[sjs514]

The first question-I am a lightweight, 120 lbs, riding a Redline flight monocog(15" frame) HT. My body gets bounced off the saddle riding roots or things like that. I know to expect this, but is there anything I can do to help with this situation like lower air pressure or something else. I run converted tubeless at 22 lbs right now. Eventually I will get a FS but not right now. I would just like a little help for when I am sitting down & pedaling. The second question-has anyone used a 38 tooth cog in back? If so, was there any issues? Thanks for any help.

 

[Cloxxki]

Have you tried putting the rear wheel in teh rearmost position? Check whether yor chain will fit around the large ring-large cog combo before riding it that way.

Else, there are nice suspension seat posts out there. I own a long travel Canecreek which is nice. Comfort is close to that of an FS, at less weight penalty, although there's often also less damping.

Of course, a larger tire, if it fits, will help a lot for comfort too.

38t will ask some from your derailer's reach. I've seen few riders report on using it yet.

 

[bobbotron]

That's pretty normal, that's what happens on a hardtail.. You have to use your body (read legs) as suspension and not be loose when your rear wheel travels over things. Or so they say, I'm still getting used to that, and it's my 3rd season off roading. If you're going to hit something big on a hard tail, get off the seat so your legs can absorb the impact, instead of your butt.

I started this thread on the local forum a while ago, maybe it will help you out?
http://www.mtbkanata.com/forums/index.php?showtopic=37658

You could also invest in a thudbuster, but I think it's definitely a technique thing as well.