Forward dropout blues
 

My cargo bike is an IGH Giant Simple 3, with forward dropouts. The shop has been trying over and over to find a way to keep me from pulling the hub forward out of the dropout enough to start throwing the chain repeatedly while i'm pedaling to no avail. (I mangled the last gimmick they tried to build..)
I'm leaving star-shaped marks on the frame where i'm pulling the thing loose, I pretzeled a plate they'd cut to hold the axle in place, it's just getting downright obnoxious. I was riding slow for a couple weeks accompanying my asthmatic wife to work, but I went into school at my usual pace and dropped the chain with it JUST out of the shop. Last semester, I generally would throw the chain between four and fifteen times each week because of this.

Do I just need to get a new bike? And if so, does anyone have any suggestions for heavy duty cruiser frames suitable for cargo and big balloon tires with REAR DROPOUTS that can handle decent abuse? Including from being used outside in the weather, which rules out Worksman bikes that are "not designed to be outdoors"? I don't care much what style, so long as I can mount oversized Wald baskets front and back (thus no suspension) and run tires wider than 2". (Drops would be nice, but somehow I don't see it happening with the other requirements)

Sounds like the IGH wasn't set up properly. Maybe they forgot the anti-rotation washer. I'd ask over at the Bicycle Mechanics section. Regardless, that shouldn't be happening.

Did you even bother to read?

OP- Like Mark said, I'd probably check out the mechanic's forum.

I just picked up some no name bmx style tensioners. They're pretty long so it looks like it might work for you.
http://i44.tinypic.com/14alr9v.jpg

They looked at those first, but couldn't get them to work. There's a fabricated metal bracket bolted on right now, but I apparently managed to mangle it at least once.

Agreed. Almost all bikes used to have horizontal dropouts and we didn't have serious problems with the axles being pulled forward. Even our tandem is built that way and it's never been an issue as long as the rear wheel is firmly secured. There should be serrated surfaces that dig into the dropout on both sides to keep the axle from slipping forward.

This is a stock bike? http://www.giant-bicycles.com/en-us/...ck/7333/44069/

Something is seriously wrong if the wheel is moving for any reason. I agree with Mark- there's probably a washer missing somewhere. The shop should either fix it or get you a working bike.

http://www.sasobike.com

Dale Saso of San Jose, CA - just a 1/2 mile up the hill from me. Makes the truck-bike with a 20" fat tire front and 26" rear. Allows a very large basket in front and of course you could install a double-side in the rear. Master framebuilder is what he is.

=8-)

The axle shouldn't be pulling forward at all. Whether it is a forward facing or rear facing dropout is irrelevant. A simple quick release skewer or axle nut should be sufficient to hold the axle in place. This isn't something that should even be necessary to bring to a shop. Something is seriously wrong here if you are repeatedly pulling the wheel out of the axle. Something must be damaged, missing and/or defective. If your LBS can't figure this out they are incompetent. Did you try another shop?

Agreed. In over 20 years as a mechanic and service manager I have never seen a hub that could not be secured in place if installed properly on a good dropout. Either something is wrong on the hub side of the dropout or that the dropout has been so damaged at this point that it will no longer hold.

I'm wondering if that's the case.

If it's quick-release, then maybe the axle pokes out too far on the drive side. Then the QR will clamp on the end of the axle rather than the dropout. I'm a big guy (250 pounds) and can put out 800 watts for a short spurt, and I've never had an axle slide in the dropouts if the QR was tightened properly.

Horizontal dropouts have been around for a century, both forward and rear facing, and rear wheels have stayed in place fine with no heroic measures or the need for added security devices. This is true both with QR and nutted wheels, with and without serrated washers. Super strong riders have climbed the alps, and sprinted on the track without their wheels moving so the first thing you should be asking is Why is my wheel moving?

It could be that axle rotation works the nuts loose, damaged threads or axle length are keeping it from being tight enough even when it feels like it is, the mating surfaces lack adequate bite to the dropout, or the dropout itself lacks flat parallel surfaces making a good mounting impossible.

Don't spend money until you've taken the time to analyze why you cannot do something that millions of people have had no trouble doing for decades. Once you know why it's slipping, and not before, then you can solve the problem. Trying to fix it without knowing the true cause is like trying to patch a tube without finding the puncture first.

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Nexus/InternalHub/SG-3C41/SI-35U0C-001_ENG_v1_m56577569830655189.pdf

I had the Nexus 4 speed on a TREK CLYDE with forward facing drop outs on an aluminum frame it was loaned to my sons friend, an athletic 22 year old 350 pound 7 foot "BIG TEXAS". He never dislodged the back axle. I suspect improper assembly (missing or incorrect anti rotation washer)

Remove the wheel nuts and check that the anti-rotation washers are not standing proud of the dropouts.
Usually, oversized track nuts with built-in serrated washers would solve the problem if you can fit Shimano 3 speed changer unit over the axle. I dont know if the changer grips onto the Shimano nuts.