On the second episode, Fonzie rode a Knucklehead chopper & wore a blue cloth jacket. After that initial episode, they gave him the leather & a Triumph Speed twin; same as Brando's bike in "The Wild One".
Remember Estrada got hurt fairly bad when he crashed while they were filming. There were several shows filmed from his hospital bed while he was healing.
I read somewhere that The Fonz was switched from a Harley in the earlier episodes to a Triumph because they sat lower and he could get his feet on the ground. The grips would push him into the camera shot and all he had to do was brake and put his feet down.
And to think I won a Fonzie look alike contest in '75. Must have been my Bronx accent in Fayettevile NC that put me over the top. Won a 1 year movie pass & dinner for two at an upscale restaurant (with table cloth). Took a good hour to get that crap out of my hair.
I think only two of the guys on SOA were riders prior to the show. Tig (Kim Coates) and Bobby Munson (Mark Boone Junior). I saw this in a recent 1 year ago, issue of HOG
Fonzie's Knuckle must have been too cool for the Fonz. Ha! I guess they thought Fonzie on a Triumph would be less intimidating to the older TV audience than a sweet looking Knucklehead bobber. Too bad, that was a sharp bike.
Henry Winkler couldn't hold the heavier Harley up so they had to use a lighter bike.