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| Round chainrings are so... last year http://dirttreaders.com/phpBB3/viewtopic.php?f=9&t=16248 |
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| Author: | chuckanado [ Thu Mar 19, 2015 4:30 pm ] |
| Post subject: | Round chainrings are so... last year |
Something came in the mail today, all the way from Poland...     I hope to find the time to get it on the bike and go for a test ride this weekend  In case you're all like WTF??? an OVAL chainring??? Didn't Shimano already do that 20 or 30 years ago with the BioPace? Well, check this out: OVAL 104BCD Chainring from AbsoluteBlack. Be sure to scroll down to the paragraph that starts off with "Word on BIOPACE..." Anyhow, once I get it mounted up and get in a few rides, I'll post a review. |
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| Author: | singletrackmitch [ Thu Mar 19, 2015 6:08 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
...are you going to lube your chain with snake oil?  Nice to see they remind the user to make a chain length adjustment. Otherwise, the math is all there...always was. Eliptical designs were a bit aggressive but the Biopace and Biopace HP gave advantages to some disciplines of cycling. Post up some reviews on how it works out for you! -Miss ya Chuck. Stop by the store sometime. 
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| Author: | chuckanado [ Thu Mar 19, 2015 6:54 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
In case anyone wants to know more about these, there's a 31-page thread about these over on empty beer. It was started by the guy who makes them (and designed, etc) and he's had to reply to a lot of skeptics. But more and more folks are getting these and the reviews that are coming in are overwhelmingly positive. |
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| Author: | Canaan [ Thu Mar 19, 2015 8:27 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
A guy I have been riding with lately is very fast and swears by these rings. |
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| Author: | tfitz [ Fri Mar 20, 2015 4:10 am ] |
| Post subject: | Re: Round chainrings are so... last year |
You can try them risk free for 30 days.  No low balls. |
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| Author: | chuckanado [ Fri Mar 20, 2015 2:01 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
tfitz wrote: ...No low balls. So it's a "no" for this cute li'l fella? 
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| Author: | PaulChavez [ Fri Mar 20, 2015 2:30 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
I thanked you for linking to the empty beer thread, but I should really be cursing you since I wasted half a work day reading it. oh wait... thanks! |
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| Author: | chuckanado [ Fri Mar 20, 2015 2:31 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
Got it mounted up and took it for a short spin. I did a quick 3-mile route around the neighborhood and into Balboa Park, with a few short, steep hills thrown in. First I rode the route with the old 32t round chainring, then came home and swapped in the new oval ring and went out and re-rode the exact course again. Trying to get a before-and-after experience and eliminate too many variables. I can truly say this thing rocks!! It felt kinda weird for about a half-block, and then it felt completely natural for the rest of the ride. Standing up and mashing on the pedals to get up a steep-assed hill was awesome - I kept it in a higher gear than I normally would but never felt like I was going to stall out. It was like... I'd mash down with my right foot, and at the end of its downstroke, almost instantly my left foot had zoomed around to the top of its power stroke. On one steep hill (on a loose gravel trail) I stalled and stopped because of a mis-shift (nothing to do with the new ring). But getting started again seemed a lot easier than usual. Here are some pics of the installation in progress and a short video showing it in action: Before:  Before, up close:  Old chainring removed:  Tools ready to go:  Sliding the new ring over the crank arm (didn't have to pull the cranks!):  The new ring bolted in:  Note the alignment tab, located behind the crank arm:  After - crank is in position for the maximum radius of the oval in the "pulling" position:  After - with the crank in position for the minimum radius in the "pulling" position:  All done and ready to roll!  Here it is in action: Hi-res images HERE. |
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| Author: | Ray Dolor [ Sat Mar 21, 2015 6:24 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
