Please help with picking the right rear spring - CRF250X
  • Deanzo
    Posts: 132
    Joined: Sun Jul 27, 2014 2:39 pm

    by Deanzo » Tue Mar 03, 2015 11:53 am

    Sooooo, Alot of hours since I installed the new springs (40+)

    With the springs I ended up with (the ones K-Tec says are right) My free sag seetings are right on the money 30mm/100mm.
    And the bike rides Great!

    So really I should stop there lol


    But,
    I'm bottoming out alot these days.
    The more I ride, the more I feel at home on the bike, so the more I push it.

    I was out riding with the wife yesterday, and I got her to video me going over the first wee jump on a track I ride alot.
    The bottoming out isn't helped by me over cooking the jump a little and missing most of the down lol.

    If you double click play and pause from 8sec to 10sec of this short video, you can see the hard time I'm giving my front end.

    http://youtu.be/nn9LB1H0DIk

    Is this just me giving the bike too hard of a time and landing to much on the flat, or does it look like I need to up the springs ?
    Any help would be great, I'm having alot of fun, but don't really want to break myself or the bike.
  • User avatar
    JimDirt
    Posts: 3390
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Wed Mar 04, 2015 8:48 am

    That was caused by 2 things , slightly flat landing the jump ,you should be landing on the down face , you were not far off landing it in the right place , otherwise your over jumping that jump just a bit , but it was not the impact killer , the 2nd and main reason is because you are not back on the throttle right before you land , if you land OFF the gas , the bike will blow thru because basically all the weight is hitting the ground from UP , basically like you standing on a table and just jumping right off the edge , you hit the ground with ALL your weight and all the force from that fall

    If you were back on the gas then the forward momentum will absorb some of the impact , because the force is now distributed between landing and moving forward , basically the same if you were on that same table , but instead of just jumping off it , you ran up to the table and used it to launch yourself off it , landing farther away on a angle instead of just down or dropping like a heavy rock , so the impact is lessened and you continue on your merry way ....make sense ???

    What your goal is , is to be able to jump all the jumps on the track and on the largest its ok to bottom or slightly bottom (if the jump is 50+ ft , but not on a smaller one like that), but not from a technique caused issue , this was caused by technique , or lack thereof , watch MX videos , and listen carefully when the riders land , they are on the gas just before they hit the ground , this will take some practice to make it a subconscious decision , instead of a forced decision , but in the long run your landings will be softer/smoother and your speed will improve

    If you would have backed off slightly before hitting the face of the jump (never back off the throttle when on the jump face , , but on the flat before , especially on a 4 stroke , otherwise , it will be a ride you will never forget , and you will find out what a ENDO really means) , if you backed off slightly and then landed on the down side while accelerating , you would have rocketed away , and hardly felt the landing at all

    Also do not forget a 250X is heavier than a 250R ,by quite a lot , so its not going to land as gently as the lighter bike will , because the mass is more so the force of the landing will be more , and momentum will be the key to a softer hit , more so than on a R

    It would be like your kids jumping in the water , and you doing it , who is going to make the bigger splash ?? , you will because of your weight/mass compared to the lighter child
    02 CRF450R
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    Weiser , Idaho
  • Deanzo
    Posts: 132
    Joined: Sun Jul 27, 2014 2:39 pm

    by Deanzo » Wed Mar 04, 2015 11:12 am

    Thanks Jim, thats a big help.

    Yep, that makes sense, and gives me something new to work on, which is both cool and free (well as free as the up keep of a dirt bike is!)


    Thanks again


    Dean
  • User avatar
    JimDirt
    Posts: 3390
    Joined: Sat Nov 25, 2006 6:31 pm

    by JimDirt » Wed Mar 04, 2015 8:47 pm

    No problem , glad to help ! ;)
    02 CRF450R
    06 CRF450X
    Image
    Weiser , Idaho

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