/vr/ - Retro Games

>>1897702
In the case of Vortex, Goudrix, and other Arrows and Vekomas it's a number of things; the side friction and/or upstop wheels not touching the rail, imperfections in the rails (which is one reason why there's a gap in the side friction and upstop wheels), awkward transitions, etc. Not every Arrow and Vekoma is like this though; there are some coasters, like Tennessee Tornado for Arrow and Millennium Coaster for Vekoma, that are surprisingly smooth due to better construction, better trains, or a combination thereof.

Pic related for the rough ones though; this is a bogie from Loch Ness Monster.

As for Mantits, I haven't ridden it but I think it is down to stand up coasters in general not aging well.