Dura Ace 167.5 9 speed cranks

[Heidi]

Anyone have a set they don't want?

[Pau11y]

Heidi, I saw this in rec.bicycles.marketplace. It's an 8 spd crankset (7402 w/ 39/53 rings). But if the BCD is correct (130mm), then it should take 9 spd rings. I believe the 8 spd rings should work tho. Anyway, check it out. Just make sure it's Octalink and not square taper.

http://groups-beta.google.com/group/rec.bicycles.marketplace/browse_thread/thread/f656bf0796a4be9c/0dd0fbc06857944c#0dd0fbc06857944c

[indieboy]

Heidi, I saw this in rec.bicycles.marketplace. It's an 8 spd crankset (7402 w/ 39/53 rings). But if the BCD is correct (130mm), then it should take 9 spd rings. I believe the 8 spd rings should work tho. Anyway, check it out. Just make sure it's Octalink and not square taper.

http://groups-beta.google.com/group/rec.bicycles.marketplace/browse_thread/thread/f656bf0796a4be9c/0dd0fbc06857944c#0dd0fbc06857944c

octalink wasn't around when 8spd cranks were.......

[splat]

Heidi, what size are your current cranks ?

Is this because of the Knee issues ?

[Heidi]

Heidi, what size are your current cranks ?

Is this because of the Knee issues ?


170, and yes kind of. I'm moderately inflexible in the hip/hamstring area and despite EXTENSIVE concentration and practice - my pedal stroke has a minor flaw...it's nothing big, but it has been suggested by a specialist that I reduce the crank size a tad bit and get my brain trained to that "perfect circle" that you hear all cyclists babble about. Again, it's nothing that big, but if I FEEL like I can't apply even pressure throughout the whole circle because my legs doesn't really like to go that far, than it isn't.

[Serial Midget]

get my brain trained to that "perfect circle" that you hear all cyclists babble about.

One of the toughest efforts to quantify but when I am fatigued it takes great concentration to power the full circle. I have difficulty doing this on the rollers and have ridden off the side when my mind wanders after 90 minutes or so.

[Heidi]

One of the toughest efforts to quantify but when I am fatigued it takes great concentration to power the full circle. I have difficulty doing this on the rollers and have ridden off the side when my mind wanders after 90 minutes or so.

Yah, I always think I am, but am not sure until I ride on the computrainer with the spin scan right there telling me my score.

[indieboy]

oh man
heidi don't fall into that perfect circle bull****. most of the top pro's couldn't and DON"T have a perfect circle pedal stroke, it's actually more oval shape. all that truely matters in the long run is what you are physically capable of pushing out

[Heidi]

oh man
heidi don't fall into that perfect circle bull****. most of the top pro's couldn't and DON"T have a perfect circle pedal stroke, it's actually more oval shape. all that truely matters in the long run is what you are physically capable of pushing out

It's really more that I can't reach the top of my pedal stroke completely, it's hard for me to snap over the top because I feel as though my leg doesn't come up that far! I already took a crapload of measurements and stuff so I know my seat height is right, and the angle of my him to my foot when in the bottom position is around 165 degrees. And that's not true, a lot of pros can and DO have a perfect circle...well, better than mine :) If you aren't using any uppull, than how efficient is that? I'm not saying I don't, but after making a couple adjustments, I am now using a lot more of the upswing and getting a crapload more power output from my hamstrings.

[Pau11y]

I tried to smooth out my pedalling by spurting into the really hi revs and not pogo-ing on my seat. I've burst upto 140s using a 160 or 165mm cranks on the exercise bikes in the gym (sustain the revs for 30 sec to one min). And you'd think in doing this, I'd get my pedalling "round". Even tho I don't pogo, I really don't think it's round. I end up using a lot of my ankle and "flicking" the pedal at around the 5 to 7 o'clock positon, and kicking at around the 10 - 1 or 2 o'clock position. Also to achieve this, I had to loose about an inch on the seat post.

Edit: my normal gym cadence is around 110, and normal bike rev is around 100 (175mm).

[SuspectDevice]

If you want, you can order you 165's or 167's from Shimano USA directly. Shimano still produces the full 7700 Dura Ace track group, and they make the cranks down to 160 for that applicaton.
It sounds to me like you have flexibility issues more than structural issues though... and even then, pedaling circles is bull****...

[Heidi]

I don't get why you guys are so against improving a pedal stroke so that you are being more efficient. You can't tell me you don't think that learning to get power throughout the stroke isn't better.

I agree, it is a flexibility issue, but I've been doing tons of stretching since I hurt it 6 months ago and if that isn't helping then I need to change something else.

