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Shock And Fork Spring Rates


boris

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hi guys ive got a 2007-8 r1 track bike. its got a wp4618 shock and i cant find the spring rates anywhere. it says 90-150. im presuming that means 90kg ??? ive looked everywhere but cannot find any info on what the markings mean, does anyone know? am i being stupid?(probably)

also the front forks have some sort of ktech upgrade as bike was a yamaha r1 cup bike back in 2008. jon kirkham rode it but obviously i cant ask him what went on in there but i have a set of 10 and set of 9 springs he gave me. i dont know what the numbers mean as theyre just in a box with the numbers on them and ktech above the numbers.

can anyone help as im having trouble finding a setup that suits my weight and was told i should look into finding out what spring rates are for me then goint from there before i try another setup at a track this year.

any help will be appreciated

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Racetech website is your friend. I'd guess you have 0.9 or 1.0kg/mm fork springs, and rear shocks are usually 8.5 or 9.0kg/mm etc

ktech might rate their springs in Newtons, but 1 Kg = 10N (ok, 9.81, but it's near enough)

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90, 150 prolly means 90(N) rate or 9.0(kg) and 150mm free length

Racetech says 0.95 and 9.4 are standard, and use 1.0 and 9.0 for racing (80kg rider) as a starting point. seems sensible to me

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ok cool. its so confusing. im getting shock and forks serviced in few weeks time when im back to work as i dont about 12ish trackdays last year (i know sad) and havent a clue when was done before that. will ask ktech to look inside and tell em im 13st with leathers on and they can either change or keep springs thats on and give me a base setup. well im sure they can anyhow.

i jus feel as tho the two garages ive tried already have twiddled away and it makes no difference and still feels like im a flea ridin a dogs ball bag!

spins up really easily on exit so i have to be really carefull then everyone comes past then when im more upright i go past em again. i can spin it up all the time but its costing me a fortune in tyres and im sure its not supposed to do it this easily.

cheers for info dude.

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spins up really easily on exit so i have to be really carefull then everyone comes past then when im more upright i go past em again. i can spin it up all the time but its costing me a fortune in tyres and im sure its not supposed to do it this easily.

Rear compression my friend.

You need to soften the compression.. Sounds like it is too hard causing your bike NOT to grip when you open the taps..

And

Based on your weight you should be looking at (about)

1.0kg/mm for the fronts

&

8.9kg/mm spring for the rear,, having said that you can also alter things by adding thicker of thinner oil.. Start off with a base setting (set your sag levels,with gear) and go from there.. IMO you would probably be better off going to K-tech or MCT, someone like that so you can have it set up while you are there.

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right my spring with 90-150 means 85kg rider weight aparantly. im 80kg with gear on so not much to worry about there. and in the front forks are 10nm springs from ktech and i have a set of 9.5's under the bed in a box. guna get the front ones changed over when the shock and forks are serviced in a few months when ive had a couple of pay packets finally!

my tyres are bridgestone r10 and bridgestone said to put rear at 25psi at working temp and front 30psi working temp but ive found the front needed to be at 31 or it feels sluggish and not right but just one psi makes a massive diff for me. the rear is great as if you go down it again feels sluggish and if you go higher it spins up just looking at it.lol. will get it serviced and get a base setting done then start looking at rear comp and height as i raised it at a trackday as i was told it would speed up turn in which after the first suspension guys had a go went all slow and sluggish.

will be april or may before im on track as wont be fit to ride till then and i doubt ill be able to go mad either due to sholder surgery

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Before you do 'anything', you need to have all your measurements!

This includes front and rear sag/compression/rebound/any geometry changes (ride height etc) and things like fork or shock rebuild info (such as oil level etc).

I'm not familiar with your tyres. Are they slicks or treaded tyres?

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ok cool. front seems lush under breaking but now youve said about the air gap and stuff it could be this thats causing em to raise the ride height to make it turn in quicker. ill send it off to ktech as theyve messed about with it for the r1 cup so ill just tell them im a small guy who does trackdays but wants to push hard. have been getting more and more fustrated with the inters group as alway seem to be stuck behind not nessisarily slow riders but riders who take weird lines and do weird stuff and takes ages to get past. although the fast group sometimes looks just right, on the other hand sometimes its packed with racers and looks intimidating. i may have to add some bigger balls to the shopping list and man the f up!

suspension refresh and spec'd to my weight then a decent setup at one of the no limits days me thinks then jump in fast group and learn from the pros

seems like a good plan.

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