michaelm101

Knee Pain Help: Oval chain rings, “Q” rings, Biopace?

Throughout my adulthood, I experienced occasional knee pain and stiffness/weakness from decades of stomping around on concrete tennis courts. The pain was under the knee cap and caused debilitation in my left knee, about once a month, for a few days. I began cycling on a more serious level in 2011 and haven’t had symptoms since…. Until recently, however, and I’m still dealing with it today, everyday 

I’m in the process of replacing the crankset on my favorite bike, an 18- year-old flat-barred Cannodale T2000. I also still own an 80s vintage Mongoose IBOC Pro MTB and it’s got “Biopace.” I still remember the sensation of that system and I truly felt it was excellent for climbing and traversing through streams. However, I was a younger man then and, perhaps, I perceived things differently than I do today.

Recently, I’ve read a few articles about the overpriced “Q”-rings, and oval chainrings that have hit the ever-changing, fad-ridden cycling market.

Can anyone with experience comment on the orthopedic benefits, if any, of the standard round chainring systems vs Biopace, “Q” or Oval systems?

Thanks in advance!

Retro Grouch 

I'm sure you will get several answers on the oval chainring question from people who know more than I do on the subject.

As long as you are planning to replace your crankset anyway, you might as well add crank arm length differences to your decision mix. You may benefit from shorter crank arms because you'll flex your knee less. The pay back for that, of course, is that you lose a little bit of leverage.

The sweet spot for crank arm length for me is 165 mm. That's between 1/4" and 1/2" shorter than you will typically find.

JohnDThompson 

I'm not aware of any orthopedic benefit to non-round chainrings, but shorter crank arms mean less extension/flexion of the knee joint, which may help your knee problem.

fietsbob

Gear lower, slow down, walk hills if they are too steep and your knees start to hurt.

Kontact 

Q rings and Biopace are both oval, but work pretty much in the opposite way. Biopace is more likely to be easier on your knees, Q harder.

But for anyone riding close to 90 rpm, I don't think you'll get any benefit.

Pronation, cleat angle, Q factor, crank length, saddle height and set back are all factors in knee health.

reverborama

^This^

There are lots of articles about adjusting your saddle to deal with knee pain like this:
https://www.bicycling.com/training/h...-out-knee-pain

If I was going to spend money on the problem I'd probably want to work with a bike fitter at a local shop to work something out before I started changing to a new type of crank.

TiHabanero

I too, suffer from knee pain when riding. There are two things that I did this past fall that helped considerably.
1. Changed the pedal stroke. How I was pushing the pedals in a way that stressed the knees. What I did was concentrate on using my gluts more and dropping the heels significantly more than what I was doing.


2. Moved the seat back so that I am well behind the pedal axle. In fact I have it as far back as it will go. I did find the Brooks saddle did not allow me to go back far enough so I changed over to a Super Turbo I have had since my racing days.


These two things cleared up the issue. Hope they work for yours!

PaddleFoot

Lowering seat helped me the most. Too far back makes my knee hurt worse. It all has to be just right.

Kontact 

The problem with this advice is that we don't know if your saddle was too high to start with or not. Other folks have gotten rid of knee pain by raising their seat.

Everything needs to be "just right", though many people are more tolerant of when they aren't. The problem is finding where right is.


(Not picking on you, it is just a good example of how hard it is to fix a biomedical fit issue from afar.)

Stormsedge

Seat adjustment is a big factor for the comfort of my knees. I have a bike with 170 cranks and two with 175 cranks...as long as the seat is set up right on whichever bike, my knees know no difference.

Also, did you recently start pushing yourself harder /raise your riding goals (speed, distance)? I tend to have knee complaints when I add too much too soon. Keep smiling.

bogydave

+1
Seat adjustment & faster cadence helped me
Got to where a 1/16th inch at a time up helped,
Took a while to dial it in. Good to go now.

Was researching professional bike fitting,
That might be an option to consider .

