On frame stiffness

On 08/06/17 05:50, wrote:
On Wednesday, June 7, 2017 at 10:39:30 AM UTC-7, Sir Ridesalot wrote:
On Wednesday, June 7, 2017 at 10:20:13 AM UTC-4, jbeattie wrote:


The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.


My old road bicycle Cannondale was a right royal pain to ride and I mean that literally. I've NEVER had a bike before or since that punished the rider like that thing did. Ride over a crack in the asphalt and that bike felt like someone was driving their fist into your kidneys. Even going to 700C x 30mm tires didn't help much. I got rid of that bike and kept my Tange Infinity frame bike instead.


My Colnago Dream Reflux and Deluxe both had the same problem. That could break your back. But my Time VXR made those Colnagos seem like full suspension bikes. It was literally unrideable on anything other than perfectly smooth pavement.


If you have some of these bikes still in your stable, would you mind
checking something for me and report back?

I have an 853 frame & fork in 1" tubes, and if I push down on the top
tube near the junction with the head tube, I can watch the front axle
move 3-4mm forward. Mostly spring in the forks I think.

If I do the same with my Columbus Spirit frame with CFRP fork and 1 1/8"
aluminium steerer, I only see about 1-2mm of movement in the front axle.

The 853 bike is smoother to ride, but a bit too flexible when sprinting
and the chain rubs each side of the front mech when I'm riding hard.

The Columbus Spirit bike gives a harsher ride, but I've tempered that
somewhat with a fatter rear tyre and lower pressure. It's much better
to sprint on though, and the chain doesn't rub the front mech at all.

--
JS

On 6/7/2017 10:17 PM, John B. wrote:
On Wed, 7 Jun 2017 07:20:09 -0700 (PDT), jbeattie
wrote:

On Wednesday, June 7, 2017 at 5:28:46 AM UTC-7, AMuzi wrote:
On 6/7/2017 12:13 AM, John B. wrote:
On Wed, 7 Jun 2017 09:34:58 +1000, James
wrote:

On 07/06/17 08:03, jbeattie wrote:
On Tuesday, June 6, 2017 at 7:09:56 AM UTC-7,
wrote:
On Monday, June 5, 2017 at 7:56:58 PM UTC-7, James wrote:
https://cyclingtips.com/2017/06/cycl...ffness-matter/



Interesting that some pros want a less stiff frame early season, and
more stiff frame later in the season.

Other interesting bits too.

Well, if you're flexing a frame and getting power back that's fine.
But at the same time there are frictional loses and you're only
getting back a portion of it.

There was a noticeable difference between riding a Colnago Dream
with carbon forks and the Colnago C40. The C40 was stiff and I had
to pedal complete circles on a hard climb or the bike would stop at
the point of one down stroke to the next. The Dream did it less. A
steel bike absolutely does not do this.

Now there may be a preference about one way or another but I don't
believe so. I think that this really is something that works better
and while I haven't said anything to the group I generally ride
with most of them are returning to steel.

The podcast is all about BB stiffness which is just one aspect of
frame stiffness.

Of course a soft frame is an energy sponge. Try sprinting on a
double-suspended mountain bike. Small difference in BB stiffness
between racing bikes, however, probably makes little difference.


Dual suspension MTB is a totally different beast. It has built in energy
absorbers (shock absorbers). Rigid frames do not.

I'm far more sensitive to front-end stiffness than BB stiffness. I
had a first-gen Cannondale 2.8 with aluminum forks that was like
sprinting on a pogo stick. I wanted to throw it away after my first
race on it but instead bought a pair of Kestrel forks which rode a
lot like steel (they had a steel steerer). I had a custom steel
sport-touring frame that rode the same way -- lots of slop. My last
steel racing bike was very stiff, but when I resurrected it last and
used it as my winter bike, it was not magical in any way. The
top-tube was too short; it was heavy and probably less "planing" than
my CAAD 3. What steel has going for it is resistance to mechanical
damage.


