Recycled Cycler

I'm having issues with knee pain that can't be corrected anatomically. It's my right leg. Neuro/muscular/skeletal issues caused by a benign spinal cord tumor cause a lot of muscle weakness on the rt side. Tumor gone but damage done. My muscles are reacting to the nerve and thus muscle atrophy and I get knee drift, along with my rt foot constantly moving heel inwards. I can't use clip pedals because of these issues so I use flat pedals with toe clips.

The knee drift, after about 1,000 miles of riding this year, has taken its toll and now I can't ride 2 miles without a lot of knee pain because of knee drift.

To alleviate issues with heel pointing in on rt side and hitting chain stay, I've used 20mm pedal extenders. They exacerbate the knee problem because they create such a large Q-Factor. But remove them and heel clips chainstays.

One possible solution might be a bike with pronounced curve in chainstay so the pedal and thus my rt heel is far enough away that it doesn't clip the chain stay.

Any suggestions?

big john

I've not heard the term "knee drift" but I toe out and I use pedal extenders. I also use shoes with narrow heels and have used a grinder to take material off of the heels before.
I hit the chainstays on some bikes. The worst was a Cannondale CAAD5, fat stays and short rear center. I have a Gunnar Sport model which has a long wheelbase so the stays are long and they are thin. I still hit the right side but not much.

My Seven has curved chain and seat stays but they are fat and the rear is short so it's wide where my heels end up.

I also use a shim under the inside of my right cleat and I concentrate on keeping my right knee close to the top tube when it starts bothering me.

79pmooney

Three questions: How important is cycling to you? Do you have to have a 16 pound bike or can you settle for a 20 pounder? How much is riding and your knees worth to you $$-wise?

If your answers were very, no/yes and a lot consider a custom steel or ti frame. A builder can bend those chainstays to work for you. And get the rest of the bike exactly the way you always thought a bike should be). (I'm guessing not all builders are set up to bend small tubes so put this question out there from the beginning to save both of you time.)

Dave Levy of TiCycles has built me two frames. The second a road fix gear with a quite unusual dropout, I've been to his shop many times and seen all sorts of very different projects going on. He thrives on challenges. Look/ask around in your area. (Local makes things a lot easier.) Don't stop until you find someone who embraces the idea and challenge. (Some quick math suggests the bends will be very far back and quite sharp. This may need to be two separate tubes with a structural spacer/joiner between. So some engineering might be needed and an artistic sense will be a blessing.)

Edit: Your issue isn't mine. I"m pigeon toed and need to have my Q-factor as low as possible, ride with my knees in and force more toe-in with no-float cleats because my knees love it. But the differences are what makes this world so interesting,

cyclezen

don't have any suggestions for off the rack bikes/frames, but depending how important this and cycling in general is... consider getting a custom frame?
there's also a bunch of images on google, if you search for 'inward curving chainstays" like this:
https://cyclingtips.com/2016/11/kine...udgets-ablaze/ very tight frame with little clearance for anything above 700 x 25...
or
https://cyclingtips.com/2019/10/mason-bokeh-review/
The challenge is modern rear width, 130+ to 142...
now if you start searching for a 'classic'/vintage bike or frame, you might find something in the 126 or even 120 rear range - but then you'll have the 'old school' wheels and drivetrain issue..
depends on your riding needs...
or
just not worry about wackin the chainstay with your shoe, and break out the rattlecan to throw on a fresh coat of paint every now and then... if it's steel or alu, your shoe will disintegrate long before the stay shows any wear - other than worn off paint... not sure how CF would react to 80 rpm wackin...
Ride On
Yuri

chaadster

Are talking about something— knee drift— which only causes the heel to rotate in on the upstroke? If so, the term “dropped chainstay” may be helpful, as it is a fairly common design feature which may buy you some heel clearance if, indeed, your heel rotates inward on the upstroke.

EDIT: I should add that dropped stays are not a road bike feature, but can be found on gravel bikes commonly. Perhaps not ideal, but possibly a solution to the heel strike.

big john

Maybe elevated stays?

terrymorse 

I was thinking about a pedal attachment to prevent the heel from striking the chain stay. It would be pretty easy to build one, maybe worth a try.

Jack Tone 

I don't know what knee drift is, but would something like this work?

https://www.amazon.com/08814-Orthope...41235081&psc=1

I raced motocross with a bad cartilage with one of these for a while and didn't notice it while riding.

big john

You mean a pedal extender? I think he gave up on that.

terrymorse 

No, I wasn't thinking of a pedal extender. Something attached to the inside edge of the pedal, that extends to the rear to block the heel from striking the chain stay.

Recycled Cycler

No - my knew drifts in on the downstroke.

Recycled Cycler

They make the knee drift worse. Actually I think I made problem worse by using pedal extenders at start of season. I started using muscles in a different way as a reaction to the 20mm extended Q-Factor. They work great in opening up your legs and eliminate a lot of chaffing in crotch, but are now causing the knee issues.

Recycled Cycler

I'm thinking about asking IF if they could rebuild this bike to create an exaggerated curve.

big john

I wonder if that would be enough? In my case, I wear size 49 shoes so my heel hits the chainstay just ahead of the axle, right at the cable stop, so no amount of curving inward would help. Getting the axle further away from the bb, (long stays) helps a bit. I think I hit the axle nut on the mtb but it has a 148mm spacing (boost).

chaadster

If that’s the case, how does the chainstay interfere?

