Q ring upgrade - Ahhhhhhhhhhhhh......

[ratz]

Close very close; Staying with the factor etching I suspect:

• That OCP#4 may function more like #3 normally would.
• OCP #1 will be massy
• OCP #3 will probably spin like #2 normally would.
• OCP #5 will probably spin like #4 normally would.

I would suggest testing #5 on that bolt; it should spin fast and accelerate really well; you might feel a slight loss at the top end when you "push really hard"

#5 is normally starts to feel out of phase; so if it feels good that would confirm my theory.


#4's affect is what you want for you current training goals.

 

[ReklinedRider]

Same question as Dave Arnold's:

 

[ratz]

Kline,

Looks like you have a 130bcd; so you have all the holes usable your 53T; that's very handy.

You are on the hole marked #4 but your #1 aligned tooth is the first fully engaged at the dead spot (assuming that's your dead spot). So that would make your #4 = #2. So I would consider that an OCP #2 setup.

You could experiment and rotate the ring 1 hole counter-clockwise; that would be an OCP #4 configuration; then go ride and you should find better acceleration; easier spin and little less mashing top end.

The general consensus from the previous "spinners" in this thread was that they liked #4 better.... (sans larry). I played with the other settings this winter and was riding #2 on the Q ring; but went back to #4 on the QXL.

 

[Dave Arnold]

Same question as Dave Arnold's:
View attachment 3187 View attachment 3188

Kline, where did you find your Rotor chainring bolts? The only place I could find them was directly from Rotor and they want more for shipping than the $17 for the bolts themselves.

 

[Dave Arnold]

Close very close; Staying with the factor etching I suspect:

• That OCP#4 may function more like #3 normally would.
• OCP #1 will be massy
• OCP #3 will probably spin like #2 normally would.
• OCP #5 will probably spin like #4 normally would.

I would suggest testing #5 on that bolt; it should spin fast and accelerate really well; you might feel a slight loss at the top end when you "push really hard"

#5 is normally starts to feel out of phase; so if it feels good that would confirm my theory.


#4's affect is what you want for you current training goals.

Thanks coach--I'll give that a try.

 

[ReklinedRider]

Kline, where did you find your Rotor chainring bolts? The only place I could find them was directly from Rotor and they want more for shipping than the $17 for the bolts themselves.

Dave, a few years ago I bought some Rotor cranks, 170mm. I am using 145mm cranks currently. The Rotor chainring bolts came with the cranks.

 

[ReklinedRider]

Kline,

Looks like you have a 130bcd; so you have all the holes usable your 53T; that's very handy.

Right you are, 130BCD, 53T, long story. Plan to change to compact QXL in the spring.

You are on the hole marked #4 but your #1 aligned tooth is the first fully engaged at the dead spot (assuming that's your dead spot). So that would make your #4 = #2. So I would consider that an OCP #2 setup.

I will never understand these things! (Yes that is the dead spot)

You could experiment and rotate the ring 1 hole counter-clockwise; that would be an OCP #4 configuration; then go ride and you should find better acceleration; easier spin and little less mashing top end.

Will do, and see how it feels.

The general consensus from the previous "spinners" in this thread was that they liked #4 better.... (sans larry). I played with the other settings this winter and was riding #2 on the Q ring; but went back to #4 on the QXL.

That is my ultimate goal.

Thanks for once again reviewing my setup!

 

[ratz]

These Voo-doo rings. These Doval come with multiple adjustments but only to fit different spiders. As far as I can tell it will only go in one position for a compact crank. Can you please give your thoughts on the position in the photo? Pedal is at full extension.

Is that oval or osemetric?

No matter....:

1. For those find the Tallest tooth. by rotating thorough 360 degrees and use the derailleur as the reference point to find it; if it's oval there will be 2 equally tall; if it's osemetric their might only be 1 tallest tooth.
2. Once on you find the tallest tooth. Mark it with a marker
3. Remove the bolts and position either the left pedal or right pedal at 50% of the way through your power stroke; should be 60-70 degrees; (about 2pm on an analog clock for most people)
4. With the crank in that position; rotate the ring on the spider so the tallest tooth from step 2 is the first tooth engaging a full chain roller by the front deraillleur.
5. Find the best bolt hole combination to get you as close to that a possible. and reboot the ring to the spider.
6. Once you find that optimal spot or near optimal. If you bias the rotate counter clockwise a set of holes you favor the masher; "Early on set of leverage" if you bias the rotation clockwise a set of hols you favor the spinner and acceleration "Late on set of leverage".

The theory is that during the first half of your power stroke you want the ring to rise up to it's tallest tooth; then as you pass the mid point you want it to fall away from the tallest tooth. Wether the ring is Oval or Osemetric that tallest tooth orientation will remain valid.

