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Anything really wrong with Biopace?

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Anything really wrong with Biopace?

Old 09-01-19, 06:32 PM
  #51  
GreenNeedle
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Originally Posted by Maelochs
The only problems I ever had with Bio-Pace was difficulty setting up the derailleur. Once set up properly the rings shifted flawlessly and I never had any issues with my knees---lots of hard miles on them. I have two sets---temporarily off the bike for other reasons, but would and will still use them if I get the right opportunity

Resurrecting earlier than the 6 years


I bought an early 90s Holdsworth that had Biopace/400 Exage as stock on it. Never heard of it before but first time I rode it I loved the bike (was meant to be for my son.) Once I decided it was gonna be mine then of course all my gear was going on it so I put the Biopace on a Sun Solo I had (and still have.) The Holdsworth now has SRAM red all over with Force brakes.


The Sun Solo has Shimano 400 Exage all over it. When I put the crank on I lined up the clamp as per normal. A penny gap between derailleur and big ring. Could not figure out what was going wrong until I realised the big ring was jamming on the derailleur. "This bloody ring is warped" I proclaimed when I realised what was happening.


Bit of research on the net and I find they are supposed to be warped. So I found the high point, reset the front derailleur and perfection. Works as well as any other setup does. Changes almost instantly as all the bikes in my shed do.


Those bikes being mine with SRAM red which of course is absolutely instant and exact, Eldest Sons with SRAM Apex which is a bit slower, a little less exact but very very good. My youngest sons Shimano Claris which is working flawlessly considering it's pricepoint. The Biopace/EX400 combo front and back is quicker than the Apex and Claris to change, Yes it is more exact but more because it is friction rather than Index so you can click it (trim) every change. If anything the Apex is the worst performer but most likely because it was my old one and has had the most miles on it.


The SunSolo is a bit of fun really. downtube shifters and the like. The Holdsworth with SRAM red is my main bike but I occasionally go out on the SunSolo (once a fortnight for a bit of change.) I rode it to work on Friday and on the way back another worker bikes with me. He was commenting how he couldn't believe how quiet my bike was. His Carrera was whirring along with noisy gear changes while I was in stealth mode, with single "clunk" changes.


So I have tried the Biopace on both. Hard to compare them because we are talking 80s/90s tech vs SRAMs top of the line but what I call "cruising speed" is what I base my assessments on. "Cruising speed" is spinning without having to push, no real effort. I can spin with no effort on the SRAM Red at 17-18mph on the Holdsworth. About the same (if not faster) than on the Alu frame with Carbon fork I used to have it on despite the extra steel frame weight.


The "cruising speed" on the Sun Solo is about 14-15mph. It is a heavier frame and of course all the components heavier. Might be fun trying out the Biopace on the Holdsworth on its own with the rest SRAM to see what it is like.


My Cadence tends to be spinning, like I suggested above in my assessment of "cruising speed." I tend to spin at about 100 and change up if I go higher. I hate to spin slowly. If I am then I change down gear very quickly. I notice no real difference with the biopace in terms of feeling the oval. Someone above does, but I don't. They do feel faster than I am going though. I think I'm zooming along at SRAM speed yet the computer tells me I am that 2-3 mph slower.


No Pains in knees, back or anywhere else.


Hmmm. Will Biopace work with 10 spd chain and Red front derailleur, lol?

EDIT. I'm sure the rings will be fine but was wondering about the spacing between rings on the original crank. Just thinking though I could just stick them on the red spider and give them a whirl as long as they are 130BCD.

Last edited by GreenNeedle; 09-01-19 at 06:44 PM.
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Old 09-01-19, 07:20 PM
  #52  
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Originally Posted by noodle soup
Zombie Alert!
QFT

Is anything really wrong with zombie threads?
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Old 09-01-19, 07:44 PM
  #53  
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Originally Posted by datlas
QFT

Is anything really wrong with zombie threads?
At least this newb has an interesting reason for waking the dead.

SRAM front derailleur and Bio-pace chainrings, what could possibly go wrong?
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Old 09-01-19, 10:47 PM
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Interesting thing about Biopace, it's the other way round from most rings. IIRC Shimano had some reason about the momentum of the rider's knees or something. Somebody did a study I read, that non round rings could be worth a few percent, oriented the way you'd think they should be, with the tallest teeth engaging when the cranks are horizontal-ish, but with no real gain when the out of round is below 9% or something.
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Old 09-02-19, 05:28 AM
  #55  
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Originally Posted by noodle soup
At least this newb has an interesting reason for waking the dead.<br /><br />SRAM front derailleur and Bio-pace chainrings, what could possibly go wrong?
Not sure I understand the "what could possibly go wrong" comment? derailleur moves the same amount just with different rings added. I've put them on the Red spider as they are both 130 BCD.

