Custom steel fork bend

[ProspectPark]

Hi all - while researching a custom build, I've noticed steel forks can be bent in different ways to achieve the desired trail. Some are awkward dog-leg bends, and some are nice graceful bends. Is it difficult to achieve a graceful bend in a steel fork? Is that something you can ask of a custom builder?

dog leg bend:
unattractive dog leg bend (http://ep.yimg.com/ca/I/yhst-84224226242177_2095_10072323)

graceful bend:
gracefully bent fork (http://3.bp.blogspot.com/_NqIVR0ONLFQ/R9VU8YcWQsI/AAAAAAAAAlc/VMCSY_1c3K4/s1600-h/100_3684.JPG)

[Pete Serotta]

Any of the builders that post here can do a graceful for you. Goodrich, Kellogg, Bedford, Ellis, Kirk, Hampsten, etx....

[ProspectPark]

What if there are no pictures of steel forks they have made? Is it fair to point to another builder who does have pictures of forks and request that the bend be kind of like that? I want to communicate my aesthetic preference clearly to the potential builder, but I also don't want to be a pain-in-the-ass customer who is dictating too much. Trying to find the right balance.

[dave thompson]

What if there are no pictures of steel forks they have made? Is it fair to point to another builder who does have pictures of forks and request that the bend be kind of like that? I want to communicate my aesthetic preference clearly to the potential builder, but I also don't want to be a pain-in-the-ass customer who is dictating too much. Trying to find the right balance.
There's no harm in showing pictures and saying "I really like this!" Realistically it's the only way that you can show what pleases your eye. If the builder can accommodate you, he'll take no offense at being shown pics of other's products.

[bigbill]

I am getting a custom frame from Argonaut and my conversations with the builder included the purpose of the bike to determine the style/bend of the fork. I plan on attending the San Diego Custom Bike Show next weekend to get ideas for paint and forks. For me, the final call is made by the builder since I am relying on his experience to build the bike.

[eddief]

i bring a photo of Dario Fanchitti. So far I'm still at least half bald. But at least the haircutter can appreciate a photo of really handsome guy with a hot wife and a fast car.

some nice bends on those Riv bikes; custom or Taiwan mass produced.

sorry, i could not resist.

[RPS]

The angle of the pictures makes some of the difference IMO. I think the two are not as different as they appear.

It would probably help to get two side view pictures to compare and to avoid misunderstandings when talking with the builder.

[Ken Robb]

I would guess that attaining a graceful arc is a bit trickier and demonstrates more skill from the craftsman than a short radius bend but I'm not a builder. Grant Petersen really cares about this aesthetic so all the Riv bikes I have seen had graceful forks.

[RPS]

I would guess that attaining a graceful arc is a bit trickier and demonstrates more skill from the craftsman than a short radius bend but I'm not a builder. Grant Petersen really cares about this aesthetic so all the Riv bikes I have seen had graceful forks.
It’s not just about aesthetics – some high-strength steels are more brittle and can’t be bent sharply without failure. That was the case with my stainless fork. The material doesn’t elongate as much so it has to have a longer-radius curve.

[DY123]

I guess it depends on what you consider graceful? Some people like lots of bend at the bottom with a tight radius and others prefer the opposite.

I prefer a large radius and a bend that starts up high and gradually makes a curve. To me that is graceful.

Here is a picture of one of my bikes that will be at the San Diego Custom Bicycle Show. If anyone rides a bike with a 56cm top tube come take a look at it.

(You’re right it is hard to take a picture that shows the fork rake clearly)

[cmg]

DY:
Pretty frame. yeap, i would consider that a gracefull bend. is there a functional advange to a flat crown fork? or it just asthetics, it does look nice.

[goonster]

I think the two are not as different as they appear.

I disagree. I'll bet that VO has low trail, and the difference in fork offset is enough to be visible to the naked eye.

[ProspectPark]

Great responses, interesting thread.

I've seen forks with tighter radius at the bottom - like Rene Herse randonneuring forks. And I've seen forks with a larger radius curve that goes up the length of the fork. Both can be fine. The only thing I want to avoid is the abrupt dog-leg bend in the middle of the fork, which I've seen on a number of custom steel bikes.

