Frame Type Experiences

Default said:

Hi, what can you tell me about the aero differences between compact & std
frame geometries? Is it possible you found compact frames to be less
aerodynamic due to rider position being more upright? Could this be true at
all? What are your takes on this issue?

Read Mike Burrows book on bicycle design.

What you want are:

Short frames, aero seat pin, proper aero rims, monostay forks and to
cycle with only one leg having had an above the knee amputation[1].

It is an informative and thought provoking bike by the man behind Chris
Boardman's superbike.

...d

[1] OK, he doesn't say the bit about one leg but he implies it..

David Martin said:

Default said:

Hi, what can you tell me about the aero differences between compact
& std frame geometries? Is it possible you found compact frames to
be less aerodynamic due to rider position being more upright? Could
this be true at all? What are your takes on this issue?

Read Mike Burrows book on bicycle design.

What you want are:

Short frames, aero seat pin, proper aero rims, monostay forks and to
cycle with only one leg having had an above the knee amputation[1].

It is an informative and thought provoking bike by the man behind
Chris Boardman's superbike.

..d

[1] OK, he doesn't say the bit about one leg but he implies it..

OK then: How do I make my legs more aero?

--
Ambrose

Ambrose Nankivell said:

David Martin said:

Default said:

Hi, what can you tell me about the aero differences between compact
& std frame geometries? Is it possible you found compact frames to
be less aerodynamic due to rider position being more upright? Could
this be true at all? What are your takes on this issue?

Read Mike Burrows book on bicycle design.

What you want are:

Short frames, aero seat pin, proper aero rims, monostay forks and to
cycle with only one leg having had an above the knee amputation[1].

It is an informative and thought provoking bike by the man behind
Chris Boardman's superbike.

..d

[1] OK, he doesn't say the bit about one leg but he implies it..

OK then: How do I make my legs more aero?

Steam roller. Shave all the hair except for a 6mm wide strip mohican
like along the front. Add overshoes to remove turbulence from
laces/straps.

...d

Ambrose Nankivell said:

OK then: How do I make my legs more aero?

Get on a recumbent, and then they present considerably less surface area
to the airsteeam. Better still, get them on a recumbent with a front
fairing.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

David Martin said:

Ambrose Nankivell said:

David Martin said:

Default wrote:
> Hi, what can you tell me about the aero differences between compact
> & std frame geometries? Is it possible you found compact frames to
> be less aerodynamic due to rider position being more upright? Could
> this be true at all? What are your takes on this issue?

Read Mike Burrows book on bicycle design.

What you want are:

Short frames, aero seat pin, proper aero rims, monostay forks and to
cycle with only one leg having had an above the knee amputation[1].

It is an informative and thought provoking bike by the man behind
Chris Boardman's superbike.

..d

[1] OK, he doesn't say the bit about one leg but he implies it..

OK then: How do I make my legs more aero?

Steam roller. Shave all the hair except for a 6mm wide strip mohican
like along the front. Add overshoes to remove turbulence from
laces/straps.

My latest shoes already have a neoprene cover for the knot, and the laces
seem to the untrained eye, although I've not tested in a windtunnel, to
promote laminar flow by the exact contours of their layout.

Steam roller hire has been booked. Care to show photos of your own so I can
gauge the profile needed?

--
Ambrose

Peter Clinch said:

Ambrose Nankivell said:

OK then: How do I make my legs more aero?

Get on a recumbent, and then they present considerably less surface
area to the airsteeam. Better still, get them on a recumbent with a
front fairing.

Nice try.

However, David's solution of steamrollering my legs suits my lifestyle far
better. 🙂

--
Ambrose

Default said:

Hi, what can you tell me about the aero differences between compact & std
frame geometries? Is it possible you found compact frames to be less

No.

There's no difference at all. The defining factor is the height at the
front and that's the same. If you want a TT bike rather than a general
purpose one then getting one a size smaller (or a TT specific frame)
will let you have a lower front

--
Arthur Clune

in message <[email hidden]>, Default

(') said:

Hi, what can you tell me about the aero differences between compact &
std frame geometries? Is it possible you found compact frames to be
less aerodynamic due to rider position being more upright? Could this
be true at all? What are your takes on this issue?

No. The rider position is not more upright on a compact frame.
Aerodynamically it should make no difference.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

A message from our sponsor: This site is now in free fall

Ambrose Nankivell said:

Steam roller hire has been booked. Care to show photos of your own so I can
gauge the profile needed?

I found that at the speeds I travel, aerodynamics plays only a tiny
part. It is more the power to wait ration going up the hills so I am
looking for a better engine.

...d

David Martin said:

Ambrose Nankivell said:

Steam roller hire has been booked. Care to show photos of your own
so I can gauge the profile needed?

I found that at the speeds I travel, aerodynamics plays only a tiny
part. It is more the power to wait ration going up the hills so I am
looking for a better engine.

Oh. Last I saw, steam rollers had a pants power to weight ratio.
--
Ambrose

Ambrose Nankivell said:

David Martin said:

Ambrose Nankivell said:

Steam roller hire has been booked. Care to show photos of your own
so I can gauge the profile needed?

I found that at the speeds I travel, aerodynamics plays only a tiny
part. It is more the power to wait ration going up the hills so I am
looking for a better engine.

Oh. Last I saw, steam rollers had a pants power to weight ratio.

