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CB750 Barn find project - First Timer
Underdog1:
--- Quote from: Green1 on June 30, 2018, 10:17:48 PM ---I did re-stake mine Just gave it a sharp belt with a punch.
The spokes soon go black if you don't clean them.
--- End quote ---
might as well just in case then if its that easy.
Im still yet to put oil in my forks as I've not got the front wheel back yet but will be doing it this week sometime. I've got Hagon progressive fork springs and im unsure about how much to put it.
On the website it state 160mm air gap:
https://www.hagon-shocks.co.uk/catalog/partdetail.aspx?partno=400-083-02
the instructions that came with the forks don't mention any air gap and are incredibly vague. is it a case of just filling the forks up to 160mm from the top of the tubes and thats it? presumably thats with springs in. If anyones got any experience fitting these then please pipe up!
The shop manual for the standard springs suggests 145CC of ATF oil in each fork. Would be easier if Hagon specified a volume rather than gap
K2-K6:
Think the 160mm air gap would be more accurate a measure if you were to drain and then refill the forks as it would accommodate any residual oil left inside the assembly and not cause you to increase the volume.
It's not too critical as 145ml should be fine to make sure all the damper functions are covered and operated as expected.
You'd trim the 160mm measurement if you wanted to get the air gap adding to the spring rate (it effectively makes an air spring if the fork seals hold the pressure) as the fork reached full compression. To be honest, it's not something most people would notice in general use.
If the fork stoke is 102mm, you've got to allow at least that before the oil hits the top of the fork cap and stops it compressing hydraulically.
So in reality, allowing for some space above the oil, you've only probably between 130 to 160 to play with total.
If they are totally dry then 145ml is accurate enough. If not certain, then with springs installed the 160mm is probably most concise.
Underdog1:
--- Quote from: K2-K6 on July 01, 2018, 07:28:37 PM ---Think the 160mm air gap would be more accurate a measure if you were to drain and then refill the forks as it would accommodate any residual oil left inside the assembly and not cause you to increase the volume.
It's not too critical as 145ml should be fine to make sure all the damper functions are covered and operated as expected.
You'd trim the 160mm measurement if you wanted to get the air gap adding to the spring rate (it effectively makes an air spring if the fork seals hold the pressure) as the fork reached full compression. To be honest, it's not something most people would notice in general use.
If the fork stoke is 102mm, you've got to allow at least that before the oil hits the top of the fork cap and stops it compressing hydraulically.
So in reality, allowing for some space above the oil, you've only probably between 130 to 160 to play with total.
If they are totally dry then 145ml is accurate enough. If not certain, then with springs installed the 160mm is probably most concise.
--- End quote ---
Forks are bone dry so might just pour in 145ml and see where that gets me, thanks for shedding some light on this.
Underdog1:
Done a few things this week, a friend sandblasted the inside of the tank with mediocre results so I’ve cut the two flat sections on the bottom out for better access, will see what that yields! Managed to get some huge chunks of resin out though.
Wheels are back and quickly stuck the rear on when I finished work, can’t seen to get the rear brake mechanism in place as it’s hitting the swingarm. Very close though so might just be that the bike needs to be on the ground to move the swingarm up to allow the linkage into place.
Also had a small amount of rust in the oil tank, soaked in vinegar all week which cleaned it up nicely, then neutralised with bicarbonate of soda. Unfortunately I got a bit of flash rust so may just use bottle brushes and carb cleaner and see how I get on
Trigger:
The rear brake mechanism goes to the front of the swinging arm (between the arm and engine). It needs to be put on (through the frame mount) before you put the swinging arm on ;)
This goes on before the arm
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