Knee issue - need suggestions

[cpml123]

Hi all,

I got a S40 last month. This is my first new recumbent bike. Due to rainy weather, I have not ridden it at all. I set it up on a smart trainer and did an FTP test on TrainerRoad yesterday. I think I have adjusted the boom ok so that the farthest pedal reach is appropriate. However, my right knee, in the back near the top of the calf, felt a little irritation. I didn't ride long enough for it to be painful but felt it may become painful if I rode long enough. I have read other threads (therefore adjusted the farthest reach of the pedal using the boom) on knee pain and would appreciate your additional suggestions. Here is what I have done so far:

1. Float on the pedals: I have the Speedplay Frogs. I tried to use Ratz' hack to make them free float completely. However, I just couldn't get the pedals to split open (guess they used too much locktite or something). However, I did turn the cleats on the bottom of the shoes as much at an angle as possible so that when I pedal, the inside of my heel could rub the crank if I wanted to. I reasoned that that's the most clockwise float towards the crank I could use anyway even if I could make the Frogs float completely. Float with heels counterclockwise is of course no problem. Anyway, my conclusion here is that I have all the float I can use.

2. Cleat location on the shoes: I placed the cleat at the closest possible setting towards the center of the foot.

3. Crank length: I have Rival 165mm.

4. I read on another thread to use this link to figure out crank length: www.recumbents.com/wisil/misc/crank_angle.asp So I tried it out. I am 6 ft tall with about 32 inseam. I entered my measurements in the calculator, and below is the screen shot. Now I am wondering if I need a much shorter crank than the 165mm one I have. For example, around 150mm? Now I am really debating..
a. If I should try a shorter crank
b. Where to find it and what brand to get
c. How to take off my Rival crank and put on the new crank. AND would it actually help with knee issue?

On the other hand - should I just keep riding on the trainer for maybe 30 min a day for several weeks to get my legs and knees used to the new S40 and forget about shorter cranks? Maybe it's just my knee problem because I only feel it on my right knee and not the left knee.

Thanks so much for your help.

 

[DavidCH]

If your feet naturally stick out in a V shape you might be naturally flat footed like me. It's quite common to have wedges fitted to the cleats more so on the problem knee foot. But an ftp test is usually only 20 minutes. Before wedges I use to get knee issues for rides longer than an hour. Try bringing the boom in a bit and move those cleats right back to their furthest position (towards the heel). After your legs are rested try again... not an ftp and see where the pain has moved. At the beginning it's all about adjustment. Once dialed in that cruzbike ride will be the best you ever had.

 

[rx7mark]

Well, I have a T50 with 155mm crank, and had a knee issues for the first couple months. My crank length analysis looked about the same as yours.

But my knee pain has slowly gotten better with time on the bike and time in the gym. So I would vote to give it some time.

Mark

 

[ratz]

Pain in front of knee boom too short
Pain behind the knee boom too long

Adjust in 5mm increment.
Frogs sometimes need a razor blade box knife to open the body

 

[super slim]

As Dave said, move the cleats as far back as possible on the shoes, and rotate them so there is equal float either side of your natural foot position!
Check that you can put your heel on the pedal at its furthest position without sliding down the seat.

Have a look at Ratz's comments on bike fit.
http://cruzbike.com/forum/threads/v20-finding-that-fit.11520/
If there is pain in the back of the knee, then move the BB back, ie shorten the boom length.

If your bent knee is greater than 90 degrees, go for 150 mm cranks from Bikesmith Design, at $219 http://www.bikesmithdesign.com/Short_Cranks/apex.html
I am 6'1" 46" x seam, and 38" inseam, so all legs, and going from 175 mm cranks to 153mm cranks, initially on the new Quest V1.0, gave me more power on climbs, and MUCH less knee pain, and better handle bar set up on the Quest and Softrider.

 

[bladderhead]

I have 145 cranks from a company called Redline BMX. I got them from American Ebay. You get cranks and a BB axle, which you need because it is their own design.

 

[Bill K]

Lots of good advice above.
One other thing to observe is your position on the seat. You can slide forward or back (towards the headrest) enough to throw off the boom adjustment a bit. It may take a few rides (or hours on the trainer) to settle in to your favorite. Then adjust the boom to that position.

