Rear sprocket, rag joint, broken spokes and destroyed hub

Nov 27, 2013
143
4
18
earth
www.Frankenbikes.com
MB running great, pulling hard. Fired it up after work, felt an odd "clunking" noticed my rear wheel was not aligned. Pulled out a wrench, set it straight-ish, discovered my rim seemed bent. Got a lift from a co-worker in a pickup.

Got home, pulled the wheel, started true the wheel, noticed that the spokes were turning - busted.
pulled the sprocket and rag joint - wow! check it out...

heh

Guess i will be trying a clamshell next.
2017-10-16 18.56.16.jpg
 

crassius

Well-Known Member
Sep 30, 2012
4,032
156
63
USA
got several coaster hubs like that - on them, damage was due to excessive heat of braking - seems expansion and contraction of hub can cause many kinds of failure
 
Nov 27, 2013
143
4
18
earth
www.Frankenbikes.com
Thanks Crassius, I always appreciate your comments.

I also assume the fact that I am using low end parts designed for children- in this case a wal-mart west coast chopper huffy bike - and apply a fair amount of force from an engine with a tiny front sprocket,while loading it up my 280 lb plus carcass daily may have something to do with it. The original build was back in 2013 so that ain't too bad, but I have been riding it a lot lately.

Digging around I discovered another identical wheel in my pile, already set up with the sprocket mounted from an uncompleted build. I may be back on the road tomorrow...

The ruined one had a 3/4" spacer, the "new" one is only 1/2" so i will see if there is a chain clearance issue, otherwise i guess pull it and redo the rag joint - and perhaps switch to a free wheel ultimately.

I wonder what the rim dimensions really are- it is a twenty inch wheel but it has those fat 3" tires- the inside rim width is only 1"
 

Tyler6357

Well-Known Member
Mar 15, 2012
1,143
170
63
Santa Barbara, CA
Wow, that's some nice grind but it sounds like you probably got your money's worth. I wonder how many miles that is? I think it's worth it to get the sprocket adapter.
 

Tony01

Well-Known Member
Nov 28, 2012
1,389
828
113
sf bay area
Coaster brake hubs suck... period.

Looks like you got lucky that the wheel didn't lead to you getting hurt..........
Nah... I've had many, many rear wheel/frame failures and none of them were scary in the least.. Multiple frame cracks, one at 40mph that was a bit scary cause it was my first, snapped rear axle on left side, felt like a frame crack... chain jumped into spokes many times and ate half the rear wheel.. popped the rear tire going about 30 once... no biggie.

No front end failures!! Guess I'm lucky. My friend had a front tire pop at 35mph and he got real lucky, but it mangled his frame. Head tube twisted in relation, bent forks, etc.
 
Nov 27, 2013
143
4
18
earth
www.Frankenbikes.com
To date most of my failures to this point involve "pulling away" from a stop. I'm guessing that is when the torque is greatest, straining against the object at rest- me.

I am kind of proud these material failures, it is interesting see what happens and hear back from the forum about similar experiences.

BTW I am a style over speed guy. I am low to the ground and usually not going too fast. I mean, how fast do i really want to go on a what is a modified kid's bike? If it feels like it is breaking, i assume that it is.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
156
63
USA
I wonder what the rim dimensions really are- it is a twenty inch wheel but it has those fat 3" tires- the inside rim width is only 1"
roll bike until filler neck is at bottom, put something on ground there - roll bike until filler is again at bottom, measure distance from there to thing on ground - divide by pi to find rolling diameter