RS5

I'm about to buy my first bike computer together with a cadence and speed sensor. The problem that I find with them is that they are attached to your bike with zip ties.

So I was wondering what people do with their sensors if they own more than just one bike:

1. Buy an additional set for each bike you would like to use the cadence and speed sensor on, or;
2. Is there an option out there that I'm overlooking that allows you to switch these sensors between bikes as easily as the bike computer itself?

Option 2 would be ideal, however, I wonder how the speed sensor would work in that case. I can imagine that the settings of the speed sensor need to be adjusted everytime for the wheel diameter it is used on, right?

stoogehand

The bike computer I have utilizes a GPS signal to calculate speed, so I can install a mount on a few bikes and easily swap the computer around with no wheel size adjustments. I have thought about buying more cadence sensors... but so far I have just put it on my favored bike, and occasionally cut off the zip ties and swapped it around as my "favored bike" changes

jpescatore

Like stoogehand, I went the GPS bike computer route (Wahoo Roam) which solves that problem - but is expensive. I do put cadence sensors (Wahoo ones that don't require both a sensor and a magnet, just a pod on your crank arm) on each of 2 bikes I ride today.

There are some other solutions:

Back when I used a Cateye bike computer, and before I switched to GPS-based, I bought a wireless Cateye model and 2 extra mounts. I then used Velcro to attach the speed (wheel) and cadence (pedal sensors) across 3 bikes. Worked fine for a few years, then I switched to the GPS way for a number of reasons.

jgwilliams

In my case it was option 1. I've been using a Garmin GPS unit for getting on for ten years now so I've managed to build up a collection of sensors.

The original unit, and Edge 705, was very fussy about what sensors it would talk to. I think it had to be a combined speed/cadence sensor which pretty much meant a GSC-10 and that was it. I bought one new with the unit and managed to pick up a used one a few years later. I now have an Edge 520 Plus which will talk to pretty much anything. A year or so back I picked up a used Giant NEOS computer for my mountain bike which came with speed and cadence sensors and the Edge 520 picks up the signal from that fine.

So, the point of that ramble was that the Garmin sensors are quite expensive but you can get cheaper options which work just fine. You don't say what computer you are planning to buy; are you after one with full GPS or simple computer? I keep the latter on a couple of my bikes simply as an easy way to record the overall mileage as well as using the Garmin for recording my rides. I'm coming to the conclusion, though, that web sites like Strada and RideWithGPS make recording mileage so easy that the basic computer is becoming redundant.

I like Garmin and get a special deal on them through my health insurance provider but a lot of people on this site will extol the praises of Wahoo, which seem to come out a bit cheaper and have a good reputation for reliability.

RS5

I was planning on buying a Wahoo Roam, which has gps since I will be using it mainly for navigation.

So far I have used my phone for navigation and a very simple and cheap bike computer (€10) that is wired to my front fork together with a magnet attached to the spoke of my wheel.

I have found that using the gps signal for speed is only about 80% to 90% accurate on my phone if I compare it to that simple bike computer, where I believe the latter is more reliable.

I’m aware of the fact that a dedicated gps unit also has acces to galileo and glonass, which could make it more reliable but I believe that only goes for when you are in the forest or in cities with high buildings.

Therefore I wanted to track my speed with a dedicated sensor designed for it... Ive found some that allow for easy swapping with rubber bands, but I cant find out how the settings work for such a sensor. Do you have to adjust the wheel diameter in the settings everytime you change it to a different bike or how does it determine your speed if it does not use gps?

stoogehand

Something like the Wahoo Speed Sensor does not use GPS, but instead it has a sensor that counts revolutions. You can easily swap it between bikes with an elastic band, but you would need to change your tire diameter in the companion app

Thomas15

I'm using a Garmin Edge 530 and have speed and cadence sensors on each bike (and Garmin mounts) that I normally ride just makes it a lot easier.

Koyote

Some of the more basic GPS computers are so inexpensive that it makes no sense to buy a non-GPS unit.

Speed sensor is not essential - I get perfectly accurate data without one. And a cadence sensor can go on your shoe.

jadocs

Speed you will have to swap, no way around it unless you just use GPS. Cadence sensor can be attached to your shoe not the bike (as long as it is wireless).

Reflector Guy

You could probably get some self-adhesive Velcro strips and use that to attach the sensor, instead of the zip ties.

I have considered doing exactly that, for those occasions when the bike I want to ride has a dead battery in the sensor.

rosefarts

Garmin watch on my wrist.

