Need stretch: stem or seat post?

Raptor wrote:
I like my new Rockhopper Comp, but it's a bit cramped. On a trail that's


Your thoughts and equipment suggestions?


Set up your saddle position correctly first.

Stand next to a wall and stick a narrow book between your legs and
crotch.
press it up there pretty good and mark a spot on the wall at the top of
the book.
measure this distance to the floor.
This will be your inseam measurement.
Multiply inseam times 0.883.
That will give you center-of-BB to cusp of saddle measured along c-line
of seat post.

Next adjust your sadlle for/aft position by using a plumb line from
knob on knees when the pedal spindle at 9-o'clock. the plumb should
fall behind (1cm) the spindle for MTB.

Next,
When you're sitting on the bike, look ahead normally, then move your
eyes down and look at where your bars are in relation to your front
hub.

If your bars are behind the hub then your center of gravity is back too
far.
I generally look for my bars to be in line with the hub to one inch in
front.
Buy a stem accordingly.

"Duncan" wrote:

"Raptor" wrote

So I'm leaning towards moving the saddle back further instead of the
bars forward. I'd like a seat post with some set back, maybe 2" worth.

I'm not really advocating it but I ride with my seat right back and a short
stem. I just ended up that way from lots of incremental changes and maybe
the fact my legs are slightly short for my height.
I like the quick steering of a short stem and tend to ride with a lot of
weight on the rear wheel (quite often 100%).
Disadvantages include front wheel washout, bent seat rails and bent seat
posts.

If you have short legs for your height, the last thing you want to do
from a biomechanical efficiency perspective is to move the saddle way
back.

The handling effects of a short stem pale in comparison to having your
weight balance wrong on the bike (as you mention above).

The key is to always (always, always) start with a bike that fits.
Trying to force fit the wrong bike means you'll spend all your riding
time having less fun than you should.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Mark Hickey wrote:

The key is to always (always, always) start with a bike that fits.
Trying to force fit the wrong bike means you'll spend all your riding
time having less fun than you should.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Mark's right.
A frame has a top tube length designed to obtain a certain
center-of-gravity.
When you go adjusting a saddle way back with a bent seat post you screw
that center-of-gravity up.

If you can't get your saddle back far enough with a regular post then
you need
to go and buy a larger frame with a longer top tube.

"Mark Hickey" wrote in message
...
snip

If you have short legs for your height, the last thing you want to do
from a biomechanical efficiency perspective is to move the saddle way
back.

The handling effects of a short stem pale in comparison to having your
weight balance wrong on the bike (as you mention above).

The key is to always (always, always) start with a bike that fits.
Trying to force fit the wrong bike means you'll spend all your riding
time having less fun than you should.

I agree with what you say but I did spend a lot of time finding the right
bike for me. I even wanted the smaller size but my LBS talked me into the
next one up (19" frame I'm 6').
It's just what works for me, I'm quite flexable so I have no comfort issues
with the bike even doing 12 hour enduros in a pair. As for weight balance,
when it really matters I stand up and the saddle doesn't play a part
anymore.
So it is a little strange, but it does work well for me.
I think there can be a fairly large margin for personal preference especialy
when you ride a lot and try different things.

Even off the seat I have a tendancy to weight the back wheel:
http://www.ftf.com.au/racegalleries/...MG0640_JPG.jpg

"Duncan" wrote:

"Mark Hickey" wrote in message
.. .
snip

If you have short legs for your height, the last thing you want to do
from a biomechanical efficiency perspective is to move the saddle way
back.

The handling effects of a short stem pale in comparison to having your
weight balance wrong on the bike (as you mention above).

The key is to always (always, always) start with a bike that fits.
Trying to force fit the wrong bike means you'll spend all your riding
time having less fun than you should.

I agree with what you say but I did spend a lot of time finding the right
bike for me. I even wanted the smaller size but my LBS talked me into the
next one up (19" frame I'm 6').

Normally, a 19" frame would be in the range for your height (depending
on a host of variables though - including how the builder measures
"frame size").

It's just what works for me, I'm quite flexable so I have no comfort issues
with the bike even doing 12 hour enduros in a pair. As for weight balance,
when it really matters I stand up and the saddle doesn't play a part
anymore.

Your seated position does have a huge effect on your balance - Mr.
Newton had a few things to say about that. If you're moving your butt
way back, and compensating with a very short stem, your center of
gravity WILL be further back, and that WILL affect handling.

