Fork

[tony west]

Has anyone any idea of a company or anybody that has/produce a straight fork, no rake, completely straight. Should have said, Road fork.

 

[stutue]

There's loads of them Tony.

Easton, Look, Deda.

Have a look at the fork section on ribblecycles.co.UK

They have pictures

http://www.ribblecycles.co.uk/pp/road-track-bike/forks-road/forr

 

[Master50]

There are lots of straight blade fork but you said no rake? Do you mean a fork where the blades are the same angle of the head tube? I can't think of any application for that as the bike would have no trail and the handling would be way too fast. You could not take your hands off the bars at all. my understanding of the subject is a little limited but I don't think anyone makes that fork. There is always a rake and trail relationship. Many years ago Colnago introduced the straight blade fork as he said the curve of most fork blades did not do anything for the ride or comfort plus I think they were harder to align. Straight blades are easy to find.
Add Wound Up to the list of aftermarket fork makers.

 

[stutue]

My goodness I hadn't notice that he said no rake.

In which case, no. I don't think you'll find a no rake fork. As master50 says its all to do with 'trail' which is about where the contact point with the ground is. The trail is put in to improve handling.

Unless you've got some kind of weird frame with a very slack headtube a fork with no rake might give issues with toe overlap and clearance of tyre and downtube.

Maybe you just meant no curve

 

[winkybiker]

There are lots of straight blade fork but you said no rake? Do you mean a fork where the blades are the same angle of the head tube? I can't think of any application for that as the bike would have no trail and the handling would be way too fast. You could not take your hands off the bars at all.

It's actually the other way round. If you reduce the rake, you increase trail and stability (for the same head angle). Think of it as moving the wheel back relative to the steering axis. More caster. The wheel will always want to straighten up. Bikes with dead straight forks (no rake) will be very sluggish. The only application I can really think of is individual track time trials. You'll also have wicked shoe overlap, if indeed the wheel clears the downtube at all.

 

[Ruby60]

A custom frame builder is in order to build a steel or aluminum fork for you. They would have to make a custom fork crown to eliminate rake.

 

[stutue]

Right about that...

...but let's wait and see if Tony actually wants a fork with no rake

 

[avanti]

Slight thread hijack here but Artistic Cycling bikes appear to have minimum trail and rake:
http://www.otoupalik-bikes.cz/en/artistic-cycling-bikes.aspx

 

[tony west]

Ive been trying to get an answer to this for some time, now ive got a rush on, yes I did mean dead straight, dropouts in line with steerer tube, we all know airo road is all the rage, I did it years ago, first with a Pinarello Razor, 1 of only 4 made for Bjarne Riis, for runner to Montelo, and a Scott Plasma, in a 54 the head tube is slack, the wheel sits so fare forward which makes the steering very very slow, 2.1/2 inch gap between Tyre and down tub, so with straight fork could get back at least an inch, just to be clear, these all have drop bars, no im not trying to speed up TT set up, ive even thought of cutting the head tub to down tub junction and pulling the head tube back a bit, then re-carbon, bit drastic though, yes I have a custom carbon/paint/decal repair shop, so come on Guys, there must be something out there, dont say turn the fork round. Mike Burrows is not the only one playing with the black stuff, or silver, or gold

 

[King Boonen]

Ive been trying to get an answer to this for some time, now ive got a rush on, yes I did mean dead straight, dropouts in line with steerer tube, we all know airo road is all the rage, I did it years ago, first with a Pinarello Razor, 1 of only 4 made for Bjarne Riis, for runner to Montelo, and a Scott Plasma, in a 54 the head tube is slack, the wheel sits so fare forward which makes the steering very very slow, 2.1/2 inch gap between Tyre and down tub, so with straight fork could get back at least an inch, just to be clear, these all have drop bars, no im not trying to speed up TT set up, ive even thought of cutting the head tub to down tub junction and pulling the head tube back a bit, then re-carbon, bit drastic though, yes I have a custom carbon/paint/decal repair shop, so come on Guys, there must be something out there, dont say turn the fork round. Mike Burrows is not the only one playing with the black stuff, or silver, or gold

Reducing the rake will slow down the steering even more.

 

[winkybiker]

Reducing the rake will slow down the steering even more.

+1.

Reducing rake is the opposite of steepening the head-tube angle and will slow the steering.