Anyways, I put them on and will have some fun later Didn't even have to move the derailleur up or down. tiny gap on the longer diameter of the ring but works. I did have to tighten the cable a bit though and open the outer limit screw a little to get it to move up so maybe these are different spacings from the spider than the Red ones.

FYI The Red 39/53 Rings weigh in at 182g. I think these are the 2012 ones. I have the 2011 ones (Powerglide?) which are a little bit lighter but don't change quite as smoothly. Small differences but the 2012 ones change as smoothly as the rear and quietly. The Biopace 52/42 rings weigh in at a whopping 304g!!!

Will test later on and give a more "like for like" opinion seeing as they are now on the bike I ride every day with the rings being the only difference.

I would post some pics but I haven't reached 10 posts yet

Last edited by GreenNeedle; 09-02-19 at 09:09 AM.
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Old 09-02-19, 09:06 AM
  #56  
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Originally Posted by Kimmo
Interesting thing about Biopace, it's the other way round from most rings. IIRC Shimano had some reason about the momentum of the rider's knees or something. Somebody did a study I read, that non round rings could be worth a few percent, oriented the way you'd think they should be, with the tallest teeth engaging when the cranks are horizontal-ish, but with no real gain when the out of round is below 9% or something.
I'm going to ride with them as they should be first. Then I'll try rotating them and "rotorizing" them.

One thing that foxed me though was that I am used to fitting inner rings with the writing/stamps facing the frame. So I did that. Looking at pictures on the net I had the inner the wrong way round and the stamps are facing out. So I've had to take it off and put it back on that way round.

Another small problem I noticed while doing that was that with me tightening the cable slightly and unscrewing the limit screw a little (so it would change) the back end of the derailleur was rubbing the back of the crank arm, so while I haven't moved the derailleur up or down (53t round ring must be about the same diameter as the 52t biopace highpoint) I ended up having to loosen the derailleur and rotate the derailleur in a bit.

All this must mean though that the outer of the biopace ring is slightly further out than the red ones. Will have to remember to readjust when I put the Red rings back on.
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Old 09-02-19, 05:24 PM
  #57  
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I've been trying a Biopace standard double 52/42 on a '93 Trek 5900 for several months. In actual practice Biopace has been okay for me. Different from conventional chainrings and took me awhile to adapt.

I'm a spinner, usually 90 rpm like clockwork after I'm warmed up. I don't even need a cadence sensor to remind me. Just comes naturally. On downhills or long downward inclines I'll get up to 130 rpm if I want to try for a new PR. But mostly I'm around 90 rpm, and only a little slower on climbs. I swapped my '89 Centurion Ironman from 52/42 conventional Suntour to 50/38 Vuelta rings. Better suits me for longer rides of 50-60 miles on rural roller coaster routes on chipseal. I'll spin out on fast downhills but I'm not trying for PRs in club rides. I prefer the easier gears and spinning cadence for a comfortable 15 mph or so group ride.

But that doesn't work for me with Biopace. As some other folks have observed, Biopace seems to work best for some of us at a slower cadence.

I've found Biopace works best for me when I consciously slow down my cadence and gear up for more resistance. Usually that's around 75-80 rpm on flat terrain, 60-75 rpm on inclines and roller coaster terrain, and 50 rpm when I stand to pedal. That's when I can feel the slight mechanical advantage of those elongated lobes kick in.

However that's so different from my natural preference that I've had to retrain my legs. My thighs were sore for about a week while adapting to mashing. But now I'm stronger and potentially better for the experience of getting out of my comfort zone. The past few rides I've snagged several new PRs on a 20-40 mile route I've ridden dozens of times over four years -- hundreds of times on some of those segments. I was surprised to discover I could improve my overall average by up to 2 mph over 30 miles just by retraining my legs to try something new.

Also, the default orientation of the chainrings may not suit everyone. I've experimented and for me the big ring feels best oriented 72 degrees clockwise from the factory standard position (yellow triangle decal opposite right side crank arm). This eliminates an awkward transition sensation I felt in the big ring. It engages the elongated lobes a bit better suited to my admittedly less-than-optimal cadence (hey, at age 61 with lots of injuries and the usual joint problems, I'm surprised my pedaling style is as smooth as it is).

That commonly re-orientation trick didn't work for me in the small ring. It created a dead spot that was immediately uncomfortable and didn't get better after a few test rides. The 42T Biopace is back to standard orientation.

