36" Unicycle Speedometer

Today I attempted to install a speedometer I got for a couple dollars at a garage sale on my 36er. It did not take me long to realize that the speedometer would not be able to be programed to calculate speed for a 36" wheel (the maximum was 26") and I was unable to mount it for several other compatibility issues.
I would like to find another one that would work, but it is hard to tell just from product descriptions whether or not it would be completely compatible. Does anyone here have a speedometer that has worked well with a 36" unicycle? Any information would be appreciated.



I use a “knog nerd” computer. It lets you set custom millimeters. The only problem I have with it is that it is wireless and has to be set farther in on the handlebar then I want it because it is out of range otherwise. But it does work and I don’t really have to have it right next to my hands like I want it.

There is a possible way you might be able to use your current one. If you got another spoke magnet you could put it on directly opposite of the other and then you could set the wheel diameter to 18" because that is half of 36". But that might be inaccurate, seeing as actual diameters vary.

I want to get a cateye cycle computer but I don’t know whether it will work because of the same problem you are having. Has anyone used one?

The second magnet idea would be cool, but unfortunately the smallest wheel size the speedometer I have can program to is 20".
A few of the other issues were that the wire was to short to reach the end of my handlebars and the magnet did not fit properly on my wheel because the spokes were to thick for what it was designed.

I just have a cheapie Bell one from Wally world. Not super expensive, and wired, but does what it’s supposed too. It comes with a booklet that tells you which numbers to put in for what wheelsizes, but I found they were just the mm distances, and just put in the 1200 or whatever number I had when I measured out my wheel diameter.

Funny this comes up, I just barely put mine back on my 36er after not having it while my drift hub was in my wheel.

I initially had issues (3 months ago when I first put it on) getting the wire to reach, and ended up mounting the display on the back of my seatpost. Tonight though, I was able to mount it right in the ‘cockpit’ with some creative wire routing and strategic placinig of zip ties.

I use a Sigma BC1609 on my 36er. It is the “wired” model and I would suggest you stay away from wireless. This thing is 99% maintenance free! I was over 1000 miles before I even had to change the battery. It did take some tinkering to set the wheel size but it now matches my wife’s Garmin 405 watch when we finish our run/ride. I mostly use it as a watch so I know when my son’s soccer practice is drawing to a close and I need to head back to the Jeep. Good luck and happy Cokering!

I’ve been researching wireless systems (mainly because the whole point of having one for me is being able to see it). Most wireless systems are only good for 70-90cm, which means poor performance if you have it on your wrist or pocket.

The best range I could find was the Cateye Strada Digital…except it costs the same as a GPS unit. So for my money I ordered a Garmin Edge 200- hopefully it will do what I need (which is speed and distance only). For HR and power etc, you can get the next unit up, which is the Garmin 500.

I have used Cateye Velo computers and they are cheap, wired, and work fine for me. I have not had any problem putting in wheel diameters in mm. I have a velo 8 on my 36". Here is one of the current models. You should probably check the series to see which features you want.



Put an extra magnet on the wheel and set the wheel size to half what it would usually be. Doing this also has the added benafit of doubling the refresh rate of your speedo’ - not that it makes any difference. :stuck_out_tongue:

Unfortunately his speedometer doesn’t have an 18" setting.

Unfortunately it sounds like you spent enough for a 20-26" unicycle speedo, but not for sizes outside of that. :frowning:

I’ll just mention that I do like my Garmin 405, which replaced my 305 but it still a few years old. For people who ride multiple cycles, why not use a body-mounted GPS device? Uh, other than cost…

Thank you to everyone who replied to this thread. I ended up getting the CatEye Velo 7 which Scott recommended. I had no trouble programing it to a 36" wheel and the wire was just long enough for my purposes. I have not had a chance to ride with it yet because of the snow but it appears that it will work great!

Thanks again everyone and have a happy new year!

Even modern smartphones can act as GPS devices (Using apps like Strava or even normal GPS apps). Unfortunately they’re not really viewable on the go unless you don’t mind pulling them out your pocket every now and then :smiley:

I use a wireless cycle computer on my 29" (It was a cheap one but seems to have fully programmable wheelsize, dunno if it’ll work on a 36er) And have been thinking about somehow attaching it to a watch-strap…

For users of cell phone apps, it is possible to mount them on a handlebar using brackets that are made for the purpose. But I wouldn’t do it, since one good drop could kill your phone. Those make a lot more sense on bicycles, which is what they’re made for.

The other difficulty with cell phone-based tracking is that it’s usually pretty hard on the battery. Many phones may not last the whole ride before they run down. It might be possible to adjust settings, between the app and your phone, to make less GPS calls, but that would also degrade your data. If you have an extended battery or a phone that goes a long time with GPS on, you may be just fine. I’ve been meaning to try out Strava, but since I have my own Garmin device I haven’t remembered to turn it on for the couple of rides I’ve done since downloading it…

I agree with John, and a dedicated device picks up satellite signals better, display your current speed a whole lot better, is less bulky and the battery lasts for ages.

I’ve been using the entry level Garmin Edge 200 and it’s perfect so far. I haven’t had issues with losing signal, and it’s really nice being able to swap between my bikes and unicycles with no fiddly calibration.

It tells me everything I need (current speed, avg speed, max speed, elevation) as well as being able to upload to the Garmin site and keep a record of my training rides, all for the same price as a wireless cycle-computer. For a little bit more you can get the next level Garmin with HR and power-meter compatibility. Note that I was after a cycle-computer first, not a GPS. It looks and feels more like a cycle-computer.

I know my answer is late, but I don’t have a smart phone, so I got a Garmin bike gps. I got it for my bike, but it works in my pocket and you can download the info to a computer after the ride. I got the least expensive model, about $130. I like it because I don’t have to reprogram every time I switch wheel sizes and it is wireless.

Well, some years later but finally I got my Garmin Edge 820, this is great item, I’m really happy and now I have more fun when riding my unicycle, it came with all the extra sensors, chest heart sensor, cadence, and speed, I highly recommend it, today after riding for 2 hrs, I got my track map, with altitude, temp, av speed, max speed, etc. I mean, all the info you need, so you compete qith yourself! Super challenging!! [/IMG]





I’d have set it at 22.4 inches (approx.) put the display in mph but read it as if it were in kph.

1 mile = 1.609 km.

36/1.609 = 22.4 (approx)

Say the uni is doing 10 mph which is 16 kph:

Speedo is set as if the wheel were 22.4 inches and therefore it displays 16 mph.

Read the 16 mph as “16 kph”.

Or — and this is radical — use your smart phone.

Mine wouldn’t go big enough for a 36", but I had spares due to a couple of speedo failures. So I put two magnetic sensors on the wheel and set it at 18" - I actually measured ten rotations on the ground in the supermarket carpark, but that’s another story.
Second advantage is that it updates more frequently at low speed.