Replacement forks query

OK, one of my usual dumb-fuck questions but with a bit of debate thrown in. Usual disclaimer: I've UTFS and there are some threads on the matter, but nothing that I'm happy answers my query, so here goes:

Sitrep is that I bashed up my Charge in the summer, forks are bent out of line, by about a centimetre. Most people's opinion seems to be that trying to bend chromoly forks will most likely either create snappage, or put unseen weakness into the metal. Either way, that seems like Bad Shit, so that option appears to be out. Anyone confirm/deny that?

So, replacement forks time I'm reckoning. Well OK, then what to choose? I've never fucked up a front fork, so I've never replaced a set. Now I could just get a like-for-like Charge front fork - job done, easy peasy. But the handling on the bike is, well, ummm... "relaxed", let's say. So I'm wondering if I can alter the handling in a positive way by changing the fork angle.

The info I have is that the standard Plug Racer forks are straight, the steering tube is 73 degrees on the large frame, but I can't find anything on the Charge website to tell me the fork angle, but you can see that they're virtually straight, maybe a degree or two of forward lean. If anyone in the know can confirm the true angle I'd be grateful.

So, here's my other query. What if I stick either curved forks or straights with a greater angle onto the bike, that'll move the wheel forward, but I believe it will also increase the trail, which I think should therefore give me sharper handling (and possibly help with the toe-overlap). But the folk in the bike shop are saying that the straight-line steering is what makes a bike sharp/squirrelly vs steers like a cow - citing the example of a Brompton. But I think it's the almost vertical steering tube on the Brompton which makes it so twitchy. And I guess you'd think the manufacturers would have chosen the fork angle for a reason - am I screwing with a winning formula, or is my thinking right?

And by the by, I'm obviously in the market for a set of forks. It's not a top-spec bike, so if someone just upgraded their forks and wants to lose their old set, there's a potential customer here. Just thought it was worth mentioning.

http://www.evanscycles.com/products/charge/whisk-fork-ec025887
Should have read your post properly, sorry.

I thought more rake - and therefore a longer wheelbase - made the steering more sluggish and relaxed.

Even modern "straight" fork will have an offset from the steerer axis to give a suitable amount of trail. Need to draw pics or look online to someone who has pics for trail, but a long rake (more curve or more offset with straight blades) will give LESS trail and hence more rapid handling.

Trail (briefly) is the distance the vertically dropped point of the axle falls behind of the projection of the steering axis, giving self correcting steering- my knowledge is feeble and rusty on this particular matter, check it all!

My understanding is that the association of long curvy forks with lazy handling is because they are required with lazy (touring) angles to bring the trail back to reasonable numbers.

here you go:

http://www.phred.org/~josh/bike/trail.html

...a long rake (more curve or more offset with straight blades) will give LESS trail and hence more rapid handling.

Sorry, meant more RAKE, therefore LESS trail. Thanks. So I had my ideas right and my terminology wrong then...

Trail (briefly) is the distance the vertically dropped point of the axle falls behind of the projection of the steering axis, giving self correcting steering- my knowledge is feeble and rusty on this particular matter, check it all!

My understanding is that the association of long curvy forks with lazy handling is because they are required with lazy (touring) angles to bring the trail back to reasonable numbers.

What I would normally do with lazy steering is just cant the bike over harder between my knees and freewheel through the corner with the bike sitting much flatter to the road than my body and one foot down. A little like this:

But I can't do that anymore since I started riding the bike fixed, which is why I want to try to fix this handling issue.

So has anyone tried this to sharpen up the handling of a lazy bike like this? Given that it'll increase the wheelbase as well, what else will that do to the feel of the bike? If it turns more sharply but on a slightly longer wheelbase, am I likely to end up back where I started in terms of the cornering?

And when you have all the figures, you can confuse yourself further with this lovely link;

http://yojimg.net/bike/web_tools/trailcalc.php

Here, http://www.cyclingweekly.co.uk/tech/bikes/24128/2/fixed-bikes.html , it says your fork rake is 43mm, and "rake" is "offset";

"Rake

The "rake" or "offset" of a fork is the distance between the wheel axle and the extension of the steering axis. This may be accomplished by bending the fork blades, or by attaching the fork ends to the front of the blades, or by tilting the blades where they attach to the crown.
Rake is one of the three factors that affect the trail of the bicycle, which has a considerable influence on the handling qualities.

A fork which is curved forward at the bottom also adds a small degree of suspension compared with one that is not, by acting as a leaf spring. "

Lifted from Sheldon Brown^^

TB, if you get the answers, could you put it into english, for the sake of all.

Seeing that the wheelbase will only change by a few mm's it should not be noticeable (moving the rear wheel in the track end can have a larger effect and do you notice that?)
You may not notice the rake increase either though and that is assuming your new fork has a larger rake, do you know what the charge fork rake is as the Plug forks always look like they have a fair amount of rake to me?.
Just read the above and if your fork is 43mm that is very average so getting something noticeably bigger is not going to give you many choices.

I have changed rake by over 5mm and not really noticed that much difference so would not be a concern for me.

Thank 36x18.

I think I understand the theory - but theories and practice are often different things. That's why that myth about trail and handling came about, from a misunderstanding about having to lift the weight of the wheel if you had more rake, that was first published in something like the 1930s I think.

The way I see it, if you take my query to an extreme analogy - suppose you had a stretch limo, it might have very sharp steering for jinking around a pothole, but it's still going to corner like a whale.

Now ok, that's my question taken to an extreme, but you take my point. I might get sharper handling if I put more angled forks on, for stuff like going wiggle-wiggle (that's the technical term BTW) and jinking around a chunk of glass on the floor, but will the extra length then increase my cornering circle? So I may improve the sharpness of the handling, but still end up with pretty much the same wide cornering in practice.

TBH, if nobody has practical experience of doing it, I'll just change the forks to see and post it back up here. I'm just loathed to waste money and time if someone already knows the answer. No sense in making your own mistakes to learn by if someone else already did it...

@kerley The article above lists the head angle at 71 degrees, but that's for the medium size Plug frame. The large frame is 73 degrees.

Using the deeply unscientific method of "a piece of stick", I reckon my trail is somewhere in the region of 100-105mm!! WTF!! I believe that what's considered to be "neutral" steering is something like 57mm. So if my stick is even vaguely accurate, that would explain my problem. Trouble is, Charge don't seem to publish the rake of their forks, so I can't do any accurate maths.

Hi

Daft question from a newbie

Is there such a thing as silver weave carbon forks?

Cheers

Harpy