Bikes: question about group-sets

[nereo]

Hoping some posters can help me understand this a bit better...

I’m reasonably familiar with the road-bike groupsets put out by Shimano and SRAM, and know that there are equivalent group-sets for the MTB category. Lately, as I’ve been searching for a bike to replace my commuter (one that’s in that “in-between’ category with no suspension but able to handle a few bumps and some packed-trails - aka hybrids/gravel-grinders/urban category), it seems like there’s no rhyme or reason as to whether a given manufacturer or independent shop puts on a MTB group-set or a road-bike group-set.

So... why go for one over the other (of similar quality)?

Example: what’s the difference between a Deore M4100 and a Tiagra on the same frame, given they have similar number.size of gears and both fall roughly in the middle of their hierarchy.  Or the same equivalent versions of SRAM...

@waltworks @GuitarStv

[GuitarStv]

MTB stuff is a mystery to me, sorry.  The closest I've got was matching a Deore rear derailleur on my winter drop bar bike with old 8 speed ultegra bar end shifters.  :P

[mschaus]

There are a few things that might be different between the models —
1. Mountain derailleurs often have a wider range since modern ones are made to work with a 1x drivetrain
2. To go with a 1x, nicer mountain derailleurs will be clutched, too (helps chain retention)
3. Mountain derailleurs might be more robust, but I don’t have data to back that up

I just double-checked and Tiagra can have a 28T in the rear, while Deore can have a 46T. Deore also has a bigger capacity (difference between smallest and largest cog)

ref:
https://bike.shimano.com/en-EU/product/component/tiagra-4700/RD-4700-SS.html
https://bike.shimano.com/en-EU/product/component/deore-m4100/RD-M5120-SGS.html