Just finished this earlier today, started out completely original. Added some Cinelli bars and stem, Panaracer Paselas,Brooks B-17, Tektro levers and Suntour Barcons. Pretty happy with it except for the half step rings. I need to find a smaller middle ring.

Wow. Looks great. Looks like it still has the original helicomatics?

Yep, original wheels. This is a very low mileage bike.

What size are your tires? Nice bike.

27” x 1 1/4”

Oh, okay. I was thinking 700c and they were looking a bit wider. I know better that the Treks were mostly 27s. I do see that you have the standard red label variety. I think they ride better than the blue label pro tite version.

Maybe you can learn to like half-step gearing--a lot of people around here do, including me. Not sure what the tooth counts on on the Helicomatic freewheel, but maybe they don't give well-spaced ratios with the existing chainrings. Given the difficulty of trying to customize the Helicomatic freewheel, it might be necessary to find a different rear wheel, or relace it to a new hub. Nice bike, though!

On my 620 with the 1/2 Step + granny, I could use both middle and large ring with any cog. If middle ring and big cog was too high a gear then it was time for the granny and the middle cog.

I’m slowly recovering from a torn meniscus, I’m slowly getting stronger but still want to even out my gearing. It’s not a huge deal changing out a $20 chainring. I can always swap it back later.

Ignore my dumb suggestion about learning to like half-step. You've been messing with old bikes for long enough to know what you like.

I am working hard at not acquiring any new bikes, but if I found a 620 in my size, I doubt that I'd be able to resist it.

You and me both,

And especially if it was the long wheelbase version.

hmmmm
This 620 looks a little short. Could be why the 1/2 step is unsatisfying?

Yes, my Helico which came on my 1984 610 was an oddball mix of gears, never suited to a half-step. I looked for ½ doubles but they never worked well. Unfortunately, the original 52/40, which could have worked well as an Alpine or crossover, still didn't work well, again due to the odd Trek interpretation of a Helicomatic.

I finally got a used set of Campy hub wheels, and started serious gear phreaking! Better, but the bike still had serious climbing problems - not least the wimpy legs of the owner, faced with big Denver rollers and the foothills of the Rockies! But I did put together a decent road half-step, just not a wide-range 2 x 6! For the day, I needed a TA crank and a 48/28 or so, to work with a 13/28 of 13/32!