Evo- front wheel liftoff

[bichinbrasilian]

Hey,

I'm pretty new to DH and I've been working on my DH setup :

I have a 2009 Evo with Purple 4 otangs and bear grizzlies.

i just put some venoms on it to try and fix my problem but to no avail.

whenever i lean on the board the front wheel tends to lift off . (i dont think this is a good thing....)

Right now i want to be able to carve a bit to control some speed yet im afraid this might bite me in the ass...

also my back wheels seems to drift out a bit on hard turns.

i have no wedged risers on it and im running with stock grizzlies. venom elim red boardside and green barrels roadside.

im basically broke right now (who isnt) and cant afford new trucks, i do have a set of 180 50s randalls lying around though.

i tried loosening the bears yet im running out of kingpin room....


any suggestions? thanks.

[CasterTown]

This happens because the dewedge in the back gives you much better leverage over the rear truck. You can balance it out by running harder bushings in the back. It should not be a problem though once you get up to speed.

[Old Guy]

This happens because the dewedge in the back gives you much better leverage over the rear truck.

It does? I thought the opposite was true.

[xjweezyx]

It does? I thought the opposite was true.

i think because the dewedging makes it lower(closer to the foot platform) and that is why you have superior leverage. i think your thinking of turning ability. you can have surpierior leverage and a bigger turning radius. correct me if i am wrong

[Old Guy]

According to the Randal website ( Randal Skateboard Trucks - General Truck FAQ ), dewedging makes your trucks turn less. Is that not analogous to, or because of, having less leverage over them?

[Bookworm]

I loled so hard at this thread.

Alright.

The evo nose is wedged. The difference between a wedged truck and a higher degree baseplate is the pivot, on a highly wedged truck the front wheel will have a tendency to "lift" since it's no longer sweeping side to side but now has an "up" component.

on an evo, the tail is dewedged, causing it to lean a lot farther relative to the amount of sweep. This means that the tail is ALWAYS "drifting" since it's not pivoting in line with the front truck. Only symmetrical setups can have "no" drift. The back wheels have to have sideways slip in order to track properly behind the front. This does make for a very nice and predictable setup.

basically, you are experiencing the same thing as every other evo owner.

You have one of the winningest boards in downhill, enjoy it, but get some crails.

[SteveC]

sigh...



Split-axis boards simply no longer turn about their centre, they rotate around a point that's closer to the tail.
(where a line through the axles cross)
if they were drifting all the time evo's and 99% of slalom boards would be slow as mud.

A low-axis truck loses less force to pushing the axle inwards, it simply leans.

a 0° truck loses no energy to turning
a 90° one loses all of it - and can not be moved by the board.

[CasterTown]

It does? I thought the opposite was true.

Dewedging gives you more leverage. Not more turn. For example, a 90a bushing in a 50 degree truck will feel much harder than a 90a bushing in a 20 degree truck despite the fact that the 20 degree truck turns much less. I'm talking specifically about how easy it is to physically lean the board whether that translates into turn or not. That has nothing to do with it.

[SteveC]

This thread has a good name so I'm going to attempt to put a good answer here.

Evos are +14 -16.


They turn about +15 -15 when you stand on them - depending on board-age and weight
There's a good argument this makes high-axis trucks start misbehaving, it's certainly borderline at 65°. The further above 45° you go the more vibration, bumps, rocks etc get turned into steering.

Dewedge, or run a lower pivot-axis front truck. (Rdh/JimZ, the prominent trucks from the era, both 35° - end up the very classic and very tasty 50&#176
42° trucks make for a quite responsive nose (57&#176, and can be turned down without gaining much height, which isn't inherently a bad thing either.


Then we come to the tail -
The board is built around slalom theory, and is, in an odd way, a big - low - slalom board.
You really can pick whatever you like here, just be aware of what it's doing.
28=13° 35=20° 42=27° 50=35° 60=45°

Well, the lower this number, the less steering created by the tail...
This can have a significant effect on turn radius, and on how you need to run it's bushings.

With a large gap between the pivot-axis, say 50/20 the larger the difference between the bushing's needs to be in order for the wheels to be driven at the road at the same rate.

The practical way to test this out is to drive one rail town with your toes, if the nose wheel lifts - it needs a tighter tail, or a looser nose, or a bit of both.
Ultimately you run a harder bushing in the tail, or a softer in the front, but you can usually get it sweet with decent bushings and a bit of testing.

[Old Guy]

Dewedging gives you more leverage. Not more turn. For example, a 90a bushing in a 50 degree truck will feel much harder than a 90a bushing in a 20 degree truck despite the fact that the 20 degree truck turns much less. I'm talking specifically about how easy it is to physically lean the board whether that translates into turn or not. That has nothing to do with it.

Dewedging isn't the same as a 20* versus a 50* truck because the angle of the entire truck relative to the plane of the deck changes rather than the angle of the hanger relative to the baseplate. I'm just having a hard time understanding how more leverage isn't going to mean more turn if all other factors, such as baseplate angle, bushing durometer, and truck tightness are the same.

[NC longboarder]

my board does the samething. when your going faster it doesnt happen.

[SteveC]

Dewedging isn't the same as a 20* versus a 50* truck because the angle of the entire truck relative to the plane of the deck changes rather than the angle of the hanger relative to the baseplate. I'm just having a hard time understanding how more leverage isn't going to mean more turn if all other factors, such as baseplate angle, bushing durometer, and truck tightness are the same.

what?

the baseplate-riser-board - is all bolted together.
how it gets the hanger to a given angle is irrelevant to how much it will turn.


of course more leverage will lean a board over further if all other factors are identical.
assuming it doesn't bind and lift. given this, it will turn more.
I think there's a missed point here somewhere

[AJ]

it happens when you stand on your skateboard motionless at full lean.
It doesnt happen skateboarding downhill.

[Old Guy]

what?

the baseplate-riser-board - is all bolted together.
how it gets the hanger to a given angle is irrelevant to how much it will turn.


of course more leverage will lean a board over further if all other factors are identical.
assuming it doesn't bind and lift. given this, it will turn more.
I think there's a missed point here somewhere

I realize that it all functions as a unit. I'm not sure how to explain my point more clearly - that's not a jab at you; the fault could be mine. I'm not sure, though, that I agree with your statement, "how it gets the hanger to a given angle is irrelevant to how much it will turn." I could be wrong there, too; I'm certainly no engineer.

Edit: Whether I'm right or wrong, this debate does little to help the OP; I think A.J.'s advice is right on, so let's stop straining out gnats.

[rodgon]

evos need a waaaay lower degree angle truck baseplate in the front in order to feel good.

50* makes it 65* which is waaaaaaay too much steering. get a 35* basplate for 12$ and use that instead ( using the randal trucks you have).

the back one at 50* makes it 35* which is fine for higher speeds, but with the correct bushing setup and the fixed front it makes for a nice carver at low speeds too.

i personally have mine with a 42* front dewedged 7* since the 42* hanger behaves better with the 180 hangers IMO and it runs like a dream at low speeds with softer bushings and harder bushings for really high speeds.

CASE IN POINT:
get a lower baseplate front.

[SteveC]

[bichinbrasilian]

ah, thanks for the help guys.

the weathers been all rain this week, so i havent been able to test it out.