Experiencing problems with Dropouts!

There's lock washers with "teeth" on the inside that bite into the steel of the dropouts, there's one's made specifically for bikes ofc and you may have them... but they just might be made poorly. I can't seem to find a pic and sorry, I just don't feel like takin a bike apart ATM lol - but even something like these (only larger ofc heh) would help should you not be able to find the bike ones;



While commonly available at any hardware store - the only problem with that type is they're disposable - you really outa replace them each time you mess w/em - but they'll getcha by till you can get the proper bike axle type

something else is wrong. i mean, it's possible that your drop outs are spreading apart, but what's causing this isn't the drop outs themselves.

is your chain too tight? this would make your engine yank on the wheel, pulling it forward. especially during starting, when it's jerking around the most. this would also happen if your chain's not aligned correctly, or if your motor's tilted to one side.

like BA says, do you have star washers, or any washers at all? i put a thin washer on the inside, and a thicker, serrated washer on the outside, the kind bikes used to come with.

do you have fender struts or anything else in between the axle nut and the drop out? these tend to squish, and can loosen up the nut, or make it not fit as tight.

or, it could just be a combination of crappy chinese parts, and in that case, your bike shop guy's right.

(edit) is your coaster brake arm clamped to the frame? if not, when stopping, the arm can spin, and the nuts with it.

are your cones in the back wheel adjusted properly? if there's a lot of play, the inner nuts could move, or if it was too tight, your axle could turn, loosening up the nuts.

yeah, you need that arm. coaster brakes are "back-pedal" brakes. y'know, you pedal backwards for the brakes to work.

that's what you have, right?

that arm connects to the frame, so when you pedal backwards to stop, there's stuff inside the hub that presses outwards on it, like a drum brake in a car. that arm stops the axle from moving when you put the brakes on. without it, your brakes will work lousy, and your wheel will loosen up.

you need to put that back on, and connect it to the frame.

i'm assuming you took it off because your sprocket wouldn't fit over the dust cap. you need to modify that...

http://motorbicycling.com/f30/coaster-brake-dust-cap-mod-1841.html