Troul 

would a knee strap, compression sleeve, or brace help maintain a better cycling stride?

Recycled Cycler

By using the extenders and increasing Q-Factor, I made problem with knee drift worse. It eliminates problem with heel hitting chainstay but is causing more knee drift and pain.

If I don't use them, my heel clips chain stay every turn.

Recycled Cycler

I am not sure. In reading about knee drift, it's cause by uneven muscle strength. I don't know if a brace would help. I'm gonna see a doctor and get opinion.

cyclezen

seems any 'adjustment' to the bike which allows the heel to 'hit' the chainstay isn;t going to address the root of the problem - which you note, causes 'Pain', which is the 'knee drift'.
it may mean less 'damage' to th ebike, but the knee drift continues and so does the 'Pain'.
So seeing an MD who specializes in these types of issues is prolly going in the right direction.
... do you have 'pain' when the knee doesn;t drift ?
or is the basic act of pedaling an upright bike at the root?
Ride On
Yuri

terrymorse 

A doctor is a good idea, especially if it's an orthopedic/sports medicine doctor.

Since you have a muscle weakness, the doctor may be able to prescribe specific physical therapy to reduce the problem.

I've had knee tracking issues that were caused by muscle strength imbalance, and physical therapy helped me.

Recycled Cycler

It's the basic act of pedaling an upright bike at the root, and I am postulating that the knee drift I see is causing the pain. Using pedal extenders causes more extreme knee drift. Without the extenders the drift is much less, but then my heel clips the chainstay.

terrymorse 

Knee wobble during the pedal stroke is just a symptom. The pain is almost certainly caused by the muscle imbalance. The most common knee pain is felt in the front of the knee, and it is called "patellofemoral pain syndrome (PFS)", where the patella doesn't track across the knee as it should. The treatment for PFS is muscle strengthening exercises to reduce the muscle imbalance.

Really, find yourself a good sports medicine doctor. They have done wonders for my knee pain. Although you're probably stuck with some muscle weakness from the nerve damage, a good sports doctor will know which exercises you can do to reduce the problem.

cyclezen

let me tell you my story.
In 2017 I tore the right ACL and PCL off the bone while skiing (partial tear of the MCL). The resolution was 'replacement' of the ligaments.
Surgery went fine and I had to wear a immobilizing brace for 2 mos. then a functional/structural brace for another 3 months - but able to do PT and rehab.
Went to PT, and with the PT, we outlined a plan to regain best range of motion and structural strength.
1. Did exercises for range of motion under PT direction, strengthening of surrounding muscle.
2. By 2nd week of rehab, I started cycling... had about 20% range of knee motion at that time. I took out my mountain bike, with flat pedals. Leaving seat at my normal height (to allow the left leg to work normally), I started to ride, very slowly, around the block. Keeping the knee in proper line, each right pedal revolution I had to 'lift' off the saddle to allow the right leg to complete a revolution.
Put very little pressure on the right pedal; just worked on getting a complete revolution. Was just about able to ride around the block once (.25 mi) the 1st few times. Exhausting. Slowly upped the circuits around the block, then loops further out, then finally a 'real' ride for 8 miles - 2 months later...
Meanwhie the right legs muscles slowly, steadily, improved as I was able to ride more. I'm again skiing, as of the beginning of 2019 season, very close to my prior level (which is quite high level and hard, difficult terrain), albeit with a brace under my pants. I am riding about as strongly as my current situation will allow.
how does this relate to you?
1. If you don;t believe you have an 'injury' (treatable), then at least see a PT, and discuss the issue, with possible methods to resolution/rehabilitation.
2. IF you experience no or signifcantly less pain when the knee moves in a normal motion. Then start your own 'rehabilitation'.
It requires taking your riding to a level which allows you to control your leg motion - how ever 'low' effort that may require.
It requires dedication to riding form which you believe is 'proper' for your legs. First ride slowly with leg motion which allows the knee to stay in line. Determine this is not causing any other issues.
Determine if the knee is feeling less painful in the proper alignment. Then ride, for whatever length seems appropriate, with FOCUS on the leg/knee alignment, a reasonable cadence which doesn;t cause you to fight to retain proper alignment, at a pedal pressure which allows smooth, round pedaling.
Continue to do this for EVERY ride. Keep full awareness of your proper pedal motion as well as adjusting any unusual on-saddle postion or upper body position - you don;t want to introduce any other anomalies to other parts of the body, while trying to fix the current one.
The objective is to 'retrain' the muscle groups to the proper and non-pain/injury causing act of pedaling. Be completely persistent on the retraining - it's a longterm process.
DO go see some level of professional - seeing a cycling/running/endurance activity PT is a good start. They would also redirect you to an MD, if there's indication for further medical treatment.
ALSO, do have your overall body alignment checked - from head/neck, spine, pelvis and legs - especially for any anomalies in leg length, knee and ankle alignments.
Leg lengths anomalies could easily be at the root of the problem.
If it's simply the re-education of muscles, that can be done to a great extent, Over Time. Identifying structural issues also helps get to other possible problems.

In my opinion, 'compensating' for your current knee issues and persistent pain, with pedal extenders, or a special modified bike frame, will only cause the problem to become more extensive and more difficult to address, down the road.
Ride On
Yuri