Road Bike Geometry: Traditional vs. Comfort (eg. Trek 1000 vs. Trek Pilot 1.0)

Gray wrote:
I'm in the market for a road bike. Given my limited funds, I'll
probably buy something off ebay. To keep from being overwhelmed with
too many options, I've limited my bargain-hunting so far to Treks,
which has led to the surprising discovery that Trek makes:

1. traditional road bikes (eg. (the 1000, 1500, etc.) marked by a
level/horizontal top tube, among other things, and

2. "comfort" road bikes (eg. Pilot 1.0, 1.2, etc.) with a supposedly
"more natural riding position," marked by a top tube sloped up from
seat post to headset, thus raising the handlebars relative to the seat
position.

Since my budget will limit me to either a Trek 1000 (traditional) or
Trek Pilot 1.0 (comfort), I wonder which way to go. In the last 3
months, I've put about 500 miles on a borrowed vintage (1983) Trek 620
touring bike, which obviously has a very traditional geometry. In all
that time, I've never experienced any discomfort or body pain while or
riding (despite not owning any padded bike shorts and the 620 being
equiped with its original seat).

Q. -- If I'm comfortable on the vintage 620, should I stick to a
traditional road bike (e.g. Trek 100)?

Q. -- Am I being short-sighted passing up a "comfort" road bike?
Especially considering that I don't see myself ever racing or trying to
ride for time.

BONUS Q. -- What brand other than Trek should I seek out to buy a new
or late model road bike? It's not that I am a Trek snob. I just have
found them more plentiful and easier to research.

THANKS IN ADVANCE.

Gray Strickland
Tulsa, OK

In spite of you maybe trying a bike at a bike shop where you don't
intend to buy it(bad), why not go to a Trek dealer that will let you
ride each for a fair amount of time...to see.

If the tradional bike feels comfy, it probably is and the high front
end bike won't do anything the standard one won't. 'Bent' over riding
position isn't automatically uncomfortable anymore than a sport
motorcycle position compared to a 'cruiser'.

FWIW... a comparision of the geometries of the 2007 Trek 1000 and Pilot
1.0 taken from:

1000: http://www2.trekbikes.com/bikes/bike...id=1413000&f=3
Pilot: http://www2.trekbikes.com/bikes/bike...id=1402000&f=4

and the 1983 Trek 620 taken from
http://www.vintage-trek.com/images/t...churePart1.pdf

Frame Size
1000: 58cm
Pilot: 58cm
620: 22.5in (57.15cm)

Head Angle
1000: 73.0°
Pilot: 72.5°
620: 73.0°

Seat Angle
1000: 73.5°
Pilot: 73.0°
620: 73.0°

Effective Top Tube
1000: 57.3cm / 22.6in
Pilot: 57.0cm / 22.4in
620: 56cm

Actual Top Tube
1000: 56.9 / 22.4
Pilot: 54.8 / 21.6
620: 56cm

Chain Stay
1000: 41.7 / 16.4
Pilot: 41.7 / 16.4
620: 44.0cm

Bottom Bracket (ground clearance? center of BB to ground?)
1000: 26.8 / 10.6
Pilot: 27.2 / 10.7
620: 7.2 (called "drop" in 620 brochure; same?)

Offset (fork offset)
1000: 4.5 / 1.8
Pilot: 5.0 / 2.0
620: 5.5cm

Wheelbase
1000: 100.4 / 39.5 (1.3% than Pilot; 2.3% than old 620)
Pilot: 101.7 / 40.0
620: 102.8

Trail (defined at
http://www.slowtwitch.com/mainheadin.../geometry.html)
1000: 5.7 / 2.2
Pilot: 5.5 / 2.2

Stand Over
1000: 80.8 / 31.8
Pilot: 78.6 / 30.9

Seat Tube
1000: 58.0 / 22.8
Pilot: 53.0 / 20.9 (9.4% shorter than 1000; 5.6% than old 620)
620: 56cm

Head Tube
1000: 14.0 / 5.5 (36% longer than Pilot)
Pilot: 19.0 / 7.5

In spite of you maybe trying a bike at a bike shop where you don't
intend to buy it(bad), why not go to a Trek dealer that will let you
ride each for a fair amount of time...to see.