 

[Master50]

It's actually the other way round. If you reduce the rake, you increase trail and stability (for the same head angle). Think of it as moving the wheel back relative to the steering axis. More caster. The wheel will always want to straighten up. Bikes with dead straight forks (no rake) will be very sluggish. The only application I can really think of is individual track time trials. You'll also have wicked shoe overlap, if indeed the wheel clears the downtube at all.

Thanks I have always struggled with that so you are describing a motor pace bike. lots of castor which always helps me understand rake and trail. Motor pace bike might have reverse blades to allow them to get even closer to the Derny.

 

[twothirds]

The reverse rake is strictly for stability. The smaller front wheel is what there partially to allow them to get closer to the derny, but mostly to add some "twitchy-ness" and responsiveness back into the steering equation. It also makes for a stringer front end, as the front wheel gets loaded more in the bankings at high speeds than the rear wheel.

 

[ustabe]

The reverse rake is strictly for stability. The smaller front wheel is what there partially to allow them to get closer to the derny, but mostly to add some "twitchy-ness" and responsiveness back into the steering equation. It also makes for a stringer front end, as the front wheel gets loaded more in the bankings at high speeds than the rear wheel.

And because of the small front wheel and the steepness of the head angle, there is a measure of trail on these bikes that works suitably for the application.

My estimation is that the sluggishness factor for a given amount of trail increases as the head angle decreases. That is, a bike with x amount of trail with a slack head angle will feel more sluggish than a bike with the same trail but a steep head angle.

 

[twothirds]

And because of the small front wheel and the steepness of the head angle, there is a measure of trail on these bikes that works suitably for the application.

My estimation is that the sluggishness factor for a given amount of trail increases as the head angle decreases. That is, a bike with x amount of trail with a slack head angle will feel more sluggish than a bike with the same trail but a steep head angle.

That is correct.

 

[42x16ss]

BMC could be the way to go for a totally straight bladed fork. Some of their fork models have no rake, or at most 1-2 degrees. You may need to get one from a frame though.

 

[Hawkwood]

BMC could be the way to go for a totally straight bladed fork. Some of their fork models have no rake, or at most 1-2 degrees. You may need to get one from a frame though.

They may be straight forks, but they still have rake, the BMC SL 048 Straight Edge Fork has a rake of 43mm. I did a quick scan of around 30 forks from various manufacturers and they were all 43 or 45mm.

 

[ustabe]

They may be straight forks, but they still have rake, the BMC SL 048 Straight Edge Fork has a rake of 43mm. I did a quick scan of around 30 forks from various manufacturers and they were all 43 or 45mm.

Yup. Trek is the outlier here, with 40 mm rake on the larger (56 cm and up) Madones.

 

[Hawkwood]

Yup. Trek is the outlier here, with 40 mm rake on the larger (56 cm and up) Madones.

That's interesting, I see on their larger models they're using a slightly steeper head-tube angle of 73.9 degrees, still within the normal range, and using a 40mm rake fork keeps the rake at 56mm. Using a `standard' fork rake of 43 or 45 would have taken the trail down to below 56mm.

I read an article yonks ago about rake, head tube angles, trail and steering, it said that it was surprising that in the motorcycle world trail was all important, but barely spoken about in the cycling world. I had a shocker of a handbuilt British frame years ago, the forks shuddered terribly from about 28-40 mph, I'm convinced the trail was wrong.

 

[Bustedknuckle]

Has anyone any idea of a company or anybody that has/produce a straight fork, no rake, completely straight. Should have said, Road fork.

See you are in the UK but

http://www.waterfordbikes.com

will...also Woundup

But you mean 'no rake'..not possible..I mean possible but with a headtube angle, zero rake, the bike would handle, like, not at all.

 

[Race Radio]

Has anyone any idea of a company or anybody that has/produce a straight fork, no rake, completely straight. Should have said, Road fork.

There is a guy who used to work for Reynolds who makes custom forks. I am not sure of his name but they are amazing.

I bought mine from http://hollandcycles.com/ I think they call it the ML custom fork

 

[ustabe]

That's interesting, I see on their larger models they're using a slightly steeper head-tube angle of 73.9 degrees, still within the normal range, and using a 40mm rake fork keeps the rake at 56mm. Using a `standard' fork rake of 43 or 45 would have taken the trail down to below 56mm.

