Overweight and a bad knee

[catherineG123]

My dog slammed into me two years ago and fractured my tibial plateau. It is a break of the upper part of the tibia that involves the knee joint. I was a little overweight before the accident and I am even heavier now.

In general, the knee hurts a lot of the time and I haven't been exercising. I would like a bike to start easy movement and to use it for commuting to work. I would like a bike that can handle someone overweight and has a easy access to step on. I don't want a bike that tips easy- so the battery should be placed at the best place- but I'm not certain where "the best place" is.

Any suggestions on what kinds of bike I should look at? Should I be concerned with power?

 

[PDoz]

I fractured my tibial plateau and avulsed the anterior tibial spine a few decades ago. Chances are our knees are different, but couple of suggestions:

Definitely go for an emtb, but you want one with instant torque sensing delivery. Think yamaha pwx ( giant pro) or brose. If I apply force through my knee whilst the femur rolls over the ridge, things get nasty - but I can cycle all day so long as I don't overload the joint. The more I cycle, the better my knee feels ( within reason) - keeping my quads strong REALY helps..

I choose to mtb because varying the angles I'd pedalling at seems to help - the constant changes in direction seems to improve my knee stability and avoids repeated loads in the same direction. Whilst you might not be ready for the trails, try to at least vary your cycling position. Those trikes lock you in the same spot and look agonising to me.

Start with shorter rides and 2 rest days each time. Try not to set up a pattern of inflammation and joint pain. Increase the ride length before increasing frequency. Most importantly, enjoy. If it's fun you don't mind a bit of pain the next day.

 

[indianajo]

Fat tires (3" up) are low pressure so not particularly suited for carrying a lot of weight. Are suited to distributing weight over soft beach sand.
2" nominal (1.9" to 2.1") tires are rated at 55 to 60 psi and can carry 400 lb gross on my cargo bike left. That is 55 mm or bigger cross section in metric sizes. I'm 170 lb but I had 110 lb of groceries on the bike a few weeks ago.
I ride 26" diameter tires because I am short, but 700 mm and 29" tires are even smoother over bumps or through pot holes. 20" tire bikes are cheap & popular, but the pavement has to be perfect for them to be comfortable, IMHO.
3 wheel bikes tip over suddenly in fast turns and I don't recommend them to anybody whose balance is okay. Especially at street speeds. Okay on the factory floor at 5 mph.
I second pdoz recommendation for a torque sensing bike that adds power immediately. Pedal assist bikes you have to pedal >half a turn yourself before the power cuts on. Besides various mid drives as giant and reiss & Mueller there is a torque sensing xtreme catalina hub motor bike. You probably want a dealer though to deal with any warrenty issues. If DC Alexandria or Norfolk is in reach there should be plenty of dealers available. Put your zip code on the base electricbikereview.com page to see the ones that pay court for visibility.
For best stability the battery should be mounted low and in the middle. The cheapest position is on a rack in the back, but having the weight high and rearward makes the bike harder to handle when pushing it.
Make sure the frame fits you. People get all wrapped up in the electric part and forget they are buying a bike. One size does not fit all, especially people under 64" tall and over 73". Dealers sometimes push the size they have in stock, rather than order something. You should be able to touch the ground with your tip toes when stopped. Your leg should be almost straight when pedaling. Your arms should be out to your front naturally. I don't like bending forwards too much and bending my head back, as ruptured neck disks run in the family. Thousands bend forwards and tilt the head back without problems.'
Finally be aware there are other exercises to build strength and lower weight that don't involve the knee. Gyms have rowing machines, arm pull down and twisting machines. I found a hand crank machine key to rebuilding my wind after 12 weeks of winter colds ruined my ability to walk (I have no cartlege in the knees & need endomorphine to walk). Warning, I caught a couple of colds in the gym down the street. They are virus hot spots.

 

[catherineG123]

My ideal budget is around 3K. I prefer not to go to high over it, but I also don't want a bike that is so cheap that I will regret the purchase because it couldn't do x, y or z. However, I don't know what x, y or z is at this point.

I currently live in a apartment complex 8 miles from my workplace and my commute to work will be mostly on bike trails. I will need to take the bike inside my apartment each night. I could take the metro to work, but aside from Covid 19, I don't see how the metro will save any time. Biking would make me exercise, take the same amount of time as the metro and save me money on either metro or parking fees.

I don't have an exact answer about trike or step thru as I am open to either. I don't know if this fact is relevant but I will share it if helps with directing me between a bike or a trike. I can't sit at high tables where they have bars stools. My knee will be very uncomfortable within a minute or two without any leg support. I am assuming peddling will give my leg the support it needs and I don't know if that is relevant or not. In terms of the actual injury, this was already my arthritic knee before my dog plowed into it. I need to make my leg stronger, especially the quad muscles to have a happy retirement.