I agree. I consider the owner, salesmen and mechanics at my LBS (which
is a Trek dealer) to be friends and I wouldn't care to waste their time
when I can't afford the $767 (with tax) for a 1000 or $831.59 (with
tax) for a Pilot 1.0. It wouldn't be right. Then again, if I can buy a
2 or 3 year old model on ebay for $400, I won't be embarassed to bring
it to them to work on. I have four children and an employee for whom I
bought a Trek Fuel 90 (MTB) as a bonus. Over the years, I've spent a
ton -- at least to me -- in that shop, but I wouldn't go test ride
bikes that I don't intend to buy. And, unfortunately for me, the Trek
dealers seem to have price discipline which would have made any 20th
century dictator proud. Maybe... if a 58cm 2006 gets dusty on the
floor, I might get a small discount, but not enough to wait for.

My buddy who has graciously allowed me the loan of his spare 1983 Trek
620 will require it back when my hybrid is finally fixed this week.
Over nearly three months of riding a road bike makes me want my own.
That's where all this investigation comes in. My buddy won't sell me
his bike (sentimental), which I love, so I'd like to find something
which rides like it. Friends have suggested looking at the 1000 and the
Pilot 1.0, so that's where my focus has been so far.

* * Chas wrote:
wrote in message
ups.com...
snip
Comfort is one issue, but any bike can be comfortable if you get your
position correct. Another key difference may be the handling. The more
race inspired bikes might feel very twitchy and be difficult to keep
in
a straight line. Perhaps the comfort series has angles more like the
touring bike you have been using which I assume has very stable
handling. I do race and ride for time, but not ever in races that
require quick handling (ie criteriums) so my preferences lean toward
straight line stability. I'd go for the Pilot.
snip
Joseph


Some bikes will never be comfortable. Early Cinellis (pre mid 1970's)
had a reputation for being "nice" riding bikes. Around 1976 someone
traded in a 56cm Cinelli frame. I'd lusted for a Cinelli for years so I
grabbed it. The frame had relaxed 72° or 73° seat and head tube angles
with about 42cm chainstays. I built it up with a Campy NR gruppo,
Cinelli bars and stem, a Unicanitor seat and sewups.

At almost 23 lbs. it was rather heavy for a 56cm bike. I soon realized
that the frame was made of Columbus SP heavy gage "pipe" tubing which
made for a super stiff frame. After a few days of bone jarring, teeth
rattling riding I pulled off my components and hung it back up for sale.

Most steel frame Treks of that era were made with fairly light gage
tubing. Smaller frames 54cm frames or less are going to be stiffer
riding especially for riders weighing under 150 lbs. Heavy gage tubing
is also going to make for a stiffer riding bike.

I remember a fellow who won our UCSF state championship road race on
year was riding a new Gios Torino. He claimed he won because the bike
was so stiff that he kept saying to himself "I got to get off this bike,
I got to get off this bike.....".

It may be true that some bikes can never be truly comfortable. When I
said any bike could be comfortable, I was more thinking of a
comfortable position. The frame, tires, saddle, etc may conspire to
make some bikes very harsh, but that is a different matter.

I used to ride an SPX frame, and I always wanted a Gios Torino...

Joseph

wrote in message
oups.com...

