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How do I adjust this Bitubo suspension?

Posted: Tue Nov 10, 2020 7:20 am
by 150pcxer
Hi all,

So I just bought and got this Bitubo rear shocks installed at the dealer's workshop.

SC209YGB01

In which direction do I turn it to make it softer? Clockwise or anti-clockwise?

And for how many rounds?

https://i.imgur.com/36xPed1.jpg

Thanks.

Re: How do I adjust this Bitubo suspension?

Posted: Tue Nov 10, 2020 7:26 am
by Jge64
We have no idea how strong the spring is, what you weigh, passenger ? Ask the people who installed it. Otherwise screw it up and down a couple times to different lengths and take a ride. Do what feels best. The general rule is somewhere between .5 and 1.0 inch of threads showing.

Re: How do I adjust this Bitubo suspension?

Posted: Tue Nov 10, 2020 7:46 am
by fish
And hopefully you will feel an improvement over the stock shock equal to the $$ spent.
Fish

Re: How do I adjust this Bitubo suspension?

Posted: Thu Nov 12, 2020 8:07 pm
by Gil
I think you are talking about adjusting the spring preload. If so loosen it until the spring is loose, then tighten it up a turn. More preload will stiffens the spring up, giving you a higher spring rate, ei stiffer. Less preload will give a softer spring rate, to an extent, but it will also reduce the travel of the shock. Start from the softest spring preload and test ride it untill you find a setting that you like. Check the manual that came with the shocks, it might have some info on how much preload to set. It's usually given in mm, as in how many mm to compress the spring.

Re: How do I adjust this Bitubo suspension?

Posted: Thu Nov 12, 2020 8:13 pm
by Gil
Also, do write a review of those shocks since there isn't much about them on the internets.

Re: How do I adjust this Bitubo suspension?

Posted: Fri Nov 13, 2020 5:04 pm
by Oyabun
Gil wrote:I think you are talking about adjusting the spring preload. If so loosen it until the spring is loose, then tighten it up a turn. More preload will stiffens the spring up, giving you a higher spring rate, ei stiffer. Less preload will give a softer spring rate, to an extent, but it will also reduce the travel of the shock. Start from the softest spring preload and test ride it untill you find a setting that you like.
Ummm. Sorry, but that's totally wrong, a complete misunderstanding of how a spring or shock works.
First of all, what can be set is spring preload.
Preload doesn't adjust spring rate at all. It just sets a preload on the spring governing how much force will be required to get it move from its original position, and how high in the stroke the shock will travel.
There are muti rate springs (usually called progressive, ut most of the time they are in reality just dual rate just as you see on this very shock two distinctly different springs) what means up until a certain compressed length their spring force is linear, and then after a switchover point when the shorter spring is compressed they turn to a higher linear rate.
Again, preload does not limit the usable stroke of the shocks at all. Moreover, higher preload usually means that more of the total travel is available, as the suspension does not sag that much under load.
Think of it as a ship, where spring is the water column, total suspension travel is the height of the water. If you load the ship with heavy cargo, it will sink deep enough to bottom to the floor when waves start hitting. However if you raise the level of water, it will ride higher and not hit the bottom even in high waves.
The height of the water doesn't change the buoyancy of the ship (read how much cargo it can carry without sinking) which relates to the rate of the spring in our analogy.
Many times therefore it is resulting in a better ride if one increases the spring preload, as most of the time the perceived harshness is due to the shock bottoming on bigger rad issues.
What I see on your shock is that it seems to be in the extrelemy low preload position. Don't lnkw what's your weight, and what is the spring rate of the shock, neither we know how the shock rides and why you think it should be "softer". But from what I see you can only increase spring preload, and most probably you also should increase preload as the harshness is most probably due bottoming of the shock. In order to get the most out of what you got learn to measure and set sag properly, and your ride will improve significantly. (do a search on YouTube Dave Moss, how to set sag on your motorcycle)
BTW to answer the OPs question turning the linear adjusters towards the centre of the spring add preload, turning them the other way around remove preload. In the setup you have to torn them to the right, to move the adjuster upwards.

Re: How do I adjust this Bitubo suspension?

Posted: Fri Nov 13, 2020 5:17 pm
by Oyabun
Here's a more lengthy and good explanation on spring rate vs preload.
https://www.cycleworld.com/sport-rider/ ... d-preload/

Re: How do I adjust this Bitubo suspension?

Posted: Fri Nov 13, 2020 8:05 pm
by Gil
Oyabun wrote:Here's a more lengthy and good explanation on spring rate vs preload.
https://www.cycleworld.com/sport-rider/ ... d-preload/
"Again, preload does not limit the usable stroke of the shocks at all. Moreover, higher preload usually means that more of the total travel is available, as the suspension does not sag that much under load."

That's a great explanation.

Thanks..

Re: How do I adjust this Bitubo suspension?

Posted: Sat Nov 21, 2020 4:33 pm
by TheDoors
Try sending an email to bitubo@bitubo.com to get installation instruction directly from the manufacturer.

If you will eventually need any help traslating from italian, let me know :-)