philbob57

I attached my Wahoo Blue SC combo speed/cadence sensor with the rubber thing they included in the package almost 2 years ago. It no longer holds the sensor in space. The magnet they send with it doesn't fit my TA Cyclotouriste crank very well. Today the 2 really didn't get along (lots of clicking), so I removed the sensor.

Holy cow! My Lezyne Macro GPS did OK for distance, but speed kept varying by multiple MPH from second to second - like 7.2 mph,, then 13.7, 15.3, 11.5, 9.8, 2.6, 12,2 .... Without cadence info I had no idea what I was doing. OK ... it's a low priced GPS unit without GLONASS, but every place I ride has trees that interfere with the signals.

Wahoo sends zip ties with the Blue SC. I have nothing to lose by trying those out.

Steve B.

It’s the speed sensor that gives you the accurate speed and distance reading, not the cadence sensor. A GPS by itself might have a few seconds lag on speed. Then you factor in signal errors due to foliage and the speed will be all over the place as you watch the GPS try to keep up.

Yes, use zip ties.

canklecat

I have a couple of older Wahoo speed/cadence magnet sensors. They're very reliable when set up properly. I use zip ties. And a dab of permanent glue stick adhesive on the back of the tiny, thin cadence sensor. It's not really permanent -- the magnet can be dislodged with a fingernail -- but it holds better than just the zip tie. The speed sensor doesn't need it -- the grippy rubber shoe for that sensor holds fine on the chainstay.

It's generally more reliable than my earth induction speed/cadence sensor.

GPS alone for speed sorta works but it depends on the phone/computer receiver, antenna, etc. I have a computer that supposedly receives all satellites and automagically switches as appropriate -- no manually select option. There's an icon that indicates when it switches but the sparse user manual doesn't explain what it means.

And I've used an old iPhone 4s and newer Android phone. While there may be occasional glitches and discrepancies on some Strava segments, the phone(s) and computer are usually within a few tenths of a mph within each other for segments and the overall ride.

John_V 

Are the "rubber thing" you mentioned the band that holds the sensor to the chain stay or the rubber pad that keeps the sensor from scratching the paint? If it's the band, you can get them at any hardware store, If it's the rubber pad, you can secure it and keep it from sliding with two sided tape before attaching the O-rings. As for the magnet, a rare earth magnet attached to the backside of your pedal works really well. I've had the same rare earth magnet on one of my bikes since 2012. Using Zip Ties to hold the sensor works great but I've noticed some scratches on my chain stay caused by the ties. My bike is white and they show up more than on darker colored bikes,

Tourist in MSN

The zip tie that held my magnet to my crackset was not working well. I removed the magnet and used some two sided adhesive backed foam to tape the magnet to the crankset. Works great. Cost a buck at Dollar Tree.
https://www.dollartree.com/super-glu...t-rolls/247744

This was for cadence, not speed sensor.

philbob57

Thanks for the double-sided tape idea.

Elvo

You can switch to the magnetless sensors so that you don't need to fiddle around with magnets and zip ties

philbob57

I'm thinkin' on that. I hate to throw away something with useful life left in it, and I've already spent a lot on biking this year. Besides, I'm 75, retired....