Short answer. Do what you are doing. Use the Adv Rider profile that you have made. Use it for any roads that you want BC to calculate to allow unpaved roads. Before you load any roads that use that profile, rememebr that the XT thinks it is just a motorcycle route - so you need to change the motorcycle avoideance to allow unpaved roads. That is the best, but not foolproof way of getting the XT to route like BC. You may need to use a few more shaping points to stop the XT heading for main roads though.tombarrington wrote: ↑21 Dec 2023 15:44 @jfheath, I'm still confused about a subtlety of my settings and the potential for recalculation. Let's say I create an ADV Riding profile in BaseCamp that is set for Faster Time and has all avoidances unchecked (Except Narrow Trails, which is not a choice in the XT. It would differ from my Motorcycling profile by only the Unpaved Roads avoidance.). I then successfully create a route following some dirt roads, using a reasonable number of shaping points, and transfer it to the XT. The XT's Motorcycle settings are set match those for the ADV Riding profile. The maps also match. The XT will display this route exactly, as you've said. Shouldn't it also reproduce this same route in the event of a recalculation?
Long Answer and explanation
I can see why you would think so, and it may do - but that will depend on how well the shaping points pin the route to the roads that you want.
1. Basecamp routes get transferred exactly as they were in Basecamp. Thousands of invisible route point maybe only a few metres apart if the road is very twisty, ensure the route on the XT is identical to the route that you plotted. That is regardless of any settings that you have either in BAsecamp or in the XT.
2. You have created a profile "ADV Riding". This is sent to the XT. The XT basically says - this isn't a motorcycle, it isn't a car, it isn't a direct route.
Ok - I'll use the default setting - Motorcycle. So that is OK in this case.
3. Whatever routing preferences are set in Basecamp - ie this little lot:
.... the XT completely ignores them. Why ? Because none of them are sent to the XT in the first place - so the XT doesn't have a clue what avoidances you set. But the XT does have the complete route identical to the one that Basecamp created. And BC used the avoidances to calculate the route. So providing the route deosn't recalculate, your route will avoid whatever your BC route avoided.
If the Zumo needs to recalculate, it will use then use avoidances that you have set for the motorcyle on the XT. Now - if you want it to avoid Unpaved Roads then when it recalculates it will indeed avoid unpaved roads. Since it uses the same maps that BC used and BC had an Unpaved Roads option that you can tick to avoid them, any reasonable person would think that the Zumo will calculate a route that is identical to the one that Basecamp would calculate. That would be true (more or less) for the Zumo 590, Slighty less true for the Zumo 595.
BUT - the Zumo XT uses a completely different routing algorithm for calculating the route. Forget 'Faster' meaning the fastest route between two points. Faster now seems to mean head for the nearest main road that would eventually get you to the next route point. In the same way that you migght expect the routing to prefer to head for a motorway.
AND - the XT build up a pretty accurate profile about your riding on different categories of roads, and takes that into account.
SO - the XT is likely to come up with a different answer. It will still visit all of the route points, so if you via and shaping points are carefully placed, it stands a better chance of coming close to the original.
No. That would work, but as you say it gives you a nightmare.tombarrington wrote: ↑21 Dec 2023 15:44 If there is a reason why the recalculation is different then is changing the Motorcycling profile in BaseCamp the solution? The thought of all those older routes recalculating (because Unpaved Roads was checked) is scary.
You have chosen the best way of dealing with this. Create a route using a different profile: Adv Motorcycle. This allows you to store all of the settings for that type of riding in Basecamp - under one named profile. When the Zumo receives the route, it will not recognise Adv Motorcycle so it uses the settings in the Zumo that you have saved for Motorcycle.
As an alternative, you could choose not to use a Basecamp profile at all. That allows you to make the same settings in Basecamp for just the one route. It is referred to as a Custom Route. Double click the route in basecamp. In the dialogue that pops up, click the Route Options tab. Then instead of using the Motorcycle Activity Profile, select "Customize Route Options". That gives you the dialogue box to make the settings for this one route. The top section indicates that there is no activity profile used, and the option to customize this route is selected. You would have to do this for every custom route though. Since you are likely to have a number of routes with the same settings, it is far easier to create a new activity profile so that you can apply that to a number of routes - as you have done. Then rely on the XT to treat it as a motorcycle route, which uses the XT's motorcycle avoidance settings. You will have to adjust these settings before loading the route.
So what you need to do before you load any routes that 'Allow Unpaved Roads' in Basecamp, is to set your XT's Motorcycle avoidances to allow Unpaved Roads. If you set it after the route is in the Zumo, it may well cause the entire route to be recalculated. (But I think that the XT asks if you want it to recalculate when this happens. Other Zumos do not. You get the identical route to the one that Basecamp created anyway. And then if the route does recalculate it will use the Zumo's Motorcycle avoidance settings.