Fork Oil Change!

2020-03-27 by Andrew Holmes

Well I finally got around to changing the fork oil on the Buell. This is meant to be done every ~16,000km but in the close to ~30,000 km I've had the bike I've never done it, I kept putting it off due to thinking it would be very difficult. But after seeing Dave Moss at the recent Shiny Side Up talk series in Auckland talking about oil changes I watched his Dump & Run fork oil change method and realised that the hardest part of this whole procedure would be removing the forks from the bike - there is no need to actually dive into the internals of the fork at all!

So armed with my floor jack and a couple if spanners I decided to give this method a crack. It ended up taking me just over three hours, though I realised later I took more of the front apart than I needed to, and also faffed around putting it back together, so I'm sure when I next have to do this I'll probably be at least 30 minutes quicker. To start, loosen off all preload, rebound and compression adjusters (making a note if you have to of how many turns were needed). Once that's done, loosen off the top fork clamps and crack open the fork tops with a deep socket or ring spanner. Don't take the caps all the way off, just a few turns should be enough. Once that's done, loosen the front axle pinch bolts and undo the front axle a few turns, then crack the lower fork clamps. Finally, remove the front fender by undoing the T27 Torx bolts holding that in place. Once everything is loosened jack the front of the bike up using the exhaust, remove the front axle and wheel (I had to also faff with the brake caliper to get the wheel out easily) and loosen off the fork clamps the rest of the way. At this point you should be able to slide the fork down through the fork clamps until you can see the snap ring near the top of the forks - remove this to clear the lower fork legs and pull out the forks.

That's the hard part over - now it's just a matter of cleaning up the fork lowers as these will most likely be dusty and covered in crap - I found WD-40 sprayed on a rag got this dust and dirt off without too much hassle. Once that's cleaned up grab a measuring jug that can hold over 500ml/32oz and place this on your work bench ready for pouring, and you can now remove the top cap and slide the outer down slightly, exposing the gap to pour the oil out of. Pour the used oil into the measuring jug, then re-attach the top cap, pump the fork a few times (you'll have to push your weight into it) against some old carpet or thick cardboard lying on the ground, and repeat the pouring process. You'll have to do this a few times - basically keep pumping and dumping until nothing more dribbles out. I ended up getting about 550ml per leg out of my forks in the end - it's impossible to get it all out without stripping the forks down and cleaning everything, but using this method you should be able to get 90~95% of the oil out, and if that's good enough for Dave Moss then that's good enough for me! After that it's just a case of measuring out the same amount of fresh oil as you poured out of the fork and carefully pouring it into the fork - once that's done it's time to put the front end back together in the reverse of how you took it apart. Make sure you follow the manual for correct torque of all bolts and the top cap - and make sure you torque the fork caps before torquing the upper fork clamps. Don't forget to set your damping, rebound and compression back to what they should be (if you can't remember, consult the owners handbook, it has all the settings for different weights).

So after all that I can't say I notice any difference in the front end, but I'd like to think I would on a fast road ride, or a really bumpy stretch of gravel road. Judging purely by the state of the oil that came out I'm sure this hadn't been done in some time (it really looked like old coffee), so I'm glad I finally got around to this, and now I know how easy the whole process is I'll not wait so long next time before doing it again.

fork oil

Old on the left compared to fresh oil on the right. It really wasn't that hard to do, and doing it yourself you can save a few hundred dollars in labour, so now while we're all stuck at home due to Covid-19 order yourself some fork oil online and have a go! If words aren't your thing then watch the Dave Moss video linked above - it is really a simple procedure and you'll gain some knowledge and satisfaction out of doing it yourself!