I read an article yonks ago about rake, head tube angles, trail and steering, it said that it was surprising that in the motorcycle world trail was all important, but barely spoken about in the cycling world. I had a shocker of a handbuilt British frame years ago, the forks shuddered terribly from about 28-40 mph, I'm convinced the trail was wrong.

I'm convinced that until the past 10 or 20 years fork rake and head angles were designed intuitively. The resultant trail dimension was probably a happy, or unhappy, as the case may be, accidental consequence.

In the '70s, the general trend in British bikes was moderate or slack head angles with a short rake, while the Italian bikes had steeper head angles with more rake. Shorter trail makes for more forgiving handling, which is good for cobbles, chip-seal, sand, gravel, mud, and puddles. The direction of the front wheel is deflected by the rough surface, but is also easily corrected by the rider. It tends to snake around this stuff rather than plow straight through it.

 

[Hawkwood]

I'm convinced that until the past 10 or 20 years fork rake and head angles were designed intuitively. The resultant trail dimension was probably a happy, or unhappy, as the case may be, accidental consequence.

In the '70s, the general trend in British bikes was moderate or slack head angles with a short rake, while the Italian bikes had steeper head angles with more rake. Shorter trail makes for more forgiving handling, which is good for cobbles, chip-seal, sand, gravel, mud, and puddles. The direction of the front wheel is deflected by the rough surface, but is also easily corrected by the rider. It tends to snake around this stuff rather than plow straight through it.

Well there was a period from around 1976 onwards when the trend in Britain was for very steep angles with short wheelbases on the basis that this was somehow faster. The trend was particularly noticeable on time trial bikes. Holdsworth produced a team bike that was either 75 or 76 degrees parallel. Heaven knows how riders with longer legs got their positions right on such bikes. I've got some Cycling mags from the time and these mention bikes with `*** paper clearances'. These bikes often had considerable feet/fork overlap, and this caused problems on some time trial courses with U turns in roads. Notable frame designs of the time include one with a curved seat-tube, and another with twin seat-tubes (the rear wheel sat between them), both to make the wheelbase shorter. I rode a mate's British made Columbus tubed tt frame for a short while in the early 1980s, it was an absolute dog, wheelbase too short, angles wrong, steering off, and extremely flexy when you put the power down. Shortly afterwards I had a frame built for me in Belgium, what a difference, stiff, easy to steer, good on descents.

 

[ustabe]

Well there was a period from around 1976 onwards when the trend in Britain was for very steep angles with short wheelbases on the basis that this was somehow faster.

I remember that period now.

My reference point is a couple of early '70s Roberts road or criterium frames, and a buddy's Knight. These were moderate in most aspects except for short fork rakes. Cornered as if on rails, but hitting a puddle or patch of loose stuff in a corner was often a hair-raising experience. The Gios I got in '79 wasn't lighter or necessarily faster, but it surprised me with its perfect poise as it plowed through whatever happened to by lying on the road.

These days I've now got a newer Madone and an '80 California Masi. With fat tubulars glued on, the Masi will go anywhere with poise. It's a little lazy dropping into corners, but it finds a groove and holds it. The Madone makes me slow down for corners on dirt roads.

 

[Hawkwood]

I remember that period now.

My reference point is a couple of early '70s Roberts road or criterium frames, and a buddy's Knight. These were moderate in most aspects except for short fork rakes. Cornered as if on rails, but hitting a puddle or patch of loose stuff in a corner was often a hair-raising experience. The Gios I got in '79 wasn't lighter or necessarily faster, but it surprised me with its perfect poise as it plowed through whatever happened to by lying on the road.

These days I've now got a newer Madone and an '80 California Masi. With fat tubulars glued on, the Masi will go anywhere with poise. It's a little lazy dropping into corners, but it finds a groove and holds it. The Madone makes me slow down for corners on dirt roads.

From what I'd heard from others Roberts has alway built decent frames, interesting about the rake though. There were builders out there in the 70s and 80s who'd build anything they were asked to build even if the geometry wouldn't work. I always like the look of the Gios frames. I rode some British frames that were real pigs. One fractured above the bottom bracket, was sent off for repair by the builder, then the head tube sheered all the way through on a descent, it was barely six months old! I then went to Ronse in Belgium and got a frame built up there by Van Hauwaert. This one was bomb proof, and steered really well. My next frame was a custom built British one that was so bad I don't even want to write about it. Then around 1997 I bought a steel Bianchi from Van Eyck in Aalst, another one that descended and generally behaved beautifully.