Well, this is the first full week of Corona Virus “lockdown” here in Michigan. Schools are in online mode, restaurants are closed (except for take-out orders), all in-person meetings and events of more than 10 people canceled. What a drag.
My health club, LifeTime Fitness, is now closed, too. I had sessions with my trainer scheduled for Monday and Wednesday, but the virus put the kibosh on that. Oh well, I figured, I’ve got workout stuff at the house, and my trainer gave me some routines, so I figured I was good to go.
I’m suited up and ready to work out. First part of the workout is some sprints on my exercise bike. Okay, let’s do this thing! I hop on the bike and start pedaling. The display is supposed to come on when you start pedaling, but in this case nothing! Shit!

Okay, let’s not panic. It’s been a while since you’ve been down here on the bike Dave, so maybe you just need to get on and pedal for a while, and the display will come back on. Well, I did that, and still nothing. Okay, this is getting irritating. I basically put the rest of my workout session on hold to focus on getting this damn bike working. That’s the engineer in me.
Time to get serious. I pull out my phone and Google “lifefitness c9i won’t come on.” (LifeFitness C9i is the model of my exercise bike). I got some hits! Looks pretty simple – there’s a 9V battery behind the display under a little door. Replace the battery and voila – problem solved. I go probing around in the designated area, and I find the little door, BUT…no battery! On further inspection, this model is different from mine – it’s not a c9i. Looks like the battery for this thing is not a standard 9V job, but some specialty custom battery. Also, the battery is not under the little door behind the display, it’s buried deep inside the body of the bike. Looks like you have to remove the right pedal crank and the whole right side cover just to get at it. Again – SHIT. Let me sleep on it.
Okay, all that was on Monday. Now it’s Tuesday and I’m riding my electric cargo bike around town to try and relieve the Corona Lockdown Boredom. There’s a Batteries Plus on the other side of town, so I decide to go in there just to see if, on a lark, they have this weird custom battery. I pull up a picture of the battery on my phone and show it to the crusty senior citizen sales clerk. He goes over to a shelf where, surprisingly, there are a bunch of batteries that look almost identical to the one I’m looking for, and whatd’ya know – they actually have one that matches the specs. ONE. I got the last one they had. What a place this Batteries Plus is!
Feeling good, I stop by Papa Joe’s market on the way home and pick up some apples and some take-out Middle Eastern food, then it’s back home to see about this goofy exercise bike. Kishna’s fixed a delicious dinner, so I decide to relax and enjoy the meal before tackling the bike situation. Mind you, it’s Tuesday night and I still haven’t accomplished the at-home workout that was supposed to take place on Monday.
After dinner, I gather my tools – screwdrivers, socket wrenches, torx bits and such – and head down to the basement to see if I can fix this doggone bike. I lay the bike on its side and start removing the pedal crank. The three large torx bolts securing the crank come off pretty easy. I thought I also needed to remove the disc that the pedal crank was screwed onto, but after futzing with this for about ten minutes I realized that wasn’t necessary. Next, I removed the seven or eight torx screws that secured the bike’s right side housing. These screws have a flat groove in addition to the torx star, and in my haste to get the job done I used a flat screwdriver to remove these. It was some trouble, but I got them off. Now the inside of the bike is finally exposed. Whew!

Now I can finally see the stupid battery – it’s the black thing sitting on top of the silver box near the front of the bike. I don’t know what would possess someone to spec such a weird battery like this for an exercise bike, and I especially don’t know why they would bury it in such a hard-to-get-at place. Here’s more of a close-up view:

There were just two screws securing the battery to the silver box, and though one of the screws was hard to get at, I managed to remove the battery without too much trouble. Then I screwed the new battery into place and connected it up. Now it’s time to reassemble this puppy and see if it works – and hopefully to get going on some wind sprints!
Reassembly was just the reverse of disassembly. I placed the right side housing over its mounting holes and used the torx/flat screws to secure it. Then I placed the right side crank assembly on its mounting disk (fortunately it was keyed with a little nub so that it would only go on in one position) and secured it with the three torx bolts. Done! I stood the bike back up and climbed on. As I did so, I happened to move one of the pedals and was greeted with a reassuring beep. I pedaled a few times and – wonder of wonders – the display came to life! My good ole exercise bike is back!
Just one thing. While I sat there pedaling, I noticed that the right side housing of the bike wasn’t fitting quite right. The bike was working fine, but it was irritating to see that the right and left sides of the bike’s housing didn’t line up quite right. What to do – leave it alone and start the workout, or disassemble the housing and fix it? You know. Engineer.
I laid the bike back on its side and removed the pedal crank. Then I removed the seven or eight torx screws, this time using the proper torx screwdriver bit. Pretty smooth. I took the housing off and realigned it with the other side. Then I screwed the housing down and re-mounted the crank assembly. Only one problem – one of the screw holes on the right side housing has no screw! I look all over the floor trying to find the missing screw. No luck. I check my pockets – nada. I set the bike upright and pedal again just to make sure that everything is copastetic. Yep, the bike is fine. The housing fits securely, and the two sides are perfectly aligned. Am I going to worry about one little missing screw? You know. Engineer.
Large sigh. I lay the bike down on its side again. I remove the crank. I remove each of the torx screws (minus 1) designed to secure the housing. I remove the housing and look around inside. Whatd’ya know! Up near the front of the bike, near the silver box, there’s the missing torx screw. Man on man, how’d I do that? Sensing impending victory, I re-mount the housing, then I re-mount the crank assembly. I stand the bike upright. I get on the bike and start pedaling. Is everything cool now? You bet it is! But after all this f-ing around, I’m in no mood for a vigorous workout. I’ll get on that tomorrow.
So here’s the final scoop on my LifeFitness C9i exercise bike, design-wise. You don’t have to plug this thing in at all – the internal electronics operate in response to your pedaling. For all this time, I assumed that meant the bike was people-powered – that it was the pedaling that provided the power for the bike’s display electronics. Turns out that wasn’t entirely correct. When you pedal the bike, you are turning a generator that charges the bike’s weird battery, and the electronics are in turn powered by the battery. The battery is a small lead-acid one, a miniature version of the kind used in cars. That fact, and the fact that it is fully rechargeable, is what allowed it to last for more than 12 years. It probably failed because I hadn’t ridden the bike for about a year, which allowed the battery to fully discharge. Live and learn.

The upshot of this story isn’t the weird battery in my exercise bike. It isn’t the inconvenient placement of the battery, or my difficulty accessing it. The upshot isn’t even my delay (procrastination?) in getting to my workout session. No, the upshot of this story is that this Covid-19 induced lockdown has this frustrated engineer spending fairly unproductive time doing something I’d have never considered even a few weeks before. It’s time to shed this virus paralysis and get productive, maybe even engineer some solutions. Stay tuned.
I did get to that workout – on Thursday.