Not for the steam roller ;-) As they say "it's got the power, you've
got the wait".

...d

Quoted message said:

Default said:

Hi, what can you tell me about the aero differences between compact & std
frame geometries? Is it possible you found compact frames to be less

No.

There's no difference at all. The defining factor is the height at the
front and that's the same. If you want a TT bike rather than a general
purpose one then getting one a size smaller (or a TT specific frame)
will let you have a lower front

--
Arthur Clune

OK is there some conversion which needs to be done then between compact and
std frame sizes?

My view is that compact frames are a step higher than std frames given a
particular size.

Default said:

My view is that compact frames are a step higher than std frames given a
particular size.

I don't understand what you are saying here.

--
Arthur Clune

Ambrose Nankivell said:

However, David's solution of steamrollering my legs suits my
lifestyle far better. 🙂

It should definitely help you to cycle flat out.

--
Dave...

in message <[email hidden]>, Default

(') said:

Quoted message said:

Default said:

Hi, what can you tell me about the aero differences between compact &
std frame geometries? Is it possible you found compact frames to be
less

No.

There's no difference at all. The defining factor is the height at the
front and that's the same. If you want a TT bike rather than a general
purpose one then getting one a size smaller (or a TT specific frame)
will let you have a lower front

OK is there some conversion which needs to be done then between compact
and std frame sizes?

No. Different manufacturers use different top tube angles. There is no
'standard' design for a compact frame, it's still evolving.

Quoted message said:

My view is that compact frames are a step higher than std frames given
a particular size.

You're missing the point. The height of the bottom bracket and the
triangle of the bottom bracket, the bars and saddle, should not be any
different at all.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; Diplomacy, American: see Intelligence, Military

Quoted message said:

Quoted message said:

Quoted message said:

Default wrote:
> Hi, what can you tell me about the aero differences between compact &
> std frame geometries? Is it possible you found compact frames to be
> less

No.

There's no difference at all. The defining factor is the height at the
front and that's the same. If you want a TT bike rather than a general
purpose one then getting one a size smaller (or a TT specific frame)
will let you have a lower front

OK is there some conversion which needs to be done then between compact
and std frame sizes?

No. Different manufacturers use different top tube angles. There is no
'standard' design for a compact frame, it's still evolving.

Quoted message said:

My view is that compact frames are a step higher than std frames given
a particular size.

You're missing the point. The height of the bottom bracket and the
triangle of the bottom bracket, the bars and saddle, should not be any
different at all.

Obviously true, as would be expected. But I feel the point requires some
clarification here.

I have definitely found a speed increase on a std (Pro-Race geometry) frame
compared to a better spec'd bike of similar/identical size in compact.

Now the speed increase is substantial (and noticable) being at least 1 to 2
mph higher on a std frame compared to the compact.

Default said:

I have definitely found a speed increase on a std (Pro-Race geometry) frame
compared to a better spec'd bike of similar/identical size in compact.

Now the speed increase is substantial (and noticable) being at least 1 to 2
mph higher on a std frame compared to the compact.

To what extent have you been /really/ fussy about keeping *everything*
except the frame identical? Unless the answer is "extremely", with
clarifications of how extremely, I think you'd best be very wary about
assuming it's frame aerodynamics. Compared to the turbulence caused by
the legs pumping either side of the top tube, the slope it's at is going
to make diddly-squat difference, would be my guess.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Quoted message said:

Default said:

I have definitely found a speed increase on a std (Pro-Race geometry)
frame compared to a better spec'd bike of similar/identical size in
compact.

Now the speed increase is substantial (and noticable) being at least 1 to
2 mph higher on a std frame compared to the compact.

To what extent have you been /really/ fussy about keeping *everything*
except the frame identical? Unless the answer is "extremely", with
clarifications of how extremely, I think you'd best be very wary about
assuming it's frame aerodynamics. Compared to the turbulence caused by
the legs pumping either side of the top tube, the slope it's at is going
to make diddly-squat difference, would be my guess.

Pete.

The question simply has to do with rider positioning on the two types of
frames. This is my query. Nothing so complicated as to do with the
aerodynamics of the frame itself.

The aerodynamics of the rider (plus) frame, yes.

in message <[email hidden]>, Default

(') said:

Quoted message said:

Default said:

I have definitely found a speed increase on a std (Pro-Race geometry)
frame compared to a better spec'd bike of similar/identical size in
compact.

Now the speed increase is substantial (and noticable) being at least
1 to 2 mph higher on a std frame compared to the compact.

To what extent have you been /really/ fussy about keeping *everything*
except the frame identical? Unless the answer is "extremely", with
clarifications of how extremely, I think you'd best be very wary about
assuming it's frame aerodynamics. Compared to the turbulence caused
by the legs pumping either side of the top tube, the slope it's at is
going to make diddly-squat difference, would be my guess.

The question simply has to do with rider positioning on the two types
of frames. This is my query. Nothing so complicated as to do with the
aerodynamics of the frame itself.

The aerodynamics of the rider (plus) frame, yes.

But the position of the rider isn't any different at all (or should not
be), and the aerodynamic difference of the frame must be marginal at
best. So I'm with Pete - I think it unlikely in the extreme that there
should be any measurable difference. Mind you, I don't know anyone who
time trials on a compact, but that's probably just TRADITION.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

There are no messages. The above is just a random stream of
bytes. Any opinion or meaning you find in it is your own creation.