 

[catherineG123]

If DC Alexandria or Norfolk is in reach there should be plenty of dealers available. Put your zip code on the base electricbikereview.com page to see the ones that pay court for visibility.

Thank you. I live near Alexandria- so I can go there- if they are open. You gave great advice and I appreciate you taking the time to answer.

 

[PatriciaK]

Your best bet is to ride as many bikes as you can find before you purchase. Even bikes out of your price range - they can still give valuable feedback about what feels good to you and your knee. That may be difficult right now because so many dealers are out of bikes due to supply chain issues and explosion in demand, but it's very important in determining the right bike for you. The feel of the assist, your preferred posture (upright VS "racing"), the placement of the bike weight, the bike geometry - these are all going to affect your comfort. The only way to figure out what works for you is to try different bikes. You'll know when you've found the right one for you.

 

[catherineG123]

I fractured my tibial plateau and avulsed the anterior tibial spine a few decades ago. Chances are our knees are different, but couple of suggestions:

Thank you-There's aren't too many of us who understand TPF's. I value your insight. I will go to the bike store in Alexandria and see what they have to sell.

 

[catherineG123]

Definitely go for an emtb, but you want one with instant torque sensing delivery. Think yamaha pwx ( giant pro) or brose. If I apply force through my knee whilst the femur rolls over the ridge, things get nasty - but I can cycle all day so long as I don't overload the joint. The more I cycle, the better my knee feels ( within reason) - keeping my quads strong REALY helps..

Is giant pro the model and yamaha pwx the battery?
Is torque sensing the same thing as pedal assist?

 

[Alex M]

Is giant pro the model and yamaha pwx the battery?
Is torque sensing the same thing as pedal assist?

1) Yes
2) Torque-sensing is one of 2 kinds of pedal assist. Power kicks in when it senses your effort (with torque sensing), the more effort - the more power.
Another kind is cadence sensing - power cuts in when you start rotating pedals, amount of power is fixed no matter how much or how little effort it takes, little power on PAS 1, more on PAS 2 and so on.

I am not sure that torque sensing is always easier to start - depends on the terrain and motor, but won't argue with people who have same injury.

 

[indianajo]

I know that I hate pedal assist. It takes a half turn of the crank for the power to come on. So for the first half turn, you are the power. This is because one has to turn the crank backwards up to 1/2 turn to put the pedal at the top to get a good start. And one doesn't want the bike to take off while he is pedaling backwards. The pedal assist on my power wheel had a minimum acceleration of 350 W and a minimum speed of 11 mph, both of which are too fast for my unpaved driveway or the horrible pavement of the berm along state hwy 3. So I use throttle all the time that I need assist, deleted the cadance pedal assist. Used throttle a lot yesterday with wind 18 mph in my face all the way home (30 miles).
Torque sense is supposed to start the assist as soon as you put weight on the pedal. I've never tried it because there are no mid drive dealers closer than 165 miles (chicago, nashville tn) and I don't want a mid drive because I like to exercise when the wind is not >12 mph in my face. But it sounds as if you need assist as soon as possible. People say torque sense feels as if one is more powerful than one really is. Which would be a good feeling with your injury. Torque assist bikes cost more.

 

[PatriciaK]

One thing you didn't mention is what floor of your apartment building you live on, and whether or not you have an elevator you can transport the bike in. Ebikes are mostly significantly heavier than regular bikes. There is a range in weight, but you generally sacrifice range to get a lighter bike. I'm thinking you're not going to be carrying a bike up steps with your knee, but thought I'd mention it just so you're aware.

 

[Alex M]

One thing you didn't mention is what floor of your apartment building you live on, and whether or not you have an elevator you can transport the bike in. Ebikes are mostly significantly heavier than regular bikes.

Good point. Ebikes are nearly twice as heavy as regular bikes.

With some tinkering cadence sensing can be set to work from dead stop. It won't kick in when you pedal backwards, magnets are only sensing rotation in certain direction. The 1/4 rotation delay is there because manufacturers want to protect themselves in case if somebody decides to sue them for bike "starting too sudden". Though they still install a throttle that may be activated any time. Expensive mid drives for some reason don't have a throttle, but Bafang mid drive does.

 

[catherineG123]

One thing you didn't mention is what floor of your apartment building you live on, and whether or not you have an elevator you can transport the bike in. Ebikes are mostly significantly heavier than regular bikes. There is a range in weight, but you generally sacrifice range to get a lighter bike. I'm thinking you're not going to be carrying a bike up steps with your knee, but thought I'd mention it just so you're aware.

I purposely chose the first floor for my apartment because of my knee.