So it is a little strange, but it does work well for me.
I think there can be a fairly large margin for personal preference especialy
when you ride a lot and try different things.

Or (as I've seen over and over), a rider can get used to a bad
position on the bike. Yes, everyone is different, but the reason the
"average position" works for most people is because the vast majority
of us have physiologies within a very narrow range. Perhaps you're
outside of this "normal range" - perhaps you've gotten used to riding
with what for most of us would be an inefficient position.

Even off the seat I have a tendancy to weight the back wheel:
http://www.ftf.com.au/racegalleries/...MG0640_JPG.jpg

That's an odd position. What can I say? ;-)

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

"Duncan" wrote:

Even off the seat I have a tendancy to weight the back wheel:
http://www.ftf.com.au/racegalleries/...MG0640_JPG.jpg

Are you sure that's a 19" frame?

It looks too small for you.

CowPunk wrote:
Mark Hickey wrote:

The key is to always (always, always) start with a bike that fits.
Trying to force fit the wrong bike means you'll spend all your riding
time having less fun than you should.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Mark's right.
A frame has a top tube length designed to obtain a certain
center-of-gravity.
When you go adjusting a saddle way back with a bent seat post you screw
that center-of-gravity up.

That's kind of silly when you realize that people are different. I have
several pounds of weight above my waist that many mountain bikers don't.
By bending or straightening my arms, I can move my COG instantly, on
most any bike.

Most high performance bikes are bought "small," the smallest frame that
fits. My bike's seat tube is long enough. The top tube might actually be
optimal for a different rider with my particular build. I've just become
comfortable leaning forward with arms more outstretched than many riders.

If you can't get your saddle back far enough with a regular post then
you need
to go and buy a larger frame with a longer top tube.

Seat tube angle and length has more to do with "proper" saddle location
than top tube length.

--
Lynn Wallace http://www.xmission.com/~lawall
I have nothing but contempt and anger for those who betray the
trust by exposing the name of our sources. They are, in my view,
the most insidious of traitors."
George H.W. Bush, April 16, 1999,

Raptor wrote:

Seat tube angle and length has more to do with "proper" saddle location
than top tube length.

So, with your rear saddle position, can you drift both wheels in a
corner,
or does one break loose before the other?

I bet your rear slides out first?

"Mark Hickey" wrote in message
...

It's just what works for me, I'm quite flexable so I have no comfort
issues
with the bike even doing 12 hour enduros in a pair. As for weight
balance,
when it really matters I stand up and the saddle doesn't play a part
anymore.

Your seated position does have a huge effect on your balance - Mr.
Newton had a few things to say about that. If you're moving your butt
way back, and compensating with a very short stem, your center of
gravity WILL be further back, and that WILL affect handling.

Absolutely, my arrangement was as much for handling as it was for comfort.
I tend to ride the back wheel, I like to keep the front light and the rear
planted. For downhills this lets me manual through dips and extend the legs
to drop the rear wheel through after. For climbing it gives lots of rear
wheel traction but I can still lean forward to weight the front as needed.
As I said this is personal choice and I know there are pros and cons. Just
this morning I did a flat track race with tonnes of 'pea gravel' and was
constantly shifting my weight forward for the faster looser corners to
prevent front wheel washout.
On the upside it gives a lot of practice saving front wheel washout that
absolutley saved my skin on the mtorobike the other day.

So it is a little strange, but it does work well for me.
I think there can be a fairly large margin for personal preference
especialy
when you ride a lot and try different things.

Or (as I've seen over and over), a rider can get used to a bad
position on the bike. Yes, everyone is different, but the reason the
"average position" works for most people is because the vast majority
of us have physiologies within a very narrow range. Perhaps you're
outside of this "normal range" - perhaps you've gotten used to riding
with what for most of us would be an inefficient position.

Well you've definatly given me reason to rethink my setup which is exactly
what a good newsgroup should do. I do occasionaly try something different
so I may well give it a go.
I do also have a 20" on-one frame that is very long and I also have the seat
quite far back on that as well.

"CowPunk" wrote in message
ups.com...


"Duncan" wrote:

Even off the seat I have a tendancy to weight the back wheel:

http://www.ftf.com.au/racegalleries/...MG0640_JPG.jpg

Are you sure that's a 19" frame?

It looks too small for you.

Yeah it's definatly a 19", brands vary a lot in shape and where they
measure. Keep in mind the bike is a race bike where agility is quite
important. Our local race courses have a tendency to by quite tight
singletrack where quick steering pays off.