277 replies to this topic

[Les Boyd]

Maybe a new class say with no fronts and a Hawk 6. Now what body to run?

Sounds like a well-designed chassis... JK has done a very good job!

[smokie]

Try a O/S COT or JK Toyota.

[Mach9]

Nice -ooking chassis.

 

Just a quick question. Are track owners really OK with having the bottoms of chassis dragging along their very expensive track surfaces like that? Having owned a track, built a few tracks, and resurfaced others, I wouldn't be cool with it at all.

 

Are a couple of skinny little front wheels really that much of a problem?

[Danny Zona]

The chassis have been rubbing the track for a long time now. At least since '05. I'm not saying it's right or wrong. It's just been going on for a while.

My home track mandates an .050" clearance on the front of chassis. My track has cross-overs though which forces the issue.

[Pablo]

Most race flexis are not nearly as heavy as they were a few years ago.

[MSwiss]

Nice looking chassis. Just a quick question. Are track owners really ok with having the bottoms of chassis dragging along their very expensive track surfaces like that? Having owned a track, built a few tracks, and resurfaced others, I wouldn't be cool with it at all. Are a couple of skinny little front wheels really that much of a problem?

When I finished my King in 2005, I found out about flexis running on the front ears/skids.

They had fronts, but none of the rules required them to touch and roll.

I was less than excited, but quickly got used to it.

Somewhere you have to realize it's a race track, not a mint '64 Shelby Cobra.

I don't think they cause much of a problem.

I'm more worried about guys trying to run with .015" rear clearance.

[Half Fast]

Flexis don't touch on the straights.
 
The stuff you see on the wings is tire schmutz, not track paint.
 
Cheers.

[Ramcatlarry]

Many years ago, a lot of tracks were painted with simple enamels or latex paints. Some clearcoated that with spar varnish. It did scratch and chip - and many more tracks used a lot more glue and solvents than most do today. More tracks have chips from end over end crashes than from chassis scrub - and Teflon pads on the frame tips was a fad for a while. I use rolling wheels for less friction than a sliding frame when I think it is better for me.
 
Most modern track should be painted with the epoxy floor enamels or acrylic epoxy latex(water base). These are harder and more resilient than previous paints.

[Danny Zona]

Don't forget about solder balls on the front ears and Lexan.
 

[MarkH]

Our rules state the front wing bottom edges should be polished to keep them from digging in. We don't care about the "purity" of the chassis as it came out of the bag. It only takes about 20 second or less to use a 400 grit felt bob and clean them up one time. This edge is already rounded from the stamping process on most flexis.

 

I know at least one stamped chassis does not have the rolled or rounded edge on the bottom and can dig in to the track. At least on the example I have.

[Ramcatlarry]

A lot of spring steel frames have tiny holes on the front wings. A pin head out the bottom has been soldered in many of those. All metal frames should be radiused to save the track surface.

[Phil Hackett]

Gator Bob said and submitted to Tim.

 

"Cheetah 2J"

 

No fronts - No backs- No matter.

 

 

That was easy.

 

Another one, newer:

 

[gc4895]

I just received my first new "A" chassis and it's a beauty. 

I checked it on my flat granite block and it's perfectly flat and square. It's my impression from this chassis that JK is committed to producing a quality product and delivering the kind of performance we are all looking for. It's really smart that JK chose to get these manufactured to such high tolerances before releasing them. Well done. 

I hope to get it on the track on Saturday.

[smichslot]

High tolerances?
 
Does that mean a large number?
 
Or do you mean that that the quality is high, indicating that the tolerance can be small, in other words: "low"?
 
Steen

[Pablo]

I'm sure he means "tight tolerances."

[MSwiss]

Agreed.

I never hear tolerances referred to as high or low.

Tight or loose.

[Danny Zona]

Very sweet chassis.

I looked at one at my track last night.

I can't wait to play around with the bite bars. I have a few crazy ideas.

[Pablo]

I got mine today - probably the only one currently in the great state of Mississippi.  

[Tim Neja]

I put one together the other night. I was amazed at how flat and straight it was right out of the package!! Usually I spend an hour straightening a chassis. Looks good - looking forward to seeing how it goes on our flat track!!

[boxerdog]

I can report after one outing that the car I built was very stable and very neutral-handling. Everything was flat and square right out of the bag. Our track owner wants to wait a week or two to legalize it until everyone has a chance to pick one up, so I can't say how it might hold up to the usual race carnage. I made no attempts at tuning and it was at least as fast as anything else I ran last night. I used a Parma Intrepid body, nothing special. 

[MarkH]

I built mine yesterday and raced it today on Slotobahn, 107ft-4 lane club track. You can see it here.

As other have mentioned the chassis was flat. The pan is a little delicate when not in the chassis as most others are. I put a Hawk7 in and compared to my X25 3Pc chassis I normally race with the same gearing. Body = JK Ultimate Peugeot HD with a diaplane. Same body on both chassis during testing.

