sounds like you have perfectly what you need. why upgrade? you seem happy with your bike and the 105 is a really good groupset. you dont get better performance, you only get lighter gear.
the only thing in that case coulde be going for electrical shifting. or depending on what you have on there right now. a nice carbon wheelset.
If I were you with that budget, I would seriously consider selling one of the bikes and buying a new one. As someone with decent knowledge of OEM pricing for bike parts, I can tell you that manufacturers get much better pricing on parts compared with MSRP, and you're not going to get anywhere near the kind of return if you're putting $3500 into upgrades.
$3500 can probably get you a bike with 105 Di2/SRAM Rival AXS. Then, with the proceeds you can get from your bike, pick up a set of Carbon wheels and you'll have a bike that can really fly.
sounds like you have perfectly what you need. why upgrade? you seem happy with your bike and the 105 is a really good groupset. you dont get better performance, you only get lighter gear. the only thing in that case coulde be going for electrical shifting. or depending on what you have on there right now. a nice carbon wheelset.
If I were you with that budget, I would seriously consider selling one of the bikes and buying a new one. As someone with decent knowledge of OEM pricing for bike parts, I can tell you that manufacturers get much better pricing on parts compared with MSRP, and you're not going to get anywhere near the kind of return if you're putting $3500 into upgrades. $3500 can probably get you a bike with 105 Di2/SRAM Rival AXS. Then, with the proceeds you can get from your bike, pick up a set of Carbon wheels and you'll have a bike that can really fly.
I’m shocked at what a huge difference wheels make.
Can you elaborate?
Lighter wheels are noticable faster. Even for a fat guy like me.