p2templin

I think there's one other vendor, iBike, who offers derived power. I can't speak to it personally, but think there's enough slop in the sensor readings necessary that it'd be "loose" at best. Garmin might be coming out with power pedals "soon", so you may think there's a marketing angle, but there are other products on the market to sense power too. Interestingly, some of the iBike models will read from a crank-based or wheel-based power sensor, and use it to derive wind resistance and frontal area or something like that.

twocicle

Other than Kurt Kinetic, I thought Minoura or some others existed too. Guess models with estimated power have mostly disappeared from the market.

twocicle

These ANT+ sensors (HR included) have an amazing range. Tested the signal up to 27 paces (+70ft) away which obviously means these are fine for even the longest of tandems.

Unfortunately, yesterday the speed sensor part (cadence & speed are combined) on our tandem failed in mid-ride. Likely this was the previous root issue I mentioned where our speed had dropped out. Cadence keeps working and the sensor is reported as connected. Doing a rescan while riding brought back the speed for a diminishing amount of time until it never did come back at all. Alas, Amazon to replace it for free. The speed/cadence sensor on my single has a lot more miles and is still rock solid.

The Edge setup is really nice with no wires and only needing one spd/cad sensor. Can have multiple HR belts and head units, no kooky interference values. Much better than our old Polar setup. I'm sure the stoker might prefer a iPhone w/GPS app, but letting her talk on the phone or texting while we ride is a deal breaker for me. Dual Edge 800s are the limit.

I've opted for these $17 Control Center mounts instead of Barflys, etc: https://www.amazon.com/gp/product/B00...ls_o03_s00_i00
The key benefits are to allow the Edge tilt to be easily adjusted while riding (as sunlight changes), to place the front unit further forward in the line of sight instead of directly down (bad - rider not watching the road), and the two bar attachements eliminate vibration (a frequently reported problem people complain about with single arm mounts). Having the correct view angle is the difference between a dark, barely readable screen vs. one that is bright and easy to read without dropping your head to see it.

This last weekend I used my 800 to nav a 112 mile preset route (.gpx) in a local GranFondo. The event organizers provided a near 1MB track file on MapMyRide which I downloaded into Basecamp and converted to a lighter weight Route instead. The turn directions all alerted perfectly. I still need to figure out how to get proximity alerts because none of the Food Stop waypoints I inserted provided any notice. Luckily in this case I knew where those stops were on the course, but in future touring abroad those points will be more unknown onroute.

Ritterview

The Garmin Cadence/Speed sensor is much maligned as poorly designed, too expensive and too frail. A Garmin user will accumulate several of these over the years as they fail.

There is no alternative ANT+, save for the Bontrager DuoTrap Digital Speed/Cadence Sensor, which is proprietary for the chainstay on Trek bikes. Why Trek doesn't take the internals for this and put it in a general purpose model is beyond me. If anyone wants to design a cycling gizmo sure to sell, it would be a plastic mount for the Bontrager that would work on any chainstay.



The only other way to avoid a Garmin Cadence/Speed sensor is with a power meter. The Garmin Vector pedals will report cadence, so users can get away with only a ANT+ wheel sensor, which need not be Garmin's.

waynesulak

I have had a few of these sensors fail until I decided to just use it for cadence. The arm now stays clamped as close to the chainstay as possible. Since then many thousand miles without a failure. This has left me with only the GPS for speed which introduces some interesting readings on a wooded trail by our house. This is part of my love hate relationship with Garmin products.

twocicle

Grrr, by these reports the sensor fun has just started. Oh how that makes me giggle.

Luckily these are only $37 at Amazon and I'll try to get my supply of failing sensors rotating through them for free as long as possible, then Garmin, then Visa which doubles Mfr warranty.

On the upside, I just figured out where I missed setting the Proximity alerts for my Waypoints in Basecamp. Happy days are here again.