With thin walled tubes (0.4mm & below), not even that.

This whole steel-is-magical thing reminds me of going back to vinyl
and realizing how many bad recordings there are. It's more about the
implementation than the material.


I agree.

One of the things I've always wondered about when people start talking
about BB flex. It would be a relatively simple problem to built a
steel frame bike with gussets of bracing for the BB, but no one seems
to have. Looking at Eddie Marckx, Sean Kelly or any of the other top
riders of the "steel Era" and none of their bikes seemed to have any
visible BB bracing.

Yoshi Konno of 3Rensho, c.1990:
https://www.pedalroom.com/bike/3rensho-njs-chrome-6748

The linking is odd so in that series go to the BB photo.

The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.

-- Jay Beattie.

But that was one or two bicycles. I'm looking at bikes ridden by top
riders, I mentioned Eddie Marckx, Sean Kelly, et al, and I don't see
any frame stiffeners or wide tubes on bikes shown in photos of the top
rider of that era.

In fact, based on memory - always a questionable practice - I don't
remember a lot of talk about frame stiffness until about the time that
Cannondale started selling aluminum bikes. .

Sean Kelly victory photo on a Vitus 979.
https://www.flickr.com/photos/chicovelo/2207332160/

(virtually overdone pasta for stiffness, not even al dente)


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Wednesday, June 7, 2017 at 8:44:34 PM UTC-7, James wrote:
On 08/06/17 05:50, wrote:
On Wednesday, June 7, 2017 at 10:39:30 AM UTC-7, Sir Ridesalot wrote:
On Wednesday, June 7, 2017 at 10:20:13 AM UTC-4, jbeattie wrote:


The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.


My old road bicycle Cannondale was a right royal pain to ride and I mean that literally. I've NEVER had a bike before or since that punished the rider like that thing did. Ride over a crack in the asphalt and that bike felt like someone was driving their fist into your kidneys. Even going to 700C x 30mm tires didn't help much. I got rid of that bike and kept my Tange Infinity frame bike instead.


My Colnago Dream Reflux and Deluxe both had the same problem. That could break your back. But my Time VXR made those Colnagos seem like full suspension bikes. It was literally unrideable on anything other than perfectly smooth pavement.


If you have some of these bikes still in your stable, would you mind
checking something for me and report back?

I have an 853 frame & fork in 1" tubes, and if I push down on the top
tube near the junction with the head tube, I can watch the front axle
move 3-4mm forward. Mostly spring in the forks I think.

If I do the same with my Columbus Spirit frame with CFRP fork and 1 1/8"
aluminium steerer, I only see about 1-2mm of movement in the front axle.

The 853 bike is smoother to ride, but a bit too flexible when sprinting
and the chain rubs each side of the front mech when I'm riding hard.

The Columbus Spirit bike gives a harsher ride, but I've tempered that
somewhat with a fatter rear tyre and lower pressure. It's much better
to sprint on though, and the chain doesn't rub the front mech at all.

Those two Colnagos are long gone and the Time is on the shelf since you cannot get the bottom bracket out and in trying it spun the insert in the BB so that it can't be removed without major work from a CF repair shop.

My wife's Colnago Super with the straight bladed fork would only move if I put my entire weight on the head tube/steering tube junction. I'm not even sure that it moves at all since the tire flattens with that much weight on it.

The two SLX bikes act differently because they have different bends in the fork.

853 tubing wasn't recommended for people more than 150 lbs is memory serves..
953 was stainless with different stiffness characteristics.

