Do the Cans of a rear shock dictate tune?

898kor

After somebody sense checking me here please:

What dictates the tune on the rear shock of a RockShox type?

A long story short is that I upgraded my normal Monarch R 190x51 to a Monarch RT3 190x51 Debonair - the tune was easy as my bike is fitted with "m" & "m".

Anyway, I have messed and faffed wround with tuning rings for the Debonair side and never really been happy with any setting or air pressure, either loads of sag or too much progression - a bit of a read up on the web and I found out debonair loses its function for the heavier rider (~120Kg for me) as the sticktion that an air shock gives to the lighter riders is not a problem as we heavys can just push past it.

So I swopped the Debonair can for my old Monarch R can (keeping the RT3 head) - what a difference, the shock performes brilliantly, lock out, pedal and downhill modes work as they should.

This leaves me with a Debonair can doing nothing, I might as well fit it to my kids bike which is also a Monarch R 190x51 but its tune is "M" & "L" and he is much lighter than me. He might as well benefit from the debonair element.

My suspicion is that this will be fine, I dont think the can dictates the tune but I am asking just in case there is some magic in there that I am not seeing.

steve_sordy

If the volume of the can is different, then the way the shock works will be dramatically affected. You are doing the equivalent of adding (or removing) air volume spacers. A smaller volume of air requires less air pressure to give the desired sag and it ramps up more quickly, thus providing that much loved "mid stroke support".

This is a right riveting read about suspension tuning. Recommended.

https://bikerumor.com/2014/10/30/bikeru ... -download/

898kor

steve_sordy wrote:

If the volume of the can is different, then the way the shock works will be dramatically affected. You are doing the equivalent of adding (or removing) air volume spacers. A smaller volume of air requires less air pressure to give the desired sag and it ramps up more quickly, thus providing that much loved "mid stroke support".

This is a right riveting read about suspension tuning. Recommended.

https://bikerumor.com/2014/10/30/bikeru ... -download/

Yes Steve, all understood and that is the basis of why a Debonair can does not suit the heavier rider.

But you can buy the RT3 in MMS and MLS - Ive done some searching around, it seems the can has nothing to do with tune (its the internal parts). So going to put the debonair can on boy mk1 and see if he feels its an upgrade.

The Rookie

Correct, the lettering refers to the damping, the external can can be swapped but the damping stays the same.

898kor

The Rookie wrote:

Correct, the lettering refers to the damping, the external can can be swapped but the damping stays the same.

Thanks Rookie - its going on tonight 8)