fleslider 

I have a couple bikes that have them my 1987 Centurion Ironman Expert and Master and my 1986 Trek 560 . i took them off the 560 when i first got it but after riding the Ironman's i dont mind them i might put them back on the 560 someday.

I remember in the late 80's in the area's i rode in they were cool, i dont think it was til the middle 90's that they got a bad rap.

Miele Man

The bad rap that Biopace chainrings got was because a lot of people believed you couldn't spin high roms with them. That was false but it was enough to kill the rings. Biopace may not feel much different in use but they do rduce the stress on the knees by a lot.

Cheers

Rice Wash

I appreciate the honest offer to my mostly tongue in cheek comment and when it comes time to build that frame I will message you!

Vonruden

I have them on my Stumpy as well, don't even notice the difference.

Loose Chain

I still have them on my Centurion. I have a new set as well for spare. I cannot really tell they are there. If not still using them, what would one replace them with on a late 80s Shimano 105/600 crank?

ThermionicScott 

I've had them on bikes and didn't notice a pronounced difference so they came back off. I sold the 48/38/28 steel set and don't miss them, but perhaps if I ever work myself up into needing a 52T big ring I'll put the 52/42 on something.

stardognine

Titanium. I just recently bought some old XT M730 cranks, mostly for the Ti chainrings & bolts. I'll be test riding today, still need to mount a bottle cage & pump.

Trakhak

Some people may remember that when Shimano introduced the chainrings, the U.S. bike magazines praised BioPace highly. However, articles began criticizing them starting about six months later, claiming that sprinters complained that they felt lumpy at high cadences.

My guess is that one sprinter complained to one or two Bicycling Magazine writers, and they ran with it.

BioPace was introduced early in the era of Shimano marketplace dominance. Once Shimano felt themselves to be in a position of sufficient strength, they told bike manufacturers that they could either (i) buy complete Shimano groups (no more cherry-picking of components) or (ii) take a hike. Another new rule: (i) accept BioPace chainrings on the cranksets in every Shimano group (no option for round rings) or (ii) see above.

Pushing around bike companies (and, effectively, bike dealers) that way might not have had a big effect on the acceptance of BioPace in the market, but it probably didn't help.

shipwreck

My right knee is sort of delicate due to using a kickwheel for pottery for a lot of years. Experience has shown me that biopace rings let me do longer days when touring day after day.
I really cant feel anything different between round and oval when just tooling around at home, it takes several days on a tour before the benefits start. So all of my bikes that see loaded tours get the biopace, sporty sprinters get the round.
It may be a Dumbos feather effect, but Ill still stick with the formula that does not leave me with a strained and swollen knee.

Knet

Thanx for all the input. I hadn't given much thought to the BioPace rings for ~20 years, back when they were very much not in fashion.

I rode the old bike with the BioPace yesterday and my regular road bike today, and I think I am kinda diggin' the BioPace rings. Leaving them on.

BobbyG

My '83 Nishiki International has 'em...or had 'em. I swapped out the smaller gear to something smaller to help with the hills. Big ring is still oval. I don't notice it at all.

verktyg 

I put together this Flickr collection of Biopace and similar types of chainrings when I was researching them back in 2010:

https://www.flickr.com/photos/282672...57625130627294

https://www.flickr.com/photos/282672...7625130627294/


Sheldon Brown wrote a nice article on BB chainrings that covers a lot of the bases (click on link below):

Biopace Chainwheels


Here's a quote:
"The marketers of Biopace made a crucial error of judgment: too much information. In particular, they mentioned that the Biopace design was optimized for cadences of about 90 rpm and slower. Many readers interpreted this as an indication that Biopace chainrings would somehow interfere with pedaling faster than that. This perception caused a bit of a self-fulfilling prophecy, and the Conventional Wisdom arose that Biopace was bad for high-performance cyclists for this reason. I [Sheldon] used to believe this myself, but I rode them anyway because I appreciated their other virtues."


I got back into riding again about 10 years ago after a number of years off the bike (plus a total hip replacement). I picked up a 1988 Colnago Technos frame. It was so weird looking to my retro grouch eyes that I decided to build it up as a frankenbike. That was during my Campy free zone era. I got a bunch of NOS Shimano Deore XT components dirt cheap on eBay including 2 triple Biopace cranks.



I have Biopace chainrings on a few other bikes:




I switched the chainrings (including some BP rings) on most of my 130 BCD Shimano cranks from 52T-42T to 48T or 49T-38T because I wanted lower gearing and I'll almost never need a 52T ring again.