Oval or oblong chain rings with more mounting holes to fine tune orientation of the lobes might better suit some riders. I'm not concerned enough to have a machine shop custom drill Biopace rings for me. I could buy a newer setup cheaper if I really wanted to invests in the concept.

And no problems with chain drops. The 52T big ring isn't that far from circular, so adjusting the front derailleur isn't difficult, at least not with my Shimano 600 setup on the Trek 5900. Works fine with indexed front shifting too. The few chain drops I've had were due to cable stretch and not re-adjusting the cable tension and limit screws. FD height over the big ring didn't seem to be any more critical than with circular rings. Most of my chain drops occurred when I temporarily replaced the 42T Biopace little ring with a standard 38T. Too much drop between 52 and 38 with indexed FD brifters, and the gear steps felt weird anyway. I switched back to the 42T Biopace after a few rides and around 100 miles or so with the 38T round ring.

Biopace was standard equipment on many mid-priced road bikes in the late 1980s, notably on the Centurion Ironman Master series and comparable mid-range road bikes from Trek and others. Mostly because Shimano leveraged its clout to coerce bike builders into an all or none group set, whether or not people wanted Biopace. That probably backfired and created some undeserved disdain for Biopace.

I'm not a Biopace fanboy and can take 'em or leave 'em. But now that I have the rings oriented to suit me and I've modified my pedaling style, I kinda like 'em. But I'm keeping the standard rings on my other road bike. It's comfortable.
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Old 09-03-19, 12:24 PM
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Originally Posted by canklecat
That commonly re-orientation trick didn't work for me in the small ring. It created a dead spot that was immediately uncomfortable and didn't get better after a few test rides. The 42T Biopace is back to standard orientation.
Aren't these rings made to work in an ideal position? Like other ring(pair)s have special positions they have to be relative to each other for better shifting?
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Old 09-03-19, 02:30 PM
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Originally Posted by GreenNeedle
Aren't these rings made to work in an ideal position? Like other ring(pair)s have special positions they have to be relative to each other for better shifting?
I'm not sure that Shimano ever published its research or rationale for Biopace. The theory is well known -- generally, to compensate for human imperfections in pedaling -- and predates Biopace. But Biopace also predates power meters and methods for analyzing and quantifying theories and impressions.

My hunch is that Biopace rings shift pretty well because they're barely out of round. The effect is mild, offering a little difference in leverage that varies according to rider. As I described above, I found a sweet spot in the big ring by reorienting it 72 degrees clockwise/forward of the standard position; while the little ring felt better in standard orientation.

Some users of more extreme ovals and oblongs report some shifting challenges, especially on rougher roads, gravel and off roads, which may be why some folks converted to single chainring setups with more cogs in the back to compensate.

Other makers of more extreme non-round chainrings offer more mounting positions so we aren't limited to the 72 degree changes in orientation available to 5-bolt cranks.

I don't know whether makers of other non-round chainrings have done thorough lab tests or published their results. I wasn't particularly interested in the topic until I got a bike with Biopace earlier this year and decided to give it a fair shake before offering an opinion. In my limited experience it seems to offer some advantages, but I had to modify my pedaling style a bit to make it work well for me.
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Old 09-03-19, 03:20 PM
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Originally Posted by canklecat
I'm not sure that Shimano ever published its research or rationale for Biopace. The theory is well known -- generally, to compensate for human imperfections in pedaling -- and predates Biopace. But Biopace also predates power meters and methods for analyzing and quantifying theories and impressions.
Shimano spent a good deal of time and money on Biopace. The lack of portable power meters meant that Biopace was
developed and tested more in the lab, where sophisticated but non-portable test equipment could be attached, than on the road.

My hunch is that Biopace rings shift pretty well because they're barely out of round. The effect is mild, offering a little difference in leverage that varies according to rider.
The eccentricity of Biopace rings varies with the tooth count. Larger rings tend to be less eccentric than the smaller rings.

Biopace was aggressively marketed for several years, but never caught on strongly. Some people really like it, others hate it, but most people were indifferent. I suspect that's why it has faded away.
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Old 09-03-19, 03:26 PM
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Originally Posted by GreenNeedle
Aren't these rings made to work in an ideal position? Like other ring(pair)s have special positions they have to be relative to each other for better shifting?
Biopace rings are meant to be used in a certain orientation with the crank arm, not for shifting reasons, but because that's how Shimano's ergonomic research indicted they should be oriented.