BTW, I had no problems getting course turn alerts from the .GPX Route I exported from Basecamp. The original map on MapMyRide was a .GPX Track but that was huge and sluggish on the Edge 800. Converting the track to route, and then doing some clean up of slight mis-selection of roads was not much of a problem. The big trick to using the preset Route on the 800 was setting up the options on the Edge. Basically followed the suggestions here: https://frank.kinlan.co.uk/garmin-edg...rmin-edge-800/ (half way down the huge page).

This is the ride data acquired from the Edge 800 during the Jedermann GranFondo this last Saturday (sry, just a single bike on this one):
https://connect.garmin.com/activity/2...FGBUxp8c.email. I killed my avg speed by .2mph by not shutting off the timer at the end while wobbling around after sprinting for the finish. One short rest stop observed at mile 67.

apage4u

"I still need to figure out how to get proximity alerts because none of the Food Stop waypoints I inserted provided any notice."

I started inserting a warning waypoint about a 1/4 mile before the point I don't want to miss.

DubT

I tried the Garmin Connect/Basecamp process and abandoned it very quickly after I found ridewithgps.com. I draw my routes on it and very simply move the route over to my Garmin 800. It is much simpler for me.i can print out the map with a cue sheet and I map the route the arrows show up for the next turn?

I also do not use a sensor. I just mounted the Garmin 800 and use it just like I would use one in a car/motorcycle. I am not interested in cadence.

Here is a link to a help page: https://ridewithgps.zendesk.com/entr...armin-edge-800

drmayer

Bontrager makes an ANT+ speed/cadence sensor that is not the duotrap: https://bontrager.com/model/11323

Kind of expensive at $60, though. No zip ties needed.

waynesulak

I see they offer separate speed and cadence sensors. Will a Garmin use those or must the combo unit be used?

drmayer

I would assume you could use the single sensors as well.

DubT

Why do you even need a sensor? I am not using one and it works great.

waynesulak

I find the cadence sensor helpful in staying in our zone which is slightly below my personal cadence zone.
I can live without a speed sensor but it is nice when in a wooded area.

twocicle

Yes, they say any Ant+ sensor will work.

Update: While we waited for a replacement sensor to arrive, we did a couple road rides using only the GPS speed. Other than lacking a Cadence value, it worked ok and I did not notice any erratic speed readings. We typically live & die (spin tempo) by the Cadence value as a safety limiter for my stoker's knees.

teamdonterri

My Garmin 305 finally quit all together so I will also bite the bullet and spring for an 800. So just to be clear the speed sensor will read ok from the back of the tandem to the captains location?

Carbonfiberboy 

Yes, that works fine. Not only that, but the captain's HRM belt reads fine on Stoker's 800.

reburns

FWIW, when our sensor failed I opened it to see if I could fix it, and it seemed clear that moisture had done some damage. When I received the replacement sensor I sealed the outside with silicone sealer. Not sure if this helps although the new sensor is still working.

twocicle

Again, these Ant+ sensors can still work up to 75 feet away from the 800 unit. Your tandem longer?

We run 2 Edge 800 units on our tandem, plus 1 rear spd/cad sensor, and 2 HR belts (obviously each Edge 800 is synced with only one of his/her belt). Works great.

Shopping tip, look for the base Edge 800 unit from CompetitiveCyclist.com without any sensors, and try to buy when they have a 20% off on accessories (TDF20 may still work). At $360 net, that is hard to beat anywhere. Then go to Amazon and pick up whatever sensors (spd/cad $38, hr $44) and if needed, City Navigator map software ($70 North America, $90 Europe). You will find this sourcing to be over $100 less than purchasing bundled packages.

If you plan on using map software and load those yourself, blank MicoSD cards are cheap. We have 8GB cards ($10 - Transcend class 10) in each unit, with 4.7GB of maps loaded... that is City Navigator with all of North America, all of Europe (coverage gets thinner in Eastern countries), and sections of Topo US and Canada.