Broken XT Cassette

Today I rode Chimney Gulch and after taking it easy for 3 days, I was feeling really good. Sadly, about 1/4 of the way up while powering (or slogging) up a particularly tricky rock section, my cassette failed. The whole affair got twisted partially into the spokes and so I couldn't coast or pedal. My riding companion, Kevin, had the idea to take the chain off so I could coast back to the car. Great idea! I had a fairly uneventful ride back to the car, where I had luckily stashed a spare wheel. So I mounted that wheel up and headed back up the hill.

The reason that I had a second wheel in the car was that this morning I was running late, as usual, but I wanted to ride my All Mountain-ish wheelset instead of the XC-ish ones. I'll digress into an explanation of my 2 current wheelsets on my Ventana El Rey.

The XC wheelset consists of 32 hole Stan's Flow rims laced to a Chris King ISO rear and a Hope Pro II front hub. My 2nd wheelset is 36 hole Sun Rhyno Lites laced 3X to Hope Pro II hubs front and rear. The Rhyno Lites are noticeably stiffer, but also nearly 200 grams heavier per wheel than the Flows, so I tend to put lighter tires on the Flows. Anyway, I'd worn out my heavier duty tires last year and so this year I've been running lightish tires. Recently I've been getting lots of flats and I'm not happy about it. For a while I was running a Saguro in the front and a Kenda Small Block 8 in the back, but the SB8 was just way too light and I could never get any confidence in it. So I put a Rampage on the front and the Saguaro on the back. I have been disappointed by the Saguaro. Running it in the "Speed" direction it spins out easily, pinch flats easily, and has some really annoying tread squirm to it that does not inspire confidence. I will switch it to "Traction" direction and hope for the best.

Anyway, I was fed up with the XC wheels and as I've been getting stronger lately, I've been feeling the limitations of the lighter wheels both climbing and descending. Today was going to be the day for the heavy duty tires (not that any 29er tires are truly heavy duty. Yet.) So as I ran out of the house this morning, I put the Rhyno Lite on the front, but just threw the rear in the back of the Forester and headed to work.

Due to generalized laziness, the rear AM wheel was not 100% setup correctly. Basically, since I'm 225+ lbs and I like to climb up steep hills, I break stuff. The most recent destruction was in the form of a blown-up Hope freehub. I have 2 warranty replacements, one aluminum and one stainless-steel, but the (weaker) aluminium was installed since I got it first. And since I know that the aluminum freehubs will not survive long under max torque, I purposely had installed an old 11-32 cassette instead of my preferred 11-34. My original plan had been to install the stainless steel freehub and an 11-34 cassette at lunch or at the trailhead before the rest of the crew showed up. Unfortunately, my brain was not fully engaged this morning, and I forgot to bring the stainless freehub.

Thus, I ended up riding Chimney Gulch with an old cassette, and I payed the price. It was a previous generation Shimano XT 11-32 cassette with 4 arms. It looks like one of the aluminum arms failed and then the rest of the cog folded and cracked 2 of the other arms.

Anyway, the ride was pretty entertaining overall and I got a rare chance to compare two tires back-to-back with most of the other variables being constant. I started the ride on a Kenda Nevegal 2.2 @ 40psi and I was loving that tire all the way up Chimney Gulch. Very planted feel, good grip, rewards aggressive efforts without spinning out, I can just dig push as hard as possible and trust that the tire will transmit all the power into the dust and loose rocks.

In contrast, the second climb was on a Saguaro pumped up to about 35. Gawd it was painful after riding the Nevegal. It spun out on every water bar, the tire folded and slid out on every rut and the sidewall collapsed over every rock making the ride seem like a constant threat of pinch flatting or just spinning out the entire way up. Finally I stopped for a few minutes and added 100 pump-strokes from my topeak minipump which improved the feel, but not the traction. I gotta remember that the Saguaro is good for fast, technically easy rides only.

On the front, I had a brand new WTB Stout. It was a promising inagural ride. So far it is a very confidence inspiring tire. Seems very sticky, no tread squirm and no feeling that it will fall-away when leaned over. The tread compound feels very soft and sticky and I noticed some noticible tread abrasion on the corners already (todays ride was only 7 miles!) so the internet reports of short lifespan seem likely to come true for me as well.

I made it most of the way up Chimney Gulch even after all this messing around, but I didn't quite make it to the top... about 10 minutes past the second road crossing, I met Kevin and Jeanne coming back down. I turned around then with them and we had a great ride back to the parking lot. At the end of the ride, Kevin and I compared odometers, both of us had exactly 7.27 miles indicated... pretty funny.

I need to get my act together and get the stainless steel freehub on my Hope Hub so I can put an 11-34 on it and start riding the Nevegal again. So I guess the moral of the story is that I should always bring an extra wheelset with me. Either that or I should actually work on my bike sometimes other than at the trail head. Nah.

On a slightly different subject, I'm liking the 22-36-bash front gearing a lot. I did screw up and shorten my chain too much, so I need to add 2 links back on, always a risky proposition, but I'll probably risk it. I had figured out that the standard gearing of 22-32-44 gave me a 30mph top speed at 90rpm, while a 22-36 resulted in about 26mph. Since I can barely maintain 30mph for 1 minute on a level dirt road, I figured that losing 4mph of max speed on the flats would be a good trade for extra ground clearance and a tighter chain. I doubt that I'll have any loss of speed on the vast majority of the terrain I ride. Makes the bike look a little tougher too.

Stats for the ride (from my Garmin 705):
Distance: 7.27 miles
Average: 3.8 mph (including time spent replacing the wheel)
Total Ascent: 1772 feet, yes it is flippin steep