46 replies to this topic

[Upfront slot cars]

How short has anyone been with guide length and still had a stable front end ?

[Hworth08]

How about ZERO?

 

In the early days it was fairly common to solder a peice of guide mounting tubing directly to the front axle tube. Worked well but realize the cars were slow then.

 

It's might actually be better to think in more of the lenght from the REAR axle than the FRONT. 4 and 7/8ths seems like a good starting point. The best length varies by track with faster tracks usually liking longer leads and slow twisty tracks prefering shorter.

[Pablo]

Guide Lead (GL) depends on type of car, how much the front wheels influence the car, and other factors. Example, on a wing car, GL does not matter because the fronts do nothing. What would matter, is overall WB like Don said.

[Dennis David]

For us it depends how much front end overhang you have

[Gator Bob]

IMO -

 

Guide lead is guide lead  ... measured from front or rear axle.

Nothing to do with wheelbase.

And it does matter even on a wing car.

[Pablo]

Wing cars don't have front axles, Bob LOL

[slotbaker]

I always thought the true guide lead was from the centreline of the guide post to the centreline of the rear axle, and the front axle only relates to the wheelbase, nothing to do with the guide.

[Upfront slot cars]

So the shorter the guide lead is , the more unstable(tippy) the car will be ? In relation to guide to the front wheels. I am not concerned about guide to therear wheels.

[MSwiss]

Andrew,

You are talking on Retro cars, correct?

[Pablo]

As long as I'm here, bored, and we are on the subject.....
for those who may have forgotten or be confused, here is the scoop.
Old timers like me from the 60's measure slot cars using these terms:
Wheelbase, which is center of rear axle to center of front axle.
Guide Lead, which is center of front axle to center of flag post.
These terms are generally still used today in retro racing/scratchbuilding by the majority of experienced builders.

In classes where the front wheels perform little or no function, such as wing cars and stamped steel cars, racers generally measure center of rear axle to center of flag post. Some may call it Wheelbase, others may call it Guide Lead, or Guide Length.

There is no way to answer the original question without knowing what type of car is being referred to.

[Upfront slot cars]

Yes , we are talking about retro cars.

[Hworth08]

There's an old therory/formula about the triangle formed if lines were drawn from the outside center of the rear tires to the center of the guide.

It used to be discussed in the old days but I don't recall any clear findings on the subject. Just from experience I can say the more narrow the rear track the shorter the guide lead needs to be. Maybe why in 1964 and 5, when the open-wheel cars ruled, a short lead worked. The rear track was 2.75 inches. As the downforce sports car bodies took over the with a 3 inch track, the lead increased.

At one time we would build two different droparms for a chassis as they were easy to change if the frame was so designed. No one at our track ever found any major difference in length.

[Gator Bob]

Upfront slot cars, on 01 Jun 2013 - 10:05 PM, said:

How short has anyone been with guide length and still had a stable front end ?

 

You ask a tough question ... there are a lot of variables... your driving skills, track, etc.

 

I'm no expert but to give you an answer ... 3/4" from the centerline of the front axle is the shortest I've run Retro.

 

Pablo, on 02 Jun 2013 - 07:58 AM, said:

Wheelbase, which is center of rear axle to center of front axle.
Guide Lead, which is center of front axle to center of flag post.
These terms are generally still used today in retro racing/scratchbuilding by the majority of experienced builders.

In classes where the front wheels perform little or no function, such as wing cars and stamped steel cars, racers generally measure center of rear axle to center of flag post. Some may call it Wheelbase, others may call it Guide Lead, or Guide Length.
 

 

Yes!  

 

But I find when Rear axle to guide center is called wheelbase not lead ... that's just silly   

[Pablo]

Finally we agree, Gator Bob

 

Andrew, now that I know what you are talking about, the answer is very easy.

Use about 4.00 WB and 0.90 GL on a retro Can Am.

Use about a 4.00 WB and a 1.00 GL on a retro F1.

[Duffy]

....................except when............................

[Dennis David]

You use less ... or more.

[Duffy]

...............because................

[Gator Bob]

Duffy, on 02 Jun 2013 - 6:28 PM, said:

...............because................

 

  ..... Pablo said so?

 

or,   my body is to short for my tongue ....  

 

 Chaim Witz

 

 

I ... like ... Stock Cars.

[Old pink can guy]

Bob sorry I have not got back too you. This week is gonna be a mess for me.

[Gator Bob]

Old pink can guy, on 03 Jun 2013 - 12:14 AM, said:

Bob sorry I have not got back too you. This week is gonna be a mess for me.

 

Soldier on my friend ... Spec-Ops needs recruits of all ages.

[MSwiss]

Upfront slot cars, on 02 Jun 2013 - 1:50 PM, said:

Yes , we are talking about retro cars.

I had at least one chassis, years ago, at 3/4", and it ran fine.

 

I think a lot of guys are stuck at about .932", just because that's what it is on the various  JK Can-Am and F1

chassis pcs. with bent uprights for the front wheels.

 

If you wanted to experiment, I would build a chassis with a square front, with the guide all the way back, like in the top pic,

where it would still turn, and be at something radically short, like 5/8".

 

That would allow you to try it, but still have the ability to stretch it out to something somewhat normal, like 7/8",

like in the bottom pic.

Attached Images

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[Duffy]

Hey, that's a pretty guide tongue, doncha think?

[SlotStox#53]

Duffy, on 03 Jun 2013 - 01:35 AM, said:

Hey, that's a pretty guide tongue, doncha think?

Yes it is

[Upfront slot cars]

Sounds good mike. Thank you everyone for your input. I will post some pics when I am done. This is my first complete scratch build. I have oly built one Jk kit and don't care for it.

[SlotStox#53]

Upfront slot cars, on 03 Jun 2013 - 03:28 AM, said:

Sounds good mike. Thank you everyone for your input. I will post some pics when I am done. This is my first complete scratch build. I have oly built one Jk kit and don't care for it.

Good luck with your first complete scratch build , look forward to seeing the finished car