rake angle alteration

[Little Rich]

Im pushing my forks up through the yokes a bit tomorrow and and not sure how far to go to get the right reaction. Has anyone else had a go and if so how far did you dare go? Im considering 20mm.

[21QUEST]

Im pushing my forks up through the yokes a bit tomorrow and and not sure how far to go to get the right reaction. Has anyone else had a go and if so how far did you dare go? Im considering 20mm.

Generally consensus is that on the curvy the most you can safely go(not measuring the fork caps) before bits you'd rather not, become intimate with one another on fully compression is 12mm-15mm. Without have checked it myself I'll say maximum of 12mm.

Easy to check yourself. by lifting front end up, undo the fork caps and slowly lower bike down till fork bottoms out. The distance between the dust seal and the bottom yoke is what you have available to play with assumming other parts that shouldn't be are not touching one another.

Cheers
Ben

[Little Rich]

Cheers Ben that is an awesome reply, Ill do what you recommend and will post my final dimension on this thread once is it tried and tested.

Thanks again,
Rich

[21QUEST]

As an aside why do feel the need to push the forks through the yokes? Having problems with way the bike turns etc?

Remember as standard the Curvy 'S' model should have the forks flush with the yokes(not measuring the fork caps). 20mm(which in anycase as said in other post is possibly dangerous) IMO is a lot especially if you are planning on doing it in one go.


I'll say, start with 5mm nad see how that feels.

Cheers
Ben

[Little Rich]

Im overhauling my handling at present, ive just fitted a set of diablo corsa pros and some hagon progressive fork springs.

In answer to your question im trying to increase the rake angle by recommendation of his royal highness Ron Haslam!

[BILLY]

Try shorter dog bones they will raise the back up by 25mm and give you a steeper steering angle!!!

[falc]

10mm at the front is good drop and with shorter dog bones as Billy says will lift the rear up giving a much more **** up head down position.

[Biker Biggles]

Might be an idea to fit a steering damper if you are trying to add as much rake as that.Small changes to the geometry can make quite a bit of difference.

[northwind]

10mm down on an SV shouldn't need that, generally, unless you're already marginal.

[jambo]

As above, we dropped a K5 SV650S down by 20mm to try and get the bike lowered with the dog bones as well and this was too much, the dust seals were toutching the bottom yoke. If you're not sure how much you've got left put a cable tie around the fork stanction and pull it down to the level of a dust seal, go out for a ride and when you come in the gap between the lower edge of the cable tie and the bottom of the bottom yoke is the clearance. This assumes you have bottomed the forks out at some point.

21Quest's suggestion bypasses such guesswork though :wink:

[21QUEST]

Might be an idea to fit a steering damper if you are trying to add as much rake as that.Small changes to the geometry can make quite a bit of difference.

A steering damper more than likely won't be needed but still I agree with BB. hence I asked why you felt you needed it.

Little Rich, It's not a case of saying, you are over hauling your suspension as there is really not set setup. You have to isolate what the problem is you are having or what you are trying to achieve. Riding style would also plays a big part in how the bike will feel or react with changes. Another reason why best to know if at all possible what you intend to achieve then go at it in little steps.

Those tyre you have one are super sticky stuff right. I can't help thinking may be a bit much with the weather getting colder.

Take Northy and probably a few others bike out here. I'll probably couldn't ride them as they'll just be too much ass-up for my the way I ride. I prefer my bike flatter to most. Maybe I'm just slow :( :) .

You said as recommened by Ron Halam. Who is this guy? Never heard of him. Does he have an SV. Oh... and if he said to raise the forks through the yokes to increase the rake angle, he is definitely a cowboy :wink:



Cheers
Ben

















:lol: :lol: @ Ron bit

[northwind]

Take Northy and probably a few others bike out here. I'll probably couldn't ride them as they'll just be too much ass-up for my the way I ride. I prefer my bike flatter to most. Maybe I'm just slow :( :) .


Troo dat, mine's a bit exaggerated :) Works for me but I'm sure it wouldn't for everyone. No way would I try it with stock suspension though.

Ron Haslam, renowned for racing raked-out choppers apparently ;)

[Little Rich]

So many questions! I rode an "ass up" bike a few months ago and loved it and am preparing the bike for a run what you brung at three sisters which is a outdoor kart track, so short streights and loads if tight corners. That is incedentaly why I have fitted a chain/sprocket set thats -1 tooth on the front and +3 on the back.

As for that cowboy look about half way down the page on http://therealdaruna.spaces.live.com/ and you will see who he is!

The truth is ive asked the a few tradespeople about it ie JHS, my local mechanic, ron haslam and JHS off the top of my head, was just interested to see what regular SV riders thought about the idea and got some fantastic information so thanks all again.

