I believe, but I am not certain, that I can turn the adjustment screws (on top of the forks) all the way out, and they won't just fall out of the forks? The purpose being that I would know the softest setting possible, and then I can add some stiffness back in.
I couldn't detect a click when turning the screw. Is there one, or do I just pay attention to the number of turns? Is one 360 degree turn enough to make a noticeable difference, or is that too small a change to have any real effect?
Thanks!
https://youtu.be/lo0kv_6hG-0
Everything you need to know about that screw on the forks
2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca
Those screws are to adjust preload. They don't change stiffness and they don't change damping.
Preload will change how low or high will be the equilibrium position of the suspension when you are on the bike. So a higher preload (screw in) means more bump travel, less rebound travel, and a lower preload means less bump travel and more rebound travel.
If you turn them all the way CCW, you can take them out.
There are no clicks: there are some etched circles on the screw body, so you can visually check the preload setting. Honda's basesline is when two lines are visible.
The idea is that you check where the suspension stays when you are off the bike, and then you seat on the bike and check how much the suspension has moved. Preload will affect that initial movement. I think you should aim for around 30mm of travel when you seat on the bike. But I am not sure about the ideal value. Someone else will know whats recommended for this bike.
[edit]: look into this thread:
http://cb1100forum.com/forum/showthread....#pid250414
You should not consider the front preload in isolation from the rear as changes here will have an impact on the bikes geometry and handling. You should concentrate on the rear preload first as it has the biggest task of adjusting for weight, e.g. pillion, luggage etc and understand that preload only changes where your shock (or forks) sits in its (their) overall travel. It would be quite normal to aim for a suspension usage of around 25%-30% of overall travel when sitting on the bike fully geared up. This is to allow for both compression and rebound travel. It is because of gravity and greater downward forces that you would aim for your shock to be at that 25-30% usage rather than somewhere in the middle of its stroke, so as to allow for more compression travel. No matter where you set your preload you will always have 100% suspension travel available, it is just how much is dedicated to the compression or the rebound side.
I have done a lot of measuring of suspension travel on this bike front and rear and the two ends are specified quite differently and I advise care not to blindly follow the 25-30% SAG figure up front though. I hope to make a video on it in the next month or so. I would set rear preload for that 25-30% SAG and it is easily achievable on this bikes rear shocks. The front however uses up a disproportionally amount of travel for a given weight and I am not totally convinced Honda are expecting users to try and adjust for 25-30% SAG as you would at the back. This is actually quite difficult to achieve anyway. What I would do with the preload at the front is to ignore any SAG targets and use the front preload as a "handling adjuster". Max it out (full clockwise) and go for a ride round some twisty roads, stop, fully wind it out (anti-clockwise) and do the same route. It only needs to be 5 minutes long. Now you know how the preload affects this bikes handling and you should find the difference quite significant.
Now you know how the bikes handles between the two extremes add back front preload one ring at a time, you want to add as much as you can UNTIL it starts affecting the handling in a detrimental way. You might end up on ring 1 or 4, but you will know what you like best. The road has to be twisty, there is little point doing this on a straight road. Wherever you end up leaving it you will still have plenty of SAG on this bike so no worries about not having enough rebound travel on the suspension, even at max front preload. If you subsequently change your tyres you may find the handling is changed, use that front preload to adjust that out. When I went from stock to T31's the bike became quite flighty and I was able to add front preload to steady that out. I am almost convinced this is what Honda had in mind for the front preload, a "handling adjuster" rather than an out and out "SAG setting adjuster". Now if you add a pillion or a pile of luggage you will find you can leave your front preload where it is and just up the preload on the rear to take that extra weight into account. Most bikes do not have a front preload adjuster, even very expensive ones, it is a bit of a bonus on the CB1100 to be able to use it to adjust the handling. I would like adjustable damping too though!
Dave Moss is a good dude... met and talked to him on several occasions. He really knows his stuff.
In stock trim, the forks on the CB are some of the worst forks on a bike I've ever owned. They pogo like crazy and offer no help for compression/rebound. I installed some AR-25's and made a huge difference, but still nowhere near on par as what a cartridge type would offer.
But yeah.... play with the preload on top and see what works for you. An easy way to slow things down is to swap to thicker oil.