krue1971

I just bought a 1987 Schwinn High Sierra at an estate sale that is in great condition. It has biopace chainrings and I've heard them knocked every time oval chainrings are discussed, so I wonder what is the knock on biopace? I haven't ridden it beyond the test ride before I bought it so I have no opinions on them although I do like my absolute black oval chainring on my ss mtn bike.

veganbikes

From what I know it was another 80s shiny marketing gimmick based in whacky land. Maybe it worked for people but I feel like it was Shimano getting a shiny new Commodore 64 in the office and being like "let's design crazy chainrings because we have a computer and will make many Yens". Maybe the rings weren't as durable or something?

Truthfully I just wanted to reply so I could say "and what's the deal with airline peanuts, I mean come on"

Soody

Sheldon liked em.

I had them on my first road bike, as part of an RSX 7 speed group.

That was a damn good bike and I never even noticed the chainrings weren't round.

They seem pretty good nic still, about twice as heavy as my 6400 rings, but hardy.

holden west

The moment they came out there was all this criticism--it's a gimmick, or it'll hurt your knees. People are still saying that. I rode a set for 30 years without a hint of knee trouble. I now ride regular Shimano round rings but haven't noticed a difference, frankly. I don't think Biopace were true ovals, it was more an irregular shape.

downtube42

Peel the sticker off, then ride worry free.

lasauge 

The knock on Biopace is that the design/science between their not-quite-oval shape has never been clearly proven to be effective, and there are plenty of doubters who argue that Biopace's orientation wasn't correctly placed relative to the crank arm and point where it would best maximize human power output. Compare that to more recent oval chainrings (Rotor) which have been demonstrated to produce measurable gains for riders.

You can find ten thousand personal opinions about Biopace if you look online for a few minutes so I won't blather on about mine but to say:
1. If you've never ridden Biopace before, give it a try and form your own opinion, some riders do like it.
2. Biopace rings absolutely do work to smooth power transfer to the rear wheel as your legs output a less-than-perfectly-even effort to the cranks - but you might never notice this unless you ride your bike up a sandy or icy incline that's slick enough that you can feel when the wheel starts to slip.

garyus

Maybe they were just manufacturing defect and Shimano didn't want to trash them. So they came up with a marketing gimmick. ��

sloar 

I have them on my Pro-Miyata, I like them but don't really notice a difference.

SJX426 

Sounds like a opportunity to combine opinions with shoe retaining devices. How much does each contribute to overall performance? Which contributes the least/most? Maybe we could include chain options too.

JohnDThompson 

Shimano actually invested a lot of time and money in biodynamic research designing the Biopace rings. They're not simple elliptical rings, and the shape changes with the tooth count (the smallest ones look almost square). but they never really caught on in the marketplace and eventually were dropped from the product line.

mstateglfr 

I have 2 SR Ovaltech rings on a triple or my '80 Voyageur 11.8 and love em. I love em because they move the chain when I pedal. Yup, i'd love about any ring that does that.


I haven't noticed any difference in performance. They aren't easier or harder to turn. Its not like on mile 45 my legs are fresh and its not like on mile 3 my legs hurt.

Use em and see. At worst, they are a conversation starter at rest stops.

sloar 

I wouldn't buy them to put on a bike. But if I buy a bike with them on there, I leave em.

roccobike

Biopace does work, but there are very few who (if any) will convert a new CF bike to biopace. I have it on the 88 Nishiki Ariel MTB that I ride on MUPs and it works fine. On a hard ride, I can tell the difference compared to a comparable bike without it. Like sloar said, I won't buy it to add to a bike, but I'm not taking it off any bike that has it.

68venable

I have Biopace on my 88 SR-500. I am faster on that bike than my newer one. For Shimano's sake I will tell you that it is from the Biopace.

randyjawa 

Perhaps it is all in my head, but I do feel that my knees feel better when riding Biopace. Probably not, but that is what I feel and I have thought about it, on and off of the bike.

The Golden Boy 

The idea is sound. You only have full force (weight) behind your pedal at two points in the chainring rotation. The idea is to extend those two points so you have that a higher level of force for a longer period of time.

I have Biopace medium and small rings on my High Sierra- I don't like it on the small ring- it's too abrupt for me, I don't notice it on the medium ring. I had a set of SR Ovaltech rings on a bike- I actually liked them all around.

What's with handicap parking at the Special Olympics?

USAZorro

Biopace chainrings exist to give me the opportunity to please others when I get rid of them.

Binky

Cute oval chain rings and the desire to re-invent the wheel (and an excuse to raise the price of wheels).

Sakae and Sugino had their own variations and pushed them for a while...

I picked up an antique Bridgestone a few weeks ago and even it had an oval chainring under the brand "Bridgestone Oval".

As far as I can tell, I have had Biopace stuff on about 40 bikes and they are just as nice as anything else Shimano makes.





Binky

ramzilla

I've got them on two of my bikes and, you can definitely tell the difference between the ride from an ordinary round chainring. It's noticable when I stand to pedal while climbing hills. Or, when accelerating. My knees are completely shot and, I can't jog anymore. But, Biopace doesn't bother my knees at all. It's a fine chainring. No reason to replace it.

Number400

I liked mine, good stuff. They really suited me for TT rides. They made me feel like I had no power but really helped to keep my leg speed up and overall times were good.

Lascauxcaveman 

I've had a couple different versions; only complaint is with one 28T inner ring it felt just too "lumpy" to get used to. The set I have on a 39-52 double feels pretty normal, barely noticeable, except while aggressively mashing out-of-the-saddle climbing the bike feels like its "surging" on the downstroke. Makes me feel like I'm a stronger masher

dailycommute

105 biopace on 1988 trek 560 has given thousands of hassle free miles over last 4 years, 600 tricolor biopace on 1989 fuso fr1 has hundreds of hassle free miles in few months riding it. Late 80s was the biopace era but personally I would leave them alone as find them rock solid and no discomfort.

Eric S.

I wanted to go back to 42T rings on a couple of my road bikes and found new, still-in-packaging Biopace rings on eBay for dirt cheap.

I can't feel the effect as much as I remembered from a couple of bikes I had in the late '80s (MTB and road). I do remember the effect being more pronounced on the smaller rings of the MTB crank, the 28T and 38T rings to be specific.

McBTC

I think the biopace idea is to shorten the "dead space" between 10 and 2.

El Segundo

My new 1988 mountain bike came with BioPace and I could not honestly tell any difference except for the smallest chainring, not negative just some difference. I have the Sugino OvalTech on my 1988 Trek 400 and to me it does not feel any different then my 105 equipped Roubaix.

Just ride it and let us know what you think.