If you can spin a crank at high rpm a Biopace will not make any difference and may even improve your pedal stroke a little... like Sheldon I have used Biopace on FG and SS bikes and found that it worked quite well and also run a Biopace triple on my Extrabike as it has benefits at the low end for maintaining cadence under higher loads.

It is a sound design.

As for tossing out the cranks that came with them... my Kuwahara Cascade came with Biopace rings mated to a Deore cold forged crank which I continue to use to this day and am looking at re-installing Biopace rings since I have a bunch of them, many are NOS.

With one good leg I find that my right leg does more work and my right knee is more prone to being strained and stressed under harder efforts but have been riding my Biopace equipped cargo bike with a 28/38/48 and an 11-30 cassette and never found that I needed a lower gear.

As I was swapping the old 11-30 out today I switched to an 11-34 and lowered the gear a little... these BP rings are running on another Deore crank and I do not part with these easily.

Biopace can be magical for people with knee problems.

I liked it for the smaller inside chainring, got it from a friend and tried it for a while. Sold the bike with everything in 88'. Would also like another one, but i'll wait untill I catch a bike with them installed.

To be honest, I don't see why there are so many people that hate on these cranks.

I have a 52/44 on my Nishiki Modulus and it rides great. If anything I think I get going off the start alot faster on my Nishiki versus the round rings on my other bikes. Maybe it's my mind playing tricks.

My climbing needs all the help it can get...I've just recently acquired my first set of these on a '87 Super Sport. Like most everyone else, I can't tell any difference in the feel. I don't have any knee problems (knock wood) and I certainly don't want any. So far, I have no reason to hate them and hope that in the long run they'll prove beneficial.

I cannot sell everything I get since shipping costs from my location often kills interest. With that in mind, bicycle stuff will just continue to pile up, and up, and up. Needless to say, I do not pitch quality gear, only entry level and/or damaged stuff, be it mechanical or cosmetic in nature.

If you think this is an issue, you should see how many complete bikes I leave at the Dump. Honestly, for every one I bring take, two more are left for the metal monster to crush, gobble up and dispose of...

http://bikeforums.net/attachment.php...hmentid=206663

All that said, I have and/or help to salvage close to 5000 bicycles in the past ten years. 500 were mine and the rest were for Bicycles for Humanity. Now, consider how much junk one collects when dealing with 5000 old bicycles and perhaps you will understand why piles of bikes and parts like this are sold to the scrap metal dealer several times a year...

http://bikeforums.net/attachment.php...hmentid=206660 http://bikeforums.net/attachment.php...hmentid=206661

http://bikeforums.net/attachment.php...hmentid=206664

And, every so often, I get a truck load of bikes, such as the one pictured. Imagine how fast stuff piles up when you get incoming loads like this...

http://bikeforums.net/attachment.php...hmentid=206659 http://bikeforums.net/attachment.php...hmentid=206662

All that said, I just might try using a Bio-pace ring set. I have a very bad right knee (42 stitches to put it back together) and had to give up my Single Speeds. The knee was getting hurt every ride on the bike.

If you were in the UK, a clean Biopace chainset will make £20 to £30 on Ebay.

I fully empathize with Randy's predicament...
I have some biopace rings that will eventually go to the coop if I don't manage to sell them. So far nobody's stated needs have aligned with what I have, which are 130bcd 52 & 42 rings plated steel, and 110 bcd 46t dark grey anodized aluminum.

I imagine it would be fun to watch someone use a Bio-Pace ring for a fixed gear bike. The chain would continually go from super slack to tight again.

It surely must look like a bike with a major manufacturing defect is being ridden... or a circus bike.

If anyone finds such a video online please do post a web page url.

Well, this is new to me.

Clever stuff :)

i made a fixie using a biopace ring and it worked fine.. no ghost ring needed

The majority of chain wheels and cogs are not perfectly round and in setting up a fg or ss you do have to spend a little time making sure chain tension is consistent and there are no points where the chain binds.

In setting up a Biopace as a fg/ssyou set the chain from the point of highest tension, back it off so it does not bind at that point and you are good to go..

I've got a 1990s Trek 830 Antelope with Biopace and a 2005 Giant Boulder SE with round rings. Unless I think about it, I can't really notice the difference when riding. Knees don't seem to care. IMHO Biopace is nothing special but nothing horrible either. I've got a second crankset with Biopace rings that will be going on a Frankenbike this winter.

A moving picture is worth a million words! Great little clip. THX.

A moving picture is worth a million words. Great little clip! THX.

And guess what I got at the Dump, the other day. Yup, a very nice Exage Motion Bio-Pace cranks set, and it was still attached to an even nicer Steve Bauer Scirocco...

http://bikeforums.net/attachment.php...hmentid=206819 http://bikeforums.net/attachment.php...hmentid=206820

I seem to remember back in the day there was a suggestion that rotating the rings one or two bolt holes was a hot tip. I can't remember if it was a rotation in the ****** or advance direction though.

Ooops. What's another option for the opposite of advance in TDC discussions. Ummm. Un-advance? Reatard works I guess.

Good thing this isn't a car forum :)

I've used a 42-tooth Biopace ring with a singlespeed--I image that a fixed gear would be the same. You'd hardly believe it, but the change in chain tension is completely insignificant. It's a non-issue.
JV

It's funny how old things become new again:

I was watching television coverage of the Amgen Tour of California this year, when the Versus network did the funniest segment. They have these segments sprinkled throughout the telecast about riders and equipment, etc... and they had a story about the newest developments in professional cycling.

And what did they claim was the hottest new technology in the peleton?

You got it: oval chainrings!

They went on about how this innovation was the newest thing to hit cycling and how it would eventually trickle down to be equipped on the bikes owned by we mere mortals some day.

Hell... I was riding Biopace oval chainrings 25 years ago! :lol:

My wife and I stayed overnight in Thunder Bay--I think it was Thunder Bay-- on our trans-continental honeymoon in '03. I should have stopped the honeymoon mobile at the dump! Beautiful Hotel there. We were asked on check in if we wanted to have a room on the water side or the sunset side. We opted sunset side. Good choice.

I save far crappier stuff than biopace! We can't all be packrats, but as you can see, no one has chimed in to support simply chucking it.

That long ago?...
I totally remember a kid in my neighborhood that had a bike (BSA or BRC, something like that) with oval chainrings, back in the early 70's. :innocent:

Does someone need to point out the BioPace aren't oval? :)

Speaking of oval...

http://www.the-bici.com/images/uploads/boobs%20107.JPG

I think they might be actually, geometrically speaking. From wikipedia:

Most people equate oval with ellipse...geometrically speaking or not.

OK... I didn't get specific enough.

I bought a 1988 Trek 1200 (I think it was a 1200. May have been a 1000)... bought it new in 1988... that came stock with Biopace chainrings. So it was only 23 years ago.

Sorry I exaggerated it to 25 years...