If you do want to experiment with short cranks like I did before buying an expensive one, you can get a cheap BB and a crank for testing:
Sunlite alloy single speed crankset 152mm, 32 tooth $18 and Shimano UN26 68 x 117.5 square taper bottom bracket $12.

 

[super slim]

Lots of good advice above.
One other thing to observe is your position on the seat. You can slide forward or back (towards the headrest) enough to throw off the boom adjustment a bit. It may take a few rides (or hours on the trainer) to settle in to your favorite. Then adjust the boom to that position.

If you do want to experiment with short cranks like I did before buying an expensive one, you can get a cheap BB and a crank for testing:
Sunlite alloy single speed crankset 152mm, 32 tooth $18 and Shimano UN26 68 x 117.5 square taper bottom bracket $12.

Great find!!!

 

[cpml123]

Thank you all for your suggestions! Here is my summary, next steps, and a few follow up questions...

Next steps:
1. Adjust boom length again: feet in shoes, heel touching the longest travel of the crank, and shorten the boom slightly. (super slim, Ratz)
2. Ride a few more times to settle in the riding position in the seat. Adjust boom again (Bill K, DavidCH, rx7mark)
3. Try to get the Frogs sliced open and hack to make them float completely and see (Ratz).
4. Try cheap shorter cranks to experiment- "Sunlite alloy single speed crankset 152mm, 32 tooth $18 and Shimano UN26 68 x 117.5 square taper bottom bracket $12" (Bill K) or "Redline BMX. I got them from American Ebay. You get cranks and a BB axle" (Bladderhead)
5. Expensive shorter cranks: "go for 150 mm cranks from Bikesmith Design, at $219 http://www.bikesmithdesign.com/Short_Cranks/apex.html" (super slim)

Questions:
1. DavidCH - what do you mean by "wedges"? Do you mean shoe insert like Superfeet? I do have a little flat foot and use Superfeet in my bike shoes and regular shoes.
2. rx7mark - what do you do in the "gym"? Any particularly leg training you do?
3. superslim "If your bent knee is greater than 90 degrees..." - at what point in the crank revolution do you measure the knee bent? I thought my knees are bent at greater than 90 deg nearly all the time.

Thank you.
Michael

 

[super slim]

Thank you all for your suggestions! Here is my summary, next steps, and a few follow up questions...

Next steps:
1. Adjust boom length again: feet in shoes, heel touching the longest travel of the crank, and shorten the boom slightly. (super slim, Ratz)
2. Ride a few more times to settle in the riding position in the seat. Adjust boom again (Bill K, DavidCH, rx7mark)
3. Try to get the Frogs sliced open and hack to make them float completely and see (Ratz).
4. Try cheap shorter cranks to experiment- "Sunlite alloy single speed crankset 152mm, 32 tooth $18 and Shimano UN26 68 x 117.5 square taper bottom bracket $12" (Bill K) or "Redline BMX. I got them from American Ebay. You get cranks and a BB axle" (Bladderhead)
5. Expensive shorter cranks: "go for 150 mm cranks from Bikesmith Design, at $219 http://www.bikesmithdesign.com/Short_Cranks/apex.html" (super slim)

Questions:
1. DavidCH - what do you mean by "wedges"? Do you mean shoe insert like Superfeet? I do have a little flat foot and use Superfeet in my bike shoes and regular shoes.
2. rx7mark - what do you do in the "gym"? Any particularly leg training you do?
3. superslim "If your bent knee is greater than 90 degrees..." - at what point in the crank revolution do you measure the knee bent? I thought my knees are bent at greater than 90 deg nearly all the time.

Thank you.
Michael

When the pedal is closest to the hip joint.

 

[rx7mark]

Questions:
2. rx7mark - what do you do in the "gym"? Any particularly leg training you do?

My gym has recumbent bikes, and I don't have a trainer yet, so when it rains I am in the gym trying to build my aerobic base three days a week. Basically a long ride keeping my heart rate under 130bpm. Typically 1.5-2 hrs and about 30 miles. If the weather is nice like today here in Seattle, I did a 2hr ride on the local MUP on my T50.

I also have started lifting weight 3 days a week, alternating upper body and lower body lifting. So squats, leg lifts, leg curls, calf raises, etc. on leg day. 3 sets of 12. This takes about an hour.

