Simonb

.020 Over
Joined
Jan 30, 2018
Messages
42
Location
North Wales, UK
Ride
Rocket 3 roadster 2014
Does anyone have any experience of adjusting the air gap on roadster forks to firm them up a bit. Even though I’m 22 stone the forks still feel very soft and go through their travel very easily. Static sag seems to be hell of a lot as well.
I’m thinking of sticking another 10ml of 10wt oil in each leg to see if this helps.
I know the answer is New springs and probably heavier oil but I haven’t had it long and I’m touring Ireland this week so I’m not going to be able to sort that until I get back.

So am I safe to drop a bit more oil in or not?
 
Stone?

Most stock suspensions can use a beef up. It's surprising how beefing up the rear can help the front. I had KFG Racing in Auburn upgrade the suspension on my VStrom and will be having him do his magic on my Touring
 
No don't add more fluid. The stock fork oil is 5W. A lot of us have installed Progressive fork springs and increased the fork oil weight to 7W. At your weight may be 10W would work.

But you do have to improve the rear suspension at the same time to get the full benefit.
 
Funnily enough I just had mine rebuilt with a smaller air gap. I use Wilber’s fork springs which are 0.93kg for their linear portion (about 85% of the useable range), vs stock 0.83kg springs.

10 weight oil
100mm gap

Bikes amazing now. Previously I had the same springs on a 110mm air gap, it was too soft. Now it’s still soft the first inch or so of travel but firms up quickly as you go through the stroke.

My recommendation would be to dump the 5w garbage, throw in some 10w and go to 100mm air gap or even 90mm since you’ve the stock softer springs.

Keep in mind the R3 has NO bottoming mechanism, mechanical bottom is when it stops, not on a ramping rate spring or hydraulic device.
 
Stone?

Most stock suspensions can use a beef up. It's surprising how beefing up the rear can help the front. I had KFG Racing in Auburn upgrade the suspension on my VStrom and will be having him do his magic on my Touring

Good peeps - know their stuff!!!
 
Funnily enough I just had mine rebuilt with a smaller air gap. I use Wilber’s fork springs which are 0.93kg for their linear portion (about 85% of the useable range), vs stock 0.83kg springs.

10 weight oil
100mm gap

Bikes amazing now. Previously I had the same springs on a 110mm air gap, it was too soft. Now it’s still soft the first inch or so of travel but firms up quickly as you go through the stroke.

My recommendation would be to dump the 5w garbage, throw in some 10w and go to 100mm air gap or even 90mm since you’ve the stock softer springs.

Keep in mind the R3 has NO bottoming mechanism, mechanical bottom is when it stops, not on a ramping rate spring or hydraulic device.
Thanks - I’ll stick some 10w in Tonight and see how it goes.
 
Keep in mind the R3 has NO bottoming mechanism, mechanical bottom is when it stops, not on a ramping rate spring or hydraulic device.
No so - There are two big lumpy bits on the damper rods that towards the end of compression go into a conical recess in the damper tube. Provides progressive bump stop. In reality - most of us are riding about an inch from that starting to take effect on stock springs. 100m airgap is really pushing it, Rob. Under a lot of severe braking you are getting close to seals going pop - or at least passing air so the forks internal pressure goes negative.

I had static sag of 44mm on OEM springs - fitted Maxton dampers which came with 1kg/mm springs and a preload to set them at 25mm sag. I think 30mm - cant remember.
I now run 120mm airgap (Maxton recommend a bit more but is was "just" bottoming out on 140mm) - recommended by my suspension guy as the min safe of Kayaba 43mm forks.
And his 5W oil. But not everybodies 5W is the same. One mans 5W can be like another 7 or 10 W

There is a known CHEAP solution that came from Wayne Tripp for those that have access to machine tools.

I got the info from Wayne this morning and to simplify things I will just copy and paste the basics here:
We have since machined a few "spacers" that tighten up the clearances on the bottoming cone piston a bit more than just using thick walled tubing. This improves the dampening even more. NO, I do not want to make more, but the details are below.
1.) Easy and cheap - 1.5 in. OD tubing, .200 wall thickness, 1.575 in long.
or,
2.) Machined for closer clearances - 1.522 OD, .955 ID, 1.575 long. - add .125 in wide by .050 deep slot along outside.
Place on top of bottoming cone (underneath spring), and cut 1.575 inches from pre-load tube above spring. Cut less if more pre-load is desired. If using Progressive springs, you will need to cut for the pre-load in addition to what Progressive recommends for the spring used.
-Wayne


The clear anodized Rocket cartridge has a bottoming cone (a hydraulic cylinder on top of the damper that goes almost to hydraulic lock to prevent the fork from bottoming. See piston nestled inside the spring) at about the 3" compression point or about 2" of travel from ride height.) This is what you feel when you grap some front brake and the bike quickly settles and then firms up. The extension Wayne suggests adds an extension on top of this one and not preload, as he states that use you cut the preload sleeve shorter by the 1.575". This adds compression damping to that of the damper, and it begins about 1/2" from normal ride height.

frontfork.JPG
 
I know it’s close but I’d rather it be firm than be bottom the forks constantly like I was before.
 
I know it’s close but I’d rather it be firm than be bottom the forks constantly like I was before.
At 120mm I never bottom out mate. Despite some real bastard speed bumps on our estate. At 170 (Maxtons original airgap setting) - loads.

Maxton now say 140mm. Damian at DMX recommended 135 mm - but we went to 120 as I wanted to kill some nose dive. I reckon at 120 I may even have lost a bit of overall movement.

Another option could be to link them and actually pressurise the airgap and I might have tried if the Maxtons had not come with the free upgrade of adjustable damping. I even have the parts sat in a box.
 
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