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Adjustable front axle tips

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  • Adjustable front axle tips

    Hi Group,

    Their are some manufacturers/cars that have an adjustable front axle height. Is there a book or something that will tell me how, how much and other information needed to do it? I have a couple of cars that have the adjustable front axle but I never mess with it and just leave it as it was shipped from the factory. Also there are guys that shim up there axles by 2mm by using plastic tubing underneath the axle.

    Can someone help or provide guideance?



  • #2
    I have not seen a tutorial for setting up a front end on this forum yet.
    I know when I first was learning how to setup a slotcar, this is the information which would have help me understand the concept better. You will get many different answers to this question. And often it depends on the type of track you are setting your car up for. I will explain how I set a car up for racing on wood or smooth(think carrera or scalextric) plastic track.
    There are basically two camps when it comes to front end setup, those who use a 3 point setup(guide riders), and those who use 4/5 point setup(wheels planted firmly on the track supporting the weight of the car).
    The 3 point setup is geared more towards 1/24 scale cars which use foam tires and glue for traction. It allows the inside rear tire to lift in a corner bleeding off traction, allowing the car to slide. It is also used effectively racing on Ninco track which is not only rough, but very undulated and bumpy. My gues is it allows the car to absorb the bumps better without upsetting the balance of the car.
    The 4/5 point setup promotes maximum grip by maintaining contact of both rear wheels with the track surface at all times. It is the best setup for a smooth track eg; wood and carrera or scalextric sport.
    The concept of the 4/5 point setup is, during cornering, while the weight shifts towards the outside of the car, the front tires prevent the car from tipping far enough to lift the inside rear wheel maintaining traction and giving more predictable overall handling. I also feel cars which ride on the fron wheels instead of the guide have less folling resistance from the front end also maintaining rear end traction. The differnce between a 4 and a 5 point setup is, the five point setup places all four tires AND the guide on the same plane, the 4 point setup allows the guide to sit just above the plane of the four tires. There is very little differnce to setting up a 4 or 5 point setup other than the amount of clearance under the guide. If you are racing on a wood track and use a flat setup block to setup the car with a 5 point setup, due to the fact that the braid on wood tracks is slightly recessed, you infact will have a 4 point setup on the track.
    The following is a brief tutorial of how I setup my cars:

    Start with the body off of the chassis with the braidscompletely flat agaisnt the guide (you dont want the braid holding up the front end).
    • Step 1: Back-off all four set screws so they are not touching the axle with the car resting on the setup block.
    • Step 2:tighten the upper set screw on one side until it touches the axle with the car resting on the setup block. As you tighten the screw, tap on top of the axle block to see if it is resting on the axle. It will feel solid when you tap on it with no 'clicking sound' when it is resting firmly on the axle.
    • Step 3: Do the same thing to the other upper set screw with the car resting on the setup block. Once both upper set screws are resting on the axle, check for clearance under the guide. Ideally the guide should be just touching or maybe a hint of clearance under the guide.
    • Step 4: Remove the chassis from the setup block and hold it upside down in the palm of your hand. While give the front wheels a spin and slowly tighten one side of the lower set screws. As the set screw comes into contact with the spinning axle, the wheels will stop spinning. Be careful not to tighten too fast or you could put too much pressure on the axle holders and break them (ask me how I know this). Once the bottom setup screw is just touching the axle, back it off a 1/4 turn until the axle spins freely again.
    • Step 5: Do the same procedure for the other side of the lower set screws. When finished, put a drop of oil on both sides of the axle and check to make sure the front wheels spin freely.
    Now you are ready for the most improtant test, with the body re-attached to the chassis and sitting on the setup block, push down on the front corner of each side of the car just above each front wheel. The opposite corner rear tire should remain planted on the track when doing this.
    If both rears remain firmly planted on the track, you are finished.


    • #3
      Good input there from our Motorcity Correspondent.

      There's a useful pdf from also, here.


      • #4
        Awesome Moby! Love the diagram.

        The only thing I add is to test the "push front right tire to see if the left rear will lift" before the body is put on too. Sometimes the body/chassis/pod interaction will cause the rear tire to lift and it's nice to narrow down where the issue might be.



        • #5
          Good enough to be stickied in tech, me thinks.

          And I, too, tap on the chassis just in front of the front tires to see if rear opposite tire raises...


          • #6
            Agreed about tapping the chassis.
            Just seemed less confusing to explain with the body on.


            • #7
              Great info John.

              I do exactly as you describe plus once I have everything set I press down on top of the guide post ( body off ), and make sure the rear wheels do not lift. This means you have the guide as low as possible but still bear weight on the front tires ( lightly ) for stability in the curves.

              Also I check on the Track as well as if running raised rails a set up block would have your axle too high in the chassis ( NINCO in particular )

              Here we see routed track with recessed braid, set the axle a little higher to account for the recess. Wood Tracks, and Scalextric Sport and Carrera is normally flush or close to it, so set up as you describe on the block.
              Old SCX and Scalextric Classic track is slightly raised so you want the wheels lower to compensate for the raised rails.
              NINCO is noticeable raised, so if running on their Track you will need the front axle/wheels a lot lower in the chassis.

              Good info, and great illustrations thank a lot.
              Alan Smith
              SCI Owner.



              • #8
                Great info John just like you showed us all at Cloverleaf Racing on Tuesday nights.
                I agree this should be a sticky.


                • #9
                  It is a sticky

                  Check where it is, made it a sticky right away!!!
                  Alan Smith
                  SCI Owner.



                  • #10
                    very nice, although I have to say I run on Ninco without traction magnets and I use the 4/5 point setup. Tripod mode has never worked for me.


                    • #11
                      A set up board to match the track's braid recess / rail height is useful.

                      The board's braid section can be recessed to the same depth as the braid, alternatively add a suitable number of layers if tape under where the front wheel sit.
                      For raised track rails, add a suitable number of layers if tape under where the braids sit.

                      All this fine adjustment doesn't mean that much if the front tyres aren't round - so that's worth checking.


                      • #12
                        ^ and I will add to your last comment, that having this adjustment option is something every performance slot car should have especially for non mag.


                        • #13
                          If you are looking to keep the front tires planted at all times you should make sure that the car's braids are not mashed up against the bottom of the guide flag. It is rare for a tracks rails or braids to be a constant depth. If you have a wood track with copper tape that would not be an issue.


                          • #14
                            Craig -

                            For the least "traction" (or better, "unwanted" friction) in the front, adjust the tires so they either JUST barely touch the track surface or about two pieces of paper (.008") up off of the track. I normally go up about .025"/.030" up off the track.

                            This will help reduce the front tire friction in all areas of the track. This will smooth the cornering and enable a little more speed in all areas.



                            • #15
                              Front wheels .025"/.030" up off the track is pretty much a 3 point setup
                              Moby Dick's post talks about 3 point setups, and seems to be recommending 4/5 point setups for this type of car.
                              I think different track conditions may favor one or the other,
                              It's easy enough to try both and see what works best in your track conditions.