Personally, i'd never leave a dog on a tie out, i'd worry that something would happen, caught in the line, kids mess with'em or anything like that, nothing good comes from a tied out dog. Did you try the invisible fence? Congrats to your dog on good taste in bikes!
AL

I don't leave him unattented with the prong collar on. I was just responding to the comments. The only time he wears a prong is when i walk him. I have tried having ppl drive by on their harleys and i do correct him and he rsponds. But it all seems to go out the door when i let him out by himself on the line and i'm not present. Maybe it is something i have to live with and be prepared for. I hired several dog trainers, i even went as far as paying a dog phycoligist(wrong spelling i'm sure, excuse me). A harley just sends him straight into the red zone. And only harleys, any other motorcicle he couldn't care less about. Other than that he is such a great dog.

this is a noise fear aggression. one of byb dog does that. I used a combination of redirection and correction. you have to start out slowly with the noise source way out and slowly bring it in. You can't fix it entirely but you can manage it. this might be where an Ecollar would be effective. Any Ecollar people out there?

Ok i said it before and i say it again..my dog only wears a prong collar on our walks. NOT when i let him out by himself on a line. And i do use an e collar with him.

This is for dennis. Do you think he can ever be "cured" of his agresion towards harleys? I don't consider myself a novice when it comes to GSD's or dogs in general ( i was born and raised in germany and have been around GSD's all my life) but him being fixated on harleys only is new to me.

My dog only wears a prong on our walks.

I'm not Dennis, but I'm going to respond anyway. As long as you leave the dog tied out without supervision, you won't "cure" him from trying to attack motorcycles. None of us like the idea of dogs being tied out (regardless of the type of collar) because as previously mentioned they can get into too much trouble.
1. tire the dog out
2. put him on a down with a long line on the pinch collar
3. Have friend drive momo back & forth & pop the dog every time he reacts, when he shows no reaction, praise him. Gradually you will be further from the dog until you are at the end of the line. This will work if he just needs to be desensitized, but not if he is bored.
4. Be patient, it may take a while to correct the problem. Don't be in a hurry to move further from the dog

OK I'm gonna try and put this as clearly as possible.

The more times a dog gets to practice a behavior without consequence, the more this becomes a habbit for the dog. So, letting your dog on a tie out unsupervised means that when a harley drives by, he has no consequence for his action of chasing after the harley... so he just learnt "hey when mommy's not around, it's OK for me to chase the bike".

So step 1: Don't allow your dog outside unsupervised UNTIL THIS PROBLEM IS FIXED.

To fix a behavioral problem, you need to elicit the behavior, by this I mean, set the dog up for failure. Put him in a controlled situation where he WILL react to the harley, and then correct him for it. Ideally you read your dog and can tell when he is gonna go into that red zone and you correct him before he has the opportunity to escalate to this point. The correction needs to be hard, and you need to be firm, but never angry.

So step 2: Have someone drive past with a Harley when you have your dog on the e-collar AND the long line with a prong IN YOUR HAND. When your dog shows signs of starting to react to the bike, correct him on the e-collar and simultaneously correct the dog with the e-collar. This sets up the association that the e-collar means the same as the prong collar.

This type of behavioral modification takes time, especially on a 6 year old dog who has been allowed to bark and lunge at harley's from his tie out for years, so you are essentially having to break a habbit that he's had no consequence for in years. The fact that he never reaches the bike just adds frustration and builds the dogs desire even more to try and reach the bike.

So Step 3: Be patient and consistent with the dog, every time he sees a Harley he will be on a prong and an e-collar, or at the minimum a prong. PRAISE when he is relaxed.

Now, as I posted somewhere in this thread:

http://www.leerburg.com/forums/ubbthreads.php?ubb=showflat&Board=18&Number=129278

The prong can act against you in an aggression situation by building the dogs drive toward something. If you find the prong is working against you, either hang the dog on the prong with his front paws off the ground, or switch to a nylon choker n hang the dog with the choker.

It takes a long time to work on this problem and you need to be absolutely 100% consistent, or it will backfire. You cannot let your dog get away with a behavior when you aren't there to supervise, or the dog will revert back to the behavior they want to practice.

Forgot to add... once he seems to be pretty good when he's on the line and collar, you can try and proof him with JUST the e-collar... perhaps behind a fence so he can't get at the bike. This is where you start on the off-leash part and proofing. Once he is absolutely solid here, you can test him with a flat collar behind a fence to see if he'll be OK without wearing the e-collar. If he is absolutely fine, you can go back to the tie out if you absolutely insist on using one... personally I don't care for it. My puppy broke her leg on a tie out, so be careful.

The prong collar is meant to pinch the neck and feel like another dog(mother, alpha dog, what-have-you), It will not hurt him indefinitely if he runs and gets pinched and stopped by the collar. Both of my dogs, one is 14 months and the other is 5 months, try to run full bore when they have the long line and the prong collar(note: dogs are not unattended when they have both of these on, I am always with them)and all that happens is that they spin around and realize "hey, I can't go that far" or "maybe I'm not supposed to go after that" when they come back I praise them twice over, but they are never hurt by this. Now if you had a "choke chain/collar" on the dog and let it run and be stopped by this, the dog would have injury, i.e. bruises, coughing, etc. Prong collars are designed, as I said, to pinch(give a correction) that the dog recieved from it mother, and would receive from the alpha or pack leader(you). Don't be worried, unless a vetrinarian has told you otherwise(such as the dog has esophagus/throat problems that you shouldn't tug on his neck. Give it a shot and see the results before your dog hurts someone of gets hurt trying to chase every Harley that drives by.