You can see the little index "pip" on the rings (bottom of each ring, in the picture):

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Old 09-03-19, 05:56 PM
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Have them on my schwinn high sierra; don't really like them. It just might be the size of the rings, but I felt slow on the bike
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Old 09-03-19, 07:42 PM
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Originally Posted by GreenNeedle
I'm going to ride with them as they should be first. Then I'll try rotating them and "rotorizing" them.

One thing that foxed me though was that I am used to fitting inner rings with the writing/stamps facing the frame. So I did that. Looking at pictures on the net I had the inner the wrong way round and the stamps are facing out. So I've had to take it off and put it back on that way round.

Another small problem I noticed while doing that was that with me tightening the cable slightly and unscrewing the limit screw a little (so it would change) the back end of the derailleur was rubbing the back of the crank arm, so while I haven't moved the derailleur up or down (53t round ring must be about the same diameter as the 52t biopace highpoint) I ended up having to loosen the derailleur and rotate the derailleur in a bit.

All this must mean though that the outer of the biopace ring is slightly further out than the red ones. Will have to remember to readjust when I put the Red rings back on.
looking forward to your review. I’ve used Biopace on my road bikes for about 6 years. I know what I feel with them but I’ll save it because most people are saying the same thing I feel! Haha.
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Old 09-03-19, 08:13 PM
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Originally Posted by GreenNeedle
Aren't these rings made to work in an ideal position? Like other ring(pair)s have special positions they have to be relative to each other for better shifting?
Those other rings have ramps and pins and cutouts, but every Biopace ring I've seen predates that business.
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Old 09-04-19, 12:16 AM
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Originally Posted by canklecat
I'm not sure that Shimano ever published its research or rationale for Biopace. The theory is well known -- generally, to compensate for human imperfections in pedaling -- and predates Biopace. But Biopace also predates power meters and methods for analyzing and quantifying theories and impressions.

My hunch is that Biopace rings shift pretty well because they're barely out of round. The effect is mild, offering a little difference in leverage that varies according to rider. As I described above, I found a sweet spot in the big ring by reorienting it 72 degrees clockwise/forward of the standard position; while the little ring felt better in standard orientation.

Some users of more extreme ovals and oblongs report some shifting challenges, especially on rougher roads, gravel and off roads, which may be why some folks converted to single chainring setups with more cogs in the back to compensate.

Other makers of more extreme non-round chainrings offer more mounting positions so we aren't limited to the 72 degree changes in orientation available to 5-bolt cranks.

I don't know whether makers of other non-round chainrings have done thorough lab tests or published their results. I wasn't particularly interested in the topic until I got a bike with Biopace earlier this year and decided to give it a fair shake before offering an opinion. In my limited experience it seems to offer some advantages, but I had to modify my pedaling style a bit to make it work well for me.
I was meaning that with other rings they are positioned together for the machining and ramps and pins etc to aide smooth shifting. So I meant if you rotate one and not the other, or if you rotate them different amounts won't the smooth shifting be affected?
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Old 09-04-19, 12:21 AM
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Originally Posted by JohnDThompson
Biopace rings are meant to be used in a certain orientation with the crank arm, not for shifting reasons, but because that's how Shimano's ergonomic research indicted they should be oriented.

You can see the little index "pip" on the rings (bottom of each ring, in the picture):
I understand that point yes. The chain stopper pin on the large ring lines up with the "pip" on the small ring to line up behind the crank arm. But like with my SRAM Red where I have the "hidden hole" rings on an older 5 hole spider I had to rotate them slightly to fit them but I rotated both rings that amount so that together they lined up with each other. Thus the pin and the pip are together to one side of the crank arm.
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Old 09-04-19, 12:23 AM
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That answers my question. So they can be orientated independently as there isn't the special machining of newer rings that should be rotated together.
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Old 09-04-19, 12:29 AM
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Originally Posted by GreenNeedle
I was meaning that with other rings they are positioned together for the machining and ramps and pins etc to aide smooth shifting. So I meant if you rotate one and not the other, or if you rotate them different amounts won't the smooth shifting be affected?
Yeah, I wondered about that. But no shifting problems. The Biopace 52T big ring isn't pinned, nothing fancy like my Vuelta SE Plus on the other bike. There's a pin that would normally be hidden behind the right crank arm that's now exposed since I reoriented the ring 72 degrees clockwise. I'm guessing the pin is intended to catch the chain if it drops. On my other bikes that pin is in the crank arm so the chainring orientation doesn't matter.
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Old 09-04-19, 12:33 AM
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Originally Posted by Tulok
looking forward to your review. I’ve used Biopace on my road bikes for about 6 years. I know what I feel with them but I’ll save it because most people are saying the same thing I feel! Haha.
I think I will disappoint you Didn't take the bike out on Monday as it rained. So I left them on and used them on my "sprint to work" today. 9 miles there, 9 miles back. I honestly could not tell they were oval, didn't affect my spin rate, didn't make me go slower or faster. I do have a light touch on the pedals though. I used the small ring half the way there and then changed to the big ring. Left it on the big ring all the way home, being naughty and "cross chaining" if necessary as I don't get any rub from 1 to 10 when on the big ring. Route is virtually flat all the way, mostly staying at 18mph. Max was 25.2mph. Wasn't pushing too hard as I need to stand up all night at work. Also I wanted to test them in the same scenario as I am used to with the Red rings.

