Bought a cheap RoadMaster MTB's as a first "grown up" bikes for my daughter. For the price (~$60 in a sale) they play nicely, but it shows the poor quality of the components.
The biggest gripe is the grip shifters (as in each and every Walmart bikes). I'd like to change the shifters to trigger type. The rear cassette is 6-speed and the derailleur (as the rest of components) is some "TD ONE" generic brand. I know the shifter must match the actual derailleur type, due to differences in the pull ratios between brands.
Any suggestion on what type of shifter would be compatible with the TD ONE derailleur?