OzVMX Forum
Marque Remarks => Yamaha => Topic started by: head on February 13, 2010, 05:21:38 pm
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Just doing up a 250H to race this year. Does any one know how the std rear spring performs? Is it stiff enough or should it be replaced? If so what rate does it need? Any help at all would be appreciated.
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Race Tech has an excellent spring rate calculator that should help you out. www.race-tech.com
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Weigh yourself with all your riding gear on and then call Nick Dole at Teknik Motorsport on 02 47322626 and he will arrange a spring for ya
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How fast are you?
How heavy are you?
How much do you really care?
Finish the bike, and go and race it. If you don't like the rear spring, then change it.
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hey head, how heavy are you? i've got a mate who races 125 and 250 H's but he's around the 80-90kg mark so he gets away with the standard springs.
i've got a 465 G banger and because i'm a 6 foot, 115kg fat b@st@rd i really need to change my springs. i'm going through the motions at the moment and talking to walter at yss to see what he can come up with. free length is around 360mm for the shock spring so there's no "off the shelf" solution for that length, so options i've come up with so far are:
- custom made spring
- custom made extended collar to allow fitment of a shorter spring (this will be at the expense of travel)
- custom made collar to join 2 springs together to make the correct length (have a look at that racetech link that camp has put there)
- try to find another "off the shelf" spring with similar dimensions and a suitable rate
speaking of spring rates does anyone know what spring rate the standard spring is and what would be suitable for my weight? this will save me going to a suspension joint to get them to measure what i've got.
sorry to hijack your thread a bit head, but i think you might be looking for something similar to what i'm after. i bottomed mine on every jump at nudgee and every jump at cd6 at conondale so i've had enough. i'll keep ya posted on whatever i uncover. did you notice that even racetech don't do a shock spring for the 465, but they have a section for a 465H project bike that is worth a look.
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Put all your gear on and measure the static sag (for example, from centre of the axle to the seat mount bolt centre) should be around 90 to 110mm. This article will help you http://www.motocross-racing-tips.com/dirt_bike_suspension.html (http://www.motocross-racing-tips.com/dirt_bike_suspension.html)
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Yeh, I think I am going to make a setup like on the Racetech site with two springs. It will take some experimenting to get the right rates. But I found a test on a yz250H and they replaced the std spring straight away saying it was to soft.The steering also suffered from the soft rear end.
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try browns spring works in broady vic as long as you have the id ant the spring rate you need hell make one up
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Car springs an option? You can buy all sorts of rates, diameters and lengths, and the 'coil over' type springs look like they'd go close.
Although, the price Walter charged me for a 'custom' spring for my YZ125X means its probably not worth f$%king around with car stuff.
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its probably not worth f$%king around with car stuff.
Probably not.....
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hey head, if your spring is a similar size to a 'G' model then just hold on for a bit if you can. i'm sending my shock and spring down to walter and he was going to have a look at getting some springs made up or at least coming up with some sort of a solution. g'day nathan, the car springs are no good because they aren't a variable rate wire like the oem yammy spring.
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Thanks paddles. Let me know when you find out about springs.
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too easy head, no doubt walter will be keen to sell a few of these springs because to make it cost effective he'll have to get them made up in bulk so i'll keep you posted on how it all goes. considering how many 'G' and 'H' models are out there in evo class, i can't believe that no-one has springs available for them.