I wasn’t in the market, but while at a car show/swap meet this past week, I came across this old Trek 520. It was too nice to pass up, and the lugged frame sealed the deal. It only needed a little tweaking, a seat, pedals, and 1 tube. I will also be replacing the cable housing for black, and installing black grip tape for my own personal taste. It wasn’t until a quick test ride today, that I realized I needed to have a 30+ year old steel framed bike in my collection 😂 let me know what you guys think of her!

Looks lightly used, congratulations!

Those 520s are classics. Great bike for touring!

That looks like it is in brand new condition. I do not think the brake pads ever touched that rim. I had trouble counting, is that a seven speed in back? Half step plus granny crank that is biopace.

Have you figured out the vintage yet? If not, this might help. I am guessing 1988.
https://www.vintage-trek.com

Looks great ! Does that have Biopace chainrings ?

Yes they say biospace, I don’t know anything about them

thank you for the info! Yes, seven out back. The rims look new. They say matrix titan t on them

If I remember correctly, it was mid to late 80's that Shimano brought out the Biopace chainrings. Those rings are not round like almost all chain rings are but rather slightly elliptical which was supposed to give the rider a more efficient peddling motion. They did not go over well and were dropped only a few years later. Some people really liked them but I developed some knee pain that I had never experienced before and changed them out to standard round rings, and my discomfort went away almost immediately. But as I said, some including yourself may luv em'

What a great find! How come I never trip over gems like that one? Looks like it spent a lot of time in the garage...Enjoy it!

robow and Op James guy-- Biopace was still around in 91 when I bought my first nice bike, it had a 50/40/28 Biopace crankset on it, and I too developed knee issues that probably were connected to the oval rings, so I too got rid of them and have had a distrust of non round rings ever since.
I'm fairly sure my issues were related to the hoppity hoppity thing that would happen to your pedal stroke at higher cadences. I'm a skinny guy and naturally prefer slightly faster cadence, or rather, my knees and legs do not like slow cadence, and I have clear memories of how annoying the uneven pedal stroke motion was as you got going faster cadence wise.

downtube shifters really didnt help as we tended to put off shifting sometimes with them, especially in urban settings etc

I do recall that oval rings changed a lot since 35-40 years ago, so the modern non round stuff that some top racers use (still use I think) have a different design, but Im not sure.

bottom line, ride them and see how they are for you. Probably depends on how much you ride, your preferred cadence and other stuff.
Biopace did disappear for a reason though.

figure out the bolt pattern , the bcd, of the crankset and look into replacement possiblities--some chain rings are super expensive, others not so much, but you're probably limited to what is available nowadays anyway. Not a big market for it probably.

I'd regrease everything, all bearing points.

The reason it disappeared:

When Biopace first appeared (on sport-touring bikes but not racing bikes), reviewers in bike magazines praised it to the skies.

Then Shimano got greedy and added Biopace to their racing bike component groups. Racers disliked the feel in general and when pedaling at high cadences and sprinting in particular and bad-mouthed it. The reviewers then did a 180 and damned it.

In response, Shimano introduced Biopace II, with much-reduced eccentricity (and some further, almost-round version whose name I've forgotten). But the damage was done, and Shimano soon gave up and dropped Biopace.

Ironically, Biopace made/makes perfect sense for the original target market.

The majority of casual and beginner sport cyclists (a.k.a. the majority of cyclists, period) have always tended to pedal a high-ish gear at a low cadence. Someone at Shimano noticed and figured that they could make cycling more enjoyable for those low-cadence cyclists by offering eccentric chainrings.

The idea was that, as a consequence of effectively reducing the gear ratio through the power section of the pedal stroke and increasing the ratio through the dead spots at the top and bottom, the rider's cadence would be higher and the load lower where it counted, with the bonus of more rest time per revolution.

A very few people have reported experiencing problems with Biopace over the years, many more have said that they've been happy with them, and the majority of users have probably been indifferent. Chances are therefore good that the OP will get along fine with them.

Even though the bike looks to be lightly used, I'd do a complete overhaul before putting any serious miles on it.

27 inch or 700c wheels?

I like downtube shifters but you may want to track down a set of indexing Shimano bar ends.

Nothing wrong with biopace rings. I'd install platform pedals on the bike though.

Great find.

I agree with everything you wrote, especially about the vast majority of folks using high ish gear and low cadence. I know a number of people who pedal often like this.
So in theory the oval thing is a nice idea, but my experience was a classic one, as soon as you start to get to higher cadences, its an issue--- VERY much compounded by downtube shifters, where we just dont shift as often as with other types of shifters.
Mine might have been Biopace 2, I got rid of the rings years ago not to be tempted to try them again.

and yes, this fellow might find them fine. Up to him.

Bike magazines made their money off of advertising and would praise anything that paid their bills. I've come to put very little faith in what "professional" reviewers claim as they're fickle and will change their views tomorrow if a better offer comes along or if the bike industry as a whole tugs at their purse strings.

Thanks for the explanation. I never rode or worked on a biopace bike, so I assumed that the eccentricity of the chainrings mucked up shifting or something simple like that. Looks like my guess was wrong.

I had biopace on a couple of Miyata 100’s (not 1000) mid to late eighties. Never thought or noticed anything weird, better, or worse about them.