* * Chas wrote:
wrote in message
ups.com...
snip
Comfort is one issue, but any bike can be comfortable if you get
your
position correct. Another key difference may be the handling. The
more
race inspired bikes might feel very twitchy and be difficult to keep
in
a straight line. Perhaps the comfort series has angles more like the
touring bike you have been using which I assume has very stable
handling. I do race and ride for time, but not ever in races that
require quick handling (ie criteriums) so my preferences lean toward
straight line stability. I'd go for the Pilot.
snip
Joseph


Some bikes will never be comfortable. Early Cinellis (pre mid 1970's)
had a reputation for being "nice" riding bikes. Around 1976 someone
traded in a 56cm Cinelli frame. I'd lusted for a Cinelli for years so
I
grabbed it. The frame had relaxed 72° or 73° seat and head tube angles
with about 42cm chainstays. I built it up with a Campy NR gruppo,
Cinelli bars and stem, a Unicanitor seat and sewups.

At almost 23 lbs. it was rather heavy for a 56cm bike. I soon realized
that the frame was made of Columbus SP heavy gage "pipe" tubing which
made for a super stiff frame. After a few days of bone jarring, teeth
rattling riding I pulled off my components and hung it back up for
sale.

Most steel frame Treks of that era were made with fairly light gage
tubing. Smaller frames 54cm frames or less are going to be stiffer
riding especially for riders weighing under 150 lbs. Heavy gage tubing
is also going to make for a stiffer riding bike.

I remember a fellow who won our UCSF state championship road race on
year was riding a new Gios Torino. He claimed he won because the bike
was so stiff that he kept saying to himself "I got to get off this
bike,
I got to get off this bike.....".

It may be true that some bikes can never be truly comfortable. When I
said any bike could be comfortable, I was more thinking of a
comfortable position. The frame, tires, saddle, etc may conspire to
make some bikes very harsh, but that is a different matter.

I used to ride an SPX frame, and I always wanted a Gios Torino...

Joseph

I always liked the color... Colnago blue. We sold a number of them
during the mid 70's. They had some of the best workmanship of any
Italian bike of the period, especially with the gold medallions in the
crown. They came packed in a great shipping container. We never got one
in my size that wasn't presold so I wasn't too tempted.

On the other hand, I always lusted for an early 70's Colnago Super....

Chas.

"Mark Hickey" wrote in message
...
"* * Chas" wrote:

Most steel frame Treks of that era were made with fairly light gage
tubing. Smaller frames 54cm frames or less are going to be stiffer
riding especially for riders weighing under 150 lbs. Heavy gage
tubing
is also going to make for a stiffer riding bike.

Common wisdom, perhaps, but I have to point out that when Bicycle
Guide magazine did a blind test 15 years ago (give or take), and had
otherwise identical bikes built from every set of tubing in the line
(from Columbus, IIRC), suddenly all the "common wisdom" disappeared...
the reviewers who'd previously waxed eloquent on the relative and
obvious changes that resulted from changing one tube in a frame were
suddenly unable to distinguish any of the frames from each other. In
fact, when they summarized the overall impressions, the lowest-grade
(heaviest) tubing got more votes for the best riding frame.

The position (that frame material, especially subtle variations in the
same kind of material - make a big difference in ride quality) is one
that many on r.b.t. have challenged. Many have disagreed with these
challenges, but none has been able to come up with a plausible
mechanism that supports the contention that somehow a vertically
inflexible structure like the rear end of a bicycle can deflect enough
to make a significant difference when masked by the much, much larger
vertical compliance of the tires, rims, saddle, bars, stem and bar
tape.

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

Mark,

I agree with you on the effects of all the components on bicycle
flexibility but a modern bike frame is a essentially a space frame type
construction. ALL bike frames can flex in every plane if enough force is
applied. Any vertical flexing is a function of frame size, geometry,
material, tubing diameter, wall thickness and rider weight. A 100 lb.
rider may never flex a "stiff" frame but a 200 lb. rider can experience
vertical frame flexing on a light weight frame made from thin wall
tubing.

Your comment all along has been "prove that frames can flex vertically".
I throw it back to you, prove that they can't! Many people would never
get on an airplane if they knew how much airframes flex in flight or
even while taxiing. Almost all lightweight structures are designed to do
that.