[splat]

I think Improving your pedal stroke is a great thing, if you can increase your power per stoke , it means more speed which in uturn means More victories, which in turn means more cool stories of you kicking butt!! :)

[DRB]

You might try emailing Lennard Zinn at l.zinn@comcast.com. He does the tech column on Velonews and he consistently comes up with sources for components out of the mainstream. I'd explain how you came to the decision to try 167.5 out (which makes perfect sense to me) he might also be able to offer some other alternatives.

[splat]

Heidi

check out
http://www.coloradocyclist.com/common/products/productdisplay2_v2.cfm?PRRFNBR=11070&S=35214,26608,35237,11180,35240,35232,11216,35243, 11276,35215,10943,10940,35216,10970,10971,35217,21 858,35218,11020,35220,11111,11108,35219,11070,1107 9,14259,14266

[Wumpus]

Maybe you should get some of these:

http://www.cyclingnews.com/photos/2005/tech/probikes/julich_csc_cervelo/dsc00678.jpg


Did anybody else notice Julich using them in the mountain and TT stages of the Criterium International?

[splat]

Campy use to make ones like that back in the 80's and then Shimano followed with Bio-pace !!!

dam how many Teeth are on that thing!!! it looks huge!

[Heidi]

Maybe you should get some of these:

http://www.cyclingnews.com/photos/2005/tech/probikes/julich_csc_cervelo/dsc00678.jpg


Did anybody else notice Julich using them in the mountain and TT stages of the Criterium International?

I did, I was wondering what they were.

[Wumpus]

For those that missed the 80's:

To get the obvious question out of the way, this isn't a resurrection of Shimano's Biopace rings of the 1980s. An elliptical chainring changes the effective gear ratio as you pedal. Biopace reduced the gear ratio as crank passed through the horizontal; the O.Symetric Harmonic increases it. The idea is that the sector of the pedal stroke where the crank is horizontal or nearly so is where you can push hardest, so it makes sense to increase the gear at that point, then drop it to get your foot through top and bottom dead center quickly. It's the same idea as British component maker Chris Bell's Eggrings and, well, just about every other inventor who has come up with elliptical chainrings since shortly after chain drives were invented.

However, while the idea has come and gone many times in the last 100 years or so, it clearly seems to work for Bobby Julich, who has used the O.Symetric rings to land an Olympic bronze medal, and to contribute to CSC's team time trial victory in the Tour Méditerranéen.

The O.Symetric rings are mounted on 172.5mm FSA Superlight cranks, a monocoque carbon fiber crank that turns on an oversized ISIS spline bottom bracket. At the ends of the cranks are Speedplay pedals, long a CSC team pick.

So who had the 'privilege' to ride biopace rings? I put round rings on as soon as the bios wore out.

[splat]

So who had the 'privilege' to ride biopace rings? I put round rings on as soon as the bios wore out.

I did !

And I put round rings on as soon as they wore out oo!

actually my wife's hardtail, still has one bio-waste ( the outer one ) on it.

Funny thing is I remeber when the Bio pace rings first came out they were hailedas a great achievemnet and all the other companies followed suit and for about a year or 2 it was dam near impossible to find round rings , then every one started getting crasier and craiser making funny shapes out of them be fore every one just went back to round rings.

the thing is the early ones really weren't that out of round almost un noticable and might have actully worked , but they got too crazy with it.

[indieboy]

he's been using those since the olympics. it's a normal sized 53t ring

[Wumpus]

he's been using those since the olympics. it's a normal sized 53t ring

" It was over a year and half ago that we saw these strange looking rings on Julich's bike in Hamilton, Ontario Canada during the 2003 World Road Championships. There he claimed that the rings, "we good for 5 seconds per kilometer."

Julich used the unusual rings at the Vuelta a Pais Vasco last year, where he beat Hamilton (Phonak) by less than one second in a time trial at the Spanish stage race. Julich also raced the technology in the climbing stages of last year's Tour de France, although he chose to run only the inner ring to satisfy his Shimano sponsorship. "

[Nitromike]

Campy use to make ones like that back in the 80's and then Shimano followed with Bio-pace !!!

dam how many Teeth are on that thing!!! it looks huge!

Looks huge but if I counted right behind the crankarm its only a 52.

[James]

My favorite was the Bio-Pace knockoff called "Oval-tech."
Ha ha ha, they were quite the cutting edge, but look at them now! I wonder what current "cutting edge" products are going to look stupid as hell in 10 years or so?

[MtnbikeMike]

My favorite was the Bio-Pace knockoff called "Oval-tech."
Ha ha ha, they were quite the cutting edge, but look at them now! I wonder what current "cutting edge" products are going to look stupid as hell in 10 years or so?

That'd be a tough one, because I don't see any parts that are out right now that have major flaws and are the only things available.....well maybe rapid rise? But I actually like it. I know! Square taper Campy cranks! :p ;)