Rich

and northy your sv looks awesome

[weazelz]

~10mm drop with 120x70 front supercorsa works for me

[RandyO]

how does raising or lowering the forks change the rake angle ?

I agree that it changes the trail, but not the rake angle

[vulcan666]

how does raising or lowering the forks change the rake angle ?

I agree that it changes the trail, but not the rake angle

Figuring this stuff out, it helps to go to extremes. Imagine you pushed the forks up 50 cm. The front wheel would lift 50 cm off the ground. The bike would tip forward, down until the wheel contacted the ground. Clearly this would reduce the rake angle.

You can also picture it by imagining the opposite and exaggerating. If you dropped the forks down 50 cm (of course you'd have to lengthen them), what would you have? A chopper; the whole bike would lean back and your rake angle would be larger.

Since you're only talking about 5 to 20 mm, it's not going to be a major angle change, but as someone else posted, subtle changes in geometry can have pretty large effects.

[RandyO]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

[northwind]

Rake, by every definition I've known, is the angle in degrees of the fork (or stem, depending on what you're measuring) from vertical.

[vulcan666]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

Like northwind said, rake is angle of forks off vertical. That's why I was describing the effect as tipping the whole bike up or down... As you correctly point out, raising and lowering the forks won't change the angle of the forks to the rest of the bike. But if the bike's front end tips up or down, by definition that will change the angle of the forks to the ground, and therefore the rake.

[weazelz]

http://en.wikipedia.org/wiki/Rake_and_trail

[21QUEST]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

[TSM]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

Unless you get some Spondon adjustable yokes.

[21QUEST]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

Unless you get some Spondon adjustable yokes.

To do what? Adjustable yokes won't change the steering head angle.

Cheers
Ben

[TSM]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

Unless you get some Spondon adjustable yokes.

To do what? Adjustable yokes won't change the steering head angle.

Cheers
Ben

Err yes it will, they have some yokes where the top part of the yoke can be moved forward and backwards to change the angle, there is another set of yokes where there is a rotating adjustment on the yoke stem and it can be changed.

Err have a look at these harris ones http://www.harris-performance.com/website/acatalog/Online_Catalog_Harris_CNC_Machined_Yokes_10.html

[21QUEST]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

Unless you get some Spondon adjustable yokes.

To do what? Adjustable yokes won't change the steering head angle.

Cheers
Ben

Err yes it will, they have some yokes where the top part of the yoke can be moved forward and backwards to change the angle, there is another set of yokes where there is a rotating adjustment on the yoke stem and it can be changed.

Err have a look at these harris ones http://www.harris-performance.com/website/acatalog/Online_Catalog_Harris_CNC_Machined_Yokes_10.html

Wrong again :P :wink:

What adjustable yokes do is change the yoke offset which in turn changes the trail. means you can vary the trail for rider feedback, turn-in etc without effecting stuff like rake, swinging arm angle etc.

Cheers
Ben

[northwind]

You could fit different bearings in some sort of spacer arrangement, with a smaller stem...

[TSM]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

Unless you get some Spondon adjustable yokes.

To do what? Adjustable yokes won't change the steering head angle.

Cheers
Ben

Err yes it will, they have some yokes where the top part of the yoke can be moved forward and backwards to change the angle, there is another set of yokes where there is a rotating adjustment on the yoke stem and it can be changed.

Err have a look at these harris ones http://www.harris-performance.com/website/acatalog/Online_Catalog_Harris_CNC_Machined_Yokes_10.html

Wrong again :P :wink:

What adjustable yokes do is change the yoke offset which in turn changes the trail. means you can vary the trail for rider feedback, turn-in etc without effecting stuff like rake, swinging arm angle etc.

Cheers
Ben

Ok, you can still do it but they might be called "Raked Triple Trees", they still come under the guise of Adjustable Yokes, just harris dont have them on their site.

[21QUEST]

that sounds like changing the trail to me

to change the rake, you would have to change the angle of the steering head,

raise or lower that front end as much as you want, the angle of the forks to the rear axle stays the same

The angle of the steering head is not adjustable(correct) but Raising or lowering the front/rear changes the rake angle and therefore we have effective changed the angle of steering head which in turn changes the trail. The important word being effectively.

Cheers
Ben

Unless you get some Spondon adjustable yokes.

To do what? Adjustable yokes won't change the steering head angle.

Cheers
Ben

Err yes it will, they have some yokes where the top part of the yoke can be moved forward and backwards to change the angle, there is another set of yokes where there is a rotating adjustment on the yoke stem and it can be changed.