On Thursday, June 8, 2017 at 5:43:52 AM UTC-7, AMuzi wrote:
On 6/7/2017 10:17 PM, John B. wrote:
On Wed, 7 Jun 2017 07:20:09 -0700 (PDT), jbeattie
wrote:

On Wednesday, June 7, 2017 at 5:28:46 AM UTC-7, AMuzi wrote:
On 6/7/2017 12:13 AM, John B. wrote:
On Wed, 7 Jun 2017 09:34:58 +1000, James
wrote:

On 07/06/17 08:03, jbeattie wrote:
On Tuesday, June 6, 2017 at 7:09:56 AM UTC-7,
wrote:
On Monday, June 5, 2017 at 7:56:58 PM UTC-7, James wrote:
https://cyclingtips.com/2017/06/cycl...ffness-matter/



Interesting that some pros want a less stiff frame early season, and
more stiff frame later in the season.

Other interesting bits too.

Well, if you're flexing a frame and getting power back that's fine.
But at the same time there are frictional loses and you're only
getting back a portion of it.

There was a noticeable difference between riding a Colnago Dream
with carbon forks and the Colnago C40. The C40 was stiff and I had
to pedal complete circles on a hard climb or the bike would stop at
the point of one down stroke to the next. The Dream did it less. A
steel bike absolutely does not do this.

Now there may be a preference about one way or another but I don't
believe so. I think that this really is something that works better
and while I haven't said anything to the group I generally ride
with most of them are returning to steel.

The podcast is all about BB stiffness which is just one aspect of
frame stiffness.

Of course a soft frame is an energy sponge. Try sprinting on a
double-suspended mountain bike. Small difference in BB stiffness
between racing bikes, however, probably makes little difference.


Dual suspension MTB is a totally different beast. It has built in energy
absorbers (shock absorbers). Rigid frames do not.

I'm far more sensitive to front-end stiffness than BB stiffness. I
had a first-gen Cannondale 2.8 with aluminum forks that was like
sprinting on a pogo stick. I wanted to throw it away after my first
race on it but instead bought a pair of Kestrel forks which rode a
lot like steel (they had a steel steerer). I had a custom steel
sport-touring frame that rode the same way -- lots of slop. My last
steel racing bike was very stiff, but when I resurrected it last and
used it as my winter bike, it was not magical in any way. The
top-tube was too short; it was heavy and probably less "planing" than
my CAAD 3. What steel has going for it is resistance to mechanical
damage.


With thin walled tubes (0.4mm & below), not even that.

This whole steel-is-magical thing reminds me of going back to vinyl
and realizing how many bad recordings there are. It's more about the
implementation than the material.


I agree.

One of the things I've always wondered about when people start talking
about BB flex. It would be a relatively simple problem to built a
steel frame bike with gussets of bracing for the BB, but no one seems
to have. Looking at Eddie Marckx, Sean Kelly or any of the other top
riders of the "steel Era" and none of their bikes seemed to have any
visible BB bracing.

Yoshi Konno of 3Rensho, c.1990:
https://www.pedalroom.com/bike/3rensho-njs-chrome-6748

The linking is odd so in that series go to the BB photo.

The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.

-- Jay Beattie.

But that was one or two bicycles. I'm looking at bikes ridden by top
riders, I mentioned Eddie Marckx, Sean Kelly, et al, and I don't see
any frame stiffeners or wide tubes on bikes shown in photos of the top
rider of that era.

In fact, based on memory - always a questionable practice - I don't
remember a lot of talk about frame stiffness until about the time that
Cannondale started selling aluminum bikes. .

Sean Kelly victory photo on a Vitus 979.
https://www.flickr.com/photos/chicovelo/2207332160/

(virtually overdone pasta for stiffness, not even al dente)

I don't know what you're seeing in that picture Andrew. I do remember seeing wheels distort on a hard sprint but not frames. Though I'm sure that someone like Kelly could. But how do you distort a frame sideways with the tires distort so much in that plane?

