Thursday, December 11, 2008

Bizarre H Plus Son Rim Failure In Japan


Our friend from Japan was gleefully skidding on his track bike with what seems like a black, SL42 anodized deep section rear wheel from H Plus Son. Then he heard the explosion. Kaboooom! Damn, I need my props. Like KABOOOOOOOOOOOM!


A friend of his noted on his blog :

"Last night, we rode bikes and had tons of fun. But when he was doing skid, I heard big explosion I've never heard. Then, the rim has bursted. Inside of rim has collapsed and tube was bursted. But tire has not bursted. Rim was just only two weeks used. It's almost new."

It looks like he had a Latex tube on




If you study these pictures closely, you'll notice that the rim blew apart right across the centerline. I have not seen a failure like this before. Its almost as if it traced a prior crack or a groove along the bed of the rim. The data we have about the size of tire that was used, along with tire pressure are not available from the user or his friend, so I won't unnecessarily take a stab at why this happened. More pictures of the failure on his Flickr page here.



The Wheel And Cross Section. More rim specific information here.


The folks at RBT are discussing this failure in more detail, along with the usual digress. Some are alluding to excessive side hoop forces while skidding, while others are theorizing at heating of an overpressurized tube and subsequent bursting causing rim failure, all during the momentary skidding. I highly doubt that scenario but what else can you expect from a debate?


10 comments:

Anonymous said...

I respect people who ride fixed gears. bUT cant understand why they trash their bikes like this? tHESE idiots belong to the circus.

Kirk said...

very interesting. im really looking forward for explanations.

Anonymous said...

Wonder when this will be picked up by BSNYC.

Phil said...

Interesting wheel section profile. This seems like a just released product from the company.

Bike_Boy said...

@ Phil - Yes, it looks different and the wall thicknesses, for some reason, don't seem to be ideal to me.

Anonymous said...

I'm imagining the wheel made of dry cake, and if anything would break it along the middle of the rim bed, I think it would be an unusual pressure on the rim sides outwards..something that would come about my high pressure over sized tires the wheel is not rated for.

Ron said...

I just wouldn't buy a wheel off some newcomer to the market however lightweight or flashy looking they may get. I think generally its these companies that would tend to have a lot of those beginner process inefficiencies in the upstream. The trickle down effect is defects and bad products.

Anonymous said...

For pete's sake, you buy a rim off a bunch of guys who don't even have a proper website, that's telling something about them. I understand your hurt whoever bought this wheel, but I won't cry with you.

marc said...

if you dont ride fixed i wouldnt expect you to understand, however, ill just say if you get the immense amount of pleasure out of riding your bike as i do "trashing" my fixed gear you may. the added aspect of skidding and other such tricks on a fixed (which may not be for everyone) makes it more than just riding a bike down a road. so if thats what you do..ride a bike in a line, im happy you get your kicks as well but as for the "hipster fixed gear trick session"..you wouldnt get it and have an unfair bias. oh and sorry my alleycat spoke cards bum you out ill take them out tomorrow morning.

Anonymous said...

I had the same problem but was using a steel rim. My tube was over pressurized for the tire and it sounded like someone was poppin caps at me. Then I realized that I was in Belmont shore and my tube had bursted, blowing off my tire completely. Due to the strenght of the steel rim there was only need to replace the tube. To our friend that is uselessy wasting the tread on his skins, let some air out of your groovy pink tires.