This goes back quite a while, but I once wrote some
unflattering things about GUSTO (hereinafter Gusto) frames
(→here)
and received the following comment in response:
That's quite prejudiced.
It's unpleasant to read.
I just received my Gusto bike, and it's a very good bike.
Such was the comment.
Unfortunately, this is nothing but
"prejudice that Nom Lab is prejudiced against Gusto"
because Gusto frames are unquestionably
shit-tier in a certain respect.
I could have pointed that out clearly back then,
but I thought this person was pitiful, so I let it go.
However, if it benefits most of the people reading here
(who are not Gusto riders), then I suppose it's fine
to explain why I don't recommend Gusto frames.
There are two reasons, but I'll write the second reason first—
which is not the essential one.
Continuing from the linked article: a regular customer of our shop
had another shop they frequented approach them about
buying a Gusto frame at a special price.
I said "don't do it, don't do it," but they ended up buying it anyway.
Among complete bikes from brands considered to have
good value (laughing), there are some priced such that
"if you bought the components and wheels
assembled on that complete bike at list price,
the rest would be basically free."
Savvy consumers notice this, of course, but the complete bike brand
naturally expects such awareness,
and such purchasing behavior itself plays right into their hands.
Some might say, "What's wrong with buying a complete bike
with good value?" Of course, nothing is wrong with it—
if it's an end user doing it.
The reason the customer was approached about buying the frame was
because a shop had bought a Gusto complete bike for the components and wheels,
moved those parts to a different frame, built a complete bike
with a non-Gusto frame, and the remaining Gusto frame was
basically worthless scraps as an internal valuation.
I even said not to go along with such imposition by the shop,
but it was so cheap that they bought it anyway.
I think it's fine for an end user to buy a Gusto complete bike,
move nearly all the parts to a different frame,
and dump the unwanted frame part on an auction site.
But when a shop does it—I'm not so sure.
It clearly shows the seller side doesn't respect the Gusto brand.
Based on just one case at one shop, you could say it's
a brand that gets its parts stripped out.
Next, the essential reason—the first one.
As for it being "essential," this reason can't be overturned
even if Gusto frames were the world's best pedaling response,
no matter how cheap they were.
Swapping parts won't change this either.
Let me talk about front center and trail.
Front center is the distance from the BB axle center
to the front hub axle.
For a 700C wheel frame,
you'd want at least 570mm.
Reading back through this article,
it seems frame manufacturers consider
around 575mm as the minimum line.
As to what's bad about short front center,
the commonly cited issue is
"when you turn the bars deeply,
your front wheel hits your shoe tips"—
but in actual riding, you don't turn the bars that much.
There is a possibility of toe-shoe contact with the front wheel
when stopped, trying to stand while waiting at a light.
Depending on crank length and cleat position adjustment,
even with a 165mm crank with the cleat fixed as far forward as possible
(putting toe position back), the contact happens rarely enough that
front center around 575mm gets quite close to the limit
(depending on the three-hole spacing on your shoes too).
If front wheel and toe contact isn't the real problem,
then what's the issue with short front center?
Simply put: it's dangerous.
Especially in cornering—downhill cornering is where the danger lies.
The proper frame size for 700C wheels
is around 560mm in top tube length.
At this size range, every manufacturer
has geometry (once called frame skeleton) without strain.
In other words, every maker designs similarly.
I call uniquely unusual geometry values "anomalies"—
large-frame riders rarely encounter frames with anomalies.
Besides front center,
another crucial value for the front end is
Trail.
In Japanese, both トレイル and トレール spellings exist,
but I'm Team Trail, so I'll use that below.
As shown in the diagram, trail is the distance
between where the steering axis extended to the ground intersects
and where a vertical line from the front hub axle meets the ground.
The perpendicular from the hub axle doesn't look quite perpendicular,
but don't worry about it.
Trail isn't something where bigger is better or smaller is better—
there's an appropriate range: around 57–60mm.
If trail is the same, steering feel is theoretically identical.
When trail is the same but one person has
a small frame + 110mm stem and another has
a large frame + 90mm stem,
the stem length change means feel differs somewhat,
so the ride feel won't be completely identical.
When trail gets larger, handling becomes
"moccha."
"Moccha" (もっちゃい) is Osaka dialect for sluggish,
an expression I've used for trail issues since way back.
The opposite of moccha is "kire-kire" (crisp).