Only difference was the shifting from small - big. I'm used to the red where I click the lever and it changes instantly. Tried that on these and it struggles to change. Had to hold the lever in until it had changed. No biggie and of course we are comparing modern top end to old tech but My son's Claris and other son's Apex don't need you to hold the lever like that.

Will give it another sprint tonight/tomorrow morning (I work nightshifts) and then try the rotation thing to see if I notice anything then.
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Old 09-04-19, 11:50 PM
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So after 4 x 9 mile trips on these rings and I can't say I notice any real difference other than the shifting. Maybe I am an outlier
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Old 09-24-19, 01:15 PM
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Just to finalise this. I have the SRAM Red rings back on now.
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Old 09-24-19, 01:16 PM
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I tried the Biopace on a total of 10 sprints to work and back. 5 in their correct orientation, 5 in the adjusted (2 clockwise position) and I honestly could not tell any difference other than shifting performance. The Red rings are a virtually instant change, the Biopace required me to hold the lever until the change was complete, they needed that extra little bit of pull.

I couldn't tell they were oval like others say they can feel but then my riding style means my feet just follow the pedals with no real pressure. My legs do the work and my feets just follow the pedals which of course still go round in a circle.

I took some pictures when I changed them although the inside ring was the wrong way round when I took the picture. Something I noticed and changed straight after. Biopace rings on SRAM Red spider 175mm GXP, SRAM Red derailleur with Ultegra chain:



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Old 09-24-19, 05:02 PM
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Yeah, BITD I could definitely feel the difference on the small ring, not so much on the big ring.

Those low-spec Biopace rings (Exage? 105?) have moved up in the world, sitting on Red cranks... are they the ones without a hole behind the sticker? I had 600 rings, which thankfully you could remove the sticker from, to reveal another hole. They did look pretty trick.
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Old 09-24-19, 11:42 PM
  #74  
GreenNeedle
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Originally Posted by Kimmo
Yeah, BITD I could definitely feel the difference on the small ring, not so much on the big ring.

Those low-spec Biopace rings (Exage? 105?) have moved up in the world, sitting on Red cranks... are they the ones without a hole behind the sticker? I had 600 rings, which thankfully you could remove the sticker from, to reveal another hole. They did look pretty trick.
No idea on there being another hole or not behind the sticker. What would the other hole be used for? These originally came with the Holdsworth the Red is on. The bike came complete (minus brake calipers) and thus stock with Shimano EX400 groupset.
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Old 09-25-19, 01:27 AM
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With the aluminum 52T Biopace that came with road bikes, behind that yellow logo is just the same three sided cutout you can see on the rest of the ring.

Dunno about the steel Biopace triples that came with some mountain bikes. The few bikes I've seen with the steel Biopace were rusted so I didn't bother with 'em.

I left the yellow sticker on for reference while I was experimenting with re-orienting the Biopace rings. After some trial rides I like the big ring oriented one tick away from the original position -- feels more natural with my cadence. But the same trick with the little ring felt weird, with dead spots and herky-jerky cadence. So the big ring is oriented a little differently from the factory spec, but the little ring is back to original position.

For several months I've ridden the 52/42 Biopace on my 1993 Trek 5900, with various 7-speed freewheels (old set of wheels from an Ironman, not the original wheels for the Trek). They're a little different, including being picky about cross chaining. That might be due to the different wheelset. I can use all 7 speeds with the little ring, but with the big ring I can hear a little chain noise any time I'm out of the 3 smallest cogs. Occasionally I'll shift to the larger cogs while still in the big ring, mostly while standing to climb, but the chain noise tells me it's inefficient.

I'm about to swipe a conventional 53/39 chainring set from an old aero TT bike with cracked frame that I'm cannibalizing for parts. So it'll be interesting to compare a conventional double with the Biopace.

I might also try some 175 crank arms. I've been using 170 on the Trek and I'm betting the Biopace will work better at lower cadence with a bit more leverage from longer cranks.
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