and development of what ever we engage in a scientific manner, HERE, it's science of Racing and Geometry. So development racers are many things and one of them things being, racing scientist 💯
Thanks for all your videos Dave, so clear cut..
@BoomVision we are reproducing more videos right now. Should be done in the next 2 weeks. At that time you will see 4 DVD's for sale. Twiddling Knobs, Introduction to Sportbike Suspension, and 2 Clicks Out Volume 1 and 2. Thanks for your patience.
Dave Moss
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Thank you sir. The whole preload thing was pissing me off trying to figure it out. The Ohlins manual has the free spring length at 210mm and suggests 10mm preload. So 200mm should be the length installed on the bike.
You saved me a shitload of head scratching.
Thanks! Your explanations are excellent.
Do you have a video which explains the effect of rear end sag on steering geometry when the bike is under power coming out of corners ? My own bike self-steers very strongly - tightens it's line and I use that to advantage. The relationship between gearing, power delivery and the trail is important. None of the MotoGP Workshop videos explain it in detail.
There are many files in the DM Tuning phone app relating to all these topics. There are some old OTT videos on these topics to as well as UStream shows feelthetrack.com/free-vidoes/ustream/
Phew finally someone explains it so I can understand!
hi Dave, nice clear video. just a quick question. You say either a fork or shock spring should have an installed preload of 8-14mm. This shock spring with164mm free length and 150mm installed, was getting a further 7mm max of adjustable preload which you said was shortchanging as max you could go to was 15mm. question...where you getting that 15mm from? like a rule of thumb, a percentage of freelength eating up compression or what? is that 15mm max same for forks too? cheers mate.
the maximum is based on the change in compression via preload of zero on the adjuster to maximum, and different types of shocks will have different ranges of none to max based on limits set by step adjustment, hydraulic range of 2 lock rings.
Mr moss. I see your dvds are not being sold nemore on ott. Are you going to get some more up i'd like to snag your set up and info dvds ya had up :) perhapes making new ones?
Hi Dave, i know this video is 9 years old now but i love to know more about your vfr400 race bike and its suspension set up. Cheers
That is a blast from the past. GP Suspension fork cartridges, .90 springs, 5W oil to 130mm. Rera shock was Penske triple clicker, 13kg rear spring, dog bones changed by 2mm for more ride height.
Dave Moss Tuning WOW thats impressive how did it perform ? Amazing i guess.
Im in the process of re-doing the suspension front and rear of my nc30. Ive fitted a 2010 bmw s1000rr shock to it but it must be re-sprung as the leverage and ratios of the dogbone is different so ive been watching loads of your videos to find out information. The standard bmw spring is 500lbs and ive been told i need a 900lbs.
@@karlogrady4907 The minimum rate on the NC30 was 1,000lbs for track use, so 900 for the street might work. Static sag numbers will show if that is correct.
Fantastic.
Hello
I just got a 2006 R6 shock from e-Bay. Can I tell if it is any good before I install it?
If the rubber bumper is clean at the base of the shock shaft, that is a good start. Check the screws are not hammered by crappy tools for compression and rebound. If the shock is very clean that could be promising. Once installed, the shock should not jump up or bounce and hydraulics from all the way open to closed should feel very different.
Thanks, rubber bumper and everything else is pristine. Soft-Hard screw is a little messed up. I am cleaning and re-greasing the linkage bearings right now. Thanks for the tip
Hello Dave. I am an average weighed man 75 kg, and since I have installed in my Bandit 650 front Ohlins springs, I did the SAG. At the rear, I have to put the preload in the position 6 of 7 to have a correct dinamic SAG (free SAG is correct also in this preload position). My question is: is that acceptable to put the preload as high in this spring or should I buy a hardest spring?
I have the front SAG adjusted and if I put the rear preload under 6 of 7, the bike doesn't enter the corners with the desires agility (I know it is not a sports bike but I can achieve a good handling on it).
Thank you very much.
Hello Juan. It is acceptable to set preload for sag numbers BUT, are you checking how much shock travel you are using? Have you checked how much fork travel is being used? If not enough, that explains why the Bandit does not handle when you change shock preload. Note that the OEM shock are good for 12-15,000 kms then performance starts to reduce.
@@catalystreactionsbw thank you very much for your fast answer. This bike is used in opened roads, not tracks, although I have meausered the front travel and the front axle is working fine when braking hard. The thing is that since the front springs are harder than the originals, I found the rear end to have to be hardened (spring preolad) to be within the original chassis geometry, because it's affected by the use of harder springs and when I enter a corner, the more opened fork angle makes the bike go out of the corner (when going fast). The Bandit hasn't many parameters to change but to achieve a good handling compromise I have to compensate the height of front and rear.
I have the rear preolad setting almost at maximum and my original question was if it is acceptable, and you said yes... Despite that, probably I'd need a replacement (31.000 km now, but it seems to work fine).
Thank you friend.
thanks for the video of 06 zx14 with black gentlemen becouse im about his weight but im 250lbs and i had almost same sag when i checked my 06 zx14 so hopefully it will help me too thanks your very good at what u do
You are welcome and thanks for watching. Al the settings we used will be a good starting point for you!
would the suspension being off before cause the bike to cut corners wide? its hard to describe what im trying to say almost like understeer? also does suspension sag out of adjustment affect a bikes behavior to wheelie or not wheelie (power wheelie specifically) mine would cause front end to skate and feel light but wouldnt lift up. guess im to fat for bike to lift front up from power but clutching it will.
Absolutely. Fork rebound is too fast the front wants to stand up too soon so you run wide. Go for the gas and the front wheel hunts for grips and feels light. Dial it in and reap the benefits of the changes :)
mr moss thank you so much for your time and help, ive been hoping to find good advice with this problem..im going to try a friends friend that rides track and he sets up his bike himself he said he would help me dial in bike if i can bring bike to him. thanks dave
excellent and share how you got on.
Good information
does adding preload lower the bike?
when you add preload, the fork and shock push themselves apart - raising the motorcycle higher