At low speed, especially while doing standing climbs
and rocking the bars, when you turn the bars,
they don't naturally return to center,
so you have to manually steer them back—
that's "moccha."
Zero-start hesitation from stopped or
the bars feeling loose when making tight circles at low speed—
that's "kire-kire."
As frame size decreases, front center shortens too.
The common way to avoid this is
slackening the head tube angle (head angle).
This pushes the front hub forward and outward,
securing front center.
However, just slacking the head angle
enlarges trail and makes steering moccha.
To avoid this, what do you do?
You increase the front fork bend—
fork offset.
Fork offset is also called fork rake,
but I'm Team Offset, so I'll use that below.
While "offset amount" is used, I've never heard "rake amount."
When trail is the same, steering feel is basically identical.
So if the upright head angle + small offset trail (red underline)
and slack head angle + large offset trail (blue underline)
in the diagram above are the same length,
then even different sizes of the same frame model
have essentially no steering feel difference.
Also, increasing offset amount
itself also lengthens front center,
which is a good condition for small frames.
From here, I'll list geometry specs
from various maker and brand frames,
extracting six items: frame size designation, horizontal equivalent top tube length,
front center, fork offset amount, head angle, and trail.
First, LOOK's 795 Blade RS.
Why bring up LOOK? Because LOOK has had exceptionally complete
geometry specs since way back, with essentially zero missing data.
This 795 Blade RS is the first generation, a previous generation model.
The current model is also officially called 795 Blade RS,
but Japanese distributors call it 795 Blade 2RS for distinction.
There's an OVA anime called "Top wo Nerae!"
and its sequel isn't "Top wo Nerae! 2" but
"Top wo Nerae 2!" Blade RS being Blade 2 RS instead of
Blade RS 2 reminds me of that.
The standout point about this frame's geometry:
first, the smallest size's front center
falls below 570mm.
But that's unavoidable—
getting 570mm front center with a top tube under 500mm
is nearly impossible.
Among the five sizes, the two smaller ones have
head angle 71.8° + fork offset 50mm,
and the three larger ones have
head angle 73° + fork offset 43mm.
When head angle and offset are the same, trail is the same.
Trail for the two smaller ones is 59.2mm,
and for the three larger ones it's 59mm.
As you'll see later, this is extremely well-designed.
While rare, if someone riding this frame's M size
had to sell it or it got damaged or stolen,
and bought the same frame again but thought
"M felt big, so let's try S this time,"
switching to S despite a 1.2° head angle difference
would result in essentially no steering feel anomaly.
The 7mm offset difference has a pretty significant effect
on front center, so S actually has longer front center than M.
This phenomenon of front center reversal across
large offset transitions is common among various makers.
Preparing two or more fork offset types is costly.
This frame uses "2 types for 5 sizes," but
brands using only one offset type for all sizes
are basically lazy, I'd say.
I didn't cite the current 795 Blade 2 RS as an example,
not because I'm cherry-picking favorable information
(though that might look like it), but because
the reference material was made before the 2 RS came out.
Just listing it in text: similarly with 5 sizes split into
the 2 smaller and 3 larger ones at
head angle 71.75° and 73°,
fork offset 50mm and 43mm,
and trail 59.8mm and 59.3mm,
with the smallest size horizontal equivalent top tube 510mm
and front center 569.8mm.
Irrelevant to this article's thesis, but a point showing
"LOOK really understands their craft":
"top tube length is an odd number."
I've listed the top tube lengths for
795 Blade RS and 2 RS.
At XS/S, M/L/X L respectively,
they change head angle and offset, but
the top tube length relative to frame size
feels like it's shifted by one size.
If the initial RS's XL was the upper limit and
no pro special was offered,
there'd be pro riders who found this top tube length unsuitable.
Top tube values at 0.1mm precision are inherently meaningless—
the reason is important.
Horizontal equivalent top tube length
bisected by a vertical line from the BB upward—
the front half's length is called "reach."
LOOK clearly designs frames around reach.
"Check reach, not top tube, for frame size!"
is how important this value is, but
I won't cover that this time.
The article title is "Let's Read Geometry Better (Front End Edition),"
and there's no plan to serialize this.
765 Optimum's XS–XL reach listing:
355/365/375/385/395mm, while
old 785 was
365/375/385/395/405mm.
Current 785 Huez (also called
785 2 Huez for distinction—how's that different from 785 Huez 2?)
has reach and top tube length
at 0.1mm precision odd numbers, so
not all current LOOK models have reach
in clean 1mm increments, but...