On 6/8/2017 9:46 AM, wrote:
On Thursday, June 8, 2017 at 5:43:52 AM UTC-7, AMuzi wrote:
On 6/7/2017 10:17 PM, John B. wrote:
On Wed, 7 Jun 2017 07:20:09 -0700 (PDT), jbeattie
wrote:

On Wednesday, June 7, 2017 at 5:28:46 AM UTC-7, AMuzi wrote:
On 6/7/2017 12:13 AM, John B. wrote:
On Wed, 7 Jun 2017 09:34:58 +1000, James
wrote:

On 07/06/17 08:03, jbeattie wrote:
On Tuesday, June 6, 2017 at 7:09:56 AM UTC-7,
wrote:
On Monday, June 5, 2017 at 7:56:58 PM UTC-7, James wrote:
https://cyclingtips.com/2017/06/cycl...ffness-matter/



Interesting that some pros want a less stiff frame early season, and
more stiff frame later in the season.

Other interesting bits too.

Well, if you're flexing a frame and getting power back that's fine.
But at the same time there are frictional loses and you're only
getting back a portion of it.

There was a noticeable difference between riding a Colnago Dream
with carbon forks and the Colnago C40. The C40 was stiff and I had
to pedal complete circles on a hard climb or the bike would stop at
the point of one down stroke to the next. The Dream did it less. A
steel bike absolutely does not do this.

Now there may be a preference about one way or another but I don't
believe so. I think that this really is something that works better
and while I haven't said anything to the group I generally ride
with most of them are returning to steel.

The podcast is all about BB stiffness which is just one aspect of
frame stiffness.

Of course a soft frame is an energy sponge. Try sprinting on a
double-suspended mountain bike. Small difference in BB stiffness
between racing bikes, however, probably makes little difference.


Dual suspension MTB is a totally different beast. It has built in energy
absorbers (shock absorbers). Rigid frames do not.

I'm far more sensitive to front-end stiffness than BB stiffness. I
had a first-gen Cannondale 2.8 with aluminum forks that was like
sprinting on a pogo stick. I wanted to throw it away after my first
race on it but instead bought a pair of Kestrel forks which rode a
lot like steel (they had a steel steerer). I had a custom steel
sport-touring frame that rode the same way -- lots of slop. My last
steel racing bike was very stiff, but when I resurrected it last and
used it as my winter bike, it was not magical in any way. The
top-tube was too short; it was heavy and probably less "planing" than
my CAAD 3. What steel has going for it is resistance to mechanical
damage.


With thin walled tubes (0.4mm & below), not even that.

This whole steel-is-magical thing reminds me of going back to vinyl
and realizing how many bad recordings there are. It's more about the
implementation than the material.


I agree.

One of the things I've always wondered about when people start talking
about BB flex. It would be a relatively simple problem to built a
steel frame bike with gussets of bracing for the BB, but no one seems
to have. Looking at Eddie Marckx, Sean Kelly or any of the other top
riders of the "steel Era" and none of their bikes seemed to have any
visible BB bracing.

Yoshi Konno of 3Rensho, c.1990:
https://www.pedalroom.com/bike/3rensho-njs-chrome-6748

The linking is odd so in that series go to the BB photo.

The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.

-- Jay Beattie.

But that was one or two bicycles. I'm looking at bikes ridden by top
riders, I mentioned Eddie Marckx, Sean Kelly, et al, and I don't see
any frame stiffeners or wide tubes on bikes shown in photos of the top
rider of that era.

In fact, based on memory - always a questionable practice - I don't
remember a lot of talk about frame stiffness until about the time that
Cannondale started selling aluminum bikes. .

Sean Kelly victory photo on a Vitus 979.
https://www.flickr.com/photos/chicovelo/2207332160/

(virtually overdone pasta for stiffness, not even al dente)

I don't know what you're seeing in that picture Andrew. I do remember seeing wheels distort on a hard sprint but not frames. Though I'm sure that someone like Kelly could. But how do you distort a frame sideways with the tires distort so much in that plane?


What Andrew is alluding to isn't visible in that photo. But about the
same time, I test-rode my friends Alan frame, which I think was pretty
similar to the Vitus. I had absolutely no trouble flexing the frame
sideways in a sprint, far enough that the chain scraped on each side of
the front derailleur's cage in turn. It was super light but super
flexible; but people did win races on it.