 

[PDoz]

Is giant pro the model and yamaha pwx the battery?
Is torque sensing the same thing as pedal assist?

yamaha pwx is the motor, it gets rebadged as a syncdrive pro in giant brand bikes - same motor, ever so slightly different tuning.

yamaha do several motors, the reason I'm suggesting the pwx is it has more pawls ( connection points) , so it engages almost immediately - literally touch the pedals and you get assistance - but that assistance stops the moment you release pressure

It has sensors for torque, cadence, as well as incline and acceleration. Plus the bike reads speed. From 2020 there are 6 lots of data it interprets so essentially you have 16 year old legs ( knees) again. This level iof sophistication isn't really necessary for the average person riding on the road - it's a high performance mountain bike motor that excels at negotiating steep rocky nasty stuff that normal people wouldn't walk up. But the magic of these motors is they take the strain out of pedalling for those of us with shot knees, yet they still encourage active cycling - the more you put in, the more you get out. You have to ride one to understand, and it might turn out you don't need this level of complexity / refinement with your injury - eg you might just get away with a giant lafree, which uses the less sensitive sport motor ( still very good)

 

[indianajo]

It won't kick in when you pedal backwards, magnets are only sensing rotation in certain direction.

Mine did. Pedal gave me a good whack in the back of the shin on the leg that was holding me up.

 

[6zfshdb]

I don't know if I would recommend torque sensor over cadence sensor.

Torque sensor won't activate unless you put pressure on pedal. In some cases, when your knee is hurting, you might not want to do that.

Cadence censored bike generally is easier on knees. The only problem is, from the dead stop, you have to rotate a little using your leg power to activate the sensor. However if you get a bike with throttle, that problem might be solved.

Does anyone know if throttle will work from dead stop? I don't have one so I don't know.

The throttles on all the bikes I tested work from a dead stop. That is what makes them so handy. You can use it to get a boost when starting and even to "walk" the bike up an incline or stairs.

 

[PatriciaK]

yamaha pwx is the motor, it gets rebadged as a syncdrive pro in giant brand bikes - same motor, ever so slightly different tuning.

yamaha do several motors, the reason I'm suggesting the pwx is it has more pawls ( connection points) , so it engages almost immediately - literally touch the pedals and you get assistance - but that assistance stops the moment you release pressure

It has sensors for torque, cadence, as well as incline and acceleration. Plus the bike reads speed. From 2020 there are 6 lots of data it interprets so essentially you have 16 year old legs ( knees) again. This level iof sophistication isn't really necessary for the average person riding on the road - it's a high performance mountain bike motor that excels at negotiating steep rocky nasty stuff that normal people wouldn't walk up. But the magic of these motors is they take the strain out of pedalling for those of us with shot knees, yet they still encourage active cycling - the more you put in, the more you get out. You have to ride one to understand, and it might turn out you don't need this level of complexity / refinement with your injury - eg you might just get away with a giant lafree, which uses the less sensitive sport motor ( still very good)

I ride a Giant La Free E+2 - it's great! My arthritic knees just love it! I live in a pretty hilly area, and wouldn't be riding a bike any more without it. Smooth, responsive assist that I mostly set on auto detect and forget about it. If you get a chance to ride one, I recommend it.

One thing some folks say is that the battery placement on the rear rack is not optimal for balance, but with a mid drive motor I don't think that's an issue - I haven't had any problems, and my balance isn't the best. The weight of the motor at the bottom of the frame is heavier than the battery on the back. If the bike were a hub drive, with all the weight on and over the rear wheel it might be different, but not with a mid drive, IMHO.

 

[Alex M]

Torque sensor won't activate unless you put pressure on pedal. In some cases, when your knee is hurting, you might not want to do that.

Cadence censored bike generally is easier on knees. The only problem is, from the dead stop, you have to rotate a little using your leg power to activate the sensor. However if you get a bike with throttle, that problem might be solved.

Does anyone know if throttle will work from dead stop? I don't have one so I don't know.

Most bikes have throttle always "hot", it cuts in the moment you push the button (or half-twist the grip), and max output doesn't depend on PAS level.
Some require 1/4 turn of pedals before it activates.
A few are only hot when PAS>0 and the output is limited to PAS level, i.e. no throttle when PAS=0, low throttle output on PAS1, more throttle on PAS2 etc.

Cadence is easier to start (than torque) when terrain is flat. When on uphill, it might not be easy - this is when throttle will help.
Torque sensor will output shortly after you start rotating - much less than 1/4 turn of pedals - and will increase output if it senses more effort, so your effort will remain low (up to certain limit of incline or headwind).
But with cadence you may keep pedaling with zero effort at high PAS levels - a.k.a. Ghost Pedaling - and PAS will work as long as you keep moving your legs, while torque would always require some pressure on pedals.
With a bad knee you should really test-ride both systems, these differences can't be explained on the paper.

Mid drives mostly have torque sensing, hubs - mostly cadence sensing. I think Bafang is the only mid-drive that comes with either torque or cadence. And there are some hubs with torque.

Mid-drive is placed 4 or 6 inches lower than where a hub would've been. Not a big difference in height, don't know whether most people would notice the difference in balance.