old's'cool

Alan and anyone else looking for biopace; I have several new or like-new biopace rings I'd gladly trade for round rings (e.g. 52/130, 49/130, or 49/110):
- 52/130 plated steel
- 46/110 grey anodized aluminum Biopace II (this one is NOS)
- 42/130 plated steel (I think I have it somewhere; not sure)

KZBrian

My '86 Super Sport came with Biopace rings. I have around 300 miles on them so far, and find they feel a little different, in a good way.
No downside that I can tell.

cooperryder

Discussed on this link as well:
www.bikeforums.net/showthread.php/606294-Shimano-Biopace-mix-and-match?p=14492471&highlight=#post14492471

cooperryder

Also discussed on this thread:

www.bikeforums.net/showthread.php/606294-Shimano-Biopace-mix-and-match?p=14492471&highlight=#post14492471

Stealthammer

I used Biopace on several bikes back in the early '90s, and found that I could sell them for enough money to buy a better crankset. Other than that I see them as gimmicks that just makeup for and encourage poor pedaling form.

jonainmi

The study only says that the Biopace rings are not as efficient as a round ring, not worse on the joints.

I noticed that too, and was wondering if the designers were just using the ideas in their heads, or were drinking, or what?

I am not sure how it could cause poor pedaling form? your foot still goes in a circle...

ThermionicScott 

Well, there are two possibilities -- either the designers had no idea what they were doing, or the Belgian mechanical engineers/mathematicians doing this study are missing something.

Stealthammer

I think Biopace "trains" or promotes you to pedal in squares rather than in true circles.

CACycling

Never experienced that on any of the Biopace-equipped bikes I have had.

jeebusaurousrex

Sheldon likes it!

https://sheldonbrown.com/biopace.html

I use the original biopace that came on the 105 cranks on my commuter. To prevent sweating I don't spin on this bike and feel like biopace works really well for this slower cadence application. They definitely feel weird for sprinting. Tried it a few times during races and just couldn't get used to it.

jonainmi

I had read that on sheldon's website a little while ago, and found it interesting. I have yet to finish the build up of the diamond back, but from what I have heard here I can not wait to get it done!

I really really want to know what it feels like to pedal in "squares"

MrEss

I used biopace on a previous bike; I liked it but not enough to put effort into using it in the future.

gearheadgeek

I've got bikes with Biopace ('89 Trek 950), Suntour/SR's version of it ('89 Fuji Saratoga), and without (newer bikes). I ride the Fuji and a later Cannondale MTB the most so I frequently switch back and forth. Some days I'll go from one right to the other. I can't say I've ever noticed a difference in knee pain or speed/efficiency.

jonainmi

I have heard from a lot of cyclist around here that BioPace is nothing special, they didn't even know they were riding it for the longest time. Most didn't think there was a difference in knee pain/painlessness.

An LBS owner I know here says they are the best thing since sliced bread.

I have the DiamondBack mostly done now, and I have a few different cranksets for it. I am going to try switching them out and doing a comparison on them. But, I am going to take the researchers at their word. :-)

Velognome 

My opinion on thses have changed.....I wore out a set of rings on a 80's Giant Iguana that was converted to HD Road chores. They were ok I thought, the lower ring was very eliptical and was only worthwhile for climbing over rocks or deep mud on my occassional detours off road. I switched it out last week for a Road triple and HOLY COW, the bike is so smooth now. Switching from bike to bike, I never noticed the difference, just thought the Iguana was a pig and lived with it. Oh how I was so wrong! There is a noticable difference if you spin, mashers might not notice but for spinning I think (my opinion) the Bio-pace rings are less than worthless on a road bike.

Lascauxcaveman 

Bingo. BioPace is for climbing. Standing on the pedals, heart pounding in my ears, sweat dripping off my brow, putting major grunt into that hill that's trying to kill me, the BioPace rings seem to vault me forward on that awesome downstroke. So, basically, I owe them my life.

Or it could just be my imagination. At any rate, the 80's-looking yellow sticker is pretty groovy. And the nerd factor is pretty high.

dyander

I appreciate the BioPace on my Mt. Bike for climbing in the saddle and anything with a steady cadence, but standing on the pedals....absolutely not.

rdtindsm

Back in the mid to late 70's somebody developed a drive system that used a cam to do the same thing. The idea was that you could use an effectively lower gear to "spin" on the down stroke, and maximize rest across the top. The chainring was round and moved forward and backward in relation to the crank. Scott Dickson, who has placed in the leading group at Paris-Brest-Paris was helping to promote the setup. Strange to watch from behind.

The BioPace chainring was reversed engineered to give the same stroke with a machined chainwheel. IIRC, there was a patent lawsuit. But this is being recalled from the depths of a very cluttered mind.

I had a Bridgestone mountain bike with biopace. Didn't make much of a difference.

edit: After some web sluething, I found that the inventor was Larry Brown and the device was called a PowerCam. Manufactured by houdille industries in Ft. Worth of Texas. Dates seem to be more mid 80's

frantik

Yeah I noticed it almost immediately when I would spin at high RPMs.. for mashers it's cool though

btw for biopace fans, i've two sets of nice alloy rings, one set for mtbs, one for road cranks.. PM me if interested..

randyjawa 

I have ridden lots of round rings and ellipitical rings and can't tell the difference. It is possible, though it might be my imagination, that the ellipitical rings are easier on my knees. However...

The rings on this old Motobecane were a bloody nightmare to ride. At a cadence of twenty rpm+, the bike started to actually feel like it was hopping...

Velognome 

^ Is it April 1st already?


randyjawa at speed

old's'cool

Nice one, 'gnome!

SJX426 

+1 frantik. So what other oversights were committed?