A somewhat pointless change of fork shape or what !!

[TheCyclingRooster]

Hi to you all out there.
Could some-one please explain to me the reason why there has been this massive shift from the 'Age Old' curved style of fork to the rather (IMHO) unattractive and seemingly pointless style of straight-line profile that seems to be spreading like a rash among the current production of cycles ?

The very first time that I ever saw it used was on a Claud Butler that my brother built-up from a new frame after a total failure with a Peugeot frame some many years ago.

I had noticed a slow change from the conventional curve and slender lines of the fork blades since the advent of the Carbon Fork but now - even that has totally gone in favour of the thicker and frankly - quite ugly/unattractive current style of fork-blade.

My only observation is the possible shorting of the wheel base by literally a few millimetres but that would/could potentially make for a slightly more difficult skittery ride and especially when cornering at speed and especially on fast descents as are often seen on the grand tours.

 

[screenman]

Strength maybe, must admit I prefer the straight look, maybe it is an age thing as I am a very young 60.

 

[PhilDawson8270]

There's a few possibilities. New materials and manufacturing techniques mean we can gain compliance in ways other than purely geometry.

Possibly it's cheaper? It may also result in much faster steering depending on the headstock geometry too.

 

[TheCyclingRooster]

Strength maybe, must admit I prefer the straight look, maybe it is an age thing as I am a very young 60.

Hi screenman. Could it be that I am an 'Old' Stick in The Mud at 71years and prefer the slender lines and beautiful curves of some of the new generation of female cyclists that grace our screens/sport/interest these days.
I put my Benotto (Avatar image) up for sale a month or so back but no takers but have reconsidered and will now look to keep it in favour of selling my 50cm Bianchi to make room for my almost completed Steve Goff frame-set.
Both of these Columbus Steel framed bikes have the wonderful curved lines and chromed forks that no Carbon forks can offer in one fork. Curved perhaps as are on my Bianchi but Chromed - I don't think-so.

 

[Ajax Bay]

I think you'll find that the offset of both types of fork are in the same range: 43mm - 60mm. One ("the 'Age Old' curved style of fork") achieves it by starting at the head tube angle and then has a small radius bend low down. The other type is either a large radius 'banana' shape or a straight (or almost straight) blade (often carbon) where the fork angle immediately below the fork crown does not follow the head tube / steerer angle but sets off a few degrees shallower, to achieve the offset required for the desired type of handling (less offset = 'quicker' steering, more offset = slower) (for a given head tube angle). The shape of the curve (or none) has no effect on the steering characteristics. That is a function of offset and head tube angle. The 'old style' will minimise the transmission of road vibrations through to the bars.

 

[TheCyclingRooster]

There's a few possibilities. New materials and manufacturing techniques mean we can gain compliance in ways other than purely geometry.

Possibly it's cheaper? It may also result in much faster steering depending on the headstock geometry too.

Hi Phil. New materials perhaps - cheaper - almost certainly but faster steering I am not sure and as for the castor action that enables riding with no-hands that certainly does not appear to have been affected.

Talking of which - I seem to have lost the ability to do just that. In my teens I could ride for ages on both fixed wheel and on gears including on ascents.
Descents with no hands could be achieved by steering with ones butt like riding a motorcycle.

 

[Yellow Saddle]

Fashion. The path the fork follows to get to the end point is irrelevant to it's performance. It is the final position that determines a few things, nothing else. Have a look at a Pinarello Dogma and then at the bike in the current Bates Nostalgia thread. Any explanation by a manufacturer is marketing nonsense post-rationalised to appeal to a gullible audience.
If you like curved, buy curved. If you like straight, buy straight. If you are bent and slightly squiggly, buy a Dogma.

 

[TheCyclingRooster]

I think you'll find that the offset of both types of fork are in the same range: 43mm - 60mm. One ("the 'Age Old' curved style of fork") achieves it by starting at the head tube angle and then has a small radius bend low down. The other type is either a large radius 'banana' shape or a straight (or almost straight) blade (often carbon) where the fork angle immediately below the fork crown does not follow the head tube / steerer angle but sets off a few degrees shallower, to achieve the offset required for the desired type of handling (less offset = 'quicker' steering, more offset = slower) (for a given head tube angle). The shape of the curve (or none) has no effect on the steering characteristics. That is a function of offset and head tube angle. The 'old style' will minimise the transmission of road vibrations through to the bars.

Hi Ajax Bay. Yes - I go along with the theories/practices involved in cycle geometry but also the depth of 700c rims now plays a huge part in the absorption/transmission of road issues through the bars.
I am currently riding Mavic CXP 30 rims with Campagnolo small flanged hubs on my Benotto (Columbus Steel with Chromed and curved profile to the forks) and the ride is really most comfortable compared to the shallow rims of old.

My shortly to be completed Steve Goff (Designer Select) Columbus steel tubing total rebuild is about to be run on Mavic Aksium hubs with slightly deeper rims than those of old. It also has slender curved Chromed Steel forks.

