Static Sag v Rider Sag
Discussion
bass gt3 said:
Ahhh yes, my bad.
Seriously, ignore Static sag. The bike can't ride itself so it's a somewhat meaningless number. The goal is to achieve the required sag numbers with a couple of turns of preload in the front and the normal 12mm in the rear. The rear is measured as spring length compared to uncompressed (free) spring length with it not mounted.
A better way to measure is to workout the stiction in the front & rear to see what condition the suspension is in.
I was wondering as I know you have to have some static sag as none is a very bad idea ... Seriously, ignore Static sag. The bike can't ride itself so it's a somewhat meaningless number. The goal is to achieve the required sag numbers with a couple of turns of preload in the front and the normal 12mm in the rear. The rear is measured as spring length compared to uncompressed (free) spring length with it not mounted.
A better way to measure is to workout the stiction in the front & rear to see what condition the suspension is in.
Stiction I can do ... Via Racetech methods... By taking an average
bass gt3 said:
Ohlins give some guidelines for static sag but if you achieve those numbers and fail on dynamic sag it's moot. Even K Tech advise to concentrate on dynamic sag only.
Doing stiction by the average method is handy but I suspect you'll be fine considering the bike is newish.
Cheers my man ... Off to read my new book... Doing stiction by the average method is handy but I suspect you'll be fine considering the bike is newish.
... More questions likely to be incoming!
You really should do a sticky post on suspension fella
... 95kg of beefcake! Measured standard ride heights with fatso here on the bike so can now work on keeping the bike balanced ...
38mm front sag = 9 turns from fully out and an increase in ride height of 6mm at the front ...
30mm rear sag = setting 6 out of 10 and an increase in ride height of 2mm at the rear ...
Forks dropped 4mm in yokes....
... That's how I roll ...
38mm front sag = 9 turns from fully out and an increase in ride height of 6mm at the front ...
30mm rear sag = setting 6 out of 10 and an increase in ride height of 2mm at the rear ...
Forks dropped 4mm in yokes....
... That's how I roll ...
bass gt3 said:
Balance is the key. As long as the bike depresses equally when pressed then you're ok. But going by the numbers above I'd say you're getting there.
Ohlins reckon 25 to 40mm rear and 35 to 50mm front as a dynamic number. I think that's a tad on the soft end at the extreme end but gives you a good idea
I've found that balance really comes from tweaking the comp screws so each end compresses evenly ... rather than the sag.Ohlins reckon 25 to 40mm rear and 35 to 50mm front as a dynamic number. I think that's a tad on the soft end at the extreme end but gives you a good idea
Rode the bike this morning and it feels great! Well impressed!
It's probably a little soft for track work but for the road its damn good... I will probably add a tiny bit of compression to both ends over the weekend but I want to go out on the bike for a few hours and experiment whilst the suspension is warm on the bike.
I'm no longer skipping over bad roads and it feels utterly planted in corners. Very confident inspiring.
Did more reading and apparently running a bit more sag in the front can be beneficial as it can prevent the wheel lifting under acceleration which is why most suspension experts recommend a bit more sag in the front than the rear. Makes sense... it also means I can get away with not winding up the preload so much on the front.
I might try going down a notch on the rear at some point as part of the learning process.
Understanding it is one thing... putting it into practice and feeling the difference is another. Hence by only changing one thing at a time you can experience the difference properly. Rather cool
t... I even sound like I know what I'm talking about! bass gt3 said:
See what I mean about instilling compliance into the bike? Yes, for track it might want a tad more comp but return to normal for road.
My work here................IS DONE!
What no more teaching!!! LolMy work here................IS DONE!
Got a track day booked so will be looking at how much compression to dial in for it ... I assume I won't need to touch anything else?
I will also be double checking sag fully kitted ... But that's for another day.
bass gt3 said:
I would start with half a turn of comp and see what the tyres are telling you. But try to avoid making the bike overly stiff, let the suspension work with the tyre, you'll be very impressed.
Well I've still to play with compression on the road yet ... A quarter turn at a time ...That will hopefully give me an idea of where I need to be at for track work.
bass gt3 said:
Problem is the static sag, as said it's pretty meaningless. However, the shop does need the rider to be present so there's a two way responsibility there.
But I'm not convinced by the rebound number being only 1 turn out. I'd suspect that'd be too slow even when warmed up.
Strange isn't it ... Maybe I should try them to see what it's like ... I'm just curious... But I'm not convinced by the rebound number being only 1 turn out. I'd suspect that'd be too slow even when warmed up.
This place has a big reputation as well as do a lot of race / TT prep bikes ...
I know for a fact though that 6 turns preload on front is going to result in about 50mm of sag with 15 stone on board ...
bass gt3 said:
What bike is it?? Model/year
And clarify topped out. Were the bikes wheels off the ground and where did you measure from?
Yamaha R1 4C8 ... 2008And clarify topped out. Were the bikes wheels off the ground and where did you measure from?
Sounds like sag is way too high to overcome preload ... The R1 likes more sag than most ... Aim for around 40mm front, 30-35 rear ...
Rick: if need hand fella pop over
I did find the R1 needed more effort to turn when pushing on... That's the bike mor than setup but your sag figures are too low.
bass gt3 said:
No, his sag figures are incorrect due to erroneous measurement process. Once the correct measurements are taken, then we can determine the sag as to being right or wrong. Don't be guessing!!
No, the R1 doesn't like more sag than most, it's a result of incorrect set up. Sag when right doesn't affect the geometry, don't be propagating urban myths which are baseless.
As for effort to turn, there's many other factors. Shallower rake, heavy wheels, forks pushed through to much, excessive trail due to triple clamp offset these will all sow the steering. Don't blame the suspension!!
Is a fair point ... Guess should confirm how the sag is being measured first before jumping the gun. No, the R1 doesn't like more sag than most, it's a result of incorrect set up. Sag when right doesn't affect the geometry, don't be propagating urban myths which are baseless.
As for effort to turn, there's many other factors. Shallower rake, heavy wheels, forks pushed through to much, excessive trail due to triple clamp offset these will all sow the steering. Don't blame the suspension!!
Edited by bass gt3 on Sunday 5th April 00:37
Edited by bass gt3 on Sunday 5th April 00:40
I ran a little more sag on front end on my R1 based of recommendations... In region of 40-45mm ... Hence my comments.
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