BTW, the owner of that frame passed away recently, and I miss him. But
before he died he sold that bike to another friend of mine. It's still
going strong - even though it's not going stiff, so to speak.

--
- Frank Krygowski

On Thursday, June 8, 2017 at 5:43:52 AM UTC-7, AMuzi wrote:
On 6/7/2017 10:17 PM, John B. wrote:
On Wed, 7 Jun 2017 07:20:09 -0700 (PDT), jbeattie
wrote:

On Wednesday, June 7, 2017 at 5:28:46 AM UTC-7, AMuzi wrote:
On 6/7/2017 12:13 AM, John B. wrote:
On Wed, 7 Jun 2017 09:34:58 +1000, James
wrote:

On 07/06/17 08:03, jbeattie wrote:
On Tuesday, June 6, 2017 at 7:09:56 AM UTC-7,
wrote:
On Monday, June 5, 2017 at 7:56:58 PM UTC-7, James wrote:
https://cyclingtips.com/2017/06/cycl...ffness-matter/



Interesting that some pros want a less stiff frame early season, and
more stiff frame later in the season.

Other interesting bits too.

Well, if you're flexing a frame and getting power back that's fine.
But at the same time there are frictional loses and you're only
getting back a portion of it.

There was a noticeable difference between riding a Colnago Dream
with carbon forks and the Colnago C40. The C40 was stiff and I had
to pedal complete circles on a hard climb or the bike would stop at
the point of one down stroke to the next. The Dream did it less. A
steel bike absolutely does not do this.

Now there may be a preference about one way or another but I don't
believe so. I think that this really is something that works better
and while I haven't said anything to the group I generally ride
with most of them are returning to steel.

The podcast is all about BB stiffness which is just one aspect of
frame stiffness.

Of course a soft frame is an energy sponge. Try sprinting on a
double-suspended mountain bike. Small difference in BB stiffness
between racing bikes, however, probably makes little difference.


Dual suspension MTB is a totally different beast. It has built in energy
absorbers (shock absorbers). Rigid frames do not.

I'm far more sensitive to front-end stiffness than BB stiffness. I
had a first-gen Cannondale 2.8 with aluminum forks that was like
sprinting on a pogo stick. I wanted to throw it away after my first
race on it but instead bought a pair of Kestrel forks which rode a
lot like steel (they had a steel steerer). I had a custom steel
sport-touring frame that rode the same way -- lots of slop. My last
steel racing bike was very stiff, but when I resurrected it last and
used it as my winter bike, it was not magical in any way. The
top-tube was too short; it was heavy and probably less "planing" than
my CAAD 3. What steel has going for it is resistance to mechanical
damage.


With thin walled tubes (0.4mm & below), not even that.

This whole steel-is-magical thing reminds me of going back to vinyl
and realizing how many bad recordings there are. It's more about the
implementation than the material.


I agree.

One of the things I've always wondered about when people start talking
about BB flex. It would be a relatively simple problem to built a
steel frame bike with gussets of bracing for the BB, but no one seems
to have. Looking at Eddie Marckx, Sean Kelly or any of the other top
riders of the "steel Era" and none of their bikes seemed to have any
visible BB bracing.

Yoshi Konno of 3Rensho, c.1990:
https://www.pedalroom.com/bike/3rensho-njs-chrome-6748

The linking is odd so in that series go to the BB photo.

The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.

-- Jay Beattie.

But that was one or two bicycles. I'm looking at bikes ridden by top
riders, I mentioned Eddie Marckx, Sean Kelly, et al, and I don't see
any frame stiffeners or wide tubes on bikes shown in photos of the top
rider of that era.

In fact, based on memory - always a questionable practice - I don't
remember a lot of talk about frame stiffness until about the time that
Cannondale started selling aluminum bikes. .