Also, not detailing this time
(and there's no "Reach Edition" coming),
but 765 Optimum and old 785
have reach offset one size for each size designation.
So the person on 765 Optimum M with
375mm reach might want to pick
old 785 S (also 375mm reach) instead.
Next, Cannondale's SuperSix EVO.
Lengths are in cm units, which I transcribed without
converting to mm myself.
Cannondale is quite solid with front center—
at around 510mm top tube they secure over 580mm front center.
This relates to large bottom bracket drop, which I won't address now.
Fork offset is "2 types for 7 sizes," with
a large 10mm difference between 45mm and 55mm.
Looking at top tube length, the 2 largest sizes
fit very few Japanese riders, so
you could argue "most SuperSix EVOs in circulation
have 55mm fork offset."
Like the 795 Blade RS before, front center
reversal happens at the offset cutover—
larger frames' front center is shorter than this size.
With cm notation, both
head angle 71.2° + offset 5.5cm and
head angle 73° + offset 4.5cm
show trail 5.8cm, which in mm would be
different in the 58.Xmm range,
but that's no major issue.
Only the smallest has 6.0cm trail,
slightly moccha but not anomalous.
Also Cannondale's CAAD 13.
After 58 comes 60, 62, not 61,
but that's irrelevant to most people.
Geometry trends are much the same.
By the way, Cannondale calls fork offset
"fork rake."
Next, Bridgestone Anchor's current RP9. RP8 has the same geometry.
Fork offset is "2 types for 4 sizes,"
with smallest top tube 518mm
managing 570mm front center just barely.
Trail is unpublished.
While some makers don't publish front center at all,
front center is easily measured with a tape measure
(if you have the physical frame),
whereas trail is hard to measure.
So I'd like to see it published.
Anchor's geometry was godlike (past tense),
but I'm not referencing that with this geometry table.
This is decent but not the best.
2015-era Anchor RIS 9 flagship.
Naturally, only rim brake models existed.
Not considering the wide rims and wide tires of today,
the fork shoulder clearance is tight—hard to gain front center—
yet at smallest size with 505mm top tube,
it secures 578mm front center.
Fork offset is "3 types for 5 sizes."
Trail unpublished, but the smallest
has the head angle 1° slacker than the next size
with identical offset, so
steering would be quite moccha.
Also, discontinued Anchor women's rim brake road RL8W.
The smallest size doesn't just stay below 500mm top tube—
it's under 490mm, yet with head angle not below 70°
achieves 574mm front center.
The 55mm fork offset is a major factor, but
"505mm top tube with 574mm front center"
is worth remembering—I'll cite it later.
Trail unpublished, but unlike RIS 9,
the smallest and next size share the same
head angle and offset, meaning same trail.
Not calculating precisely, but
RIS 9's smallest probably has more moccha than RL8W's smallest.
Isn't this geometry godlike? This model's disc version,
current RL6D, also excels at front center, but
disc bikes and recent fat-tire roads
have longer rear center and fork shoulder, longer wheelbase—
generous design—making
"505mm top tube with 570mm+ front center"
easier than the rim brake era.
Incidentally, Anchor calls head angle "caster angle."
Not written until now, but across frame makers and brands,
front center is prioritized over trail.
Even frames with "one offset type for all sizes"
slacken head angle across sizes—
that's the minimum effort they make.
"Making several forks is expensive, so we won't,
but honestly small frames with short front center are risky,
so we absolutely slack head angle even if steering gets moccha."
That's the logic.
The extreme example:
2005–2008 era Orbea.
Not discontinued by 2008, older aluminum frames
called "Aerin" and "Eroica" were released seriously in
15-size increments from 48–62 in 1cm steps.
But after the carbon flagship Orca debuted with 5 sizes,
road frames became this geometry alone.
Even Aqua, the budget aluminum model, uses this geometry, while
the mid-tier carbon Onyx mysteriously
has head angle an additional 0.2° slacker, yet
everything else is the same numbers.
You'd expect 0.2° head angle to change others by 1mm+, but no.
Possibly sloppy—or otherwise just the same numbers.
Only the largest front center is unpublished—reasons unknown.
Well, no one riding that size worries about front center anyway.
Notable in the geometry table:
the smallest size's head angle is a full 3° slacker.
Head angles below 70° are pretty rare.
