Front Forks Rebuild? By jomama0867 (Read 1,627 times)

[jomama0867]

Hello to all and HAPPY NEW YEAR! Has anyone out there had any experience with rebuilding front forks? I recently noticed seals leaking, and when I approached the subject with some local GY6 enthusiasts, they all replied "who rebuilds? just buy new ones"! That seems easy enough, but anyone who has read my threads KNOWS that it's just not my style . . . besides, why spend $75 on new forks when I could spend $8 on new seals! I've seen a few youtube vids on the subject and compared to my engine rebuild, it seems fairly straight-forward. My question is: for 18 1/2 inch forks, how much oil should I be replacing (judging by the mess on them now, I know whatever I drain  won't be the full amount)! Also, any thoughts on changing the springs?!?

[cyborg]

Seals are easy peasy if you can find the correct replacements,,,,as far as volumes that's manual spec stuff there,,, I always run an ounce or two over to have a bit of a stiffer fork ( the air column over the oil is a spring as well,,, forgo the springs and run 3/4 inch height 3/4 inch sechedule 80 irrigation pipe for more preload,, and I run 15 or 20 w belray

[jomama0867]

Thanks cyborg . . . I figured you might respond, and I love the idea of the preload pipe! I guess you lost me at the 15 or 20 with belray though?!?

[cyborg]

The fork oil numbers is the weight or viscosity,, or thickness,, the heavier the weight the slower or harder it is to go thru the damping valves for better control( if you ride like I do which is hard and aggressive ),,, when you go thru like rapid stutter bumps thin oil will go thru too fast and won't let the fork fully extend back to "rest" and you get a condition called " pump down",,, the fork legs fully compress down to the end of the stroke and you have no suspension ,,, ( had that happen on a bike and it almost got me killed because I ran out of suspension in a curve and I bounced into the other lane ) thank the gods no one was coming the other way or we wouldn't be talking right now,, I literally did the grandpa ride home and I disassembled the front end within the hour,,,I didn't ride that thing again till I reworked the forks

[cyborg]

Oh Belray is the brand of fork oil I use,,, it just harkens back to the days when I flat tracked,,, they were the only decent fork oil company at the time so I've kind of stuck with them

[tvnacman]

its not a hard job, I think there are some videos around. Try to measure how much oil comes out for reference when you need to put oil back in.

John

[jomama0867]

Thanks guys for the info. and the "heads up" (especially that part about the near-death experience)! I had noticed an oil build-up underneath my bike and had convinced myself that it was coming from my valve cover vent (I don't have a catch can - I use an old gas filter). If I hadn't had to change a headlight I never would have noticed the oil build-up on my wiring UNDERNEATH the front cowl . . . didn't take long to discover the origin! Anyway, there is a really good bearing/seal company locally I used to use when I was in the printing industry, and they have had EVERYTHING I've asked for so far (except a gearbox seal; which they couldn't find ANYWHERE; had to go to Taotao for that one), so I'm fairly confident they will fix me up! Also, I did find a couple of vids online (enough to give me a general direction), and as usual I'll dive in head first into the deep end and swim for it!

[cyborg]

LOL,,,we must be related

[jomama0867]

Okay kids; for the record, I'm VERY familiar with jumping head first into the deep end of the pool . . . even if I don't always backstroke leisurely, I'm pretty good at treading water . . . but with this one I must admit I find my arms and legs flailing wildly!  The "anchor" pulling me down is that damned little 6mm machine screw at the bottom of the forks. I've researched several YouTube vids, and they all show the thing just falling out of the bottom of the tube, but after breaking mine loose they just spin not backing out at all)! I have tried with the forks intact AND partially disassembled (cap off, spring out) but no change. Unfortunately, this is my only form of transportation, so I ended up just changing the oil (better than nothing).   I KNOW there is a simple explanation, I just don't know what it is! My arms and legs are getting tired of treading water . . . HELP (gurgle gurgle)!

[cyborg]

There's a nut on the inside that's spinning

[jomama0867]

Actually that HAD crossed my mind . . . if I knew what size it was, I could probably link all of my extensions together, maybe borrow a couple from my neighbor, and reach it . . . maybe this is why people just replace them!?! I won't give up that easy though; anyone out there have an EDUCATED guess at what size this "spinning nut" is (before I start at 6mm and work my way up)?

[cyborg]

Probably a 10,,,that seems to be the running theme with these things

[jct842]

If you should be able to get it loose have you given any thought to how to get it back in there tight again?

[jomama0867]

Details . . . minor details!  Actually, that thought had crossed my mind. I finally found a picture of the screws out of the forks, and it looks like there are NO NUTS! Maybe mine are just being stubborn?!? It will be a few days before I get a chance to try again, but I'll post what happens . . .

[jomama0867]

Wow! Those couple of days passed quick! Actually, I ended up on a BAAAAD stretch of road (resurfacing, when they strip it down to the grooved concrete, and all that's left are the "patches") for about 2 miles . . . needless to say didn't do the leaking forks much good . . . but on my way back on a DIFFERENT route, SAME THING!!! Anyway, by the time I got home there was very little oil left, so I bit the bullet and tore 'em down again.
  The GOOD news - the top of the damper (the part the infamous screws hold together) actually has an allen socket on top to hold it (go figure)! It's a 10mm, and if it's not full of oil it's pretty obvious to see!
  The BAD news - I ordered 31mm x 43mm x 10.5mm seals based on extensive research and many consultations, contrary to popular opinion, mine are 30mm x 42mm x 10.5mm and will NOT fit (believe me, I tried)! I've ordered the correct ones and re-installed the worn ones - with fresh oil, of course - at least now I've had plenty of practice! Hopefully I'll try again Tuesday (my Valentine's Day gift to my scoot), and be able to do the whole job in an hour or less!