Secondo parere sulla manutenzione della bicicletta

I don’t understand what your question is? The bikes are very different. In both cases typical consumables are being replaced.

I think the question is: do you want an ebike or a gravel bike?

…this is why I do all my own work on bikes 😉 If you get all work done in a shop it quickly becomes as expensive to run as a car. All this work you could do yourself in an afternoon with maybe 200CHF of tools as a one-off purchase, but obviously I understand not wanting to spend all your free time getting mucky and making a mess of your apartment working on bikes. I am not a bike professional and tbh I am a bit lazy with maintanance, running a “real” workshop with skilled staff is obviously very expensive.

I can’t comment on if all that work actually needs to be done immediately without seeing the bike.

In general chains need to be regularly replaced, you can check if that needs to be done with a chain wear gauge.

You need to replace a casette every 2/3 chains (but if you let the chain wear too much, it will wear the casette faster – so better to replace the chain early since they are much cheaper than casettes)

Chain rings only very rarely need to be replaced unless damaged

Brake pads need to be replaced when they wear thin or if they get contaminated with e.g. chain lubricant

Bleeding brakes needs to be done if the feeling ever goes soft and squishy

Overall if you are reasonably happy with the performance of the bikes, none of that work needs to be done immediately. If the casette and chain are at the end of life, then there’s no harm running them into the ground until shifting is a bit bad and you get chain slippage, then replacing both.

-> Probably overall you are getting quotes to make the bikes “as good as new”, rather than to fix a specific problem. Maybe you could ask the shop again to clarify what work is strictly nescessary to keep them running through the winter, and postpone the other things until spring. Unless something is actually broken or not working I normally only bother putting on nice parts in spring, because in winter bikes quickly get dirty and mucky, under which conditions you wear parts much quicker.

Händs der sVelo mit Trüffelöl gschmiert und mit Blattgold überzoge😂

Kommt drauf an wie oft du deine Kette gereinigt und geölt hast, zu welchen Bedingungen du gefahren bist, aber das kann schon sein dass man die nach 4000km austauschen muss.  

Prüf das am besten mal selbst mit einem chain measure tool nach

Bremsbeläge halten weitaus länger, und Bremsschreiben muss man so gut wie nie austauschen. Dass man die entlüften muss kann aber plausibel sein.