Sean Kelly victory photo on a Vitus 979.
https://www.flickr.com/photos/chicovelo/2207332160/

(virtually overdone pasta for stiffness, not even al dente)

This is compelling enough to let any man preach. Even me.

On Wednesday, June 7, 2017 at 6:39:30 PM UTC+1, Sir Ridesalot wrote:

My old road bicycle Cannondale was a right royal pain to ride and I mean that literally. I've NEVER had a bike before or since that punished the rider like that thing did. Ride over a crack in the asphalt and that bike felt like someone was driving their fist into your kidneys. Even going to 700C x 30mm tires didn't help much. I got rid of that bike and kept my Tange Infinity frame bike instead.

I'm not so sure it is all about the material chosen for the frame, though clearly some materials present greater design challenges for any desired compliance/stiffness. I had a Peugeot mountain bike, right at the top of their range, that killed my back, regardless of the tyres I put on it. It was steel, beautifully fillet brazed. I suspect the tubes were just wrongly specified by the designer. Back in the 1990s there were a lot of bikes like that..

Andre Jute
Overbuilding that elsewhere in engineering may be virtuous, in bicycles is a crime. And I'm not even a weight weenie.

On Thursday, June 8, 2017 at 7:38:28 AM UTC-7, Frank Krygowski wrote:
On 6/8/2017 9:46 AM, wrote:
On Thursday, June 8, 2017 at 5:43:52 AM UTC-7, AMuzi wrote:
On 6/7/2017 10:17 PM, John B. wrote:
On Wed, 7 Jun 2017 07:20:09 -0700 (PDT), jbeattie
wrote:

On Wednesday, June 7, 2017 at 5:28:46 AM UTC-7, AMuzi wrote:
On 6/7/2017 12:13 AM, John B. wrote:
On Wed, 7 Jun 2017 09:34:58 +1000, James
wrote:

On 07/06/17 08:03, jbeattie wrote:
On Tuesday, June 6, 2017 at 7:09:56 AM UTC-7,
wrote:
On Monday, June 5, 2017 at 7:56:58 PM UTC-7, James wrote:
https://cyclingtips.com/2017/06/cycl...ffness-matter/



Interesting that some pros want a less stiff frame early season, and
more stiff frame later in the season.

Other interesting bits too.

Well, if you're flexing a frame and getting power back that's fine.
But at the same time there are frictional loses and you're only
getting back a portion of it.

There was a noticeable difference between riding a Colnago Dream
with carbon forks and the Colnago C40. The C40 was stiff and I had
to pedal complete circles on a hard climb or the bike would stop at
the point of one down stroke to the next. The Dream did it less.. A
steel bike absolutely does not do this.

Now there may be a preference about one way or another but I don't
believe so. I think that this really is something that works better
and while I haven't said anything to the group I generally ride
with most of them are returning to steel.

The podcast is all about BB stiffness which is just one aspect of
frame stiffness.

Of course a soft frame is an energy sponge. Try sprinting on a
double-suspended mountain bike. Small difference in BB stiffness
between racing bikes, however, probably makes little difference.


Dual suspension MTB is a totally different beast. It has built in energy
absorbers (shock absorbers). Rigid frames do not.

I'm far more sensitive to front-end stiffness than BB stiffness. I
had a first-gen Cannondale 2.8 with aluminum forks that was like
sprinting on a pogo stick. I wanted to throw it away after my first
race on it but instead bought a pair of Kestrel forks which rode a
lot like steel (they had a steel steerer). I had a custom steel
sport-touring frame that rode the same way -- lots of slop. My last
steel racing bike was very stiff, but when I resurrected it last and
used it as my winter bike, it was not magical in any way. The
top-tube was too short; it was heavy and probably less "planing" than
my CAAD 3. What steel has going for it is resistance to mechanical
damage.


With thin walled tubes (0.4mm & below), not even that.

