ben315r Posted January 12, 2009 Report Share Posted January 12, 2009 Hi all My forks seem to have developed a lot of 'stiction'. When the forks start to compress from full extension, it seems to catch a little bit. I've changed the fork oil and seals, and it's had no effect. Has anyone else ever had this problem? I thought it might be the Headstock bearings, but there doesn't seem to be any play in them, and wanted to ask on here before I go ahead and replace them anyway! Thanks in advance, Ben Quote Link to comment Share on other sites More sharing options...
motovintage Posted January 14, 2009 Report Share Posted January 14, 2009 are the bushings worn? they could be binding?? if it's the seals sticking spray some silicon spray or teflon spray on the fork tubes, work it into the seals by compressing the forks, if it really is stiction that should fix it, you might have to pry up the dust seal and spray some onto the forkseal Quote Link to comment Share on other sites More sharing options...
fastducs Posted January 16, 2009 Report Share Posted January 16, 2009 This may be obvious, but have you checked your forks for alignment? Perhaps they are twisted in the triple clamps? Take a straight edge and put it across both fork tubes right above the seals. Take another straight edge and put it across both fork tubes near the top triple clamp. Now sight down the tubes and see if straight edges are parallel to each other. Best to use long straight edges, since longer ones will exaggerate small amount of misalignment, and thus make it easier to notice. Or maybe as simple as bow-legged forks? Perhaps if you changed front tire in a hurry? Loosen the front axle pinch bolts on the right side of the bike, bounce the front end a little to let the right fork settle where it wants, and then tighten pinch bolts again. Any chance you bent a fork tube? Or over-tightened the triple clamp pinch bolts? IMHO, headstock bearings shouldn't have any impact on fork stiction. If you decide to get into the headstock bearings, be careful. Upper triple clamp sits on top of a ring nut which sets tension on the upper bearing. This nut is threaded onto the steering stem. There is a large bolt through the top of the triple clamp which threads into steering stem and tightens upper clamp against the ring nut. This is all very common on many other bikes, but what makes it different on the 315r is that everything is aluminum rather than steel. The rather thin ring nut is aluminum, and so is the steering stem. This means you have just a few turns of soft aluminum threads to counteract 69 N-m of torque from that large top bolt. When I bought my bike, the top bolt was very loose. Upon further inspection I found that the steering stem threads (where ring nut threads on) didn't hold up. I didn't feel like paying for a new stem, so I machined a custom distance collar to sit between upper and lower bearing races, similar to what you find inside your wheel hubs. Quote Link to comment Share on other sites More sharing options...
ben315r Posted January 19, 2009 Author Report Share Posted January 19, 2009 Thanks guys. When I changed the fork seals there was a load of grease in between the fork oil seal and the dust seal, so this may have been an attempt by the previous owner to stop it. I'll check the alignment. Quote Link to comment Share on other sites More sharing options...
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