AbsoluteBlack serves up the Taco bash guard, plus new 94BCD oval narrow-wide chainring

When I first saw the picture and read Taco I thought this was a repurposed bike part made to be used in a kitchen. So I guess it’s time to eat…

@Chasejj, wasn’t there a whole discussion on here a few weeks ago in regard to an announced release of RaceFace type direct mount oval rings, and how the adjustment increments are way too big? Basically the manufacturer (cant recall if it was AB or not) was making the same claim as you, but peeps with Rotor and other non-round experience were pointing out rotating a single spline on a RF crank sweeps you beyond the extremes of most other non-round ring adjustment ranges.

Also, when you say “When you retard the clocking so the crank arm is at the largest radius (top of chain) you really unlock the potential I have experimented at the 4:30 position from stock at 3:30.” I’m having a bit of trouble reconciling the beginning of the sentence with the end. The end makes sense, that you have clocking set so the arm is at 4:30 at the point of max radius, but the first part sounds like you have it so “the crank arm is at the largest radius”, which is BioPace style, not Rotor style.

Glad it’s working for you, but just wanted to clarify a bit because your real world experience doesn’t seem to square with what else I have heard.

Hi,
Marcin @ absoluteBlack here,

There seems to be some small confusion here regards timing (clocking). We have done really extensive research about that and shape of the oval in last 2 years and I personally think that timing around 3.30 o clock (which is about 115-120deg from 12 oclock position) is best possible way to use ovals in the shape we have.

While some experienced oval riders may feel that later timing works better for them (like 140deg) than the timing we propose, our research shows us that there is absolutely no benefit to move timing over 120deg.
There is a quite a big thread on mtbr about that where I wrote reasons behind that statement. In short:
Some people think that most of your power is generated close to full extension of your leg which points at about 140deg in general and this is where they wnat to have max radius of the ring. But truth is that you actually generate most of your power earlier. This is quite complicated to explain here as you have to involve kinematics to the equation and do not look only at geometry of the leg position and crank. Your force delivery to the pedal that propels crank in circular motion is low after 135deg.

It was us that made a RF cinch ring with indication that you can move timing if you wish. But we also stated that this is reserved for people who know what they do and this is what they think is best for them. Moving one notch on RF cinch interface moves you by 22.5deg. That gives you roughly 140deg angle.
I say roughly as each of our oval chainring size has a bit different timing and ovality to account for different pedaling behaviors.

Concluding. For 99% of people out there our signature timing of the ring is best what you can get. The only people who think about experimenting with timing are the ones that are long time users of the oval rings (years of riding). The more aggressively you time the ring the more changes you also need to make to your riding position. And this without proper knowledge, professional fitter and measuring equipment is not something we recommend to try yourself.
Stick with our signature timing and you are good to go from the start with no modifications. Don’t over think it. We have done all the thinking for you.

Kaiser and Marcin- I questioned the effectiveness at 330clocking and tried 230 and then 430. The clocking refers to top of chain at tangent of largest radii crank arm at the time on the clock. RF lobes being 22.5D apart gives you really only 330 and 430 to play with as 230 is just not going to work with anybody I can think of.
For my pedal style and pace the 430 seems to work better. Seems to make more effective use of my quads as well. It pedals easier and allows me to gain a gear and sometimes 2 over round or the 330 clocking.
My guess is that I would be maybe a very small % of users that have that experience since I am way outside the typical rider profile in size. Pedaling style is definitely a factor.