Maelochs

I am not a doctor, though I play one on the internet.

I recommend auto-surgery .... ice the knee, take a steak knife, and saw it open .... probe around in there, jab various stuff .... then spray it full of WD-40 and super-glue it shut.

Can't be worse than asking for critical medical advice on the internet.

I have to sort of agree with Kontact---Everything has to be adjusted to suit the specific rider, and we don't know anything about the set-up or about the rider. We also don't know if the pain is organic degradation, stress, some mis-alignment or a tendon slipping into a joint or .... Anything.

We could give all the set-up and fit advice in the cosmos and if the guy needs knee surgery ... we could be advising him to do more damage.

As far as it goes, I bought a set of BioPace cranks off EBay a couple years ago ... they might still be some more out there, lightly used. And I would try all sorts of set-up adjustments.

I hate doctors ... but at some point, if nothing else worked ... I might decide to get something examined while it might still be repairable, rather than after.

But even that is bad advice, because I know nothing about what sort of pain it is. It could be the OP has lousy mechanics, or a terrible fit, or he likes to stand up and grind on the hills and when you do you hyper-extends his knee. Or it could be an old tennis injury, or it could be cartilage breaking down.

Sure, try all the adjustments. Buit if it were me, I would have to think long and hard about what kind of pain it was and when I felt it and whether I was trying to play tough guy and just push through it to my own detriment.

I used to attend a spin class where it seemed half the riders had had knee replacements ... including one youngish (comparably) ex-tennis player who seemed too healthy to have broken-down joints. I bet a lot of them started with a nagging little pain ("I can push through it and after I ride I take aspiring and it isn't so bad") and ended up on an operating table with titanium Terminator joints being installed.

Aubergine 

Knee pain in the front suggests that your seat is too low. So my suggestion too would be a bike fit.

I agree with the rest that oval chainrings of whatever sort are unlikely to help. The one thing that did help for me was pedal float (the ability to rotate my foot while on the pedal.)

work4bike

I also suffer from chronic knee pain, which I first noticed in my late 20's on my first bike tour, a 1,500-mile self-loaded ride around the east coast; the doc told me I was just getting old and get use to it and eventually you'll have to have surgery.

Over 20-years later and after also picking up mountain hiking and running as a hobby, I've still haven't had surgery and don't plan on it; however, I still have this nagging knee thing (result of a childhood injury) that I have to manage.

I manage it thru weightlifting. Don't fall for the excuse (as I did) that because you are active in cycling, running, hiking (or tennis) that you don't need to work the lower body in the gym. I found out the hard way that that mindset is absolutely wrong.

The problem is, that most of these activities are quad-intensive activities and the posterior chain, i.e. the hamstrings, glutes, lower back.... don't get the same muscle stimulus in these activities. I now lift weights, both heavy weights and light weights that are designed to stimulate all muscle groups, things like deadlifts...and many more.

Muscle Imbalance and Common Overuse Injuries - Sports Injuries, treatment and performance information

BlazingPedals

Good advice, I think. Even though I don't understand the meaning when you put the words together that way.

In the 'bent world, the advice would be to get shorter cranks and smaller rings. Spin more to offset the decrease in leverage. Your feet will be going the same speed but with smaller pedal circles your cadence will be higher.

fietsbob

One setup , the largest radius of the oval is at top & bottom dead center , gear lower through the power stroke,

the momentum of your foot , increased , gets carried through the BDC...


then it gets a power surge from the kinetic energy of your foot finding it a little easier from that lower geared portion.the lesser, radius




..

BobbyG

+1 Crank length.

In my late 30's, back in 2000 or so, on a whim, I installed longer 175mm, or 178mm cranks on my Nishiki Blazer MTB-based commuter along with taller gearing. It really cooks.

Eighteen years later I own two other bikes; road bikes with shorter cranks. First a 1984 Nishiki International OLE edition road bike, with eliptical gears, and a 2015 Charge Plug.

