CBF1000

CBF1000 => Suspension, Forks, Steering, and Chassis Set-up => Topic started by: edger on 24 January, 2018, 04:18:04 PM

Title: Fork oil /air gap
Post by: edger on 24 January, 2018, 04:18:04 PM
2009 MK 1
Is it me or what?
Changing the fork oil today Haynes say 437 cc plus or minus 2.5 cc and 129 mm air gap.
However if I put in 437cc the air gap is 95mm?
To get a gap of 129mm I must remove 30cc of oil
AM I JUST BEING DUMB / Have I missed something?
Have Honda changed the spec's, is it a miss print in the Haynes

Going out to walk the dog now and try chill a bit before resuming.
Any and all suggestions are good (and yes I have searched  :mfrlol:)
Title: Re: Fork oil /air gap
Post by: jm2 on 24 January, 2018, 04:26:42 PM
Air?  Did the level settle at all when pumped?
Title: Re: Fork oil /air gap
Post by: edger on 24 January, 2018, 05:43:53 PM
As far as I know  its all good ..But its still wrong if you get my drift.
I took the dog out for a hoon round the woods to allow time for the oil to settle and air escape  back now still the same.
I will leave it over night and start again tomorrow.
Title: Re: Fork oil /air gap
Post by: Bifferman on 24 January, 2018, 06:21:54 PM
Edgar

The MKI Honda Service Manual is particularly good at explaining how to drain and reflil the forks.  Worth reading.  I presume you have downloaded a copy.

It does sound as if you had not drained all the old oil out OR you still have air in the refill.  Obvious really because it can't be much else.  Did you use SAE10W grade.  As I said the HSM is VERY good on this.

Andy
 :149:
Title: Re: Fork oil /air gap
Post by: edger on 24 January, 2018, 08:33:25 PM
I am sure all the old oil was out, they were upside down suspended from my work bench for the best part of a week The old oil was 15wt but felt to harsh on anything other than perfect road surfaces  so I reverted to 10wt and was going to fit spring preload spacers
I went daft and treated myself to a Ohlins rear shock  so sorting the front is my aim now without breaking the bank anymore than I  already have.

I have never had a problem changing oil and springs in the past but this has me stumped.
If they haven't settled by tomorrow I will drain them again and start again,
Sometimes its best not to fiddle in the first place :mfrlol: good thing the weather is pants gives me time to get the stove going in the shed and whirl the spanners .
New tyres are waiting for spring fitting.
Title: Re: Fork oil /air gap
Post by: Ali-bear on 25 January, 2018, 10:24:50 AM
*Originally Posted by edger [+]
Changing the fork oil today Haynes say 437 cc plus or minus 2.5 cc and 129 mm air gap.
However if I put in 437cc the air gap is 95mm?
To get a gap of 129mm I must remove 30cc of oil

129-95=34mm.
30cc is a slightly generous single spirits measure.

I would ignore that part of the Haynes instructions. Having said that you can modify the effective spring rate by adjusting the amount of air. My Hyperpro springs came with a recommended air gap smaller than standard.
Title: Re: Fork oil /air gap
Post by: edger on 25 January, 2018, 01:47:46 PM
OK so I have put it all together again and measured off the top of the tube to the surface of the oil 129mm (near as spit)
I knew I should have left well alone!
Just got to stick the wheel back in and we're good to go.
Title: Re: Fork oil /air gap
Post by: DCSF on 07 August, 2018, 04:32:26 PM
Hi
I am fitting wilbers progressive springs on my 2008 Mk1...any idea what air gap I would need?
Title: Re: Fork oil /air gap
Post by: richardcbf on 07 August, 2018, 07:55:11 PM
*Originally Posted by DCSF [+]
Hi
I am fitting wilbers progressive springs on my 2008 Mk1...any idea what air gap I would need?
Didn't / don't they come with instructions?
Anyway, how about what they (Wilbers) say here...

(With ABS) "Air Chamber: 120mm"
https://www.wilbers-shop.de/en/Motorcycle/Honda/CBF-1000-A-SC58-wilbers-27/Promoto-Fork-Spring-progressive.html?cur=1&manufacturer=amu19a4f1346a0757072421f9a2d3c9c&year=2008&catname=0ac0bd839080f672a2819b0ef31f204f

& same again here...
https://www.wilbers-shop.de/en/Motorcycle/Honda/CBF-1000-A-SC58-wilbers-27/Wilbers-Fork-Spring-Zero-friction-progressive-wilbers.html?cur=1&manufacturer=amu19a4f1346a0757072421f9a2d3c9c&year=2008&catname=0ac0bd839080f672a2819b0ef31f204f

 :027:
Title: Re: Fork oil /air gap
Post by: DCSF on 07 August, 2018, 10:38:34 PM
Ah that's excellent...many thanks.
Instructions don't mention it...never thought of looking at website  :164: