Lost my way a bit?

[Bitza]

Hi all, well I've had my bike for over 25yrs now and along the way have altered pretty much everything. In more recent years I've become aware that I had kind of lost my way with the handling/suspension, but you can actually ride pretty much anything. Then I moved house to an area where potholes, rumble strips etc are a real issue, to the point that sometimes it really hurt, so I decided that it was about time for a rethink.
I decided to assume that the main problem might be that I had the rear too high/front too low. So working one setting at a time, I've shortened the shock (complete with softer spring) and reset the forks lower in the yolks. Now I have an issue, with no preload I've only 22mm of static sag on the forks. So should I try to reduce the packing on the spring, or should I try a weaker spring?

[stopintime]

Progressive or linear spring?

Front or rear or both?

Linear is ok to soft if 22.

[Bitza]

Linear springs fitted to front fork cartridges.
I'm aiming for 25mm sag, so with no preload if I only get 22mm sag then the spring is too hard.

[Mr Gazza]

The static sag on it's own is not really telling you very much.
It's the difference between static and dynamic sag which will tell you whether your spring rate is right.

22mm is near enough to 25 to not worry about, so long as the forks don't top out on the rebound if you get it airborne!

MCT recommended 28mm static sag +/- 2mm for my adjustable Showas.
10mm +/- 2mm for the rear Ohlins.

Assuming from your mentioning shims that these are non-adjustable forks?
If so you're not going to do much with them, unless you spend a lot on professional tuning and modifications. Probably better to service and fit an adjustable pair?

[Bitza]

OK the forks will be familiar to Mr G cos they are off a 2001 900sie, but fitted with Maxton cartridges.
Yes 22mm is pretty much there, but I tend to smell a rat when I'm on/passed the limit of adjustments. Please tell me more about the rider/static sag and spring rate.

[Bitza]

In parallel with this thread I also contacted Richard at Maxton to ask the same question. He suggested reducing the spring rate, in my case from 0.85 down to 0.8 or 0.775 mm. However he also said something quite interesting, simply lifting the wheel off the ground is often insufficient to fully extend the forks. He suggests pushing the wheel down with your foot, often revealing a further 8-10mm of extention. Unfortunately in my case it was just 1mm.

[Mr Gazza]

Well if the spring alone won't extend the forks fully when off loaded they never will use that extension in the real world so it's a bit academic!

I'll did my sags and settings out in a bit, but they are not going to all work on yours as we are different weights, riding positions and cartridges.

[Bitza]

Re the extra being academic, I tend to agree although possibly the shake rattle and roll of thundering down the road would help overcome a bit of sticktion?!

[stopintime]

Did you say linear or progressive?

[Bitza]

The springs are linear

[stopintime]

10-15 is usually good for static - depending on how much (word...?)(mounted compression?) Another ~20 with the rider. This is a sporty set up. Your request for comfort might be unrealistic if the cartridge kit is less than great. Also, there's a limit to how soft a fork should be.

[Bitza]

Stop in time, thanks for your input but the figures you quote would seem better suited to the rear end. My current issue is with the front forks, sorry if I didn't make that clear.

[stopintime]

The difference front and rear isn't that great... About 120mm front and 100 rear?

If the front is much softer than my ball park numbers, it'll bottom out on challenging roads and/or spirited riding.

Front and rear should be equal(ish) for a planted ride.

[Mr Gazza]

From my notes;
Front Static = 28mm
Rear Static = 12mm
Unfortunately I have not recorded my dynamic sags, so I assume these were within range and not comment worthy.
A general guide would be static + 20mm when loaded with rider clad in typical riding gear and in the riding position. I tend to do this close to my bench and just lean against it at as slight an angle as possible to get my feet up. Ideally A N Other would do the measuring at this point, but I tend to try and look at a rule taped to something handy, sometimes with the aid of a mirror.

For reference I am using EXP15 oil 100mm from top. (As MCT filled them.)
He recommended the thicker oil to give the standard cartridges something to work on.
Your cartridges will likely work best with whatever oil Manxton recommends.

MCT start settings were
Comp 2 clicks out.
Reb 7 clicks out.

I found that rather harsh on Norfolk roads and altered as follows.
Comp 4.
Reb 8.
That was worse to be honest so I consulted with Darren at MCT. I'll never forget his advice, now my mantra, "Always do more to the rebound than compression."
So I had another tweak to;
Comp 5.
Reb 11 clicks out.

That's how it's stayed and the steering is still sharp, but I just live with the worst of the bumps. (Still nothing like suffering the ride you get in a car!!.. 4X as many bloody bumps!)

I will just add that tyres are part of the suspension as well and different ones are more or less compliant to bumps.
Best I've had for bump absorption are Metzeler Roadtec 01 on the Monster.
Bridgestone 023GT work well on my heavyweight, but would not suit a Monster.
That is a 2020 bike and has Showas with a spring in one leg and the damping in the other. I've set that up with what I learned from Darren and it rides a treat.

[Mr Gazza]

Here's something Rob posted some time ago.
It's a bit verbose but explains the set up method.
It doesn't separate the Static from the dynamic sag in the way other guides do, but does imply a dynamic (loaded) sag of about 20mm when the static sag is subtracted.

Basically if you have about 20mm of extra sag loaded, after your static sag, then your springs are in the ball park.