Oval chainrings

[DirtyFrank]

9 spd as well. But yes 1 X. For 2x or 3x it is ROTOR

How do these work with the derraileur, seems like it should affect the shifting given the variance in diameter or is this negligible?

[EVOBIKES ONLINE STORE]

Negligible. Have absolutely no issues on Roadbike and had no issues when I was running x 2x on MTB

[Rick Sanchez]

http://www.evobikes.co.za/absoluteblack-oval-104bcd-chainring.html

 

is this a narrow wide ring? ie 1x setup without a retainer?

Yes it is.

[Prophet]

I'm in the process of up-sizing  wheels to 650b on my "hard" dual suspension bike.  It seems to be the right time to also go 11x1 but I am fearful of the granny ratio.  Even with a 30T chainring the granny ratio is compromised by about 10% when compared to the current 9 speed granny gear set-up.  My fearfulness in this regard stems from my 93kg weight, middle age, being mostly a weekend warrior and having to climb a lot when riding (not much flatness where I live and ride). 

• From what I have read here it seems that an oval chainring can help alleviate the granny gear worries with say a 32T oval (or even 30T if such a beast exists)??? 
• if a 32T does not alleviate it, it could at least give more or less the same ratio as a 30T round for climbing but with a bit more available at high speed?
• My second bike will remain on round chainrings.  question is if I am going to frustrate myself in riding the one then the other?   

Advice/Input will be appreciated.

 

PS - loosing weight is much harder than upgrading bicycles!!!

[supertorro]

I'm in the process of up-sizing  wheels to 650b on my "hard" dual suspension bike.  It seems to be the right time to also go 11x1 but I am fearful of the granny ratio.  Even with a 30T chainring the granny ratio is compromised by about 10% when compared to the current 9 speed granny gear set-up.  My fearfulness in this regard stems from my 93kg weight, middle age, being mostly a weekend warrior and having to climb a lot when riding (not much flatness where I live and ride). 

• From what I have read here it seems that an oval chainring can help alleviate the granny gear worries with say a 32T oval (or even 30T if such a beast exists)??? 
• if a 32T does not alleviate it, it could at least give more or less the same ratio as a 30T round for climbing but with a bit more available at high speed?
• My second bike will remain on round chainrings.  question is if I am going to frustrate myself in riding the one then the other?   

Advice/Input will be appreciated.

 

PS - loosing weight is much harder than upgrading bicycles!!!

Can't speak for the oval rings, but as a lard arse myself (approx 88kg) the move to 11x1 (34t on the front, 10-42 rear) was no problem, except on the absolute steepest of steep hills. And even that wasn't a problem if I kept up a bit of regular riding. This was on a 26" full sus 150mm beast with very plush suspension. Also looking to moving the 650b bike to a single ring and will likely go with 34t ring up front anyway. I wouldn't worry too much about whether you can pedal it, just grit your teeth and soon it'll be like normal

[Prophet]

 

 

thanks for the feedback. The bike earmarked for the upgrade is a fairly stiff dual sus with only 80/100mm travel and it accelerates very well compared to my 160mm trail bike.  I can therefore pick up the speed/cadence relatively easily with a few pedal strokes.  I guess the only way I am really going to know  is for me to try various chainring sizes starting with a 32T.  The only worry with this approach is whether or not the bank is going to get broken!

[Hardi]

 No - negligible. You will not know the difference or feel it.

I disagree, having ridden 1 year with a 34 Q-ring (10%), then changing to a wolftooth 32T(10%) for Sabie, I actually prefer the 34T because the 10% diff on 34(30.6/37.4) is bigger than on 32(28.8/35.2). Having said that, it also might be the deadspot angle difference

[EVOBIKES ONLINE STORE]

I disagree, having ridden 1 year with a 34 Q-ring (10%), then changing to a wolftooth 32T(10%) for Sabie, I actually prefer the 34T because the 10% diff on 34(30.6/37.4) is bigger than on 32(28.8/35.2). Having said that, it also might be the deadspot angle difference

The OP was refering to the same T but different manufacturers... 32T Wolf vs 32T AbsoluteBlack.

[I FLY]

Would an oval ring work on a SS bike with horizontal drop outs?  

[Donovan Le Cok]

Any one have any feedback regarding how long (if at all) it takes to get used to these and will I struggle at first?

 

Rotor says it takes about 40 hours of riding for your legs too adapt. I am sure it is dependent on your level of fitness.

 

For me it was 2 or 3 hours and I felt comfortable, I am  sure it took longer to get the full benefit though.

[IH8MUD]

Would an oval ring work on a SS bike with horizontal drop outs?  

 

Yes, Or that is what I have read. 

Even  though the ring is oval and distance change or appears to change it works. 

Something about the number of teeth meshing with the chain is  the same or something like that. 

[Mawbs]

im thinking a 32 oval up front with the new praxis 10sp wide range cassette and job sorted 

[HenkvE]

I'm amazed with the technological advances in sport these days. Just saw this diagram which shows all the different muscles used on oval chain rings.

 

muscle_activation.jpg

 

Nice diagram!

 

I think it's interesting to note that the exact same muscles are used with round rings. The leg position / crank angle as point of muscle activation is also most probably the same.   The difference caused by oval rings is the time of muscle activation as well as the duration of a particular muscle that's activated. There are also claims that different types muscle fibers (slow vs fast twitch) are activated. Just my 10 cents worth...

[HenkvE]

Yes, Or that is what I have read. 

Even  though the ring is oval and distance change or appears to change it works. 

Something about the number of teeth meshing with the chain is  the same or something like that. 

You've read correctly.  The gear ratio remains exactly the same, regardless if you use oval or round rings.  If you have a 36T chain ring (round or oval) it moves the chain through 36 links per revolution.  

 

The benefit (and purpose) of the oval ring is in the rotational speed variation through one revolution of the crank. The rotational speed is faster through the "dead spots" -vertical position of the crank and slower through the horizontal position of the crank.  A greater force (torque) is applied to the crank through the horizontal rotation and since it goes slower through that part of the rotation, the greater force (torque) is applied for longer (first benefit).  The crank goes faster through the vertical position of the crank where the lesser force/torque is applied and therefore less time is spent per revolution in the "low torque range" (second benefit)

 

Another claim by the oval ring fraternity is that different type muscle fibers (slow twitch vs fast twitch) are activated.  When a "10% ovality" ring is used the claim is that more slow twitch fibers are activated which benefits marathoners. When the ovality is higher, fast twitch fibers are activated which benefits sprinters. 

[Lance Roberts]

The OP was refering to the same T but different manufacturers... 32T Wolf vs 32T AbsoluteBlack.

Is there any ETA on oval chainrings for the new XT M8000 crank? I saw on the Absolute Black Facebook page that they have a new one specific to the M8000 crank... Is the BCD on the XT crank the same as the XTR M9000 crank?

[Bosbrommer]

Hi all,

 

Is there anyone that can give feedback on a Rotor QX1 34t oval chainring? 

 

Currently on 34t round - but would struggle if I have to do a stage race with lots of climbing so thinking of trying either a 32t or 34t oval. The Rotor QX1 104BCD only comes in 34t or 36t. I am running a XTR crank so need 104BCD.

 

Thanks