This qualifies as an "anomaly."
The reason: to match the next size's
575mm front center by forcing
the head tube slack.
Fork offset is "1 type for 5 sizes"—lazy.
This proves "makers prioritize front center
regardless of trail."
The larger Orbea sizes are fine, but
the smallest is almost unridably
moccha in steering.
It contradicts road bike character.
How am I so certain? I've ridden the smallest Aqua.
Obviously small for me, but
the head tube is short and,
as written before, at the shop where I worked,
I checked every rentable frame size I could
and this was one where I couldn't detect
centering issues with my eyes.
This isn't because Orbea builds well—
it's more miracle than planned.
Like building dozens of wheels without a center gauge,
relying only on runout—
maybe one or two land dead-centered.
I swapped in a 50mm offset fork,
but steering still felt quite moccha.
Small-frame riders often end up with moccha bikes,
so "that's just how road bikes are" they figure.
If a woman rider on old godlike Anchor's
smallest or next size tried those bikes, they'd be
shocked by how kire-kire they are.
Specialized's Amira also had decent geometry
(though research later showed the smallest wasn't special)—
results appear later in the article.
Next, Trek's Emonda ALR.
Trek doesn't publish front center.
As noted, front center is easily measurable if you see
the physical frame, so unpublished isn't a huge deal.
I brought it up because someone once asked
about buying the 2019 Emonda ALR 5
(obviously not sold at our shop)
regarding sizing—a woman, though not the smallest two sizes,
so I didn't advise against buying, and she did purchase.
Trek's smallest two sizes, especially the minimum,
shouldn't be bought.
Even looking at LOOK and Cannondale's published trails earlier,
67mm trail is ridiculous.
The next size's 61mm aside,
the smallest's 67mm is anomalous.
This seems to be Trek philosophy—
fork offset is small overall.
"2 types for 7 sizes" is fine, but
45mm and 40mm is the range,
on the small side.
With trail like this, smallest shouldn't exist.
But if you ask me, "If you ran Trek's shop,
how'd you sell to short customers?"
I'd struggle to answer.
A shop carrying Trek among others
would explain the geometry issue
and suggest other brands unless they really want Trek.
Back when integrated headsets could use universal standards
like 1-inch compression or oversized 1-1/8" integrated headsets,
you could swap forks, but
modern frames aren't designed for third-party forks.
Looking at the geometry table,
all 7 sizes have different head angles,
so the larger two sizes' 5.8cm trail is technically
58.Xmm with precise decimals differing.
Trail reversal also happens at the offset transition.
"Smallest trail alone is anomalous"
means "anomalous trail prioritizes front center."
Makers care most about front center, managing trail
only if fork offset variety is feasible.
It's like a summer homework assignment you might or might not do—
no one yells if you skip it.
But people paying attention notice, so
I respect makers who do it right.
This Emonda ALR's smallest might work better
with a 50mm offset fork rather than 45mm,
but why not? Cheaper aluminum model?
So here's Madone SLR.
Very similar to Emonda ALR, but
where Emonda's smallest head angle was 0.9° slacker than next,
Madone's smallest is identical.
Yet both show the same 6mm trail difference—
strange but still anomalous.
Even pricier Madone SLR uses nearly identical geometry,
so Emonda isn't lazy for being budget—
it's Trek's general approach.
Using LOOK logic: Emonda ALR's smallest→Madone SLR buyer
downsizing will definitely notice
steering mocchiness.
Without knowledge, they'd think "carbon is like this,"
a complete misunderstanding.
Trek's philosophy accepts the smallest size
having anomalous trail, and
small-frame riders should accept Trek's ethos—
that's how my draft ended, but...
The newly announced 8th generation Madone SLR's
geometry shocked me.
Incidentally, size designations changed from numbers to SML.
ML is "Medium Large."
Wait, the smallest size offset is now 50mm?
Head angle's 0.6° slacker but
5mm offset difference is the dominant factor, so
trail actually reverses after the next size—
escaping the anomaly
(the most moccha size is now the second-smallest).
Head angle slacking and offset increasing both
extend front center.
So for the smallest, front center lengthens while
moccha steering improves—win-win.
Trek admits the smallest's 45mm offset
didn't work, validating my position.
7th gen smallest owners are basically told
"it got even better!"
showing they had the bad version.
