adlai

Looks interesting, to say the least.

Basically, it has a chainring which is not perfectly round, but has slight variations to account for the human body's legs.

Seems good in theory. THoughts?

Kopsis

We just went through this religious war less than a month ago

https://www.bikeforums.net/bicycle-me...esistance.html

Sixty Fiver

They work for me.

Biopace Chainwheels

davidad

They are a fad that comes and goes.

Sixty Fiver

You keep using that word, I do not think it means what you think it means...

Fad.

1. an intense and widely shared enthusiasm for something, esp. one that is short-lived and without basis in the object's qualities; a craze.

It is only now that people seem to appreciate Biopace for it's solid design... our knees are getting older too.

davidad

Shimano no longer makes it for a reason. It did not work for everyone. If it did they would still make it. There are many fads in bicycling that different manufacturers resurrect.

Looigi

Biopace were ~elliptical rings with a specific phase relative to the cranks, roughly 90 degrees out of what you see on elliptical rings nowadays where the major axis is basically perpendicular to the crank arms. I had a bike with a biopace chainset ~25 years ago. My impression back then was it made little if any difference.

RaleighSport

I've got a wide range of shimano biopace from some road stuff most people wouldn't notice isn't circular to some really weird egg shaped triples.. they're a gimmick but they work just fine.

FBinNY 

This idea and similar ones are as old as chain drive bicycles. They seem to come back into vogue, or get reintroduced as a new idea every 20 years or so. Regardless of merits, the drawbacks seem to overcome them and after a short while the idea goes back on the shelf to await the next generation of potential customers.

Sixty Fiver

I have many customers who ride them citing the improvements they get in relation to reducing loads on their knees and although I also ride round rings I have a number of bikes set up with Biopace as it helps with the imbalance I have between my right and left legs.

Rode them back in the day and I really appreciated them more on my mountain bikes than I did on a road bike... I know how to spin so did not need them for that.

Having trashed my knee some years ago I found that you could really feel how much load was reduced when I was using a Biopace equipped bike for recovery purposes.

tcarl

I personally like biopace for some situations. The first biopace to come out was a 28-38-48 triple (which they said would feel like a 26-36-46). I still prefer that 28-38-48 for mountain biking and loaded touring - high power, lower rpm situations. In normal riding situations they feel weird at first, you do get used to them, but they're not necessary. After coming out with the triple, they came out with a 42-52 road biopace which is less extreme. I have that on one bike and ride it occasionally. The 42 is nice for hills, OK for flat land but again, not necessary. I'd think it would be better for someone with a lower cadence (60-80 rather than faster 80-100). The 52 biopace I can hardly tell any difference, but I sometimes think it feels better than a 52 round. I also have a 50T biopace (I don't know where that came from) on a general use touring bike. I can definitely feel it and really like it - better than a round chainring for that bike.

fietsbob

I was a Mere Child back then , thought my then GF who had had 2 knee surgeries, may benefit from the shape ..

Tim_Iowa

I have a 48-38-28 XT-M770 crank on my townie bike (Schwinn KOM), and I don't mind it. It seems a bit easier to crank than the round chainrings on my other bikes. Which is nice, because the KOM is a tank, especially with the studded tires in winter.

I also really like the size of the chainrings on this Biopace crank; they're just about right for touring/commuting/just toolin' around. I wouldn't search for a Biopace crank specifically, but I don't mind them.

Eric S.

I was feeling nostalgic a few months ago and put a 42T Biopace ring on one of my road bikes. Found it new-in-packaging on eBay for $15.00. The feel is not as pronounced as I remember from the late '80s, but I like having a 42T over 39T. I recall the feel being more obvious with the smaller gears of a mountain bike (I used to have an '88 Stumpjumper).

Gonzo Bob

Hahaha! Not nearly as bad as real religious wars, though!

I like Biopace rings for climbing. But I prefer round rings for spinning. I've run my 110mm BCD crank with a 38 Biopace inner and 50 round outer and thought the combo worked quite well.

FBinNY 

I don't know if anybody still does it, but for a while it was fashionable to use a biopace granny on a triple with round rings.

JohnDThompson 

Biopace rings are not the same as simple elliptical rings. Shimano invested a great deal in researching the proper shape for Biopace chainrings, and that shape changes with the tooth count; the smallest rings look almost square, while the largest look almost round. They work very well for some people, but not everyone, and they never really caught on in the market.

bike4mike

I just removed my biopace chainrings yesterday, after many years of toiling with them. They just kill my knees, because they have a "soft" spot at the apex of the crank cycle, thereby enticing the rider to remain seated in the crux of the cycle, instead of attacking the downstroke with a straighter leg position, causing undue stress on the knee joint, IMHO. I'm going with round chainrings.

lsberrios1 

I use it all the time, 40% of the time. I like it a lot. Ride them on my 1988 Panasonic and my 1987 Grizzly. Shifting is wonderful.

1speeder

Bing, Bing, Bing, we have a winner! Yes, when the Biopace rings came out, I put down my green backs to buy them. Cool, felt like I could climb in at least one gear higher, but the downfall was after a certain rpm, the bike felt like it was surging. So, like many, I went back to the round things.... Hum, come to think about it, it was weird to set up the front derailleur...

Memories,
Mike

FastJake

They've worked really well for lots of people for the last 25 years or so. They are a unique shape, not just a simple elliptical shape.

Also, lots of people think they're stupid. I suppose it keeps the price down for those that appreciate them.

Sixty Fiver

I never mixed them up but did blow a few people away when I'd be climbing walls with a 28 tooth Biopace granny on my mountain bike... the power transfer is very smooth.

I rode my hybrid today as it is my spring bike... it has cross tyres and I upgraded the stock parts to Deore LX and DX with a Biopace equipped crank.

bradtx

adlai, Generally ellipsoidal chain rings make little or no difference to many riders. There are some that love and some that despise them. I have some, but not a lot of experience with them and basically I'm neutral on the subject. I have a project bike in the works that will use them. Who knows, I may join one of the feuding extremes. Certainly worth an experiment.

Brad

RandomTroll

I had them in the '90s. I didn't notice a difference. I'm not a discerning customer though.

frantik

at lower cadence they seem cool and make pedaling a tiny bit easier even.

at higher cadence they suck and make me pedal in a weird pumping manner.


I really dont like them and replace them with round rings immediately. my gf doesn't mind them and has them on her bike