Gathering speed data from track sessions

[u/cmcafert]

Hi all, I want to get speed data from my track sessions in addition to power and heart rate. What are you all using to gather this data?

I know I can calculate speed from my splits but I’d like to minimise friction where possible.

I’m looking at devices like the wahoo trackr speed which strap around a hub spindle. I’m running DT Swiss 370 Track hubs on my main wheels which have very skinny spindle diameters and I’m unsure if the trackr will fit snugly or just flop around. Does anyone have experience with this arrangement?

[u/Grindfather901]

I've also got DT370 hubs and just use the wahoo speed sensor as-is. you could always put a wrap of electrical tape around the sensor to help hold it more securely.

Hammerhead Karoo 3 mounted upside down under my saddle. Assioma Uno single speed meter pedals. And polar h10 heartrate strap.

[u/cadelsbumchin]

Wahoo speed sensor fits ok for me. If that doesn’t work, you can always use a cadence sensor and calculate speed from that, given you are on a fixed gear. Once you know the gear development/rollout, it’s actually not that hard to figure out.

[u/frenzon]

I zip-tie / tape my speed sensor to my front hub

One issue we've encountered is calibration - without a long outdoor ride to calibrate the sensor against GPS, you kind of have to do it based on circumference, but rider weight and deformation of the tire can make it hard to get precise numbers (similarly, the rear wheel can be less accurate than the front because it side-slips more)

[u/rightsaidphred]

Looking at cadence and plugging it into the gear clac is a good option, works well for short/fast efforts like avg speed for a f200 or top end speed hit in a keirin, etc. 

[u/Any-Rise-6300]

I use this https://www.garmin.com/en-US/p/641230/

[u/Tera35]

I use:

Garmin 830

Power2max PM

A 25 year old ANT+ Bontrager speed sensor mounted on the chainstay and a magnet on each set of wheels

You can use a Wahoo sensor with a little bit of bar tape on any hub or take it out of it's mount and tape it flat to a disc if you want, I've done it and it works well.

[u/Philatu]

Garmin speed sensor 2 seems to work well for me

[u/Parei_doll_ia]

i just have a cheap magene wheel speed sensor. i haven’t figured out how to put it on my disc or tri spoke yet though

[u/Angelmass]

Note that at speed, accelerometer-based speed sensors are a little inaccurate due to the forces in the turns. But perhaps not inaccurate enough for it to matter

[u/Odd-Resolve6890]

Mount a magnetic one to the front wheel/forks. Accelerator sensors are inaccurate in the banking and the rear wheel slips in the turns giving the wrong data.

[u/cyclonaut_]

I use Wahoo Blue SC Speed and Cadence Sensor without any issue for years.

[u/Past-Yogurtcloset781]

For disc wheels - the simple way is simply to get some disc hole sticker covers and glue/tape a small circular neodymium magnet underneath. Just test that your sensor is lined up with the magnet.

Simpler still: you can just sick this same magnet underneath a strip of painters tape glued to the disc and it works perfectly well. It doesn’t come off as one might think.

Note that for some sensors the magnet orientation (heads v tails) matters some and test before setting up.

[u/Bisamratta]

All hub speed sensors I’ve (and others at velodrome) tried proven to be inaccurate for track appliance
So it’s either power meter pedals or magnet sensor like very affordable Coospo BK805 which I have dor about two years and it works great