If I owned 7th gen smallest,
I'd swap to the 50mm offset fork if possible
unflattering things about GUSTO (hereinafter Gusto) frames
(→here)
and received the following comment in response:
That's quite prejudiced.
It's unpleasant to read.
I just received my Gusto bike, and it's a very good bike.
Such was the comment.
Unfortunately, this is nothing but
"prejudice that Nom Lab is prejudiced against Gusto"
because Gusto frames are unquestionably
shit-tier in a certain respect.
I could have pointed that out clearly back then,
but I thought this person was pitiful, so I let it go.
However, if it benefits most of the people reading here
(who are not Gusto riders), then I suppose it's fine
to explain why I don't recommend Gusto frames.
There are two reasons, but I'll write the second reason first—
which is not the essential one.
Continuing from the linked article: a regular customer of our shop
had another shop they frequented approach them about
buying a Gusto frame at a special price.
I said "don't do it, don't do it," but they ended up buying it anyway.
Among complete bikes from brands considered to have
good value (laughing), there are some priced such that
"if you bought the components and wheels
assembled on that complete bike at list price,
the rest would be basically free."
Savvy consumers notice this, of course, but the complete bike brand
naturally expects such awareness,
and such purchasing behavior itself plays right into their hands.
Some might say, "What's wrong with buying a complete bike
with good value?" Of course, nothing is wrong with it—
if it's an end user doing it.
The reason the customer was approached about buying the frame was
because a shop had bought a Gusto complete bike for the components and wheels,
moved those parts to a different frame, built a complete bike
with a non-Gusto frame, and the remaining Gusto frame was
basically worthless scraps as an internal valuation.
I even said not to go along with such imposition by the shop,
but it was so cheap that they bought it anyway.
I think it's fine for an end user to buy a Gusto complete bike,
move nearly all the parts to a different frame,
and dump the unwanted frame part on an auction site.
But when a shop does it—I'm not so sure.
It clearly shows the seller side doesn't respect the Gusto brand.
Based on just one case at one shop, you could say it's
a brand that gets its parts stripped out.
Next, the essential reason—the first one.
As for it being "essential," this reason can't be overturned
even if Gusto frames were the world's best pedaling response,
no matter how cheap they were.
Swapping parts won't change this either.
Let me talk about front center and trail.
Front center is the distance from the BB axle center
to the front hub axle.
For a 700C wheel frame,
you'd want at least 570mm.
Reading back through this article,
it seems frame manufacturers consider
around 575mm as the minimum line.
As to what's bad about short front center,
the commonly cited issue is
"when you turn the bars deeply,
your front wheel hits your shoe tips"—
but in actual riding, you don't turn the bars that much.
There is a possibility of toe-shoe contact with the front wheel
when stopped, trying to stand while waiting at a light.
Depending on crank length and cleat position adjustment,
even with a 165mm crank with the cleat fixed as far forward as possible
(putting toe position back), the contact happens rarely enough that
front center around 575mm gets quite close to the limit
(depending on the three-hole spacing on your shoes too).
If front wheel and toe contact isn't the real problem,
then what's the issue with short front center?
Simply put: it's dangerous.
Especially in cornering—downhill cornering is where the danger lies.
The proper frame size for 700C wheels
is around 560mm in top tube length.
At this size range, every manufacturer
has geometry (once called frame skeleton) without strain.
In other words, every maker designs similarly.
I call uniquely unusual geometry values "anomalies"—
large-frame riders rarely encounter frames with anomalies.
Besides front center,
another crucial value for the front end is
Trail.
In Japanese, both トレイル and トレール spellings exist,
but I'm Team Trail, so I'll use that below.
As shown in the diagram, trail is the distance
between where the steering axis extended to the ground intersects
and where a vertical line from the front hub axle meets the ground.
The perpendicular from the hub axle doesn't look quite perpendicular,
but don't worry about it.
Trail isn't something where bigger is better or smaller is better—
there's an appropriate range: around 57–60mm.
If trail is the same, steering feel is theoretically identical.
When trail is the same but one person has
a small frame + 110mm stem and another has
a large frame + 90mm stem,
the stem length change means feel differs somewhat,
so the ride feel won't be completely identical.
When trail gets larger, handling becomes
"moccha."
"Moccha" (もっちゃい) is Osaka dialect for sluggish,
an expression I've used for trail issues since way back.
The opposite of moccha is "kire-kire" (crisp).
At low speed, especially while doing standing climbs
and rocking the bars, when you turn the bars,
they don't naturally return to center,
so you have to manually steer them back—
that's "moccha."
