Honda GXH50 Kit - failure of gearbox, with photos, warranty claim in progress

Sketch

Member
Local time
10:33 AM
Joined
Nov 18, 2009
Messages
87
(please see attached photos)

Just before Christmas, I received my Honda frame mount kit from bicycle-engines.com. I put it together over a period of about 5 days and spent a couple days test riding it for a few hundred yards at a time, attempting to get the problems with the chain alignment worked out. Finally, I switched the orientation of the rear chain sprocket and started to get something that worked without kinking and the chain coming off. With more work on the chain tension, I finally felt that the whole thing was coming together.

I checked bolts and screws for tightness after the test rides. I checked my oil level and the gearbox level, making adjustments. I had followed all the instructions, as best as they could be interpreted.

After my first longer ride, which was about a half hour of travel time, the gear box had developed holes (see photos 1 and 2).

I am currently making a warranty claim, hoping to get an entire new gear box.

Photo 3 shows my bike. It's a little beat up because the trip included getting hit with a snow storm on the trip back to the house. I don't think that could have had anything to do with the metal failure of the gearbox housing.

Right now I am a little frustrated, but I know these things can take time to work out. I suspect that the "flatness" of the two sides of the gearbox weren't manufactured perfectly enough, and that the pressure from joining them created the stress that caused the cracking.

Given the failure, it makes me also think that it's a little frustrating that nowhere in the assembly instructions, which are meant for a shop technician it appears, are there torque requirements - which I would kind of like to see for this type of project.

Comments welcome???....
 

Attachments

  • tn_Bike Photos 001.jpg
    tn_Bike Photos 001.jpg
    327 KB · Views: 608
  • tn_Bike Photos 002.jpg
    tn_Bike Photos 002.jpg
    291.2 KB · Views: 550
  • tn_Bike Photos 003.jpg
    tn_Bike Photos 003.jpg
    330.7 KB · Views: 870
I have never, never heard of a failure like this. Frankly, I can not imagine how it could happen without a manufacturing problem.

I have had the previous generation gearbox (Stage II) for over 2 years and have never, ever had a gearbox problem of any kind. In fact, yesterday I took the gearbox apart to check things out and everything literally looks like new.

I hope you get this straightened out. This looks like an oddball failure and I would not let this put you off the Honda/Grubee system. I love mine.
 
I haven't finished digging into the gearbox so I will do that tomorrow. I was in a hurry to get the photos because the bicycle-engines.com service guy asked for a photo when I contacted him about a warranty claim. I was busy with family/holiday stuff for a few days which kept me from taking the time... It sure looks like something might have busted through, I agree. Or, my original theory was just that the two parts of the cast where not flush and the tightening of the cover plate, combined with the vibration of running for a while causes a stress fracture.
 
It looks to me as if the case was busted out from something on the inside hitting or being jammed into the case. It should be covered under the warranty. Let us know how you make out on your claim.
 
Seeing that both sides of the case broke I would look internally. I have heard of problems with the newer gear boxes such as broken teeth. I have many thousands of miles on the type II's with minimal problems. I personally don't use gear oil, makes the gear box run hot.
 
I got an email reply - they are going to replace. He says I can keep the centr. clutch attached to the shaft and just send the gearbox and gears. ...I'm happy - I'll be back on the road soon.
 
that's cool

I got an email reply - they are going to replace. He says I can keep the centr. clutch attached to the shaft and just send the gearbox and gears. ...I'm happy - I'll be back on the road soon.

that's cool

wonder if that THING got dropped somewhere
causing a hairline crack
which later developed into what we see now ??

since it involves both halfs of case -- ?? thinking not ??

MM
 
Back
Top