I assume if you lift the rear wheel off the ground and spin it, it stops fairly quickly? Plenty of advice above, chain tension would be my first thought - check if there are any tight spots when you turn the cranks as well. After that, check brakes aren't rubbing, hubs etc etc as suggested above.
I assume if you lift the rear wheel off the ground and spin it, it stops fairly quickly? Plenty of advice above, chain tension would be my first thought - check if there are any tight spots when you turn the cranks as well. After that, check brakes aren't rubbing, hubs etc etc as suggested above.