Zero-start hesitation from stopped or
the bars feeling loose when making tight circles at low speed—
that's "kire-kire."
As frame size decreases, front center shortens too.
The common way to avoid this is
slackening the head tube angle (head angle).
This pushes the front hub forward and outward,
securing front center.
However, just slacking the head angle
enlarges trail and makes steering moccha.
To avoid this, what do you do?
You increase the front fork bend—
fork offset.
Fork offset is also called fork rake,
but I'm Team Offset, so I'll use that below.
While "offset amount" is used, I've never heard "rake amount."
When trail is the same, steering feel is basically identical.
So if the upright head angle + small offset trail (red underline)
and slack head angle + large offset trail (blue underline)
in the diagram above are the same length,
then even different sizes of the same frame model
have essentially no steering feel difference.
Also, increasing offset amount
itself also lengthens front center,
which is a good condition for small frames.
From here, I'll list geometry specs
from various maker and brand frames,
extracting six items: frame size designation, horizontal equivalent top tube length,
front center, fork offset amount, head angle, and trail.
First, LOOK's 795 Blade RS.
Why bring up LOOK? Because LOOK has had exceptionally complete
geometry specs since way back, with essentially zero missing data.
This 795 Blade RS is the first generation, a previous generation model.
The current model is also officially called 795 Blade RS,
but Japanese distributors call it 795 Blade 2RS for distinction.
There's an OVA anime called "Top wo Nerae!"
and its sequel isn't "Top wo Nerae! 2" but
"Top wo Nerae 2!" Blade RS being Blade 2 RS instead of
Blade RS 2 reminds me of that.
The standout point about this frame's geometry:
first, the smallest size's front center
falls below 570mm.
But that's unavoidable—
getting 570mm front center with a top tube under 500mm
is nearly impossible.
Among the five sizes, the two smaller ones have
head angle 71.8° + fork offset 50mm,
and the three larger ones have
head angle 73° + fork offset 43mm.
When head angle and offset are the same, trail is the same.
Trail for the two smaller ones is 59.2mm,
and for the three larger ones it's 59mm.
As you'll see later, this is extremely well-designed.
While rare, if someone riding this frame's M size
had to sell it or it got damaged or stolen,
and bought the same frame again but thought
"M felt big, so let's try S this time,"
switching to S despite a 1.2° head angle difference
would result in essentially no steering feel anomaly.
The 7mm offset difference has a pretty significant effect
on front center, so S actually has longer front center than M.
This phenomenon of front center reversal across
large offset transitions is common among various makers.
Preparing two or more fork offset types is costly.
This frame uses "2 types for 5 sizes," but
brands using only one offset type for all sizes
are basically lazy, I'd say.
I didn't cite the current 795 Blade 2 RS as an example,
not because I'm cherry-picking favorable information
(though that might look like it), but because
the reference material was made before the 2 RS came out.
Just listing it in text: similarly with 5 sizes split into
the 2 smaller and 3 larger ones at
head angle 71.75° and 73°,
fork offset 50mm and 43mm,
and trail 59.8mm and 59.3mm,
with the smallest size horizontal equivalent top tube 510mm
and front center 569.8mm.
Irrelevant to this article's thesis, but a point showing
"LOOK really understands their craft":
"top tube length is an odd number."
I've listed the top tube lengths for
795 Blade RS and 2 RS.
At XS/S, M/L/X L respectively,
they change head angle and offset, but
the top tube length relative to frame size
feels like it's shifted by one size.
If the initial RS's XL was the upper limit and
no pro special was offered,
there'd be pro riders who found this top tube length unsuitable.
Top tube values at 0.1mm precision are inherently meaningless—
the reason is important.
Horizontal equivalent top tube length
bisected by a vertical line from the BB upward—
the front half's length is called "reach."
LOOK clearly designs frames around reach.
"Check reach, not top tube, for frame size!"
is how important this value is, but
I won't cover that this time.
The article title is "Let's Read Geometry Better (Front End Edition),"
and there's no plan to serialize this.
765 Optimum's XS–XL reach listing:
355/365/375/385/395mm, while
old 785 was
365/375/385/395/405mm.
Current 785 Huez (also called
785 2 Huez for distinction—how's that different from 785 Huez 2?)
has reach and top tube length
at 0.1mm precision odd numbers, so
not all current LOOK models have reach
in clean 1mm increments, but...