Have you ever ridden a curly stay Hetchins or Bates frame with "pencil"
stays in the rear triangle. You should follow one and watch it as it
goes over bumps. You can see the rear triangle flexing up and down. I
had a 1954 Hetchins with a 44" wheelbase and 46cm chainstays. I could
ride over a speed bump and hardly feel it. Surprisingly the bottom
bracket had very little lateral flex.

Carbon fiber can be up to 12 times stronger than steel and 4 times
stronger than aluminum for the same weight. The rule of thumb in
engineering products is that aluminum has 1/3 the weight, strength and
rigidity of steel. Some aluminum alloys such as heat treated 7075 T6 can
be stronger than annealed low carbon steel: 7075 T6 = 73200 PSI tensile
strength vs. 39900 PI for tempered 1018 steel. Titanium has 2/3 the
weight and rigidity of steel; strength differences depend on the alloys.

A properly designed carbon fiber frame is probably going to be the least
flexible per pound followed by alloy steel then titanium and aluminum.
Rigidity can be controlled by frame geometry and tubing diameter.

Chas.

Gray wrote:
In spite of you maybe trying a bike at a bike shop where you don't
intend to buy it(bad), why not go to a Trek dealer that will let you
ride each for a fair amount of time...to see.

I agree. I consider the owner, salesmen and mechanics at my LBS (which
is a Trek dealer) to be friends and I wouldn't care to waste their time
when I can't afford the $767 (with tax) for a 1000 or $831.59 (with
tax) for a Pilot 1.0. It wouldn't be right. Then again, if I can buy a
2 or 3 year old model on ebay for $400, I won't be embarassed to bring
it to them to work on. I have four children and an employee for whom I
bought a Trek Fuel 90 (MTB) as a bonus. Over the years, I've spent a
ton -- at least to me -- in that shop, but I wouldn't go test ride
bikes that I don't intend to buy. And, unfortunately for me, the Trek
dealers seem to have price discipline which would have made any 20th
century dictator proud.

That's not quite fair. Bicycles are not cars, there are no 'facory'
stores and Trek dealers don't get 'kickbacks' or inventory returns on
not sold items(like your local Toyota dealer). Bicycles have the lowest
margin of anything in a bike store and when you discount, most lose
money. Remember it takes around 35-37% margin to break even in the bike
biz. Bicycles often are around 40% margin when not discounted so taking
$100 off a $800 bicycle means the dealer loses money. Price discipline
is not a bad thing if you want that bike dealer that you are friends
with and respect, to be around next year.

Maybe... if a 58cm 2006 gets dusty on the
floor, I might get a small discount, but not enough to wait for.

My buddy who has graciously allowed me the loan of his spare 1983 Trek
620 will require it back when my hybrid is finally fixed this week.
Over nearly three months of riding a road bike makes me want my own.
That's where all this investigation comes in. My buddy won't sell me
his bike (sentimental), which I love, so I'd like to find something
which rides like it. Friends have suggested looking at the 1000 and the
Pilot 1.0, so that's where my focus has been so far.

"Qui si parla Campagnolo" wrote in message
ups.com...

Gray wrote:
In spite of you maybe trying a bike at a bike shop where you don't
intend to buy it(bad), why not go to a Trek dealer that will let you
ride each for a fair amount of time...to see.

I agree. I consider the owner, salesmen and mechanics at my LBS (which
is a Trek dealer) to be friends and I wouldn't care to waste their time
when I can't afford the $767 (with tax) for a 1000 or $831.59 (with
tax) for a Pilot 1.0. It wouldn't be right. Then again, if I can buy a
2 or 3 year old model on ebay for $400, I won't be embarassed to bring
it to them to work on. I have four children and an employee for whom I
bought a Trek Fuel 90 (MTB) as a bonus. Over the years, I've spent a
ton -- at least to me -- in that shop, but I wouldn't go test ride
bikes that I don't intend to buy. And, unfortunately for me, the Trek
dealers seem to have price discipline which would have made any 20th
century dictator proud.

