up travel
 

how does up travel works on your car....and how high?

Up travel is not really something we mess with on on-road RC cars (or off-road for that matter). Most cars are set up so the chassis can bottom out before the suspension does.

what's up travel?

up travel is another way to say droop. Its the travel "up" when lifting the suspension before the wheels leave the ground. so 2mm of up travel in the rear means that if your ride height is set at 5mm then when lifting the rear dead center(usually with an exacto knife) both wheels should leave the ground at 7mm. 7mm-5mm = 2mm of up travel. This method is also used as a quick droop adjustment method. If one tire lifts up before the other, most likely your droop is off, or you are tweaked or possibly shock lengths are different. More than likely though your droop is off.


As far as the other posts saying this is not used... Its definately used, it effects how much the weight transfers from front to back. I wont get into details but there is a book called XXX main chassis setup that I recommend you pick up, its talks about droop and a whole lot more. If you have more specific questions please PM me and I will try to answer them, I'm no expert, but I can tell you what the book says :)



Woody

I would say droop is DOWNtravel.

UPtravel would be the amount the suspension can compress. It is used sometimes on full size race cars but I have never seen it used on an RC one.

My 950R has up and down stops. Now,im not an expert 8th scale race, but I would guess that up travel limiters would be used to stop the car from bottoming out. At least when your suspension is fully compressed, you still have rubber touching the ground, but when you bottom your chassis on the ground, you lose most of your grip.

In our world uptrable is often used to describe how much the chassis ryses (tables up) from the static ride heith.

I will generaly set it by mesuring with the RH gauge, the use the droop gauge to make sure it's eaven from side to side

On asphalt I consider 2, to 2.5mm is a good starting point.

From Losi JRXS:

Up-travel limiters: ... More up-travel is recommended for bumpy surfaces or track layouts that use berm edging or track dots. This will allow the suspension to work over those objects....testing showed that limiting the up-travel helps the car react faster and improves corner speed.

I'd agree with Fastburn that it helps to keep the chassis from draging plus what Losi says for bumpy tracks and berms...

Pucho, sosidge... just a little off. :D

E

Pucho and woody, you're both talking about DOWN travel. Up travel is how far the SUSPENSION can move up from the ground, or how far it will compress. Down travel is how far the suspension moves down when lifting the chassis or encountering a hole in the track. Droop is just a term invented by a lazy typist that didn't want to put "down travel limit".

I agree with your definition, However I was going off in my local circles how we describe up-travel. Also in the on-road TC world and I know the setup sheets that I have looked at for the pro-drivers like Tosolini they will put for example 2mm of uptravel. Meaning from say a 5mm ride height it "travels up" 2mm before the tires lift off the ground. I'm not disputing what you said, I'm just stating how we use term and how I'm familar with it.

Woody

Yeah I can see where you're coming from Woody. A lot of people that have little more experience with full size cars than puting gas in them, often get terms confused when talking R/C suspension. I don't mean you, just R/C racers as a whole.. That confusion in terminology, when used by a top driver, gets filtered down through the masses and becomes the norm. I am a master mechanic with a lot of experience tuning race suspension, so it sometimes bugs me when I see things described bass ackwards. Not singling you out in any way, it's just a generalization.

Tony

To be honest, I don't have a ton of experience with it, but I know going from limited to unlimited up or "Bump" travel, the car became less precise around the track. This was with a JRXS.