Thursday, August 26, 2010

No More Breakin’ (Hopefully)

Since I’ve been kind of a frame killer these past few weeks, I decided that it was time to do a little investigating. I’ve never even considered the fact there there could be some kind of flaw in the frame design, nor an issue with the quality of bikes with the name Diamondback on them. At least that ruled out something.

I don’t think that my weight isn’t really that much of an issue either. At 225 pounds and well over 6 feet tall, I’m hardly fat. In fact, I see much bigger (and fatter) guys riding the shit out of aluminum frames, and they seem to take the abuse. I’ve ridden plenty of other bikes over the years, and I didn’t start breaking shit until lately. So, what could it be?

One thing I initially ruled out is probably now what I consider the main culprit. What, you ask? Well, smarty pants, it’s my seatpost height. Since I’m severely long-legged, I have to ride "jacked-to-the-max" to have any kind of efficient pedal stroke when I sit down to climb. On both of my recently broken frames, I had each seatpost inserted well below the minimum point labeled on the post. I though I would be safe in doing so, but turns out that’s only half the story. Sure, having enough seatpost inserted in the frame is the way to go, but in my case I don't think that what’s recommended on the seatpost was enough. After I broke the Big O, I took note of where the frame actually failed:

My seatpost was inserted at the “4” mark, with the minimum point being just below the “1.” This might have looked okay to the casual observer, but the bottom of the seatpost is exactly where the frame cracked (coincidentally it was at the weld though.) After doing some research on the Internets and also asking around, I realized that my seatpost should extend well below where the top tube meets the seat tube to keep this from happening again. Even though the seatpost looked like it was inserted properly, the leverage from such a short post is probably what caused the failure (in my not-so professional opinion.)

Here was my current configuration, and you can see that there is plenty of seatpost down in the frame:

I needed a fix, and I needed it quick. The frame size is an XL (22 inch), so moving to a bigger frame it not an option. I needed a longer seatpost, but at 350mm for my current one, I didn’t have too many options. I had to scour the Internets to find a longer post, and I finally did. A few days later, this box showed up at my door:

Of course the box was of no use to me, so I opened it up to find a new seatpost inside:

I know it doesn’t look much different than any other seatpost, but I assure you it is. It’s an Easton EA50 400mm jobby, which should give me plenty of extra post to violate my frame with. I swapped over the seat to the new post, and installed my new, extra-long seatpost. As with all of these parts replacement blog posts, this one took longer than normal since I had to stop and take photos.

After a little driveway testing session, I got the seat height dialed in, and there was still plenty of post down in the frame. Let’s hope this shit works. I’m kind of counting on it actually, since I have to do the same thing on my other bike. Of course, a full report will be in order sometime in the near future. Now, it’s time to go for a real test ride on an actual trail. Yeah I know, it’s kinda boring just talking about my seatpost and stuff, but that’s all I had. What, no talk of the River’s Edge Mountain Bike Marathon? Not yet. I’ll get into that tomorrow for sure though.

1 comment:

Anonymous said...

God bless you..Thats alot of shit..i'm making you a custom off of the new platform.

Richard BR