That's not quite fair. Bicycles are not cars, there are no 'facory'
stores and Trek dealers don't get 'kickbacks' or inventory returns on
not sold items(like your local Toyota dealer). Bicycles have the lowest
margin of anything in a bike store and when you discount, most lose
money. Remember it takes around 35-37% margin to break even in the bike
biz. Bicycles often are around 40% margin when not discounted so taking
$100 off a $800 bicycle means the dealer loses money. Price discipline
is not a bad thing if you want that bike dealer that you are friends
with and respect, to be around next year.

I couldn't agree more.


Maybe... if a 58cm 2006 gets dusty on the
floor, I might get a small discount, but not enough to wait for.

My buddy who has graciously allowed me the loan of his spare 1983 Trek
620 will require it back when my hybrid is finally fixed this week.
Over nearly three months of riding a road bike makes me want my own.
That's where all this investigation comes in. My buddy won't sell me
his bike (sentimental), which I love, so I'd like to find something
which rides like it. Friends have suggested looking at the 1000 and the
Pilot 1.0, so that's where my focus has been so far.

"* * Chas" wrote:

I agree with you on the effects of all the components on bicycle
flexibility but a modern bike frame is a essentially a space frame type
construction. ALL bike frames can flex in every plane if enough force is
applied. Any vertical flexing is a function of frame size, geometry,
material, tubing diameter, wall thickness and rider weight. A 100 lb.
rider may never flex a "stiff" frame but a 200 lb. rider can experience
vertical frame flexing on a light weight frame made from thin wall
tubing.

Thin walls and tubing diameter do make a difference, but it's all
relative to other non-flexible structures. It would be akin to
changing the wheels on your car from steel to alloy - yes, there's a
difference in their flexibility, but there are so many other "squishy
bits" above and below them that the difference would be entirely
indistinguishable (note - this assumes the wheels weigh the same - I'm
well aware of the other differences in changing the unsprung weight in
a wheel).

Your comment all along has been "prove that frames can flex vertically".
I throw it back to you, prove that they can't!

It's been measured many times - you can do it easily yourself. Start
loading weight on the saddle of a bike and compare the vertical
movement of the various points. The tires and the saddle will compress
many, many more times than any "normal" rear triangle.

Try to compress the rear structure of a conventional frame by a mere
1mm. You'll be astonished at how difficult that is.

Many people would never
get on an airplane if they knew how much airframes flex in flight or
even while taxiing. Almost all lightweight structures are designed to do
that.

Long, cantilevered structures flex or the break. But a bike frame is
essentially a bridge truss - a tetrahedron is essentially the least
flexible structure you could find.

Have you ever ridden a curly stay Hetchins or Bates frame with "pencil"
stays in the rear triangle. You should follow one and watch it as it
goes over bumps. You can see the rear triangle flexing up and down. I
had a 1954 Hetchins with a 44" wheelbase and 46cm chainstays. I could
ride over a speed bump and hardly feel it. Surprisingly the bottom
bracket had very little lateral flex.

But that is entirely tangential to our discussion, as are softtail
frames and suspension bikes.

Carbon fiber can be up to 12 times stronger than steel and 4 times
stronger than aluminum for the same weight. The rule of thumb in
engineering products is that aluminum has 1/3 the weight, strength and
rigidity of steel. Some aluminum alloys such as heat treated 7075 T6 can
be stronger than annealed low carbon steel: 7075 T6 = 73200 PSI tensile
strength vs. 39900 PI for tempered 1018 steel. Titanium has 2/3 the
weight and rigidity of steel; strength differences depend on the alloys.

"Strength" and flex aren't related.

A properly designed carbon fiber frame is probably going to be the least
flexible per pound followed by alloy steel then titanium and aluminum.
Rigidity can be controlled by frame geometry and tubing diameter.