This whole steel-is-magical thing reminds me of going back to vinyl
and realizing how many bad recordings there are. It's more about the
implementation than the material.


I agree.

One of the things I've always wondered about when people start talking
about BB flex. It would be a relatively simple problem to built a
steel frame bike with gussets of bracing for the BB, but no one seems
to have. Looking at Eddie Marckx, Sean Kelly or any of the other top
riders of the "steel Era" and none of their bikes seemed to have any
visible BB bracing.

Yoshi Konno of 3Rensho, c.1990:
https://www.pedalroom.com/bike/3rensho-njs-chrome-6748

The linking is odd so in that series go to the BB photo.

The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.

-- Jay Beattie.

But that was one or two bicycles. I'm looking at bikes ridden by top
riders, I mentioned Eddie Marckx, Sean Kelly, et al, and I don't see
any frame stiffeners or wide tubes on bikes shown in photos of the top
rider of that era.

In fact, based on memory - always a questionable practice - I don't
remember a lot of talk about frame stiffness until about the time that
Cannondale started selling aluminum bikes. .

Sean Kelly victory photo on a Vitus 979.
https://www.flickr.com/photos/chicovelo/2207332160/

(virtually overdone pasta for stiffness, not even al dente)

I don't know what you're seeing in that picture Andrew. I do remember seeing wheels distort on a hard sprint but not frames. Though I'm sure that someone like Kelly could. But how do you distort a frame sideways with the tires distort so much in that plane?


What Andrew is alluding to isn't visible in that photo. But about the
same time, I test-rode my friends Alan frame, which I think was pretty
similar to the Vitus. I had absolutely no trouble flexing the frame
sideways in a sprint, far enough that the chain scraped on each side of
the front derailleur's cage in turn. It was super light but super
flexible; but people did win races on it.

It was worse than that. I bought one just for the comparison point. It would shift when sprinting.

On Thursday, June 8, 2017 at 7:38:28 AM UTC-7, Frank Krygowski wrote:
On 6/8/2017 9:46 AM, wrote:
On Thursday, June 8, 2017 at 5:43:52 AM UTC-7, AMuzi wrote:
On 6/7/2017 10:17 PM, John B. wrote:
On Wed, 7 Jun 2017 07:20:09 -0700 (PDT), jbeattie
wrote:

On Wednesday, June 7, 2017 at 5:28:46 AM UTC-7, AMuzi wrote:
On 6/7/2017 12:13 AM, John B. wrote:
On Wed, 7 Jun 2017 09:34:58 +1000, James
wrote:

On 07/06/17 08:03, jbeattie wrote:
On Tuesday, June 6, 2017 at 7:09:56 AM UTC-7,
wrote:
On Monday, June 5, 2017 at 7:56:58 PM UTC-7, James wrote:
https://cyclingtips.com/2017/06/cycl...ffness-matter/



Interesting that some pros want a less stiff frame early season, and
more stiff frame later in the season.

Other interesting bits too.

Well, if you're flexing a frame and getting power back that's fine.
But at the same time there are frictional loses and you're only
getting back a portion of it.

There was a noticeable difference between riding a Colnago Dream
with carbon forks and the Colnago C40. The C40 was stiff and I had
to pedal complete circles on a hard climb or the bike would stop at
the point of one down stroke to the next. The Dream did it less.. A
steel bike absolutely does not do this.

Now there may be a preference about one way or another but I don't
believe so. I think that this really is something that works better
and while I haven't said anything to the group I generally ride
with most of them are returning to steel.

The podcast is all about BB stiffness which is just one aspect of
frame stiffness.

Of course a soft frame is an energy sponge. Try sprinting on a
double-suspended mountain bike. Small difference in BB stiffness
between racing bikes, however, probably makes little difference.


Dual suspension MTB is a totally different beast. It has built in energy
absorbers (shock absorbers). Rigid frames do not.

