Fork curvature battle!
04-06-22, 06:35 AM
#26
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You people lack imagination:
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04-06-22, 06:35 AM
#27
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one thing i've noticed is that i must have a particular fondness for a particular curvature as almost all my bikes share a distinctly similar bend across most of the length of the blade:
except for the this one - and truth be told, it was one reason i never really took to it:
a subtle curvature across most of the length just looks "right", i suppose. To my eye, for sure
dd
except for the this one - and truth be told, it was one reason i never really took to it:
a subtle curvature across most of the length just looks "right", i suppose. To my eye, for sure
dd
04-06-22, 07:29 AM
#28
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Yeah, YMMV but I like all of the various curvatures except "none at all", although I suspect those work just fine.
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Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
04-06-22, 07:58 AM
#29
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Vintage french forks FTW. Straight blades with no bend, yuck!
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04-06-22, 08:33 AM
#31
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04-06-22, 08:48 AM
#32
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I like low-trail and am always tinkering to get the handling I want. I have two modern forks that both have over 2.5" of rake. One is the "beauty", a 1st version Electra Ticino. Chromo with huge tire clearance and a beautiful low bend.
And the "Beast" is this reclaimed RAns recumbent 26" fork. Aluminum and slightly too short axle-crown for these tires, but it handles a load nicely. Thinking about moving it to another frame.
It looks like I cased the landing. ..."You should have seen it, I was 20ft in the air..."
And the "Beast" is this reclaimed RAns recumbent 26" fork. Aluminum and slightly too short axle-crown for these tires, but it handles a load nicely. Thinking about moving it to another frame.
It looks like I cased the landing. ..."You should have seen it, I was 20ft in the air..."
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04-06-22, 09:48 AM
#34
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Straight Forks Vs. Other Styles
You call that a KNIFE... er bike? No BLING!
Back in 2006 a frame builder friend was cleaning out his shop and pulled this 1st generation Colnago Technos out of a box. I was aghast! Having led a sheltered C&V life for over 30 years, I'd never seen anything like it! He'd taken it in as a partial trade for a new custom frame back in the 90's. The PO brought it to him complaining that it pulled to one side. Realigning the fork didn't do much so it sat in a box for over 10 years.
It was so off the wall with the straight Precisa fork, bulged and fluted oversize Columbus Gilco tubing plus the paint, I decided to build it into a frankenbike! I had a NOS 1987 Shimano Deore XT MTB gruppo so I used the hubs, triple crank plus the front and rear derailleurs.
When I got it home and put the frame up in the stand, I could immediately tell that something wasn't right! When I checked the alignment, the rear triangle was off 11mm to the drive side. I took it back to my buddy's and we put it on his layout table. Not only was the rear triangle off but the head and seat tube were out of alignment by over 1/4" (6mm) in opposite directions!!! The main tubes were over 1/2" (12mm) off of the frame center line! So much for sacred holy Italian craftsmanship!
To add to the bizarrity, I later installed a prototype set of Bonntrager Speed Limit brakes! I have to say, when I lock them up I can feel the beginning of retinal detachment.
The bike rides and handles really sweet and climbs like a mountain goat. Looking down on the stem while ridding there seems to be ZERO flex in the forks. Shock absorption comes from front and back flexing of the head tube due to the thin walled top and down tubes.
A problem that I discovered with the Precisa forks is a tendency to turn sharply to one side when coming up over small bumps at very low speeds like riding up onto a sidewalk at a crosswalk. The front wheel turned, threw me to the left and I did a face plant on 2 occasions. I caught myself several other times. They were bumps that a curved fork would have no problem going up over!
Vintage French forks? 1955 Motorex Randonneur with REAL fork rake!
Straight forks? In 1975 we brought several of these Bickerton aluminum folding bikes into to our shop for folks who planned on traveling. My friend who owned the shop took one over to Europe, bought a Eurail Pass and traveled all over France and Italy with it visiting lots of bike and component manufacturers. Very light but scary flexy. They were truly like pushing a wheel barrow!
1820 Draisne
verktyg
It was so off the wall with the straight Precisa fork, bulged and fluted oversize Columbus Gilco tubing plus the paint, I decided to build it into a frankenbike! I had a NOS 1987 Shimano Deore XT MTB gruppo so I used the hubs, triple crank plus the front and rear derailleurs.
When I got it home and put the frame up in the stand, I could immediately tell that something wasn't right! When I checked the alignment, the rear triangle was off 11mm to the drive side. I took it back to my buddy's and we put it on his layout table. Not only was the rear triangle off but the head and seat tube were out of alignment by over 1/4" (6mm) in opposite directions!!! The main tubes were over 1/2" (12mm) off of the frame center line! So much for sacred holy Italian craftsmanship!