 

X25 setup ran an 3.71 with 3.76-3.79 being pretty easy, The handling felt good and normal. The rear has good drift and is very easy to drive as expected with the amount of experience I have.

 

JK-A setup. No lead, stock bite bars. The car drove a little different through the center and off the corner. It did not seems to drift out as much which allowed me to throttle off the corner a touch harder. When the car did exceed the threshold of traction it let go real fast. A bit faster than the X25 setup which is easier to see the car is about to go off. Fast time was 3.71 with easy 3.78s.

 

 

Conclusion: The x25 is still a very competitive chassis. The JK-A drives easy enough and is probably a bit smoother though not dramatically. I would feel comfortable racing either in an Enduro but if I were to drive at 97-98% of maximum the JK-A might be easier over the long runs.???

This of course is after just one race where I ran the gutter lanes for 15 minutes each and about 200-250 laps pf testing. So very preliminary for sure.

[gc4895]

Got to test today. Reinforced the tail with 0.055 wire and an excellent Chicagoland guide brace( really love their products). Yanked the ProSlot s16d motor (Chinese arm, only) and tires from my best (fastest) x-25 (0.09 mm thickness) and installed them both into the A.

Track is a swoopy king, recently cleaned and lightly spray glued.

Initial results with a full thickness Koford guide were really fast but complete surprise de-slot, especially at the first turn after the bank and in the dead-man. Replaced the full thickness guide with a Koford cut-down guide effectively lowering the front of the chassis by 10 thou (adjusted for spacers subsequently inserted).

Wow, huge change! (Caution!!!: as always, YMMV! Please don't accuse me of anything subversive. This is my test, done my way. You can and may have a very different experience. May God bless.)


So, with the reduced guide set up I experienced 0.1 to 0.2 (depending on the lane) improved (faster) lap times. As a reference, this is from 4.65 to 4.55, for example. I had, importantly, the same reliability, in terms of staying in the lane confidence (did not de-slot) as with the x-25.

As a control (sort of, since we all know motors are quite fickle and vary to the consternation of all that seek motor "parity", I raced my newly re-motored (same home-built ProSlot s16d set-up, etc.) x-25 on the same lanes. (Also tried to match tire size) The decrease in lap times experienced with the A chassis were confirmed IN MOST CASES. Please note: in some lanes the advantage (reduced times) of the A were a tenth less vs. the c-25 or the x-25 equaled the A times. Was this motor differential or chassis? I can't prove this but my "impression " was that the A car was faster. The A car was clearly faster than the times I had posted previously using the x-25 before swapping the motor and changing tires.

Conclusion: "A" chassis are begging to be modified and played with. The x-25 is wonderful, and quite effective. I made no attempts to play with the bite bars of the A today. Honestly, for our track, I think I would potentially increase the size of the bars (I.e. Less movement). But maybe not both bars, depending on how they respond to changes in one vs. the other.

The great thing about this design is that it is open to your interpretation of what you want in a chassis.

As always, YMMV. I'm just another racer like all of you with no agenda. Well, that is except beating the other guys I race against- of course. Somebody has to win.

[JK Products]

I really like all the positive comments and thanks everyone for trying the Aeolos. We are obviously very excited about it as it tested so well during our development. You always worry that you might be "drinking your own Kool-aid" when you get such overwhelmingly positive in-house test results. It's nice to see our data being confirmed.

 

I'm also glad you can see the manufacturing focus we are putting into all of our products (that's my background and what I really like, I'm much more of an engineer than a marketing or finance guy). Be it the low variability of our motors, or the Super-Flat™ tooling we developed for this very hard steel chassis. We will continue to improve the quality of our products always. We will occasionally miss, but hopefully not often. Thanks again.

[MarkH]

Thanks to you Tim for continuing efforts in this small hobby.

 

You mentioned one thing I forgot to cover. The JK-A chassis is much stronger than the X-25 at least judging by effort to incline the guide tongue. Not sure what the new material or process is on the A chassis. Is the whole chassis being coined to ensure flatness when the rear bump in front of the motor box is being formed?

It would be nice if the guide tongue was stamped at the 2 degree up angle needed when the car is sitting on the rears and guide/braid. Small issue that others may not be concerned with if they are bending the front of the chassis parallel to the track in the ready to race condition.

[Pablo]

It would be nice if the guide tongue was stamped at the 2 degree up angle needed when the car is sitting on the rears and guide/braid.   

Concur 100% - it sure would be nice to not have to tweak it to get it right.

I doubt there are many racers who will run this race chassis level front to rear.

It is very hard to tweak to adjust the tongue to the proper angle without tweaking other things along with it.

 

I got mine the other day and look forward to building it.

The tongue on mine is actually angled down a hair.