You're chasing a myth. Lateral flex IS important, though the relative
stiffness has more to do with tubing diameter limitations than
material per se.

But this has been discussed here ad nauseum. You can take my word for
it, or you can continue to believe that there's really a lot of
compression going on in those seat stays, contrary to every known
materials principle. It's trivial to test this to see that I'm right.

Essentially, you end up believing the engineers or the ad writers.
It's your call.

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

"Mark Hickey" wrote in message
...
"* * Chas" wrote:

I agree with you on the effects of all the components on bicycle
flexibility but a modern bike frame is a essentially a space frame
type
construction. ALL bike frames can flex in every plane if enough force
is
applied. Any vertical flexing is a function of frame size, geometry,
material, tubing diameter, wall thickness and rider weight. A 100 lb.
rider may never flex a "stiff" frame but a 200 lb. rider can
experience
vertical frame flexing on a light weight frame made from thin wall
tubing.

Thin walls and tubing diameter do make a difference, but it's all
relative to other non-flexible structures. It would be akin to
changing the wheels on your car from steel to alloy - yes, there's a
difference in their flexibility, but there are so many other "squishy
bits" above and below them that the difference would be entirely
indistinguishable (note - this assumes the wheels weigh the same - I'm
well aware of the other differences in changing the unsprung weight in
a wheel).

Your comment all along has been "prove that frames can flex
vertically".
I throw it back to you, prove that they can't!

It's been measured many times - you can do it easily yourself. Start
loading weight on the saddle of a bike and compare the vertical
movement of the various points. The tires and the saddle will compress
many, many more times than any "normal" rear triangle.

Try to compress the rear structure of a conventional frame by a mere
1mm. You'll be astonished at how difficult that is.

Many people would never
get on an airplane if they knew how much airframes flex in flight or
even while taxiing. Almost all lightweight structures are designed to
do
that.

Long, cantilevered structures flex or the break. But a bike frame is
essentially a bridge truss - a tetrahedron is essentially the least
flexible structure you could find.

Have you ever ridden a curly stay Hetchins or Bates frame with
"pencil"
stays in the rear triangle. You should follow one and watch it as it
goes over bumps. You can see the rear triangle flexing up and down. I
had a 1954 Hetchins with a 44" wheelbase and 46cm chainstays. I could
ride over a speed bump and hardly feel it. Surprisingly the bottom
bracket had very little lateral flex.

But that is entirely tangential to our discussion, as are softtail
frames and suspension bikes.

Carbon fiber can be up to 12 times stronger than steel and 4 times
stronger than aluminum for the same weight. The rule of thumb in
engineering products is that aluminum has 1/3 the weight, strength
and
rigidity of steel. Some aluminum alloys such as heat treated 7075 T6
can
be stronger than annealed low carbon steel: 7075 T6 = 73200 PSI
tensile
strength vs. 39900 PI for tempered 1018 steel. Titanium has 2/3 the
weight and rigidity of steel; strength differences depend on the
alloys.

"Strength" and flex aren't related.

A properly designed carbon fiber frame is probably going to be the
least
flexible per pound followed by alloy steel then titanium and
aluminum.
Rigidity can be controlled by frame geometry and tubing diameter.

You're chasing a myth. Lateral flex IS important, though the relative
stiffness has more to do with tubing diameter limitations than
material per se.

But this has been discussed here ad nauseum. You can take my word for
it, or you can continue to believe that there's really a lot of
compression going on in those seat stays, contrary to every known
materials principle. It's trivial to test this to see that I'm right.

Essentially, you end up believing the engineers or the ad writers.
It's your call.

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

Every test I've found on the web or seen quoted here are static tests.
The flexing that I'm talking about comes from road shock and impact
caused by bumps, pot holes, rough road surfaces, and so on.

I agree, the horse is dead. BTW, I like the geometries that you use on
your frames.