RobE30

Just a few quick questions regarding Shimano Bio Pace chain rings. I have 600 cranks (pre tricolor I think) w/ 52/42 Bio Pace rings. Even on the small front and the biggest rear cog I'm struggling w/ climbs (I know suck it up) so I'd like to swap to a smaller front chain ring. What sizes did the Bio Pace come in that would work w/ my crank (fc-6207)? Also, is it worth staying w/ the Bio Pace setup? I like it so far and so far have no complaints.

roccobike

I'm not aware of any study that conclusively shows Biopace is superior to regular chain rings. If it was truly superior, they'd still be making them or at least the old rings would be in high demand, but they're not. I have them on some bikes and not on others. I'm not taking any off and I'm not adding them to any bikes that don't have them. I think its sort of a wash.

Zaphod Beeblebrox 

I have at 48t, pretty sure you can get 46 as well.

I've only recently started using a biopace chainring and I'm not sure I understand what Its supposed to be doing. I've got no complaints.

khatfull

I found a 40T 130BCD steel Biopace on eBay and another C&Ver told me that he's heard of a 39T, but looking at the 40 I don't know how they'd make a 39T.

The 2T difference makes a little difference, but not much. What's the rear cluster? You might have more options there.

So I'm running a 52/40 and a 13-26 in the rear...it's not too bad.

roccobike

In theory, Biopace maximizes your power stroke as compared to the upstroke. I think Sheldon may have a section on them because he liked Biopace.

illwafer

unless you want to get a new crank, i would forget about getting another chain ring. your best bet would be to get a new cassette/fw with a big granny ring (30T). your RD should be able to accommodate 30T.

RobE30

My current setup is 52/42 up front and 11-28 out back (7spd cassette). If I switch back to my matching hubs (specialized sealed bearings) I'd go back to a 6spd freewheel 12-23. I can do "normal" hills and climbs now that my rear d/r is adjusted properly but on anything that is long (the one route I attempt has an 8% that is about 1.5 miles) I just about die half way. I guess I just need to concentrate on getting stronger and more endurance....

Barchettaman

Rob, I would keep the set up you have and use it as training motivation. Get into hill repeats and you´ll be flying over that hill in no time at all. Best of luck.

One option would be to lose the Biopace 42 inner ring and put in a 38 tooth non-BP. I assume your crankset is 130mm.



Another option is a second hand MTB triple, like this 48-38-28 currently at €1 on eBay germany:



But have a look at this video regarding getting your climbing a bit better:

https://www.youtube.com/watch?v=DteVYs5pgmY

Triathlon-orientated, but useful information. Happy training. I started hill repeat training this spring and the difference it makes in a short time is remarkable, the legs respond very quickly.

miamijim

Biopace has its place in cycling, its all a matter of using it as it was intented. Back when Biopace was introduced alot of riders found that they 'bounced' in the saddle at high pedal RPM. Shimano subsequently introduced Biopace II which was less out of round.

Does it work? Yes.
Do people still use it today? Yes. Many riders in the Tour de France Peleton use a similar concept called Rotor Rings.

miamijim

https://www.rotorbikeusa.com/science.html

CardiacKid

Conclusively?

Barchettaman

Of course, you can make your own budget Rotor Rings by moving the BioPace chainrings back 2 positions on your crank arm

From this:



To this:



Guaranteed 10% extra power on your pedal stroke, ideal for time trials. I might have made that last bit up.

miamijim

I dont know, I never said, 'conclusively'.

EjustE

All you ever needed to know about Biopace (from Sheldon Brown). Great writeup on the subject.

I really like Biopace. I have Biopace rings in 3 of my 5 road bikes and the 4th has the similar (but not as good) SR Ovaltech rings. The 5th has Campy. My son's bike I just built also has Biopace. It is a personal preference and I do prefer to mash than do high rpms.

As far as chainwheels go, you could have a max 15 tooth difference so if you have a 52, a 38 would probably be the smallest you can get. A triple might be a good idea (but you'd need different FD, RD and BB) Also, MTB biopace rings are not swapable with road rings (different BCD). A compact double might be another option (like 42-3x) but I am not sure how low the 130 BCD biopace rings went. Another possibility is to replace your inner chainring with a 38, your freewheel with a newer megarange with a 34 big cog (they sell those new for not that much) and get an (MTB sgs or maybe gs) RD that can handle that. Some older Deore XT GS (has to be GS) RDs could handle a 34 and will be compatible with 6sp SIS shifting (you just got to adjust them). 38/34 should be alright.