Err have a look at these harris ones http://www.harris-performance.com/website/acatalog/Online_Catalog_Harris_CNC_Machined_Yokes_10.html

Wrong again :P :wink:

What adjustable yokes do is change the yoke offset which in turn changes the trail. means you can vary the trail for rider feedback, turn-in etc without effecting stuff like rake, swinging arm angle etc.

Cheers
Ben

Ok, you can still do it but they might be called "Raked Triple Trees", they still come under the guise of Adjustable Yokes, just harris dont have them on their site.

I know what you mean but that is not adjustable yokes as we know it :wink: . Harris won't do them as they do stuff main for proper bike innit
:lol:

Those things only worth mentioning if you start talking about choppers and the like and even then if my memory serves me right most builders there are questions about forces acting through said yokes.

You could also in theory change rake angle by boring the holes in yokes for the forks at an angle and infact think of it one or two manufactures have done that.

So all told except you like choppers etc/have a bike with adjustable steering head you won't be getting any yokes of the shelf to change the rake angle. The only other way is to raise or lower the bike.

Cheers
Ben

[Little Rich]

OMG I have never seen so much quoting! :)

Anyway! I went for 20mm and took the bike for a spin earlier, I tried jabbing the breaks and feeling for some kind of metal to metal contact or anything out of the ordinary and all seems well.

Early indications for me are a fantastic improvement but I would expect that given ive jus fitted decent rubber, progressive springs and stiffened up the back. Im going to Skelmersdale tommorrow (it has no traffic lights and tons of big roundabouts) and im really gonna give it some and see how it performs, that said I can already tell it is an improvement and ill never change any of it back so im made up!

It is rake by the way :twisted:

[northwind]

I'm not going to swear by this, but I'm about 90% sure that 20mm will allow hard impacts on full compression- braking's not a very good test of that, since even with squishy SV forks you get bigger compression on impact. Go and nail it over some speedbumps, see what happens :wink:

[Little Rich]

You nutter! you can bang any bike off the stoppers on speed bumps if you try!(memories of a scooter on holiday come to mind)

Im going out for a proper ride tomorrow so well see what happens. Perhaps I should have bought crash bobbins first. :P

[northwind]

Aye, but there's a difference between bottoming out the forks and driving the sliders and seals into the yokes ;)

The best test, was to compress the forks when the springs were out. My specialist subject? Pointing things out too late...

[Little Rich]

Naa you rightfully told me that before I had it done but the chap who did it for me assures me "it'l be reet that lad" so we will just have to see! And if it all goes tits up Ill let you be the first to assume sagelike status and say those age old words,

I TOLD YOU SO! :smt075

[Graham]

I can only raise the staunchions on my 2000 curvy by 5 mm before the sliders can hit the triple clamps. 20mm could be lethal, or at the least very painfull

[21QUEST]

WAIT!!! DANGER :!:

Okay now I've got your attention :).

Maybe I'm overreacting but reading you last few posts gave me goose bumbs. I would suggest you take another look at what people are saying regarding going 20mm (just on safety aspects if nothing else). It won't be a good thing for you to suddenly have no suspension under say hard braking. If one is unlucky, they may not have the chance to make a diffferent decision.

Now I don't know the guy who has done it and who has assured you that it'll be alright but not a lot of places would even recommend pushing the forks through that much in one go. Did the guy check to make sure by taking the caps off?

I'll say this I've got a really bad feeling in my bones about all this but sincerely hope I'm wrong. Hope all goes well.


Cheers
Ben

[Little Rich]

Right! I have been out and thouroughly hammered the bike all over the place in a quest to discover the handling improvements of my bike. So...

First of all accellerating in a streight line is much better than stock thanks to stiffer setting on the rear shock and the different size chain and sprocket kit.

On tight corners I have noticed a great improvement. This is due to the settings of the front and rear shocks, the fancy fork springs/oil and the ubersticky tyres that are fitted. My definition of great improvement here is that I find it much much easier to get round tight corners quickly.

Medium/fast corners. Nothing amazing here just a greater sense of control and feedback. And strangely an improved sense of stability.

the greatest improvement is chicanes, in which I was able to move the bike much quicker. Its great fun and quite a buzz to be able to ride an SV like that.

The only downer Ive noticed are that I manageged to lock the back wheel up yesterday on a down change in the wet. A slipper clutch would fix this but at £500 a shot plus fitting I have decided to be more careful of my downchanges.

Note: At no point during my ride today did I manage to bang the forks off of the yokes, which leads me to the conclusion that cronic obesity is rife within our community. :P
Just kiddin!

[arenalife]

When setting up forks, it's handy to put a cable tie around the fork leg, this will get pushed up during riding, then you can monitor the fork travel.