To add to the bizarrity, I later installed a prototype set of Bonntrager Speed Limit brakes! I have to say, when I lock them up I can feel the beginning of retinal detachment.
The bike rides and handles really sweet and climbs like a mountain goat. Looking down on the stem while ridding there seems to be ZERO flex in the forks. Shock absorption comes from front and back flexing of the head tube due to the thin walled top and down tubes.
A problem that I discovered with the Precisa forks is a tendency to turn sharply to one side when coming up over small bumps at very low speeds like riding up onto a sidewalk at a crosswalk. The front wheel turned, threw me to the left and I did a face plant on 2 occasions. I caught myself several other times. They were bumps that a curved fork would have no problem going up over!
Vintage French forks? 1955 Motorex Randonneur with REAL fork rake!
Straight forks? In 1975 we brought several of these Bickerton aluminum folding bikes into to our shop for folks who planned on traveling. My friend who owned the shop took one over to Europe, bought a Eurail Pass and traveled all over France and Italy with it visiting lots of bike and component manufacturers. Very light but scary flexy. They were truly like pushing a wheel barrow!
1820 Draisne
verktyg
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Don't believe everything you think! History is written by those who weren't there....
Chas. ;-)
Don't believe everything you think! History is written by those who weren't there....
Chas. ;-)
Last edited by verktyg; 04-06-22 at 09:58 AM.
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04-06-22, 10:28 AM
#35
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Not to be crude, but I can think of other curvatures that don’t get universal agreement. “Beauty is in the eye of the beholder”.
04-06-22, 11:03 AM
#36
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I humbly nominate my mid 70's Peugeot PR10, which has a distinct lack of Frenchness in it's 'swoop' (or lack thereof):
and my mid 80's Zunow. I know, non drive side, but it was a better shot for this purpose:
and my mid 80's Zunow. I know, non drive side, but it was a better shot for this purpose:
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04-06-22, 11:06 AM
#37
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Colnago lost me when they started with these straight forks. I remember seeing one for the first time and I thought "what a smart idea for cost cutting but the looks... the horror, the horror" ;-)
I bought this Master Piu frame new and it would have been a deal breaker if it would have come with a straight fork.
Straight bladed forks just killed it for me, just as much as brifters, unicrowns, ergo bars and non-quill type stems did...... yechh....
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04-06-22, 11:31 AM
#38
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04-06-22, 11:44 AM
#39
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I had a Raleigh once that had all the bend down near the hub - that bike had terrible wheel flop... maybe that wasn't the reason, but I never liked that shape.
I'm going to say that DeRosa has the more appealing bend, by a sliver, over the Masi... although the Masi's long head tube might be affecting my choice.
I'm going to say that DeRosa has the more appealing bend, by a sliver, over the Masi... although the Masi's long head tube might be affecting my choice.
04-06-22, 12:01 PM
#40
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No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
04-06-22, 10:34 PM
#41
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Several years ago, while walking in Paris I saw this great looking Dancelli. Nicest bend I've seen. I asked my wife to stand alongside.
I haven't seen another one quite the same. Bike or wife..
I haven't seen another one quite the same. Bike or wife..
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04-07-22, 07:42 AM
#42
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So...is the pattern that the Italians have a nice sweeping curve, while French bikes have a more abrupt curve towards the end of the fork?
04-07-22, 11:53 PM
#43
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Fork Rake and Fork Benders
I've seen advertisements for fork bending tools. As I recall some have a 9" radius and others have a 6" radius.
I think that a short fork rake looks best when done with a large radius. Larger fork rakes (>/= 45mm) can look good with either radius.
I've seen forks bent with a single radius and also some done with double radius. The double radius fork starts curving gradually at the top of the bend, and the curve 'accelerates' as it gets closer to the fork tip.
One of the best fork bends I've seen is on this 1972 SW Cotten, built by Bill Hurlow. See the attached photo. It looks like a double radius bend to me. A single radius bend often looks a bit 'straight' just above the fork tips.
I think that a short fork rake looks best when done with a large radius. Larger fork rakes (>/= 45mm) can look good with either radius.
I've seen forks bent with a single radius and also some done with double radius. The double radius fork starts curving gradually at the top of the bend, and the curve 'accelerates' as it gets closer to the fork tip.
One of the best fork bends I've seen is on this 1972 SW Cotten, built by Bill Hurlow. See the attached photo. It looks like a double radius bend to me. A single radius bend often looks a bit 'straight' just above the fork tips.
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