Good luck

rhm

Rob, I know you like your crankset (especially if it's the one with the blue ring) but if you want lower gears --and I think you do-- give it up. Shimano made cranksets in both 110 and 130 BCD, and they look very similar; but with the former you can mount considerably smaller rings.

As for Biopace, I really like it too; but remember, all Biopace's advantages and disadvantages, whatever they are, are very subtle. If you can get a smaller ring by sacrificing Biopace, I'd say go for it.

khatfull

Biopace....I've found over the last few months for various reasons that I'm a much better and efficient rider at lower cadences than when spinning. I think some of the reason may be that I have very large legs and spinning at 95+ makes me waste a lot of energy juts moving these things. I've been riding the Biopace rings for about 6 weeks and while I can't attach any hard data to it I just feel more efficient.

When I finally get around to building up a commuter bike it will have a MTB triple with Biopace on it.

RobE30

I've got enough bikes/ frames in the basement that need to be built up, perhaps I'll just make one of them better suited to climbing until I have the stamina to do the long climbs. Until then, hill training seems to be in order

Phil_gretz

I've had Ovaltech chainrings on a tourer that I didn't like (mostly because the tooth sizes weren't right for my preferred range).

But recently, I literally trash picked (worthy of another thread) most of a complete 1989 Club Fuji in my size. I've only ridden it ~35 miles in its first two days, but I really like the overall feel, including the 42/52 Biopace chain rings. Just like this previous poster says, it feels more efficient and powerful to me, and I can't put my finger on it. Just to keep this thread active, and to say that so far I really like the feel of this particular bike. It's 7-speed indexed Shimano Exage Sport LX group throughout, and really clean looking in a retro sort of way. The BL A451 levers are terrific aero models, I think. I wouldn't change a thing.

Drakonchik

[QUOTE=Barchettaman;10878909]Of course, you can make your own budget Rotor Rings by moving the BioPace chainrings back 2 positions on your crank arm


Better to use Sugino Cycloid if you are going to do this because Cycloid are a genuine oval, unlike Biopace and Sakae Oval-Tech which are both a kind of rounded trapezoid.

WNG

Another vote for non-round chainrings. They have their intended place. I first noticed the improved climbing up a steep long overpass on a Bianchi mtb with Suntour XCM oval rings. I will assume these were OEMed by Sugino. On relaxed cadence rides, I felt fresher.
Not sure if there's any other option than those already stated. I'd try a standard 38 tooth inner ring. If that isn't enough, go to a 30 tooth low gear cassette.

20grit

I think there's a 39 tooth ring on my peugeot.... I'll have to look tonight. I'm fairly certain it is one, but might be a 42. Both numbers are coming to mind. if it is though, there are probably other ones floating around in the world.

USAZorro

Biopace just seems a gimmick to me.

Yes. I have tried it. If I get my hands on one, it gets sold just as fast as all things helicomatic.

RobE. rhm has it right. Touring doubles are the schniz.

Grim

Why not change the Freehub or Cassette if you like the frame?

Personally I like around a 28 tooth in the back and 36 on a double or a 40 middle on a triple on the cranks for hills. That said if you have the derualer to handle a 36 on the front then you can probably handle a 32 on the rear and that would be the same effect as 36 on the front.

Glennfordx4

My main bike that I rode for the last 20 years was a Pug-oh MTB that was set up for street riding and it has Biopace rings on it and I loved the way it rode for me it seemed smooth and didn't bother my knees as much so I was able to ride at at a higher pace then if I was riding with round rings. I have a large collection of Biopace and Biopace ll rings along with Ovaltech (which I haven't tried yet ) and I am going to set up a few of my better rides with them and compare them to some of my round ring bikes and see how it does.

snafu21

^^^^

+1. I have a 1990 MTB with Biopace on a triple Exage chainset. It's very comfortable for me, and I stripped and bent the chainrings back into shape, rather than just replace them so I get to keep it. I'm quicker with Biopace too. Easier on my knees, I think. I ride the bike mainly offroad.