How high can I safely adjust saddle height?

[zoejojo]

I'm a starving student. I'm stuck in a foreign city for one semester. My savvy craigslist $20 purchase is a wee bit small. It's too short for my legs but the smaller frame is comfortable for my arms.

I understand how much leg extension I need - how high can I extend the seatpost? If I extend it past the max height line, but keep the post inserted enough that it's a few mm past the ears, what can go wrong?

[GeorgeET]

Well a few mm is just not enough, the leverage of the seat post may become to great for the frame.
The lean to the handlebars too extreme.

Get use to riding BMX style . Its only for one semester. Sometimes savvy is not enough. If you absolutely have too try a longer seat post.
IMO its done learn to live with it, unless it causes you pain.

[cyclerUK]

If the seat is too low then you knacker your knees, and very quickly.
(we are going to have a lot of people who will need knee operations soon.)
On the other hand if you take it beyond the "max" mark then you do so at your own risk.
If you have any cycling buddies will they do a swap if you can find a suitably longer one?

[zoejojo]

Thank you. I've never heard of a bent frame but I'd hate to impale myself. It's tempting to disregard unknown physics. BMX style it is, then. 15 weeks to go.

(01-30-2011, 04:00 PM)GeorgeET Wrote:  Well a few mm is just not enough, the leverage of the seat post may become to great for the frame.
The lean to the handlebars too extreme.

[GeorgeET]

Ye that seems the easiest solution. We got lots of guys around here riding on 20 inch kids bikes.:-))

BMX bikes are very popular in Venice California.

As per bend frame they do bend and crack .

[nfmisso]

you can purchase 400mm seat posts for under $20.

Be warned, that they can be bent. The aluminum ones have thicker walls, and are less likely to buckle than the steel ones.

[RobAR]

nfmisso is on it. A longer post might be your answer. BMX style would burn my quads big time.

The main thing is to be certain that the post inserts deeper than the lower weld of the top-tube / seat-tube junction.

[GeorgeET]

Ahh, you guys are a bunch off woosies. We got real bikers here in Venice. Hi , Low and in between.

BTW I suggested tall seat post too but a post would coast more than his bike. :-)))

[JohnV]

I sure would hate to do an emergency dismount on that first bike. I'm thinking that he doesn't ride it in traffic. I wonder where he carries the ladder to get on and off.

Going back to the question at hand. Have you tried looking for a seat tube in a junk yard or dump that can fit inside the seat tube on your bike. If you can find one, use the smaller diameter seat tube for the seat and cut the seat mount off the current tube. Then you can slide one into the other and run a bolt or two through them to hold them together or see if a seat tube clamp will keep them from sliding into one another. Not the best way to do this, but certainly the cheapest.