Damping Adjustment affecting Gear Shifting ?

David said:

I have a full-sus bike fitted with a Rockshox SID Rear damping
adjustment. I havent touch any of the setting on this shock until a
couple of weeks ago when I put some more air in both the pos and neg
chambers. Unfortunately since "about that time" the bike seems to jump
between small rear cogs: about 6-7 of 9 when the large front cog is
engaged.

Sounds like the indexing is slightly out -- could be that the cable has
stretched a bit. How long have you had the bike and have you ever had the
gear cable re-tightened? Just coincidence that it became apparent at the
same time as your sus adjustment.

David said:

I have a full-sus bike fitted with a Rockshox SID Rear damping
adjustment. I havent touch any of the setting on this shock until a
couple of weeks ago when I put some more air in both the pos and neg
chambers. Unfortunately since "about that time" the bike seems to jump
between small rear cogs: about 6-7 of 9 when the large front cog is
engaged.

There is a red knob for damping adjustment which I dont recall
touching but it appears to be set to minimal damping.

Another behaviour I have noticed is the loss of power and more "slack"
in the pedals when I am riding.

I try adjusting the damping when I next go out, I am curious: are the
two problems likely to be related to the suspension setup ?

Any help appreciated.
Dave

Check the length of the cable housings between the main frame and rear
triangle. I have come across situations where they are marginally too
short for full travel which results in ghost shifts when it approaches
and leaves full travel. Its just possible that your damping adjustment
has extended the travel range and exposed the problem. OTOH it could be
coincidence.

Tony

in message <[email hidden]>, David

(') said:

I have a full-sus bike fitted with a Rockshox SID Rear damping
adjustment. I havent touch any of the setting on this shock until a
couple of weeks ago when I put some more air in both the pos and neg
chambers. Unfortunately since "about that time" the bike seems to jump
between small rear cogs: about 6-7 of 9 when the large front cog is
engaged.

There is a red knob for damping adjustment which I dont recall
touching but it appears to be set to minimal damping.

Another behaviour I have noticed is the loss of power and more "slack"
in the pedals when I am riding.

I try adjusting the damping when I next go out, I am curious: are the
two problems likely to be related to the suspension setup ?

The gear problem is unlikely to be related, except if the cable outer of
your gear cable is too short and is pulling tight at some point in the
suspension travel. Loss of power is highly likely to be related. An
underdamped rear shock will tend to bob badly when you're pedalling,
and that will result in loss of power - essentially your pedalling
effort is going into compressing the suspension.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

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Quoted message said:

The gear problem is unlikely to be related, except if the cable outer of
your gear cable is too short and is pulling tight at some point in the
suspension travel. Loss of power is highly likely to be related. An
underdamped rear shock will tend to bob badly when you're pedalling,
and that will result in loss of power - essentially your pedalling
effort is going into compressing the suspension.

Thanks for the help, with the damping now set correctly the loss of
power problem seems reduced, and the gear skipping still happens,
although less frequently.
Dave