And believe it or not, my diet has helped a great deal. I started the Keto (Atkins) diet that is talked about in the training forum. My joints feel much better, and my recovery is quicker after my workouts. If you are interested check out the book, The New Atkins for a New You. I am also taking 2g of Omega 3's fish oil daily, and Glucosamine twice a week, both seem to help. I got my T50 less than 3 months ago and have lost 20lbs so far, and my strength and endurance have greatly improved. My knee still complains a little, but now a little ice, and its better the next day.

Good luck on your journey, just take it slow and easy, and listen to your body. When I started I could only ride one day a week, my knee would be sore all week. Now I ride every other day, and could probably go every day by this spring.

Mark

 

[DavidCH]

what do you mean by "wedges"?

They are little slices of angled plastic/carbon that go between your cleats and shoes ... so you bolt them in between. Some of us try it out and if the knee problem disappears then leave it. Long distance riders feel it more than others. If you are out training every day then a weakness will build up. Most riders aren't perfect and predominantly it will be the left leg knee that has the issue. Most people have a dominant right side. The body is great at making adjustments for the dominant side. If pain persists go and see a biomechanics specialist. However... on a recumbent it might be difficult for them to judge. They might prefer you to be on a DF... I was looking at an incredible system the other day called Guru bike fit. Quite an awsome device that dials in your stats and gives you the perfect bike.
It's not cheap. A packet of wedges is a whole lot cheaper.

 

[ed72]

ITB irritated, move the boom in. (Shorten the distance to the crank)

 

[jphipps]

use shoes without cleats and petals from pedaling innovations that support both the ball and heal of your foot, so you don't need super stiff bike shoes and cleats that cause repetitive stress injury to your knees.

 

[LarryOz]

It has been my experience that either too much knee bend on the back stoke (need shorter cranks), or you foot is turned too much in or out at the pedals (power pedals will report that angle) are the leading cause of knee pain.
Oh yeah - then there is just pedaling too darn slow "all the time" - that will also do it. I know, that is what I have been doing a little lately, "just for fun" and some experimentation.

 

[ccf]

Stretching every day helps me.

 

[cranky cyclist]

use shoes without cleats and petals from pedaling innovations that support both the ball and heal of your foot, so you don't need super stiff bike shoes and cleats that cause repetitive stress injury to your knees.

I have found these difficult to use with my SilVio. Particularly when starting and hill climbing. I do like the feel of them and yes I did have less knee pain. I am looking to buy shoes with the mid foot position cleat.

 

[cpml123]

Progress so far: I shortened the boom and that helped. I have been riding it on the trainer about 20-30 min per day to get my muscles used to S40. It seems that I use the muscles/tendons below the IT band and right below the back of the knees much more than I would on a DF bike. They get sore rather quickly and I am trying to condition them. I am also trying to stretch my hamstrings and IT bands daily.

I feel my knees, at the shortest point, is bending a lot. I got a protractor and measured the angle at about 82ish degrees.

1. Does that mean I now need to move the boom a little longer?
2. Or I do need a shorter crank like the crank length analysis says?
3. I have Sram BB and Rival crank with 50/34. Can I get this Origin8 crank with 150mm length https://www.amazon.com/Origin8-Alloy-Crank-Arm-Set/dp/B000AO9W3C?th=1&psc=1, unbolt the Sram crank, put the Sram 50/34 rings on the new crank, insert it into the Sram BB, and they would all fit together? I have no idea what crank works with what BB.

Thanks.

 

[ratz]

3. I have Sram BB and Rival crank with 50/34. Can I get this Origin8 crank with 150mm length https://www.amazon.com/Origin8-Alloy-Crank-Arm-Set/dp/B000AO9W3C?th=1&psc=1, unbolt the Sram crank, put the Sram 50/34 rings on the new crank, insert it into the Sram BB, and they would all fit together? I have no idea what crank works with what BB.

The Crank is GXP BB
The Origin 8 is Square taper

They aren't compatible you'd have to change both. The COBB cranks https://cobbcycling.com/collections/cranks/products/alloy-short-cranks are compatible. Specifically the mid compact matches your SRAM Gear.