ild Geese

Thursday 11th November

Another quiet day like the previous Thursday. We stayed fairly local and rode around the coast and hinterland both days and had lunch at Gympie the previous Thursday and Eumundi this day.

I watched a video on motorbike suspension the other day. I watch several different general topics on YouTube regularly, and one of those topics is motorbikes, so links appear on my YouTube home page and I pick something to watch. After watching this one I went down the shed and pulled my front forks off and changed the oil. The professional guy in the video strips and cleans all the fork components but I don’t think that is always necessary since when engine oil is changed no one strips the engine into bits and cleans every part individually so an oil change in forks can be just the same I reckon. Fully drain the old oil and replace it. Oils wear out so fresh oil is a good thing. If you were to find any particulate matter or dirt in the oil then maybe the bushes and seals are wearing and the forks would need a full service with new bushes and seals etc. (These forks in this video had done over 150,000kms and maybe the seals had already been leaking too…)

Anyway my springs were in original spec length but the oil I took out looked a bit discoloured. I let it stand in a clear jug for a few hours and then decanted the oil off and there wasn’t even a smear of anything in the bottom of the jug. I guess I’ll see if there is any noticeable improvement in the feel of the suspension next ride with fresh oil…

(In this video this guy is distracted by the interviewer as he works. The tighter wound coils of a progressive spring are on the bottom from my experience (my Honda and my Yamaha and also this Suzuki’s workshop manual says they go at the bottom too). Early in the video you can see when he removes the spring that’s the way it is… Later when he replaces it, he is busy yapping and puts it in with the tight coils on top… I had a look down the comments and seen a couple of other viewers noticed it too… In reply to these comments the Bennetts Bike guy asked the tech guy and he said it was OK and that the washer sits better on the tighter coils. I reckon he is just defending a mistake he made when he was distracted because the washer fits better with the more open coils on top since the diameter is not reduced like it is in the tighter coils.
In the comments they also note that the tighter coils displace more oil and that is significant since with the small diameter of a fork tube a few mls of oil makes a difference to the air gap. But I also know from a suspension specialist years ago that the air gap can be changed from the factory spec if you want to since less air gap means less compressible air and more non-compressible oil and that will mean a stiffer ride without having to buy new different springs. So the factory spec might be 150mls of air gap and you might change it to say 130mls. As long as both forks are identical is the most important thing…)

Find out how motorcycle suspension is setup, serviced and maintained as we visit K-Tech Suspension in Derbyshire to see a set of 95,000 mile forks being stripped and rebuilt.
Video Title: Motorcycle suspension servicing & setup | Be an expert
YouTube Channel: Bennetts Bike