The Pointless Flip

[Harvo]

I think these trucks with stock parts and a few adjustments are great. There is one handling quirk that bugs me though. It might just be in my build but I have seen other XR10's exhibit the same quirks.

Over insignificant sections of rock that you would normaly zip across, or reversing from a gate... sometimes the truck flips over stupidly easily. It looks like a wheel drives up on a rock and then suddenly unloads the opposite corner and flips. (usually its the rear that unloads).

My suspension can't get any softer without taking away from performance and there is NO binding. My shocks don't rebound too quickly either.

I know I could weight the rear wheels and it would help, but is there a trick with the geometry that will lessen this?

I am attributing this quirk to the significantly narrower rear track, which i like... but may get rid of if it corrects the flipping thing. I also blame the narrow rear for how the truck likes to hike up the uphill rear wheel on a steep sidehill.

Any thoughts? Thanks

[dpdsurf]

I know what you're talking about as my truck did this early on. It was almost like a traction twist when the rear was put under any kind of strain. At the time I had Losi grays and the stock 30 or is 35wt all around. I added 65wt to the rear and losi whites. Left stock oil in the front and added losi yellows. This tamed it big time for me. I know shock angles, vehicle weight and link placement could make our trucks handle very different, but if you already have the springs play around with it.

[Harvo]

So you put yellows inthe front and whites in the rear?

I currently have grays in the front and whites in the rear. I may bump up to whites in front and see how that does.

[dpdsurf]

Originally Posted by Harvo

So you put yellows inthe front and whites in the rear?

I currently have grays in the front and whites in the rear. I may bump up to whites in front and see how that does.

Yeah, I felt that with the extra weight in the front a firmer spring in front would slow down the articulation. It seams to have worked.

[sococrawler]

i too had the issue but then went to grey's up front and gold's in the rear and 22 1/2 in the shocks and she's smooth as butter! no pun intended! it's all in how we like our rig's i guess! since i did this i've been in the podium consistenly it feel's like my berg did when i ran it!

[ol' gravy leg]

When I first went narrow and light with my berg, I had this problem. I'm used to it now so it hasn't been an issue. Softer suspension will help. I run golds all around and they are still too stiff imo. My rig performs best when I can push it down on the table and it stays.

[Eritex Inc.]

I had the same issue with my Losi MOA and when I first started driving the XR10 with the narrowed rear. Once I softened the suspension with Losi golds and put wheels on that has the front at 10.875" wide and the rear at 10.4" I found the weird pogo flops and flips stopped.

[Rig Rocker]

I've been trying to tune this problem out too. It just wants to flip instead of dig front in for traction like a berg. It's having a problem "clinging" to verticals because of this. I have tried all combinations of golds, grey's, and white losi springs w/ stock 30wt fluid and best to me so far is grey front w/ white rear.
I think this torque twist like lift might be due to the motors spinning opposite way of a berg. ???

Also, where do the axial and losi springs cross reference?

Are yellows about the same as axial red, ??

[Eritex Inc.]

Originally Posted by Rig Rocker

I've been trying to tune this problem out too. It just wants to flip instead of dig front in for traction like a berg. It's having a problem "clinging" to verticals because of this. I have tried all combinations of golds, grey's, and white losi springs w/ stock 30wt fluid and best to me so far is grey front w/ white rear.
I think this torque twist like lift might be due to the motors spinning opposite way of a berg. ???

Also, where do the axial and losi springs cross reference?

Are yellows about the same as axial red, ??

Axial
http://www.axialracing.com/ftp/ax10o...0_springs.html

Losi
http://www.teamlosi.ru/techtips/spring_chart.htm

...and the Losi golds are 1.4 pound rate

[Rig Rocker]

Thanks Eritex

The axial link is wrong though. i couldn't find the comp springs anywhere on their website either, even by part#.

But here are the axial rates for 14x70mm springs that I did finally find on a spare parts sheet for the 72-103mm comp shocks

Red = 2.07 lbs
White = 2.47 lbs
green = 2.85 lbs
blue = 3.55 lbs

So I will try the red up front since I don't have losi yellows

[Harvo]

Originally Posted by Eritex Inc.