Also, not detailing this time
(and there's no "Reach Edition" coming),
but 765 Optimum and old 785
have reach offset one size for each size designation.
So the person on 765 Optimum M with
375mm reach might want to pick
old 785 S (also 375mm reach) instead.
Next, Cannondale's SuperSix EVO.
Lengths are in cm units, which I transcribed without
converting to mm myself.
Cannondale is quite solid with front center—
at around 510mm top tube they secure over 580mm front center.
This relates to large bottom bracket drop, which I won't address now.
Fork offset is "2 types for 7 sizes," with
a large 10mm difference between 45mm and 55mm.
Looking at top tube length, the 2 largest sizes
fit very few Japanese riders, so
you could argue "most SuperSix EVOs in circulation
have 55mm fork offset."
Like the 795 Blade RS before, front center
reversal happens at the offset cutover—
larger frames' front center is shorter than this size.
With cm notation, both
head angle 71.2° + offset 5.5cm and
head angle 73° + offset 4.5cm
show trail 5.8cm, which in mm would be
different in the 58.Xmm range,
but that's no major issue.
Only the smallest has 6.0cm trail,
slightly moccha but not anomalous.
Also Cannondale's CAAD 13.
After 58 comes 60, 62, not 61,
but that's irrelevant to most people.
Geometry trends are much the same.
By the way, Cannondale calls fork offset
"fork rake."
Next, Bridgestone Anchor's current RP9. RP8 has the same geometry.
Fork offset is "2 types for 4 sizes,"
with smallest top tube 518mm
managing 570mm front center just barely.
Trail is unpublished.
While some makers don't publish front center at all,
front center is easily measured with a tape measure
(if you have the physical frame),
whereas trail is hard to measure.
So I'd like to see it published.
Anchor's geometry was godlike (past tense),
but I'm not referencing that with this geometry table.
This is decent but not the best.
2015-era Anchor RIS 9 flagship.
Naturally, only rim brake models existed.
Not considering the wide rims and wide tires of today,
the fork shoulder clearance is tight—hard to gain front center—
yet at smallest size with 505mm top tube,
it secures 578mm front center.
Fork offset is "3 types for 5 sizes."
Trail unpublished, but the smallest
has the head angle 1° slacker than the next size
with identical offset, so
steering would be quite moccha.
Also, discontinued Anchor women's rim brake road RL8W.
The smallest size doesn't just stay below 500mm top tube—
it's under 490mm, yet with head angle not below 70°
achieves 574mm front center.
The 55mm fork offset is a major factor, but
"505mm top tube with 574mm front center"
is worth remembering—I'll cite it later.
Trail unpublished, but unlike RIS 9,
the smallest and next size share the same
head angle and offset, meaning same trail.
Not calculating precisely, but
RIS 9's smallest probably has more moccha than RL8W's smallest.
Isn't this geometry godlike? This model's disc version,
current RL6D, also excels at front center, but
disc bikes and recent fat-tire roads
have longer rear center and fork shoulder, longer wheelbase—
generous design—making
"505mm top tube with 570mm+ front center"
easier than the rim brake era.
Incidentally, Anchor calls head angle "caster angle."
Not written until now, but across frame makers and brands,
front center is prioritized over trail.
Even frames with "one offset type for all sizes"
slacken head angle across sizes—
that's the minimum effort they make.
"Making several forks is expensive, so we won't,
but honestly small frames with short front center are risky,
so we absolutely slack head angle even if steering gets moccha."
That's the logic.
The extreme example:
2005–2008 era Orbea.
Not discontinued by 2008, older aluminum frames
called "Aerin" and "Eroica" were released seriously in
15-size increments from 48–62 in 1cm steps.
But after the carbon flagship Orca debuted with 5 sizes,
road frames became this geometry alone.
Even Aqua, the budget aluminum model, uses this geometry, while
the mid-tier carbon Onyx mysteriously
has head angle an additional 0.2° slacker, yet
everything else is the same numbers.
You'd expect 0.2° head angle to change others by 1mm+, but no.
Possibly sloppy—or otherwise just the same numbers.
Only the largest front center is unpublished—reasons unknown.
Well, no one riding that size worries about front center anyway.
Notable in the geometry table:
the smallest size's head angle is a full 3° slacker.
Head angles below 70° are pretty rare.
This qualifies as an "anomaly."
