The folder is "Routes".
Just to digress for a moment, this will contain the routes that have been manually (ie cable) transferred as I understand that the routes done the normal way, ie through the app) actually reside in the app/phone.

I just tried a gpx file, as this is what I normally use and OSMand only gives the option to save as a gpx file.
Wahoo does support other file types, such as TCX (gives turn by turn) but these files need to be created or edited in specific apps/websites such as ridewithgps. In that case, you're online already, so no need for the cable.
I've had no need for turn by turn directions, but I have tested the idea of inserting my own cues for example "Campsite ahead, next one 20 km" so I can think about if I want to stop or go on. But I'd only be doing that level of planning at home, not on the road.

Thanks.

I have a process that lets people install routes on Garmin devices. I'd like that process to support the Wahoo units too.

It appears the Wahoo units don't look like normal USB drives (like the Garmin units do). It looks like I need to play with an actual Wahoo unit.

I understood what you were trying to do (I've done similar things with Garmins). I'm doing something different.

Rwgps lets you add custom cuesheet items but the amount of text might much shorter than your example (the Garmins only support very short labels).

[MENTION=443116]HobbesOnTour[/MENTION]: I'm glad that file transfer from phone to Elemnt Bolt using otg cable works. Wahoo rocks! It mates with OSMAND route planning with no internet required. That's a very nice feature that no one is talking about.

It's a niche feature, but incredibly important for a subset of users out there (both Garmin & Wahoo).

I popped off a note to Wahoo to let them know it can be done, but I got the distinct impression they weren't that interested.

In any case, I'm a happy camper now.

Thanks for your patience and your pictures. They were very helpful!

While I agree that OSMand to Bolt is a niche feature, the transfer of GPX files while in the field is a vital capability. If I'd had my OTG cable, I could have used it again yesterday to transfer a GPX file. My friend with the Elemnt Bolt did not load the route for our group ride and showed up expecting to do a familiar course. She took a wrong turn and almost got lost. That's twice now. It's more than a niche feature when you can be Johnny on the spot and just transfer files without a data connection to any bike computer.

Holy thread resurrection!

Today, I noticed for the first time, that Wahoo have done away with the need to "ping" (their expression) the cloud to process a new route.

They said they would look into it and (a few years later!) they have!

This means that it is now possible to create a route totally offline (Osmand) and transfer that route to a Wahoo gps device with absolutely zero need for data or internet connectivity or cables/adapters.

Can't comment on Garmins, but this is a great boon for tourers in remote places.

It's been possible to do this for many years with the Garmins.