Setting the correct ride hight

[juergen_jl]

Hi,

for christmas I got the KF and the AERO. For both cars I tried to build them, following the setup from Tom from his last events. All is /(more or less) fine, beside the ride hight.

He sets up the car at 18mm. The lowest hight in the rear I can "realize" is: 21mm.....

The adjusting collar at the damper is "screwed" at "top position" the spring is RC Core red for the K1 and Black for the KF, both "the long" ones. Pin-hole is low, as in the setup. (for KF I am still using the moulded ones, so no high-low pin-whole..)

Any idea what might be wrong??

[Jsmith]

I might be stating the obvious but you have got electrics and batteries in??

[juergen_jl]

Yes, "all is in" the car. "ready to race". (OK, I could add a few more stickers...)
Even the transponder is in..

How do I measure the hight?
- the car is on the set-up board
- i compress and release it several times
- and then I have a gauge for the hight (5-22mm)
- the measuring point is in the front an in the back "right in the middle" and/or left and right and the rear and front directly behind the wishbones.

I build the shocks with 50% rebound.

The only thing i can imagine is, that the shocks are too long. But the ball studs are build with the "distance" displayed in the manual....

Other ideas? Using pin hole high in the rear?

[tomtom]

I would rework the shocks for 0 rebound.

[Paul Field]

I had this with my car with 0 rebound.
I run with the the shocks mounted at the rear which helps. I also run Core greens front and rear with extra weight on the spine.
But other Schumacher drivers run with the K1 (not Aero) rear shock tower.
This allows a lower ground clearance as the shocks are mounted higher. Good for running indoors. But droop will be less.

I hope this helps

Cheers

Paul

[jonathan may]

were did you get the spine weight to paul

[Paul Field]

I made my own. But Trishbits make one.
There is thread here in this section with details.
Cheers

[juergen_jl]

See, my issues are a bit different. At the moment "carpet racing" is in my mind....

And I want to get these 18mm of ride hight plus an appropriate amount of droop.

This is how it looks, now:
- no spacer in the shocks,
- 30% rebound
- core blue spring, long
- the length of the shocks, red is 96,2mm, even shorter as Tom mentions in his setup-sheet

On one figure you will see the 20mm of ground clearance, position "maximum low" after some "compressions. On the other figure you will see the maximum droop..... 46mm... quite a lot.

so, at the moment I see the following solutions:
- accept as it is
- something is mounted "wrong"
- use the old shock mount, which is "higher", which will reduce the ground clearance by these 2mm
- add a 2mm spacer in the shock to reduce this enormous amour of droop
- "extend" the thread on the piston rod by 1 or 2 mm, and shorten it, then...

Further ideas?

[MattW]

My car is currently in bits, so I can't check anything.

However, there are 2 simple things that you can do.
A) cut some from the lower shock mounting ball gripper - I'd suggest 1-2mm.
B) get some "lower" spring cups - as I said on the other thread, I'm 99% sure that AE B4 ones will do it.

Your suggestions on shock length will make no difference - either with spacers or shaft length will make no difference to ride height, only to droop. Rebound will make no difference either.

[juergen_jl]

Hi Matt,

thx for the answer. I found 2 "ultra short" ball grippers in my box.

BUT!!

Please have a look at the figure......

The mounted ball grippers are already the ultra short ones.. 5,4mm shorter than the standard ones.

--> no result. Or will you even shorten these ones?

The spring cup adds -maybe- 1 mm.... I don`t think, that this will help.

So, for shortening the shock I run out of ideas...

How is Tom getting these 18mm? BTW: it works great with the medium springs.... But then, you have the effect, that the spring becomes loose, when the shock absorber is on full length. So, this is not a result.

You are right, shortening the shaft will primarily reduce droop, not the ride hight.

I will use the pin wholes in "high" position and measure then.

[JustARcFan]

My guess is that your car is too light.

What is the total weight?

[juergen_jl]

1721gr.

But, there is a "shorty conversion" coming soon... And then?

I have mounted the old rear shock mount. With this one 18mm can be realized, because the shock mount is "higher". But I really like the new ones, both, front and rear..... Lower c.o.g and shorter "arms", when it comes to a crash. I have broken some of the shock mounts, front and rear....

Maybe we oversee something obvious.

[JustARcFan]

My car is at 1660gr and I'm at 18mm without a problem with a core green spring.

Do you have rebound in your shocks? What oil?

[JustARcFan]

A shorty is even lighter and will make the car even more front bias so in my opinion not a good idea.

[MattW]

Yeah you have the right parts fitted, I don't understand why you have the issue - although I don't think you are the only person who I've heard say it - another of the team guys I know had the problem - and he just shortened the ball gripper!! Take 1mm off of it, and see how it is.

[phil c]

Just as a thought what tyres are you using ? As proline tyres for example have a higher side wall making the car sit higher ??

[juergen_jl]

Hi Phil,

I am using the Proline 8228 rear and 8227 front on the AERO. (at the moment I am talking about the AERO only, but for the KF I have the same issue).

These tyres are "more or less" the same (by dimension) as the mini pin yellow. It even seems, that they are a bit "more flat" than the mini pins.

See, I am preparing both cars for the EOS round 2 in Berlin on 15.01 - 17.01. And these tyres are "given". As set up for the AERO I am using the setup from Tom of the MCCD christmas race, and for the KF I use the setup sheet from Tom of the EOS round 1.

Today I have no inspiration to work on my cars, but tomorrow I will shorten the ball gripper by another mm. I have measured: the thread on the piston rod is 6mm long, the thread in the gripper can be 7mm.

This is all, what I can do....... Maybe I will add a 2mm spacer in the shock to reduce droop. At least the AERO tend to "grip roll" on the carpet surface (but we cut the outer line of pins rear and the 2 outer lines front, this mostly reduced grip roll).

Maybe I will go for a tool to tap the tread on the pistons by another 2mm and then, shorten them by these 2mm (I dislike to have spacers in the shocks).

Don`t get me wrong, I raced both cars on 27.12 and 28.12 on different surfaces and my son was very, very happy with them. We own the SX, the SXII and the SXIII, but these two new cars are the best to drive directly "out of the box". But these little details will improve satisfaction

As oil i am using the "original" Schumacher oil.

Thx for all suggestions

[juergen_jl]

How does it goes on?

Yesterday I cut the ball gripper by 1 mm. OK, OK.... at the end it was a bit more.

The result looks like:

Today I will do it for the other shock absorber. For me, this is "the maximum" I can do. I will report, about the ride hight, when all is fitted.

As told by Matt, this work won`t change the droop. To "reduce" the droop, I either have to use a spacer in the shock, or to shorten the piston. Using a spacer is WAY easier....

[Hans Wynants]

have u got a result yet on the changes you made ?

grts

[juergen_jl]

Sorry for delay. I have to work, to get the money I am spending for my cars

I treated the other shock in the same way and as a result the ride hight (in full racing "equipment", like Lipo, Transponder...) is now 19mm.

I have no idea how they get these 18mm. Anyway, I did not shorten the shafts. We will do the EOS race next weekend in this trim, and I will have a look at Toms car. Maybe something is built badly.

BTW: I was always talking about the AERO. I have the same issue with the KF. But here, I did not cut the gripper. My son will race the car "as-it-is"