This photo shows my Qring set that way. Note the blue line should be pointing 2 chain pins to the the left; I drew poorly back when I did this. If you look where the chain disengages from the front ring, you can see the (TW) labeled on the ring, that's the tallest tooth. The other one is directly across the ring from it;

 

[Bentas]

I'd like to know what you think of the Dovals ,compared to round ,Hardy once you get a few miles on them.

 

[ratz]

Hmm, I'm a bit slow with this. I can't move the chainrings into the other holes on the Doval. They are for other spiders. If not mistaken I must live with one position. But based on your high tooth theory I am guessing this set up is about dead center. Is this what you are seeing?

I see your crank arm align with the "crank arm" marking on the ring for a DF bike. That biases you about 5 degrees counter clockwise into a mashing configuration. you have a micro adjuster screw; it's currently set to 3 (I had to go read their manual). I move that screw to hole number 5 that should rotate the ring clock wise 5 degrees or so. Then go test ride. I think you will find that spins better and accelerates better.

Should look something like this contraption.



between the 5 holes on the ring; and the 5 on the adapter it does appear these things have a wide range of adjustment.

 

[ratz]

You may have to unmount them change it and play with it to see what I mean. I found some videos but the are not in English and the only cover the default. Similar discussion on slowtwitch where it baffled people until they fiddle and the bulb went on. Still looking for better guide.

 

[Jeremy S]

Ok how about this?

Assuming the pedal is in your dead spot the big ring looks pretty good. Before you were about 90 degrees off.

 

[ratz]

I agree with Jeremy, that looks a lot better. The crank arm marking is a for a diamond frame. What I could not tell from the videos that were in Chinese was whether moving the adapter was going to cause you to have to install the ring on different holes which it appears you had to. or whether it was going to rotate the ring and keep the same mounting positions.

I would experiment with #5 and #4 and see which you like better. Getting this figure out could be a big win. I Just read a 173 post thread on MTBforums.com and it is cleaner he Dovals have come a long way in 4 years

 

[ReklinedRider]

What would be the advantage of these over Rotor?

 

[ratz]

What would be the advantage of these over Rotor?

Besides price? These are migrating towards double oval. Giving you potentially an osemetric ring with adjustable clocking. The osemetric brand won't work on a recumbent, and Nor will the ones from absolute black as both assume a DF position/orientation in their design so no clocking adjustment via an OCP offset, my guess isabsolute would be open to making a recumbent version if their was enough demand they get very involved in the forums.

The question remains if doval are truly a double oval or a chopped symtrical ring. They have been changing the rings enough as they become a polished product I'm not sure which it is. It looks double oval to my eye, but that means nothing, it's just subjective.

how it rides is what matters and Hardy seems to be on to the best test we've had so far in pspite of the headache it's giving him.....I can sympathize that MTB thread gave me a headache too.

http://forums.mtbr.com/drivetrain-shifters-derailleurs-cranks/oval-vs-asymmetric-rings-936577.html

 

[ReklinedRider]

That mtb forum...indeed the whole gamut of non-round chainring concepts....reminds me that I'm not an engineer
As if I needed any reminding!
But still very interesting and enlightening, despite the headache inducing eye crossing confusion factor.
What's next? Rounded triangular cogs to synchronize with the double oval rings?
Thanks for the link and explanation!

 

[ratz]

I made my test run with the chain ring in the new position this morning. The route was on my 26.2 mile out and back (700 feet ascent). Out was 20.4 mph. Back the total avg dropped to 20.1. Last week I did the same run at 20.7 out and 20.5 back. Essentially this difference is inside the margin of error. I did feel a difference when first starting but the jerkiness sensation soon smoothed out. What does it all mean?

It means go find some rollers to go up and down; and if you have the patience try and get about 200-250 miles on that configurations. The theory is that you will climb with less exhaustion and descend faster with a smoother spin.

If you can make a slow motion video of the crank turning with the chain attacked that would also let us confirm what we see in the static pictures. These are "new" to all of us so verification and triple checking doesn't hurt. Again just cool to have someone blazing the trail; the "theory" is the same so it's just making sure we are applying what we already know going back to John T's analysis correctly.

 

[ratz]

Yes that looks good; #5 or #4 are going to be very friendly to the recumbent position. If you want more "spin" and "less" mash you might want #4 to be your test case. Even though those holes are close together they represent 3-5% clocking change and that's quiet a bit. And #5 There looks very Larry O friendly as it gets "big" early in the stroke. Yes I think #4 would be the way to go... Anyone else see what I'm seeing?

 

[ratz]

It seems with 140 mm cranks you would want big early in the stroke because you dont have much stroke in the first place. I didn't swap the small chain ring over. I think I'll give this a few hundred miles and then swap both rings to #4.

Reasonable; if the knees baulk then do it sooner.

 

[cranky cyclist]

I am interested in the Doval rings. I will follow your post to see how they perform.