After riding 38T small rings with 28T FWs for quite a few years, I noticed something when I got a 1988 Peugeot Biarritz with 52T-42T BP chain rings. While this is totally subjective, when climbing the pedal effort of the 42T BP ring is about the same as with a round 38T ring!



My bikes equipped with Shimano BP triples seem to climb easier too!


verktyg

Chas.

Standalone 

Like them. Dislike the granny. See post #2 in this thread.

exmechanic89

I like Biopace as well. I wouldnt say I'd go out of my way to get it onto a bike, but I'm totally good with it being on bikes I've bought.

motogeek 

When I had my custom Veloce built in the mid '80s I spec'ed a Sugino AT crank with 48-44-26 Biopace chainrings. Still run the combo but the granny has been swapped to a round ring. Never noticed any substantial difference but they kinda took a bad rap in the 90's.

vintagerando

My 1988 Schwinn Voyageur has Biopace......they take 1.3sec off each mile I ride. Biopace, yeah baby!

RiddleOfSteel

After having a pleasant experience with a Biopace set on a just-purchased '89 Schwinn Tempo (I thought I had lost my keys on a test ride and was retracing my steps...er, spins), I sought them out a few years later when I was building my do-anything Nishiki build. First gen Biopace with the more pronounced deviations from round--a 52-42-28 setup. They are really smooth and often after riding round rings, pedaling the Nishiki (on 6500-era Ultegra triple cranks, no less) feels velvet-y. I make it work with an 11-34 rear cassette and it gives me no trouble.

Sporty bikes, as other(s) have said, get the round rings and the non-sporty Nishiki gets the funky stuff. Interestingly, I feel like I can hold a slightly lower cadence than I would with round rings without any extra strain, usually up inclines. The 28T ring does feel like pedaling a square, but it's a nice square that my knees don't hate. Biopace rings are always a cast-off at the few major used shops I frequent here in Seattle. They should just have an Oddballs With Merit section where that can go into. They can stick Rapid Rise Shimano rear derailleurs in there too, but not mine because an XTR example is on my bike and works a treat.

If you like the Biopace feel, rock it! If you like forgotten and/or esoteric stuff that works well (I do), then that will increase your draw to it.

top506

Biopace fan; helps beat-up old knees get up hills.

Top

mrchaotica

My wife's circa-1987 Lotus Excelle mixte touring/commuter has Shimano Biopace chainrings and my circa-1990 Specialized Hard Rock commuter has Sugino Bionic chainrings. I have no complaints, and as far as I know, neither does she.

Are there any real differences between genuine-Shimano BioPace vs. other non-circular chainrings such as my Sugino one?

ThermionicScott 

Per Sheldon's article, SR's "Ovaltech" and Sugino's "Cycloid" were designed similarly to BioPace. Other, more "performance-based" non-round rings tend to be oriented 90° off, so that the biggest part of the gear is when the cranks are horizontal.

carbomb

I enjoy BioPace so much I run it on my fixed gear. Just make sure to tension the chain at the tight spot in the rotation and not the loose spot I receive no shortage of people wanting to lecture me on how I'm doing it wrong, how I'm going to throw a chain (hasn't happened in 5 years), but if I go, "Sheldon Brown did it" then all of a sudden it's okay

More than half of my bikes run it and I think it allows me to push a higher cadence and not bounce in my seat as much. Switching back and forth between a bike with round chainrings or with BioPace is uneventful, I could live with either setups. I do enjoy the novelty of BioPace so I don't replace it when I pick up a bike with it.

noglider 

Hmm, I wonder if this would be a good application for our tandem. I doubt my wife and I are going to pedal more than 120 rpm together, but I could be wrong. We need higher high gears, though.

Paramount1973 

Do Biopace rings shift more smoothly? Reason I ask is that for some period of time Shimano offered round chainrings with a series of shortened teeth opposite each other on the chainring and marketed it as an aid to shifting. These were eventually replaced by ramps and pins. I'm wondering if the oblong BP chainring helps in the transition as the chain moves between chainrings.

top506

No.
In fact, I think the reason they died is index front DRs. Granted, they weren't pinned and ramped, but every bike I have with Biopace launches the chain outboard of the big ring every 200th shift or so. I think if the shift occurs at just the right low spot with just the right power applied it'll overshoot the teeth of the big ring. And I haven't been able to get them to work well on my sole 10 speed brifter bike.

Top

carbomb

Yes? I've never experienced anymore difficulty shifting my BioPace bikes compared to the ones with a normal setup. I've got a Nishiki Modulous that's BioPace and Shimano Light Action throughout. If my experience were determined by internet hearsay then that bike shouldn't work at all.