I had the same issue with my Losi MOA and when I first started driving the XR10 with the narrowed rear. Once I softened the suspension with Losi golds and put wheels on that has the front at 10.875" wide and the rear at 10.4" I found the weird pogo flops and flips stopped.

What I noticed about Losi springs on these shocks is that to get the golds to hold up the truck you have to crank up the preload... then it seems too stiff. The whites and grays obviously start out stiffer, but don't feel as stiff because you can use less preload. At least that is what it seems like to me.

I tried golds, but to make them feel good I had some considerable suspension sag that didn't feel right on this truck. Are you running them with sag or more preload?

I also widened the rear yesterday and it felt much better .

[Harvo]

Originally Posted by sococrawler

22 1/2 in the shocks

22 1/2 what?

thanks.

[ol' gravy leg]

Originally Posted by Harvo

22 1/2 what?

thanks.

shock oil

[The Violator]

So is this an unloading issue? Heavier oil and a lighter spring would seem to slow things down. BUT, is it aggravated by the width difference from the front to back. I am just trying to wrap my head around the theory behind this phenomenon.

[dirk379]

Harvo, do you think the steering has anything to do with it? I am noticing all sorts of weird quarks that come with the off set c's/knuckles. Normally on my berg in situations where i could settle the rig with the steering, i have not been able to do as successfully with the xr10. Sometimes i will even end up flopping onto the face of the front wheel, almost like it steers its self under the rig, i don't know, hard to explain.

[Eritex Inc.]

Originally Posted by Rig Rocker

Thanks Eritex

The axial link is wrong though. i couldn't find the comp springs anywhere on their website either, even by part#.

There is a chart under the picture showing the rates for the 14 x 90mm springs.

Originally Posted by Harvo

What I noticed about Losi springs on these shocks is that to get the golds to hold up the truck you have to crank up the preload... then it seems too stiff. The whites and grays obviously start out stiffer, but don't feel as stiff because you can use less preload. At least that is what it seems like to me.

I tried golds, but to make them feel good I had some considerable suspension sag that didn't feel right on this truck. Are you running them with sag or more preload?

I also widened the rear yesterday and it felt much better .

I have about .100 of preload on each gold spring and it feels great to me. Preload does not effect the stiffness of the spring unless it is a progressive spring which the Losi's I am using are not. Preload simply adjusts ride height.

[Harvo]

Originally Posted by dirk379

Harvo, do you think the steering has anything to do with it? I am noticing all sorts of weird quarks that come with the off set c's/knuckles. Normally on my berg in situations where i could settle the rig with the steering, i have not been able to do as successfully with the xr10. Sometimes i will even end up flopping onto the face of the front wheel, almost like it steers its self under the rig, i don't know, hard to explain.

Yes! Steering its self under is a good way to describe the other quirk I can't figure out. Put the two issues together on a sidehill and it makes for a very unstable "feel".

[dirk379]

Originally Posted by Harvo

Yes! Steering its self under is a good way to describe the other quirk I can't figure out. Put the two issues together on a sidehill and it makes for a very unstable "feel".

I agree. So i just did a change that helped out the issue. I'm not sure which position your c's are in, mine were previously clocked all the way back. I just moved them up to the middle position, ran for about 15 min and found it helped out with the steering pushing the outside of the wheel into the ground and under the rig issue. On a side hill before, driving straight, and turning up the hill, the inside of the tire would lift off, and the outside edge would push into the rock (best way i can describe it) which if you weren't careful, could cause you to lose your grip, with the c's in the middle position, it mellowed out the arcness of the steering. Just my thoughts...

[EeePee]

Interesting. I wonder if it's that kingpin inclination...

[RcBro]

I have found that when you have a softer spring that cannot hold the rig up, I'll add just alittle more preload to make up the difference, this so far hasn't negatively affected my rig from what I've seen as as mentioned it is used to adjust ride height which I learned alot from on onroad racing. I do the opposite when running a stiffer spring by removing the pre-load. Some pateince and a caliper will get each side near identical.

Most forget to try experimenting with preload adjustments before trying different springs, ride heights can do wonders to rigs.