Z1B fork oil.

[floydsz1]

I've cleaned out the forks but was just wondering before I refill them, what oil / amount etc anyone recommends. Or is it best to just go with standard.

[jimmock]

I've cleaned out the forks but was just wondering before I refill them, what oil / amount etc anyone recommends. Or is it best to just go with standard.

There are probably better options now than standard.

Modern oils have came on heaps the last few years.

[floydsz1]

170cc 10w is standard but was just wondering if 15w would be better.. I seem to remember in the past ive mixed the two.

[z1bman]

i would use the 15w

[floydsz1]

Thanks for that. I'll try the 15w

[johny brando]

Thanks for that. I'll try the 15w

"Snap" with the 15 weight Oil choice & I have found ( & it seems common practise now too ! ) that rather than measuring out an equal fluid volume for each leg ..... it is best to use a "measurement" down to the top of the oil level inside the leg itself ...this from the top face / edge/lip of a fully compressed fork stantion "this with the spring removed" apparently it's a better means to Skin this particular Cat, it's all down to the apparent internal variations within each of the legs during the manufacture process . What I do is ........First flush the emptied fork leg by putting some clean Petrol in it & then pump the leg/dampers to get this all around the internals then turn it upside down n pump several times again to help remove it , then leave it standing upside down to fully drain for another 20 minutes . Then fill just one leg with the correct manual spec volume of new 15 weight oil, then work the fork up & down "no spring fitted" about 10 strokes ..this ensures the dampers are fully filled ...then let it stand for 20 mins to let the then entrained air bubbles in the oil come to the surface and then burst & disappear. Now ensure the leg n Station are held in a true vertical position Then stick a magnet on top of the Stantion & place the flat face of a Steel rule onto it , then slide the rule (thats now stuck to the Magnet ) gently down inside the leg & using a pen torch to see inside , gently continue sliding the rule down until you JUST see the surface tension of the oil "just move" this as the Steel rule tip touch's the Oil interface. Now take the measurement of the Steel rule at the bottom edge of the magnet ( n ,this is now your oil height datum ) and now set the other leg to 'exactly' the same height ( I have found a fair difference before .....like up to 10 ml) From this base line you can now.... if you so wish .......vary the Oil quantity to adjust the damping to own specific requirements. I'd now take the bike for a good ride & see how the bike feels
If you wish to go one step further with your Forks, you can also adjust your 'tired fork springs=pre-load" by nipping down the Hardware shop n buying a dozen or so large Flat Steel washers that'll just fit inside your Stantions n by experimenting, adding 1 washers at a time under each of your Fork Cap nuts...... until it's firm enough for your liking ! Sounds a lot of faffing around but it's not really !!!!! & the benefits can be very pleasing. I personally have found it best not to make to many modifications at once but ride n try each one as you go , as if you don't do this..... you'll really know what was the positives or negatives of each change you made . Hope this may help a little. Johny Brando.

[floydsz1]

Thanks for that johny.
I've got a measuring tube /syringe for the forks so that's the way I'll go. I remember back when I was racing my lc and ypvs we used 10pence peices on top off the springs.