How are fork blades bent, now that we're thinking about this? Does anyone have pictures that show how it is done?

[ProspectPark]

I guess it depends on what you consider graceful? Some people like lots of bend at the bottom with a tight radius and others prefer the opposite.

I prefer a large radius and a bend that starts up high and gradually makes a curve. To me that is graceful.

Here is a picture of one of my bikes that will be at the San Diego Custom Bicycle Show. If anyone rides a bike with a 56cm top tube come take a look at it.

(You’re right it is hard to take a picture that shows the fork rake clearly)

This is beautiful.

[RPS]

I disagree. I'll bet that VO has low trail, and the difference in fork offset is enough to be visible to the naked eye.
My comment only addressed the shape of the curvature and not trail. In my experience pictures taken from different angles can fool us easily.

[Peter P.]

You have to ask the builder if they're equipped to build forks with different curves. Some have only one mandrel over which they bend their fork blades. Some can offer different radii to change the aesthetic of the fork. It's not difficult to achieve, but possessing the various mandrels to bend the blades over can be an issue. Most of these mandrels are custom made. Here's the mandrel Richard Sachs uses:

http://farm2.static.flickr.com/1180/749098507_b923941c80.jpg

Some builders use pre-bent blades.

[Erik.Lazdins]

Your picture of graceful is Mike Zanconato's work! :beer:

[ProspectPark]

You have to ask the builder if they're equipped to build forks with different curves. Some have only one mandrel over which they bend their fork blades. Some can offer different radii to change the aesthetic of the fork. It's not difficult to achieve, but possessing the various mandrels to bend the blades over can be an issue. Most of these mandrels are custom made. Here's the mandrel Richard Sachs uses:

http://farm2.static.flickr.com/1180/749098507_b923941c80.jpg

Some builders use pre-bent blades.

That is really cool to see that. Thanks.

[ProspectPark]

Velo orange article on fork bending (http://velo-orange.blogspot.com/2009/04/bending-forks-and-designing-boats.html)

[DY123]

IMO, bending your own blades is a way to further express your personal style.

Here is mine. I cut it on a band saw and then grooved it with a router and gouge. Can you read all the notes written to myself on the tape?

[Climb01742]

as a bit of a tangent, i've always loved the look of double-plated fork crowns, like the ones dario uses on luigino forks. visually stunning, says i. :D

[Steve in SLO]

You have to ask the builder if they're equipped to build forks with different curves. Some have only one mandrel over which they bend their fork blades. Some can offer different radii to change the aesthetic of the fork. It's not difficult to achieve, but possessing the various mandrels to bend the blades over can be an issue. Most of these mandrels are custom made. Here's the mandrel Richard Sachs uses:

http://farm2.static.flickr.com/1180/749098507_b923941c80.jpg

Some builders use pre-bent blades.

Gonna be hard as hell to mount a wheel on that. Too many Twizzlers that day?

[mister]

I guess it depends on what you consider graceful? Some people like lots of bend at the bottom with a tight radius and others prefer the opposite.

I prefer a large radius and a bend that starts up high and gradually makes a curve. To me that is graceful.

Here is a picture of one of my bikes that will be at the San Diego Custom Bicycle Show. If anyone rides a bike with a 56cm top tube come take a look at it.

(You’re right it is hard to take a picture that shows the fork rake clearly)

hey that's a really nice lookin frame.
i like the radius the lugs have.

the curve of the blades looks to be about the same as my davidson has...which is nice looking.

[DY123]

Good eye. Those lugs are Pacenti Artisan with an extra fillet added for a smooth radius. Before and after pics.

[Peter P.]

Gonna be hard as hell to mount a wheel on that. Too many Twizzlers that day?
YOU probably already know the answer to this one, but I'll share for those less knowledgeable:

What Steve's talking about is the dropout is at a right angle to the direction of the fork blade bend. Doesn't make sense, does it?

The reason is, Richard inserts a dummy dropout into the end of the fork blade when he bends them, to support the open end of the blade so it won't collapse under bending pressure.