Would you recommend Q rings

[wendfan]

I'm just waiting for the LBS to tell me my middle blade needs to be replaced then I'm also getting Q-Rings for the Mtb.

 

 

On a Mtb, how does the wear and tear on Q Rings compare to the other brands (Sram, Shimano, etc). Not talking about negligence.

[The Guy in Pink]

I'm sorry Ivan, I did not explain myself clearly. <?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

With oval rings there is a loss of effort in continually lifting the chain 20-30mm  twice each revolution, even when the cyclist is just spinning without producing any power.

 

This loss can be caculated:

Power= Mass x acceleration x speed.

The acceleration is against gravity so.

Power = Mass x (acceleration+9.8) x speed

 

<?:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Watts = Mass x (distance/ time ? + 9.8) x distance /time

 

lets us assume that 100gramms of the chain is lifted 25mm vertically in 10? of rotation at a cadence of 90rev/min (1.5rev/sec).

Mass = .1kg

distance =25mm =.025m

time = 1.5*10/360 = 0.041666sec

 

power = .1kgx(.025m/ 0.041666. ? + 9.8 )x .025 /.041666

= 1.45watts

 

This loss of 1.45watts  may not seem significant, but it is there all the time when the peddling , even when there is no corresponding gain in power as the cyclist is idling with low power output.

 

My calculation is above rough, but I suspect that this is energy loss I have shown is the reason why oval rings were not pursued  move actively with arrival of the Bio Pace ring.  I am sure all combinations of power angle was analyzed then, and found offer minimal advantage for the added complication.  .

The Guy in Pink2007-04-14 06:06:07

[Ivanb]

well Our first set of Q Rings with Cashandra Slingerland was October 2005 she is still on the same set.

 

We had four sets in last years Epic those guys rode the same sets this year and there were more.

 

If you go to the product reviews you will see comment about wear.

Not good for us if they last like that Haa ha.

 

Richard Beswick has been riding his MTB set since July 2006.

 

signs are allgood

[Ivanb]

Guy in Pink, the Biopace was dramatically different. I can't answer you questions in the science of it but I will pass it on to Rotor . it is great to have these descussions as it proves the interest and hopefully that we are putting out the truths.

 

Biopace placed their big gear in the dead spot position. They also did not sceintifically design the 'oval' for a perfect pedal stroke. Rotor if you watch in spin scan is a true circle.

 

I will let you have answer soon to your comments.

 

Thanks again for that I am interetsed to find the answer. 

 

By the way whats your occupation with all this science and technology informations

[fandacious]

The power loss on lifting th chain is one thing, but what about power spared when the chain drops off the back of the q-ring again. Thats when you have gravity working WITH you. If you factor that into yoru calculation you'll find a very small NETT difference...

[Ivanb]

Thanks fand, this is beyond me all I know that we have great response with good results so they do work. In fact the replies show results far higher than we quote.

 

Maybe I should ask all Q ring riders to send before and after results and give a prize for the biggest margin improvement.

 

Must be tangible results that we can check by downloads etc

[BikeMax]

 

Thanks fand' date=' this is beyond me all I know that we have great response with good results so they do work. In fact the replies show results far higher than we quote.

 

Maybe I should ask all Q ring riders to send before and after results and give a prize for the biggest margin improvement.

 

Must be tangible results that we can check by downloads etc

[/quote']

 

How will you rule out any other factors that might have led to the improvement.....decent hard training for example

 

[Ivanb]

well the results we have seen have been literally the day the rings go on.

 

So it would need to be results within a week of placement or summin.

 

Have you guys done any tests with them?

[The Guy in Pink]

Ivan,

The maths involved to describe accurately what happens to the chain and the power required to lift it would take about a month to do, (and I would need to hit the books for six months to remember all the intergral calculas it would need.)

With oval or eleptical rings the accelerations are not uniform , the mass  of chain lifted varies continously etc, and at times during a revolution of the cranks it is not lifting at all

 

My caculation was a civil engineer's caculation - accurate to the nearest bulldozer - but it did show there are some losses, which may be half or double the 1.45 watts estimated.  

 

In short events I have no doubt the benefits of properly designed oval rings can outweigh disadvantages.

[Ivanb]

Thanks I am sure your 'ideas' if thats the word are good. It would be great to be able to do some testing on that line and more if we could and how could we? Obviously to show all advantages and disadvantages (if any)

[GoLefty!!]

Longevity:

 

Been using since mide february for the Lighthouse to Lighthouse MTB marathon. Still running strong with very little signs of wear.

 

Gearing:

I find I canhold onto a gear now at a lower cadence than previously. So my range has moved to around 60rpm to 100rpm on the MTB. At high rpm it feels as if you're running to light a gear and you want to shift up.

 

Endurance:

Certainly has lowered HR on the same climb in the same gear at the same speed and similar temp. Anecdotal indeed but not everyone has a lab and this not about power but about ability to maintain power.

 

Shifting:

Better than everything Except M960 XTR chainrings.

 

On a Full sus bike:
I ride a Cannondale rush and have found that the Q-rings give better traction. Theres no bob in the full open (no propedal damping).

 

On the road bik I also find i have bigger range of usable cadence.

 

Have given the power losses banter some thought but I think this is erally splitting hairs cos the power loss due to lifting the chain would be significantly less than that required for overcoming fricion within the chain.

[Ivanb]

All I can say is GO LEFTY!!!! GO thanks nice piece thanks

[fandacious]

Thanks for the info! I'll definitely be getting 2 sets of Qrings in the near future!

[Joobs]

My question is how much does it cost for a set for the small blade and big blade on a road bike?

 

And where is there more information online?

 

Thanks

 

[TNT1]

So, Ivanb, who got OB on QRings? The last thing we need is him producing more power... So far he seems un-convinced that they work though... 

[Ivanb]

Ob? dunno he needs to check his heart rate and speed for ride that was the same before and after q rings.

 

Most guys are getting lower hr higher power and cadence and speed.

Road R1500.00 set MTB R1750.00set TT and XTR are R1950.00