When I acquired the Nishiki road bike I put in a smaller chain ring up front to better deal with the hills of Colorado Springs. So My large ring is oblong, and my small ring is round and to tell the truth, I feel no difference between the shapes.

Focusing back on crank length, the Nishiki International has the shortest cranks, and I feel like I don't get enough leverage. The Charge Plug has slightly longer cranks and they are perfect for me.

The Blazer mountain bike is now my utility/snowbike. It gets slicks in the non-snow months and I ride it often. But a couple years ago at 54 years old, I noticed my knees would feel a little tender after riding it, and last year at 55, I noticed I was aware of my hips after riding it.

Last Sunday I rode a 56-mile-a-year birthday ride on the Charge Plug and my knees were absolutely fine.

Every year I find I mash less and spin more. Infact my Blazer MTB not only has the highest gearing of my three bikes, but also the lowest. Going up hills I shift way down, grab the elbow rests of the aero bars and sit bolt upright to slowly spin myself up the major inclines of my routes. So I'm certain any knee discomfort is not due to mashing.

Anyways, that's my 34-cents.

Carbonfiberboy 

The for-sure fixes for knee pain are cadence, round pedal stroke, and directed exercises for the specific problem, if necessary.

canklecat

I'd like to try a Biopace or newer style oval chain ring, at least on the smaller ring. I'm a slug on continuous climbs but fairly consistent in neutral conditions (little or no wind), usually pretty close to the same speed and time on those segments. So it would be easy to test the effect.

I don't have any knee twinges now that I have my bikes dialed in but it's likely that anything that maximizes efficiency at the same effort would minimize the risk of wear and tear and injuries.

Carefully practicing deliberately paced squats and lunges helped my knees too. But I didn't have any knee deterioration or surgeries -- although it runs in the family, on both sides -- so I was starting with reasonably good joints for 60 years old.

fietsbob

(looking it up earlier) Q ring on smallest 4 bolt circle was just 10% out of round

IronM

Knee pain is common, but the causes are not. Very timely subject for me, as I haven't had knee pain for 2 years until yesterday (I very hard gravel ride). I manage knee pain though use of orthotics (proper leg alignment), a good bike fitting, and posture - especially the hip flexor (causes hamstring tightness which stresses the knee). I've also shortened my crank arm from 175 to 172.5, which came about in the bike fitting. Lastly, I train on maintaining a higher cadence, which helps with knee stress. I use to run with a asymmetrical chain ring, but it made no difference for me, personally. I get pretty good results if I can 'spin in circles' vs mashing the pedals in squares; but when I'm not thinking about it, yeah; I mash with low-cadence squares

michaelm101

Perhaps, my thread is being misunderstood. Cycling is not causing the knee pain and my bike fit is technically correct. Further, my orthopedist examined X-rays of my knees and said they looked great!

I think I know the culprit: my new obsession with pickleball! It's like serve & volley tennis, but everything's scaled much LOWER. LOWER net, much LOWER bouncing ball, means I gotta get much LOWER... OUCH!

My thread was an effort to get commentary on the orthopedic benefits, if any, of the standard round chainring systems vs Biopace, “Q” or Oval systems, which perhaps, may allow me to play MORE PICKLEBALL!

Thanks for all the excellent replies!

Sojodave

Last year, I was having painful knee problems. I got a fit, and he said that the leg with the painful knee was slightly shorter. He changed my fit, put a wedge on my cleat and that fixed my knee problem. I know it sucks to pay someone to fit your bike, but it is worth it.

Kontact 

Did the wedge merely address the leg length, or did it also adjust your lateral foot angle?

work4bike

I understood your OP. I didn't answer the question about chain rings, because I think any orthopedic benefits of the Biospace chainrings are minimal, at best, if any at all. I used them once in 30-years of cycling...I wasn't impressed.

Your orthopedist performed an X-ray on your knees and didn't see anything, yet you still have pain.

I resubmit my post, quoted above.