bloggy business

Kinn Bikes (or why people who aren't bicycle designers shouldn't design bicycles)

So, I normally do not like to criticize other bicycle maker's (designer's, fabricator's, framebuilder's) work. But every once in a while I run into something so appalling that I feel it's part of my civic duty to the bicycling community to speak up about it. 

I took in a Kinn bike the other day for a repair. Kinn was a small production brand out of Portland, OR (now out of business). They designed a bike meant as a 'midtail' cargo bike/family transportation. Not a terrible idea for a bike. Somewhere between a regular bike and a long tail cargo bike (hence the midtail monicker).

The bike originally came in because the kickstand plate had had experienced a lot of rust and eventually torn off. The owner thought the problem originated from the fact that there wasn't any drain holes in the BB shell and the seat tube had filled with water. While this is a huge problem on it's own (I'll do a write up on drain hole theory later...), the seat tube didn't even have a hole into the BB shell. The corrosion problems around the kickstand plate were all external, due to water pooling up on top of the plate and getting in under the powder coat where the joint wasn't welded all the way around. Not a particularly great design feature in itself, but also by far not the most concerning thing going on with the bike.

As I was stripping the bike down to do the work on it, I noticed something going on with the fork. There was a 1/8" deep groove worn into the back of the steerer tube about an inch above the crown race. This is pretty much exactly at the most stressed point of the entire bike frame (the top of the fork crown where it meets the steering column). Any damage to the fork there can easily cause catastrophic failure. As in you hit a pothole, the fork separates into two pieces, and the rider hitting the ground face first. If you're really into seeing pictures of people's faces that had their noses ground off by the pavement, do a Google search for what happens when your fork breaks on you... And this is even more concerning because the Kinn bikes were meant to also carry children as well. I don't even want to think about what happens to the kid in this situation.

So it immediately occurred to me to figure out what had caused the fork damage. Had to have been something inside the headtube rubbing on the steerer. CORRECTION: According to Todd from Clever Cycles (the shop that sold the bike) the pointy thing inside the headtube was meant to be part of a fork locking system, see Todd's comment down below. (The good folks at Clever are in the process of contacting all owners of the Kinn bikes they sold, to have their bikes checked out. Thanks for your effort in keeping people safe!). [MY ORIGINAL TEXT: A quick inspection revealed that there was an attempt at using a carbon brush as an electrical grounding contact for a taillight between the frame and fork up in the HT at just the spot where the groove is. This ill conceived design feature is similar to something they used to do on high end French rando bikes back in the day. However on the old French bikes they would braze a contact plate to the steerer for the carbon brush to rub onto, and they would use a wide, flat brush to spread the contact point out. This was all to prevent damage to the fork. On the Kinn frame the brush is small and pointy and rubs directly onto the steerer.] Over the two years the owner of the bike has had it (it was bought new), there developed significant damage to the steering column. Enough to where I would say without a doubt that it could cause the fork to fail and the rider(s) to be injured, possibly fatally. I was so concerned that I filed a Consumer Product Safety Commission report about it. Hopefully that will have some traction and word will get out to bike shops and Kinn owners, and they will have their bikes checked out. This definitely deserves a recall IMO.

Now what does this have to do with bike design and why people who aren't bicycle designers shouldn't design bicycles? 

I would say that the guy who designed the KInn bikes had a decent idea. Mid-sized cargo bike. Smaller and lighter than a typical cargo bike. You could even throw it on the front rack of a bus to expand your biking range with public transit. Pretty good idea. Now, the part where it all fails IHMO is that he didn't have anything resembling adequate experience to safely design the bike himself. Would you trust someone without any experience in designing buildings to safely design you an apartment complex? Would you trust someone without experience to design you a car? A bridge? I wouldn't think so. You would want someone with years of experience. Someone who knows intricately everything that goes into the design process. 

What makes bicycles different? (Especially bicycles meant to have children as passengers). There are plenty of fly-by-night bike makers out there that throw their name up on a website and BOOM! people assume that they are knowledgable and capable to design and build them a good and safe bicycle. Definitely not true, see case in point. In the current age, ideas and marketing seem to speak more to people than experience and knowhow. In the bicycle world it's hard to not be swayed by a smart idea, a sexy website, and fancy paint schemes.

But really, what people should be looking at is how many years experience does the framebuilder or designer have? What is their track record of failed products?  Can they actually do what they say they can do? Should you place your trust in them or not? At least in the case of Kinn Bikes, I would think not.

*Please note that the fabrication of the Kinn Bikes frame was done by Zen Fabrications in Portland, OR. The fork is a Surly Disc Trucker fork that has been repainted to match the frame. To all appearances the actual fabrication of the frame and fork was done well. The failure here is in the design of the bike. 

Kinn Cascade Flyer

Kinn Cascade Flyer

The original problem. Kickstand plate broke off due to a combination of design and the powder coat holding water in next to the steel. 

The original problem. Kickstand plate broke off due to a combination of design and the powder coat holding water in next to the steel. 

The groove in the steerer tube.

The groove in the steerer tube.

You can kind of see the  pointy business    [not a     carbon brush]   inside the head tube here.

You can kind of see the pointy business [not a carbon brush] inside the head tube here.