Terrified of motorcycles

Need some advise folks...again.
Tommy is coming on a treat, almost 19 weeks old. His behaviour is great, he's been brilliant with other dogs and overall he is a pleasure. However more recently he is very nervous when walking near the road; if he hears a motorbike engine, even faintly, his ears fold back and his tail tucks in and he almost crawls along the pavement. If the motorbike comes near, he goes into a blind panic and just tries to run.
Is there anything I can do to help him?

Hi
I think I would ignore any negative reaction he shows and walk on confidently and then praise him whenever he reacts confidently to situations . There are usually lots of bikers about in the mornings at weekends , so you could take him out then and give him lots of exposure to it. You could go on you tube and play some motorbike sounds in the house where he will feel more confident , and gradually turn up the volume whilst having playtime .
I am not an expert on training though so am sure others with more knowledge will be along

Suki was the same way for motorcycles and trains. Have you taught the watch me command yet? It helps if they are focused on other things when they hear the noise. Other than that it's just repeated exposure to get them used to it.

I had the same problem with Densil = he used to have real panic attacks when noisy cars/bikes went by. The trainer told me to get him to look at me and give him a treat (hot dogs/cheese) as the car goes by so that he associates it with something good. had to do this several weeks before he got better and even now he will still look at me sometimes if it is a particularly noisy or fast car.