Shock in question is a DU1430 and fitted on a 998S. Thought it about time to put a heavier spring in the rear, A, cause I’ve put a good few kilos on and B, because I’ve just fitted a longer swing arm. Did a bit of home work and also spoke to FTR suspension in Braintree. He suggested going up 1 rate for my extra weight and 2 rates for the longer arm. Each rate equates to about 10Kgs. So pulled the shock out last night and got the spring off. New spring turned up this morning and cracked on fitting it. The spring on the bike was rated -19/70 and the new one is -26/85 First thing I did was measure the free length of the spring, 160mm. Spring length when fitted with manual preload ring nuts at 5mm down, gave a spring length of 148mm. 12mm difference so so far so good. Fitted it back on the bike, tensioned the chain and then measured height from rear axle to a datum mark on the seat unit. Rear wheel unloaded. 560mm Both wheels on the ground, upright. 552mm Sag, with the remote preload about a 20% wound on, 40mm. Now I know the rear sag should be between 30 to 35mm but got loads of preload to get that right. So, I think the spring rating looks ok but wanted somebody with more knowledge to say if it looks right or not as I can send it back and exchange it for another. Cheers, Ian
So free length will be the same If you use the same measure points If you had say 10-15 mm bike and a total bike and rider 30-40 that souls be better
Ok but still got more then half of the remote preload to go at. Just wanted to know if the suspension bloke can get it something like or a different spring required. Cheers
And that needs another 10 Kgs +- adding to rider weight as just in jeans and t shirt. I know it’s not really the ideal way to do it, just after the ballpark numbers...
http://www.ducati-upnorth.com/tech/suspensionspring.php Might be useful - obviously the longer swingarm is going to affect any recommendations based on the stock bike but it’s a good article.
Cheers mate. I read loads of articles over time but have always left it up to Alpha suspensión to tune it. I’m really only after knowing the spring is the correct one so if not, I can exchange it.
Cheers Andy. Mostly, nearly all road. Am toying with the idea of a bit of track time but even if I do, won’t be much.