[northwind]

First of all accellerating in a streight line is much better than stock thanks to stiffer setting on the rear shock

I still reckon you should reduce the drop on the front, but that's your call. But with the rear, don't mix up the preload adjustment with stiffening the rear, they're very different. Preload is purely for setting up sag- making sure that the bike uses the right amount of suspension just to carry its weight and yours, basically. If you turn up the preload, the spring actually remains exactly as stiff. It can trick you into thinking it's stiffer, because when you climb on it doesn't sink as much- this is just because it's "pre-sunk", if you like. Having too little sag on the rear can cause bad roadholding problems...

Or, maybe you've got it spot on, don't know ;)

[21QUEST]

I still reckon you should reduce the drop on the front, but that's your call.

very true that.


Ok I'm going to do this one last time. I've checked some figures and 20mm definitely too much on the 'S'.

On my naked bike I've got 10mm before the dust seal contacts the bottom yoke. That's with the forks 9mm through the yokes.

It may appear from what I've just said that you are not too far off but lets say the top yoke from the 'N' and 'S' have further differences apart from the very obvious.

Carry on riding as you have it you will crash if you ever ride hard enough to use almost all of your available suspension stroke(as you should) as some point.
Best of luck


Cheers
Ben

[jamesobrady]

Hi all....been reading this thread with interest.....a few points if i may.... feel free to flame me :)

Firstly....dropping the forks, as we know, will quicken your steering.....but it will also make your bike less stable at speed....what makes a front end sort out a tankslapper on its own is rake,trail and castor.... now, dropping the forks lessens rake, lessens trail, and makes castor less effective at sorting out a slapper. hence as someone pointed out, a steering damper might not be a bad investment as "oh ****" insurance.

Think a shopping trolley.....its easier to steer by pushing from behind than it is to stand on it and propel yourself with one leg....same stuff only different shape.

AS for the whole changing all the suspension and dropping your forks..... well and good...all things to do to improve handling and steering etc....but, you really should do one thing at a time, run with it, get a feel for the changes you've made, alter something else once you have a new "bottom line"...get a feel for the new change, see how it suits you, change something else......etc... Progressively is the word.

Its up to yourself man...tis your bike and your money. My own feeling is that id like to learn little by little and at the end of it know how each change ties in with the other.... how it may work against some other aspect and how it may improve in conjunction with another adjustment.

As for it not bottoming out.....thats not the main point....you could in theory stiffen it up so much that even with 5mm travel it doesnt bottom out.....think race/drift cars and hard suspension....very little travel, but no bottoming out. Thats no use on a bike....you need a range of USEABLE suspension and not just a simpleup and down either.....not just to make sure its not bottoming out. Hence you need to look at static sag etc and get it setup by someone who knows what they're doing.... if you've done that then great....if you havent then you need to be looking at the guy who has adjusted your suspension and realise he hasn't done the most basic of checks for you.

The only other thing i can think to point out is "lateral suspension" as such.
When you go into a corner, the more you lean over the less your forks work as suspension, and the more the actual forks and frame/yoke/steering head etc take up the forces. Basically, a bikes frame has to have a degree of flexibility to allow this flexing,else every small bump you hit in a tight/low corner would sent you lowsiding front first.

You may recall one of the race teams this season making small cuts on a bikes frame with a hacksaw to help de-stiffen the frame for cornering...?
The point? Shortening the forks puts more emphasis on the frame taking the loads during fast cornering, not to say anything will break, but the bike being a budget bike would be less stable, less comfortable, and may tank slapper or lowside easier...especially with very stiff suspension.

Bottom line? If you really want good adjustable suspension....put a gsxr front on it.....much less hassle, and much more worthwhile/upgradeable in the long run.

And aside from all that.....enjoy yourself :) but do realise that nobody here is intending to lecture...just help..... in much the same way that if someone posted "im removing a front brake caliper to save weight seeing as i use mostly engine braking anyway,what you guys think?" would be advised in the name of safety why it may not be a good idea !

Safety over function over style...........

[Little Rich]

Well you sound very knowledgable on the subject and even though I havent had any problems riding Im going to heed your words and visit maxton. Ill also get a damper and tell the wife you told me to so be warned! :P

Honestly though I hammered it yesterday as hard as ever, round bumpy roundabouts and down some pot hole ridden roads and all was well, but you seem so sure of impending death Im starting to worry just a bit.

Anyways heartfelt thanks for taking the time to research and discuss this subjct for me,

Rich

[Razor]

Why not just space the clip ons lower? A hollow spacer and longer bolt to accomodate the lower postion on the fork leg. Get you that bum in the air position you're after.

I went the dog bones route, for the record :wink:

[Little Rich]

Cos i want the bike And me to be ass up not just me. :P

I might get dog bones yet but havent made my mind up...