 

[Ajax Bay]

the castor action that enables riding with no-hands . . . I seem to have lost the ability to do just that

A bike designed with neutral steering eg many touring and expedition bikes, should be extremely difficult to ride 'no-hands'. Their offset/head tube angle is deliberately chosen so that steering is unaffected (or at least affected only a small amount and not enough to allow easy/safe 'no-hands'). However a racing bike should be very responsive to leaning and therefore relatively easy to steer no-hands. Also one's weight must be well back, but off course this means one is further away from the 'safety' of grabbing the bars. Like you (tCR) I suspect that the natural reduction in risk tolerance that most experience/exhibit with advancing years means we get caught in the too far forward and on a relaxed geometry bike 'no man's land', and this manifests as loss of ability.

 

[TheCyclingRooster]

Fashion. The path the fork follows to get to the end point is irrelevant to it's performance. It is the final position that determines a few things, nothing else. Have a look at a Pinarello Dogma and then at the bike in the current Bates Nostalgia thread. Any explanation by a manufacturer is marketing nonsense post-rationalised to appeal to a gullible audience.
If you like curved, but curved. If you like straight, buy straight. If you are bent and slightly squiggly, buy a Dogma.

Hi Yellow Saddle. My understanding of the quirky multiple curves on the PInarello Dogma front fork was that it was purely/solely for the breaking-down of road shocks in a similar way to those of the Bates forks of old and also the Vibrant Triangle on Hetchins (Curly) frames.
I can speak personally of the Hetchins because I used to have a 19.5" 1937 Hetchins Vibrant - 2 day Brilliant Track frame which I rode for many tears before having the rear widened and converted with road drop=outs to take a 5spd block.
I foolishly sold it way back in 1967 just after getting married because of nowhere to store it - total idiot - I would/could probably have still had the Hetchins - the wife only lasted until 1992.

 

[Yellow Saddle]

Hi Yellow Saddle. My understanding of the quirky multiple curves on the PInarello Dogma front fork was that it was purely/solely for the breaking-down of road shocks in a similar way to those of the Bates forks of old and also the Vibrant Triangle on Hetchins (Curly) frames.
I can speak personally of the Hetchins because I used to have a 19.5" 1937 Hetchins Vibrant - 2 day Brilliant Track frame which I rode for many tears before having the rear widened and converted with road drop=outs to take a 5spd block.
I foolishly sold it way back in 1967 just after getting married because of nowhere to store it - total idiot - I would/could probably have still had the Hetchins - the wife only lasted until 1992.

He he....perhaps you didn't see the words "post rationalised" and "gullible audience" in my text. (insert friendly smiley thing here).

Nope, there's definitely no compliance up that fork, Dogma or Hetchins or that Bates one. Explain to yourself what would happen if the brake blocks are engaged on the rim (brakes applied) and the fork now suddenly compresses to absorb shock. Do they go into the spokes? Do they move halfway down the rim? Don't they go anywhere at all? A, B or C?

 

[Ajax Bay]

the depth of 700c rims now plays a huge part in the absorption/transmission of road issues through the bars [eg . . .] Mavic CXP 30 rims

Why should deeper rims absorb more road buzz?

 

[TheCyclingRooster]

A bike designed with neutral steering eg many touring and expedition bikes, should be extremely difficult to ride 'no-hands'. Their offset/head tube angle is deliberately chosen so that steering is unaffected (or at least affected only a small amount and not enough to allow easy/safe 'no-hands'). However a racing bike should be very responsive to leaning and therefore relatively easy to steer no-hands. Also one's weight must be well back, but off course this means one is further away from the 'safety' of grabbing the bars. Like you (tCR) I suspect that the natural reduction in risk tolerance that most experience/exhibit with advancing years means we get caught in the too far forward and on a relaxed geometry bike 'no man's land', and this manifests as loss of ability.

Hi again Ajax Bay. I still ride the same size and geometry of frame as was my 19.5" 1937 Hetchins Vibrant of old albeit the Bianchi is a 50cm frame (very very close) also the saddle position - if anything is slightly further back which should theoretically make it easier to ride both of my current Italian Steeds.

The one obvious thing to me - that is - the curve of the fork is more pronounced on the Hetchins than that of both the Benotto and the Bianchi albeit the Bianchi has a slightly curved Carbon Fork.
This image was taken late 1964 and just before the bike was stolen and then recovered but totally stripped and then rebuilt with Chromed Forks.

 

[alecstilleyedye]

the reason for the whole diaderant forks (bates) and the curly stays (hetchins) lies in the fact that back in the day, racers were not permitted to display the manufacturers name on the bike (not sure why), which meant manufacturers had to come up with ways of making their bikes obvious if they won races…

 

[screenman]

Why should deeper rims absorb more road buzz?

I was trying to work that one out myself.