In July, four of us will be cycling from Bellinzona > San Bernadino (night 1), > Splugen (night 2) > Thusis.

Without spending a night in Thusis, two of the four are then wanting to go to Zermatt for three nights (before heading to Murren for 5 nights).

Questions:
1. We will be renting road bikes. Thinking of renting them in Bellinzona. Will we have to drop off our rental bikes in Bellinzona or can you think of an alternative to save us time?
2. We are thinking we could take the 2:16pm Glacier Express from Chur to Zermatt. Would you recommend this method?

2. We are thinking we could take the 2:16pm Glacier Express from Chur to Zermatt. Would you recommend this method?>

Yes the quickest rail route to Zermatt from Chur - does not stop as much as local trains and has commentary on board and unique tilting wine glasses.

For lots of info on Swiss trains check www.sbb.ch - www.seat61.com; BETS-European Rail Experts and www.swisstravelsystem.com.

Contact the bike rental co as you aren't the first renters who have had this situation. They may have a sister store or some drop off arrangement that could work for you.

There are some direct trains from Thusis to Zermatt.
But I don't think that you can drop off your bikes at Thusis.
SBB bikes can be given back at Chur or Ilanz.

https://www.sbb.ch/en/station-servic...gh-season.html
https://www.rentabike.ch/en/stations


Ilanz - Zermatt:
Trains every hr from 7.33 until 17.33. 5 hrs 40 min journey. 3 connections with only 1 change (at Disentis). For all other connections you have to change at Disentis, Andermatt and either Brig or Visp.

Chur - Zermatt:
Trains every 30-60 min from 6.39 until 19.09. 4hrs 40 min journey. Change at Zurich and Visp, for some connections at Berne too.

It's very easy to cycle from Thusis to Chur. The itinerary to Ilanz is much more scenic, but more strenuous (continuously up-and-down).
You may also board regional trains Thusis - Reichenau - Chur or Reichenau - Ilanz with your bikes (you have to pay for the bikes too, however).

Does not SBB have a baggage forwarding service - I know you could send to a station and have them pick it up but I think you can send it right to an address.

....yes, it's possible, but it lasts 2 days and costs 18 CHF/bike
But frankly: the bike trail from Thusis to Chur is only 27 kms long: less than 2 hrs by bike.
And lazy people or people in a hurry can take their bike in any regional train for 8 CHF only.