I do have a cadence sensor that attaches with a rubber band.

Pop N Wood

Cateye sells wheel sensor units separately. I put a wheel sensor on each bike than swap the single head unit across bikes. The head units always have an A and B wheel size.

Now I have an old GPS unit, I only care about speed, distance and time.

pdlamb

Old school. I have wired computers (with cadence and speed sensors). Funny thing is one of those per bike costs less than the combined speed and cadence sensor package for each bike to hook up to a GPS.

msu2001la

Have you thought of just buying sensors that don't require zip-ties? Most speed and cadence sensors I'm familiar with use rubber straps/bands that are simple to remove/reinstall. It only takes a few seconds to move from one bike to another. If you have a GPS head-unit, it'll (likely) automatically calibrate the speed sensor.

GlennR

That's what I did... Garmin 530.

surak

The Wahoo RPM cadence sensor is just a pod that you can attach to your shoe or even stuff inside it. Speed sensors, it's easier to just have multiple, or not use at all.

cloud

I would still use at least 1 zip tie.I don't trust the self-adhesive . I have a couple bikes and run the sigma bc1900 on all of them. I am sure there was a cheaper way to do it. But for me it was easier than always changing out the sensors.

Reflector Guy

Maybe a twist-tie from a loaf of bread. Easy on and off without any tools.

I think the only ones I worry about are those stretchy O-rings which secure the bracket to the stem. Especially since it gets stretched SO tightly (especially on my beefy Bianchi stem). But if that snaps while I am riding, at least there's a reasonable chance I will notice pretty quickly and can go back and look for it.

cloud

That's pretty clever .Never thought of twist-tie.

stoogehand

For the most part, I have a high tolerance for error in my speed. If it passes the gut check, I'm good with it.

My Bolt head unit does a pretty good job of passing the gut test, but as I was thinking about how to answer your question, I realized that the GPS does have its limitations. The terrain around here is pretty flat and open. However, you will occasionally happen upon some corridors of tall and thick trees. When going in to such a corridor, my Bolt may go from reading 18 mph to 12 mph, which is a significant difference, and as I am riding, it does not pass the gut test. So if you frequently ride in areas with structures that block GPS signal, you may well want a wireless speed sensor.

Your question got me curious, so I busted out my Wahoo Speed Sensor (the one piece of the ELEMT Bolt bundle that I never used) and I played around with the settings. Turns out, you can set it to automatically calculate your wheel circumference. Don't ask me how it does it, or if it is as accurate as manually setting it, but there it is. Or, as others have mentioned, you can buy a sensor for each bike$$

force10

If a speed sensor is paired with a GPS computer, which speed reading shows on the display?

Steve B.

On a Garmin, if there's an active speed sensor, the device will use that data instead of the GPS data.

As comment about using and needing speed sensors. I have a Garmin 1030, have had a 1000 and 810. I have 4 speed sensors on assorted wheels. I use them on my mt. bike, my gravel bike on 2 sets of wheels and on my road bike. The mt. bike so as to reduce errors when riding in wooded cover. Ditto the gravel bike. On my road bike it's to give me a more accurate speed at that moment, as there's always a few seconds delay of the speed generated with GPS only and that can be less then useful when trying to maintain a steady speed in a road paceline.

On my touring bike that I use to commute, I don't use a speed sensor as I really don't need accurate speed and I've found that the GPS only track is accurate as to location and overall distance, as compared to a track whose speed and distance were from a wheel with a speed sensor. In typical conditions, GPS units (IME) are as accurate as to distance as when using a speed sensor. When you get into heavy leaf coverage, canyons in Utah or NYC, or such, is when a speed sensor is useful.

WhyFi

Speed sensors are really only beneficial if you want an accurate reading at any given moment while you're actually riding. Without a speed sensor, your indicated speed may fluctuate a little as you go in and out of cover but, over the course of the ride, your average speed reading will be more than accurate enough.

As far as the directly answering the question, I'd recommend getting dedicated sensors for each bike. As a bonus, the Wahoo should be able to log each bike ride to the proper bike by way of the ID of the sensors being used.

WhyFi

The difference here is likely down to how the speed is being calculated. Some default to average speed, from start to finish, while others display average *moving* speed. IOW, stop lights aren't being held against you.

genejockey

I have those AND I have a set for each bike. Swapping cadence sensors, especially with the modern fat crank arms, is a PITA.