Hey I'm getting my first bike fit next week wanted to know if I should tip the fitter,as a former bartender I always think you should tip but from time to time I've found in certain service areas people can get offended or uncomfortable. Any advise would be appreciated 

Bike fits are expensive and what you are buying is the service itself... so I have never tipped the bike fitter. 

On the other hand I'm not from the US, so maybe my behavior here is rude... 

I would wait for a few more responses. 

Thanks Diego, im also not from the US so I think I over tip from the  fear of being rude haha

I always tip.  And since my bike fits often take about 3 hours, I also bring food, bars or half sandwiches, for us to eat while we take a break.
I also tip my mechanic, no matter what work they've done.  Tipped when they changed a flat for me last winter because I was so grateful not to have to do it with wet, frozen fingers.

Thanks Bruce. I figured I should tip but didn't think about snacks!

I'm originally for oversees and over the years I have tuned my tipping so that I tip employees, but I don't generally tip the owner of a business. Owners set the rates for services, but employees do not and instead get paid a wage.

The one exception to this rule is my local bar, where I do tip the owner (but then I do practically drink there free of charge)