The guy I ride with several nights a week, has also been an avid velodrome racer, on and off, for almost as long as the velodrome has been there, by the looks of it. (JK....t looks great!) I expressed some interest about these rings to him, and basically, he just pointed out that nobody racing at the track has, to his knowledge, tried them. And as you know, Chuck, the velo track is a very hard-edged place. People are gonna do whatever they can to get an itsy-bitsy increase in the performance of those single speed, fixie bikes out there. That said, I'm still very interested to hear your report on it. I was just out there in Florida canyon with him last night, doing a couple of laps. I was riding the old Joker I have, which is now a 1X10, and I can manage anything west of the 'real mountains' with it........but I'm always looking for a bit extra, too... So please, do tell, but pay attention to your knees, too. I dunno about you, but I ain't gettin' any younger. |
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| Author: | Canaan [ Sat Mar 21, 2015 7:14 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
Ray Dolor wrote: And as you know, Chuck, the velo track is a very hard-edged place. People are gonna do whatever they can to get an itsy-bitsy increase in the performance of those single speed, fixie bikes out there. Years of riding a fixed gear bike really smooths out your pedal stroke -- maybe that minimizes the advantage these rings provide to people who don't pedal squares. |
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| Author: | Dirtrider [ Sat Mar 21, 2015 7:17 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
Not wanting to poo poo the idea but I would think that any bike manufacture/ component provider would be doing this by now. Sounds like the marketing would spur interest quickly I had an older bike (still do but gave it to my sons GF) that was bio pace but I can't remember how it rode. I would be slow with or without it 
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| Author: | OhNooo [ Sat Mar 21, 2015 7:39 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
I used to ride biopace rings on my old GT Avalanche. This was late 1980s, since I was riding up in Fullerton with these rings before moving to San Diego in 1990. I had all 3 chainrings with biopace, but I had to change out the smallest ring to circular. There was something really odd in the way that a climb in granny gear felt with the oval rings that I couldn't stand. I'm a stand-up masher on the climbs, not a seated spinner, so they just didn't work for me. But I did like the oval rings on the upper two rings, as it feels better on my knees in the higher gears. I would have expected your new rings to have the same odd feedback in the lowest climbing gears. Maybe they've figured that out in the last 25 years? |
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| Author: | Ld00d [ Sat Mar 21, 2015 8:30 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
seems like they would be like switching gears in the middle of your stroke. |
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| Author: | chuckanado [ Sat Mar 21, 2015 8:56 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
Well, over the last 2 days I've done a few rides on my local trails (Florida Cyn) with a good mix of hills (dirt and pavement) and rolling single track. So far it feels very natural; I somehow feel stronger on the climbs but maybe it's just that I'm getting back in shape. You can't really compare this with the BioPace rings from 20+ years ago - for whatever reason, BioPace positioned the oval at about 90 out of phase from the current ones. With BioPace, the largest radius of the oval is in the pulling position (at the top where the chain is at a tangent to the ring) when your stroke is at its weakest, meaning at the very top and bottom of the stroke. At your strongest (cranks horizontal) the BioPace has its smallest radius pulling the chain at the tangent point. The current generation (including AbsoluteBLACK and Rotor brands) does the exact opposite - the small radius is pulling the chain at the weak part of the stroke, and the large radius is pulling when you have the most power (on the downstroke, with the cranks at around the 3-4 o'clock position). The idea is that when you're generating the most power, it's harnessed via a larger gear ratio. Then when your legs can't generate much power, they coast through with a lower gear ratio. Overall the ratio is the same - i.e. the number of wheel revolutions per crank revolution is the same as with a round ring. Supposedly there are a few top TdF riders using oval rings. We'll see if they catch on and if any of the bike manufacturers throw their hats in. |
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| Author: | mongooseboy [ Sun Mar 22, 2015 2:59 pm ] |
| Post subject: | Re: Round chainrings are so... last year |
Brad Wiggins won the tour De France using Rotor oval rings. I think Chris Froome uses them as well. http://www.ovalchainrings.com/ |
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