waltergallons Posted December 18, 2007 Report Share Posted December 18, 2007 Hello everyone .... I've rebuilt my Fantic 240 recently, including stripping down the forks and rechroming the forklegs...... I've noticed on the few times I've ridden it that the forks bottom out quite easily........ The oil I've got in the forks at the moment is 'Putoline HPX10 synthetic'....... I was advised to put longer spacers in the top of the forks...... The ones in there originally were about 1" and I'm led to believe that they are original Fantic (but I'm not sure)....... I had 2" spacers made up and replaced the originals but it's still bottoming out..... The other thing that I was advised to do was to put heavier fork oil in, but I haven't done this yet........ Any suggestions from anyone about what type and quantity of oil I should use, or any other ideas that may cure this problem ......... Thanks. Quote Link to comment Share on other sites More sharing options...
big john Posted December 18, 2007 Report Share Posted December 18, 2007 It all depends what weight you are and how coil bound are the springs (assuming they are originals). You could try increasing the quantity of oil by say 20cc each leg, as the fork oil weight, if it is SAE 10, is about right. Big John Quote Link to comment Share on other sites More sharing options...
bilco Posted December 18, 2007 Report Share Posted December 18, 2007 The fork's on my 200 do the same,as Big John say's it could be down to the spring's,i was going to look toward's the spring's myself a while ago but decided it was'nt really worth messing about with. Quote Link to comment Share on other sites More sharing options...
motojojo Posted December 19, 2007 Report Share Posted December 19, 2007 I always used atf and its about 7wt. Big John is right about adding a little more oil to adjust the stiffness of your forks just not to much or you will blow your seals. If this don't work I would get stiffer spring, or make some find an old yz 80 and cutt down the spring to fit. Quote Link to comment Share on other sites More sharing options...
axulsuv Posted December 19, 2007 Report Share Posted December 19, 2007 (edited) When I got my 240 , I received a complete (in a box ) parts bike to go with it . So of course I built 1 set of forks out of the best peices of the pair . Both of mine are the dual fork seal ealier style sliders , but one set had the short springs and the other the long . I ran the long ones w/ the the short spacer and that was ok . But when I got my Falcons for the rear ,I got a set of WES progressive springs for the forks too. The wes springs are longer than the long set of fantic springs so at first I ran them without a spacer ... Mistake !#1 I also neglected to bounce the front end hard before final torqing of all the fastners as I had replaced the steering stem brgs. too.Mistake # 2 Mistake #3 , I loaded my bike and drove 12 hours to a event before riding it in the yard to check the suspension ... I rode day one of a 2day event with a bound up bottomed out (rigid...) front end ! Bike turned great but my wrists took a beating ... Loosened axle and pinch bolts and lower triple clamp bolts , bounced bike forks freed up tightened bolts ...Much better but too much sag . When I got home I made some pvc spacers (just remember to put a flat washer between pvc and springend ) I tried differant lengths of spacers , 11/2 ,2 and 3 inch . It really is amazing what a inch of preload spacer will do w/progressive springs ! My final set up so far is a 1 3/4 inch spacer w/ toyota valve springs under them . NO bottoming , font end and rearend drop the same with my weight on bike and feels better than it ever has for me ! I also run 10w synthetic fork oil and the dmpening seems a bit heavy , may change to a seven weight . But being the crappy ridder that I am I don't think it'll make a differance in my score ...... Glenn , KEEP THE TWINSHOCKS ALIVE !!!! Edited December 19, 2007 by axulsuv 1 Quote Link to comment Share on other sites More sharing options...
waltergallons Posted December 20, 2007 Author Report Share Posted December 20, 2007 Thanks everyone..... I'll try adding a touch more oil to the forks and see where that takes me ..... Big John, I'm only a light weight (11 stone..ish)..... How do you tell if the springs are coil bound ?..... By this do you mean knackered ? Thanks again ! Quote Link to comment Share on other sites More sharing options...
big john Posted December 20, 2007 Report Share Posted December 20, 2007 Fork springs, like any component of a motorcycle, suffer from wear and tear over time. The spring starts to slowly compress and not return to normal length after prolonged use. This in effect shortens the overall length and serviceability of the spring and it stops doing its job efficiently.... In other words knackered! You can sometimes pull the spring back to length by getting a friend to grab the opposite end from you and pull against each other, however it is a matter of a short time until it "sags" again. Regards Big John Quote Link to comment Share on other sites More sharing options...
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