Just received from Amazon, assembled, and successfully used the following:
Folding Exercise Bike with 10-Level Adjustable Magnetic Resistance | Upright and Recumbent Foldable Stationary Bike is the Perfect Workout Bike for Home Use for Men, Women, and Seniors (Black)

I am a senior that wants to use the exercise bicycle indoors for moderate daily exercise. I regard the purchased exercise bicycle as a good deal for the money. However, its wiring is bad, so I don't get any speed/distance readings. Since I own a stop-watch, all I need to compensate for the bad wiring is to install an external odometer (if possible).

The manufacturer subsequently came through, very nicely, shipping me a replacement. There was simply a temporary communication delay. Anyway, the responses to this article were great, re this is not an uncommon problem.

I emphasize that the odometer does not have to be accurate. However, I do need the odometer to be consistent from one day to the next.

As the following image shows, I do not have access to any spinning wheel on the exercise bicycle.

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Therefore, the only idea that I have is to (somehow) find a moderately priced (under $50) odometer that I can attach to one of the pedals, and then have its readout located near the top of the exercise bicycle, for my easy viewing.

My research has completely struck out re attaching an odometer to a pedal. Is this do-able? If so, what type of odometer should I purchase? If an odometer can not give consistent (not necessarily accurate) results when attached to a pedal, is there any other approach that I can take?

As indicated by the responses, the do-able approach involves adding the odometer magnet to the crank arm rather than the pedal.

  • I'd hope you left a bad review on amazon ? – Criggie Dec 8 '20 at 0:25
  • Would having the odometer on the floor in front of you, and the measurement on below the lowest downward stroke of the pedal be an alternative? – Stian Yttervik Dec 8 '20 at 13:04
  • @StianYttervik "...be an alternative?" depends on what you are asking. If you are asking whether the technical theory is sound, I am not qualified to have an opinion, so I would advise leaving the comment/question after one of the answers. If (instead) you are asking me whether your approach would be a viable solution for me personally - and if you are intending that the distance reading is not visible while riding but only visible if I stop and look on the floor, then my response is that I could live with it if I had to but would prefer to see the distance change while riding. – user2661923 Dec 8 '20 at 15:22
  • @user2661923 it was the latter, thanks. – Stian Yttervik Dec 8 '20 at 16:14
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    @Criggie The manufacturer subsequently came through, very nicely, shipping me a replacement. This changes the Amazon review that I will leave to a very positive one. – user2661923 Dec 14 '20 at 1:55

For your requirements this would work fine. The speedo readout would not reflect a real-world value, but for comparing efforts on the same bike it would be ideal.

I'd suggest the lowest priced wired Cateye bike computer (velo9 or similar) because it lasts years on a battery. I've had cheaper bike computers, and they can eat batteries in a few days.

For fitting, I'd try mounting the receiver end of the wire somewhere near the L of Landis on the housing, using double-sided sticky foam tape. Secure the magnet on the inside of the crank, such that it won't get banged by your shoe.

Great work for finding a solution.

  • Extremely helpful answer, thanks. If problem(s), will post separate query linking to this one. – user2661923 Dec 8 '20 at 0:42

Putting the sensor on the crank would work in principle.

In terms of if it would mean anything in the real world, you'd first have to ask what has real world meaning on an exercise bike, anyway? Even with an actual multispeed bicycle on a trainer roller, what significance does the tangential speed of the tire really have, anyway?

Really, in a simulated situation, all that matters is cadence and torque load. You could argue that this torque and this cadence is comparable to riding this bike on this route this fast... but that's a model guessing at all sorts of things which may or may not be true.

Cycle computers typically let you enter the distance covered by one rotation of the wheel in millimeters. If you like to ride really mashing the pedals into resistance, then you are effectively riding in a "gear" where the wheel covers a lot of ground per turn of the cranks - in the old language, you'd be pushing a lot of "gear inches" or equivalent wheel diameter.

I just stuck a battery in a spare head unit of a very cheap Bell 150 wired computer, and was able to run the setting up to 5999 millimeters. That's 75 gear inches, or the equivalent of a truly enormous Penny Farthing direct drive. It's also about like driving a 29 inch wheel through 2.5x gearing. People certainly ride in such gears (and higher!), but for all-around usage you'd probably chose something there or lower, which the computer also easily accommodates.

In short, I think this is going to work, and be as meaningful as anything else you do on the exercise bike. You're going to have to decide what "gear" you want to ride in and set the computer accordingly, but once you do, you're basically on a fixie - you get distance credit for turning the cranks, no more, no less.

(I can also confirm the Bell 150 will run thousands of miles on a battery; what you have to be careful of is anything that damages the cord, or the flimsy plastic display mount)

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    +1: Interesting answer. Re "I emphasize that the odometer does not have to be accurate." I will start the resistance at 1 (lowest setting) and ride about 20 minutes at reasonable pace. Assuming that I feel that this was a reasonable exertion, then whatever the odometer says becomes my daily goal. As I progress from resistance 1 to 2 to .., the daily odometer goal will be constant. This way, on days that I don't feel like pushing it, I will simply ride longer to reach the odometer goal. Just ordered Amazon $32 velo9 cateye, per previous answer. ...see next comment – user2661923 Dec 8 '20 at 2:45
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    Amazingly, the Amazon answers to the corresponding question were all negative, that it wouldn't work on a stationary bike if you were attaching it to the pedal. Moderately priced exercise bikes with defective wiring are (re my research) common and who cares what the actual distance is? – user2661923 Dec 8 '20 at 2:47
  • @user2661923 I suspect that's because we've both answered a different question, about adding the magnet to the crank arm and not to the pedal itself. That would probably be a good edit to the title and question. – Criggie Dec 8 '20 at 4:21
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    @Criggie Query title edited. – user2661923 Dec 8 '20 at 4:24
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    Note you don't have to use the stock magnet. Your picture looks very much like you have steel cranks, so you could probably just stick any small magnet on them. The end of the pedal stud where it threads through the crank might work to. The weaker the magnet the closer the sensor will have to be. Also I was surprised to find the most sensitive spot was not quite the middle of the sensor housing. Waving a little magnet rapidly past it before mounting can be a good idea, also a nice test if it ever gets flaky. – Chris Stratton Dec 8 '20 at 4:32

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