Seat post - how little can you get away with?

Got my first fixie on the road today! But I want to raise the seat and i've got a pretty short seat tube. How little tube can you get away with actually in the frame? I know some seat posts have a marker but mine don't...

Leave a couple of inches in the tube to be totally safe. Anything below 1 inch is perilously deadly. Between 1 and 2 inches and it's subjective depending on quality of components, maintenance, etc.

most seatposts have a mark as to how much has to be left in.

i'd suggest you follow that

Below the top tube/ 80mm is a fairly good yard stick.

most seatposts have a mark as to how much has to be left in.

i'd suggest you follow that

You can always get away with quite a bit more than this, they're manufactured with a pretty big safety factor.

Depends on the frame too, if the seat tube extends well above the top tube and seat stays it will be in danger of damage if you only have a really short bit of seat post in.

Below the top tube/ 80mm is a fairly good yard stick.

i'd go with this, unless the seat stays are lower.

yard = 914mm come on guys. really?

http://www.lfgss.com/thread3196.html

Tynan's brilliant picture is missing now though.

Cheers guys. Think im gonna need a new post. Just rode home with an inch in the grip of the frame and it went a bit wobbly! Bad move! also any good links to cycling position and posture? My current position leaves me with a bar of tension across my shoulders, yet I was really careful getting the right frame size for my height

Sounds like it's too small. what's the standover like?

Loving "tynans line" (i wasn't even close, naughty naughty...) Standover? Pretty poor. Close to 0cm

Any good links to cycling position and posture? My current position leaves me with a bar of tension across my shoulders, yet I was really careful getting the right frame size for my height

http://sheldonbrown.com/pain.html#shoulders
http://tinyurl.com/ydtmsvh

Google is your friend here.

Sounds like it's too small. what's the standover like?

Or too big, having to stretch too far/too much weight forwards.

Murray, just do lots of research with Google and mess around with different positions/setups. Failing that, go to a bike shop and get fitted. They'll sort you out.

Cheers weslito. Did a bit of fiddlin, raised the bars to the max (which ain't that high) and moved the saddle back a bit cos I felt all a bit scrunched up. Tilted my saddle forward too to stop the lady-bits getting squished but the guys in my bikeshop today said never do that. I'll put it back to level, but if squishing persists I might have to buy a ladies saddle.

I think the general consensus is to set the saddle position using KOPS, then adjust reach with stem length/frame size. Moving the saddle back will mess around the leg position in relation to bottom bracket. Although if you're worried about comfort over performance then by all means.

Saddle angle forwards will put a lot of strain on your upper body to stop you sliding off and potentially make your shoulders worse. Make sure your saddle fits properly (your weight should be on your seat bones, not in between) and you shouldn't have too much of a problem with squishing. And some good shorts. Failing that, HTFU.

Cheers weslito. Did a bit of fiddlin, raised the bars to the max (which ain't that high) and moved the saddle back a bit cos I felt all a bit scrunched up. Tilted my saddle forward too to stop the lady-bits getting squished but the guys in my bikeshop today said never do that. I'll put it back to level, but if squishing persists I might have to buy a ladies saddle.

The notion of just mess around is so wrong

bike fit is v v technical and you could spend a fortune changing parts etc to get it to fit

a discrepancy of 5 mm from ideal fit for any of the contact points will compromise the fit

I don't see any harm with a bit of educated-messing-about for the murray with the components she's already got. I learned loads about fit initially from doing this.

Murray, you've got an old conversion, right? Just do loads of research on fit, get it as best you can with what you've got and see where you're at. No need to start throwing money at it just yet.

*emphasis on educated. Or just get fitted to keep DJ happy.
How much does a fitting cost?

I had been riding with about a inch and a half of seatpost in my frame for a couple of weeks, got paranoid thinking that it would snap and I would not be able to get the part out of the frame...