OK, “ultimate” recumbent trike pedals is a bit of an exaggeration, but you can do better than you have now. Given shoes with good tread, pinned moutain bike pedals and correct boom length, you can ride in comfort without the risk of leg suck.
Leg Suck
Let’s start with a story. There is a situation that is not so fondly (or accurately) called “leg suck”. It happens if your foot slips off the pedal and touches the ground. The trike attempts to run you over – leg first. Your calf muscle takes the hit. At best, you will bruise in a way that will hurt for weeks. On her first ride, my partner suffered from this disorder. We did not know at the tike that it was because the shortest boom length was still too long for her.
Clipless Pedals
We immediately switched to “clipless” shoes – the ones that lock into a unique pedal.
There are a few problems with this solution. Firstly, the shoes have a metal piece under the foot, making walking on hard surfaces challenging and potentially damaging. Recumbent trikes are comfortable to ride but trying to change shoes while sitting in one requires acrobatic skills. At least your don’t fall over when using these as recumbent trike pedals.
The boots aren’t exactly cheap either. The show-stopper for me was pain. Since the point of contact is the ball of the foot, stress on the ankle magnifies. By moving to the arch or heel, I found I could ride long distances without discomfort. Clipless shoes don’t have this option.
Board Pedals
My first idea was to distribute the weight across the entire foot – as we do when standing. I created the board pedal prototype that connects to the pedal using clipless mounts. I used this method successfully for over three years. Velcro straps stopped my heels dropping into leg suck position but I found I did not need them if my boom length was adjusted correctly.
Mountain Bike Pedals
I finally found that mountain bike pedals did the trick. They are wide and have pins that wedge into the tread of our shoes. Just don’t ride in thongs :). I did find that placing the pedal under my instep or heal allows me to ride long distances without problems.
I should elucidate. Recumbent trike pedals work better on long rides when they are centred on your instep or your heel. I used to get a lot of foot pain with clipless pedals centred on the ball of my foot. Think about it. How long can you stand on your toes compared to having your feet flat on the ground and your weight is taken on your heels? A pro cyclist, like a runner, will use ankle movement, but it is a lot of extra effort for not a lot of gain (at least for mere mortals).
Boom Length for Safety with Recumbent Trike Pedals
It turns out that leg suck is more to do with the boom length and type of pedal than anything else. I had to cut off a section of the inner boom to suit my partner’s leg reach.
When adjusting the boom, make sure there is still a slight knee bend at full leg extension. That, with the pins in the mountain bike pedals, protect you from leg suck.
While we are talking about pins, I prefer the ones that are screw thread pins such as these. I think they grip better. It is essential if you wear sand shoes. Hiking boots have a tread with more significant gaps, and the moulded pins also engage well.
This article discusses optimal knee bend. Conservatively I would recommend that knee bend should be between 5 and 85 degrees. The boom length needs to be set to a minimum of 5 degrees. If your leg bends beyond 85 degrees, consider shortening the crank.
Straps for Recumbent Trike Pedals
If you are still nervous – as my partner is after feeling the aftermath of leg suck – you may want to strap your feet. Unlike an upright bike, you are not going to fall over when you stop. There are many different pedal straps on the market, but I think the best you make yourself with minimal effort.Buy a roll of double-sided hook and loop take from your local hardware shop. Most mountain bike pedals have gaps on all four sides. Feed the strapping in as illustrated and adjust it to your shoe size. To put them on, point your toe towards the boom and slip your foot under the strap. When you point your foot forward, the belt will tighten and hold you in place. Reverse the process to get out. The straps probably work better with sand-shoes. Hiking boots tend to lock to the pedal, making it difficult the release. You can always choose to pull the hook and loop strap to remove yourself.
Pedal Extenders for Recumbent Trike Pedals
Ah, hiking boots. I love mine, but they are wider than the average shoe. The solution is a pair of “pedal extenders”. They are readily available from eBay or Amazon. I think they make a recumbent trike easier to ride no matter what size your feet or type of boot.