I'm far more sensitive to front-end stiffness than BB stiffness. I
had a first-gen Cannondale 2.8 with aluminum forks that was like
sprinting on a pogo stick. I wanted to throw it away after my first
race on it but instead bought a pair of Kestrel forks which rode a
lot like steel (they had a steel steerer). I had a custom steel
sport-touring frame that rode the same way -- lots of slop. My last
steel racing bike was very stiff, but when I resurrected it last and
used it as my winter bike, it was not magical in any way. The
top-tube was too short; it was heavy and probably less "planing" than
my CAAD 3. What steel has going for it is resistance to mechanical
damage.


With thin walled tubes (0.4mm & below), not even that.

This whole steel-is-magical thing reminds me of going back to vinyl
and realizing how many bad recordings there are. It's more about the
implementation than the material.


I agree.

One of the things I've always wondered about when people start talking
about BB flex. It would be a relatively simple problem to built a
steel frame bike with gussets of bracing for the BB, but no one seems
to have. Looking at Eddie Marckx, Sean Kelly or any of the other top
riders of the "steel Era" and none of their bikes seemed to have any
visible BB bracing.

Yoshi Konno of 3Rensho, c.1990:
https://www.pedalroom.com/bike/3rensho-njs-chrome-6748

The linking is odd so in that series go to the BB photo.

The Serotta Colorado used an ovalized seat tube at the BB to add stiffness. That was '86-87. Earlier steel frames also used chain stay bridges. If you wanted a super-stiff BB after the late '70s early '80s, you bought a Klein or Cannondale, assuming you could handle the aesthetic shock of fat tubes.

-- Jay Beattie.

But that was one or two bicycles. I'm looking at bikes ridden by top
riders, I mentioned Eddie Marckx, Sean Kelly, et al, and I don't see
any frame stiffeners or wide tubes on bikes shown in photos of the top
rider of that era.

In fact, based on memory - always a questionable practice - I don't
remember a lot of talk about frame stiffness until about the time that
Cannondale started selling aluminum bikes. .

Sean Kelly victory photo on a Vitus 979.
https://www.flickr.com/photos/chicovelo/2207332160/

(virtually overdone pasta for stiffness, not even al dente)

I don't know what you're seeing in that picture Andrew. I do remember seeing wheels distort on a hard sprint but not frames. Though I'm sure that someone like Kelly could. But how do you distort a frame sideways with the tires distort so much in that plane?


What Andrew is alluding to isn't visible in that photo. But about the
same time, I test-rode my friends Alan frame, which I think was pretty
similar to the Vitus. I had absolutely no trouble flexing the frame
sideways in a sprint, far enough that the chain scraped on each side of
the front derailleur's cage in turn. It was super light but super
flexible; but people did win races on it.

BTW, the owner of that frame passed away recently, and I miss him. But
before he died he sold that bike to another friend of mine. It's still
going strong - even though it's not going stiff, so to speak.

--
- Frank Krygowski

I wonder how the Vitus descended. If you're a nervous descender, being on a spring is the kiss of death.

I've been content on lots of different materials, but I have to say that my CF SuperSix is the best descending bike I've ever owned. It's hard to explain without sounding like a dopey bike review, so I won't.

I had an original 1984 Cannondale that I really liked. Super-stiff, but the biggest advancement in stiffness was years earlier when I switched from my Detto cycling/bowling shoes with nail on cleats to Duegi with birch soles and plastic bolt-on cleats. Super fast!

-- Jay Beattie.

On 6/8/2017 9:01 PM, jbeattie wrote:
On Thursday, June 8, 2017 at 7:38:28 AM UTC-7, Frank Krygowski wrote:

I had an original 1984 Cannondale that I really liked. Super-stiff, but the biggest advancement in stiffness was years earlier when I switched from my Detto cycling/bowling shoes with nail on cleats to Duegi with birch soles and plastic bolt-on cleats. Super fast!

Were they red? That would account for a lot.


--
- Frank Krygowski