The reason: to match the next size's
575mm front center by forcing
the head tube slack.
Fork offset is "1 type for 5 sizes"—lazy.
This proves "makers prioritize front center
regardless of trail."
The larger Orbea sizes are fine, but
the smallest is almost unridably
moccha in steering.
It contradicts road bike character.
How am I so certain? I've ridden the smallest Aqua.
Obviously small for me, but
the head tube is short and,
as written before, at the shop where I worked,
I checked every rentable frame size I could
and this was one where I couldn't detect
centering issues with my eyes.
This isn't because Orbea builds well—
it's more miracle than planned.
Like building dozens of wheels without a center gauge,
relying only on runout—
maybe one or two land dead-centered.
I swapped in a 50mm offset fork,
but steering still felt quite moccha.
Small-frame riders often end up with moccha bikes,
so "that's just how road bikes are" they figure.
If a woman rider on old godlike Anchor's
smallest or next size tried those bikes, they'd be
shocked by how kire-kire they are.
Specialized's Amira also had decent geometry
(though research later showed the smallest wasn't special)—
results appear later in the article.
Next, Trek's Emonda ALR.
Trek doesn't publish front center.
As noted, front center is easily measurable if you see
the physical frame, so unpublished isn't a huge deal.
I brought it up because someone once asked
about buying the 2019 Emonda ALR 5
(obviously not sold at our shop)
regarding sizing—a woman, though not the smallest two sizes,
so I didn't advise against buying, and she did purchase.
Trek's smallest two sizes, especially the minimum,
shouldn't be bought.
Even looking at LOOK and Cannondale's published trails earlier,
67mm trail is ridiculous.
The next size's 61mm aside,
the smallest's 67mm is anomalous.
This seems to be Trek philosophy—
fork offset is small overall.
"2 types for 7 sizes" is fine, but
45mm and 40mm is the range,
on the small side.
With trail like this, smallest shouldn't exist.
But if you ask me, "If you ran Trek's shop,
how'd you sell to short customers?"
I'd struggle to answer.
A shop carrying Trek among others
would explain the geometry issue
and suggest other brands unless they really want Trek.
Back when integrated headsets could use universal standards
like 1-inch compression or oversized 1-1/8" integrated headsets,
you could swap forks, but
modern frames aren't designed for third-party forks.
Looking at the geometry table,
all 7 sizes have different head angles,
so the larger two sizes' 5.8cm trail is technically
58.Xmm with precise decimals differing.
Trail reversal also happens at the offset transition.
"Smallest trail alone is anomalous"
means "anomalous trail prioritizes front center."
Makers care most about front center, managing trail
only if fork offset variety is feasible.
It's like a summer homework assignment you might or might not do—
no one yells if you skip it.
But people paying attention notice, so
I respect makers who do it right.
This Emonda ALR's smallest might work better
with a 50mm offset fork rather than 45mm,
but why not? Cheaper aluminum model?
So here's Madone SLR.
Very similar to Emonda ALR, but
where Emonda's smallest head angle was 0.9° slacker than next,
Madone's smallest is identical.
Yet both show the same 6mm trail difference—
strange but still anomalous.
Even pricier Madone SLR uses nearly identical geometry,
so Emonda isn't lazy for being budget—
it's Trek's general approach.
Using LOOK logic: Emonda ALR's smallest→Madone SLR buyer
downsizing will definitely notice
steering mocchiness.
Without knowledge, they'd think "carbon is like this,"
a complete misunderstanding.
Trek's philosophy accepts the smallest size
having anomalous trail, and
small-frame riders should accept Trek's ethos—
that's how my draft ended, but...
The newly announced 8th generation Madone SLR's
geometry shocked me.
Incidentally, size designations changed from numbers to SML.
ML is "Medium Large."
Wait, the smallest size offset is now 50mm?
Head angle's 0.6° slacker but
5mm offset difference is the dominant factor, so
trail actually reverses after the next size—
escaping the anomaly
(the most moccha size is now the second-smallest).
Head angle slacking and offset increasing both
extend front center.
So for the smallest, front center lengthens while
moccha steering improves—win-win.
Trek admits the smallest's 45mm offset
didn't work, validating my position.
7th gen smallest owners are basically told
"it got even better!"
showing they had the bad version.
If I owned 7th gen smallest,
I'd swap to the 50mm offset fork if possible
Related Products on Amazon
* Amazon affiliate links — prices may vary