fusilierdan

I just replaced my rear freewheel geared wheel with a 3 speed coaster brake wheel. It was done by a bike shop. Now when I start out and apply heavy pressure to the pedals the wheel pulls out of the drop out on the gear side. I've tightened the bolt but it still does it. I don't own a torque wrench. It seems the axle doesn't sit all the way back in the drop out. I have bio-pace chain rings on the front.

Should I add a link to the chain? Add lot's of links and a chain tensioner? Replace the chain ring with a round one?

I would really like to avoid a chain tensioner as I'm using the bike for a winter commuter and want to keep tings simple.
Taking it back to the shop is a hassle though I'm sure they'll take care of me.

Thanks.

Bill Kapaun

Do the axle nuts have serrated (anti skid) washers under them?

Homebrew01

Do Biopace chainrings work without a chain tensioner ? Seems like your chain would be tight-slack-tight-slack as you pedal.
+1 on the serrated washer.

waldowales

It seems to be a common misconception that Biopace chain rings tighten and loosen the chain as they rotate. By watching the rear derailler as the cranks rotate, it is obvious that the effective diameter of the chain ring stays the same. The derailler take-up is rock steady.

mechBgon

Some of these would help: https://www.jbimporters.com/web/check...t_number=37144 Your LBS can order from this distributor if they don't have these, or something just as gnarly.

The axle doesn't need to sit all the way back in the slot, by the way.

DannoXYZ 

No, because the bottom run of the chain does the opposite. If anything, the only effect is a variation in rotational-velocity of the rear hub. That's already lobsided by the natural uneven pedal-stroke anyway.

Simonius

Do you have a quick release axle? If so and the axle extends too far the QR will tighten against the axle instead of the dropout, which causes slipping.
The relative hardness of the dropout and the serrated hub or washer can be a problem. A high quality dropout may be too hard for a cheap soft washer to bite into. I have an old Nishiki International that worked OK with a Dura-Ace QR nut but slipped with a few cheaper nuts which I tried on the same skewer. Or maybe it was the axle length problem, I hadn't thought of that before finding the blingy nut solution.

bboy314

Check for serrated washers, then why not just take it back to the lbs that did the work?

MichaelW

Use a large track nut with a built-in washer. Tighten with a ring wrench rather than an open crescent wrench, you can apply force more easily.
Use a wrench the right length. If you are strong: a short one. If you are weak: a long one.
You can apply some careful foot pressure on the wrench.
Make sure that the dropouts are the correct width for the hub, there is no excess side to side movement when the axle nuts are off.

FastJake

1) It's not the Biopace ring. I've used Biopace on SS/FG bikes with no chain tensioner without issue. The tension does vary a bit, more on the smaller rings (38T for example) but it has never been a problem for me.

2) No one has taken a stab at the fact that this is a coaster brake wheel. I don't often use these but I know they need a reaction arm to brake. Maybe this is mounted improperly and making it impossible to tighten the wheel?

3) The work was done by a bike shop. They screwed up, so take it back and make them fix it.

ThermionicScott 

https://sheldonbrown.com/coaster-brakes.html