I flipped my stem to drop it ~2cm and now my suspension bobs less but the shock bottoms out more. Why is dat?
beside the fact I doubt your faster.....
the shock bottoming out more could be a lack of ability to absorb terrain as well, but I really have no idea with out MTBing with you and probably still wouldnt be for sure after that.
Well, for the first part I can haz computer ... hard to do 2 mph faster on 104 BCD without actually spinning faster.
It is the second part I am clueless about: what does a proper "terrain absorption stance" feel like? With the bars high up, I felt like I was on a comfort bike and seriously hated climbing even though the rear shock felt like it was more towards the middle of the range.
And how do I know when it's my bad terrain absorption and when it's a suspension tuned for someone even fatter than I am?
Makes sense to me. If you are bent over more you engage your glutes (butt) muscles more which can result in more power to the pedal. (Sounds like you were too upright.) Also you have shifted your center of gravity forward which helps with climbing-more weight on the front wheel as well as more power to the pedals..
However, there is a trade off and that is with descending. You are more likely to endo with the shifted COG.
It sounds to me like you need to fiddle with your shock and fork settings to optomize your new riding position.
Getting a better more comfy fit lets you spin smoother, sounds like it led to reduced bob.
As far as bottoming... if you are riding faster, then bottoming more could be due to that... maybe... But given the fact that your suspension was very sensitive to bob before from just cadence changes, it sounds like your shock was never turned optimaly. And if you are bottoming multiple times durring your typical ride then your spring rate is too low.
What's your bike anyway?
If you are bottoming out the rear shock then you need to adjust it, assuming it is holding air pressure and you have not blown a seal. If you do not have a manual, then you can look at (or download) one on line for your model shock. Start by setting the sag, and then the rebound.
Another possibility is that your front shock is not set up right. Now that you have more weight up there because of the stem drop, when you hit a bump it might be rebounding you onto the back shock causing it to bottom out. If your front and rear are not adjusted properly for your weight and riding style, and somewhat in sync, they can bounce you from one to the other instead of absorbing the bumps.
I was thinking exactly what Mudfoot posted.
I think that you shifted your center of gravity so far forward it essentially unweighted the shock and induced the bob while you are on flattish terrain. Probably works well for climbing...
If setting the Sag and rebound doesn't work try these thins.
Release all the air pressure and 'cycle' the shock through its whole stroke. Make sure nothing is catching, or sticking, make sure the seals are properly lubed.
Make sure none of the mounting harware is damaged, cross threaded, etc.
Look out for bunched up paint, paint chips in the pivot points, and hardware.
It could also be a 'break in' problem. Some of the shocks I've used simply don't ride well until they are broken in...