I broke my blogging streak. It (shamefully), has been about a month since my last confession.
I’ll be doing some catch-up postings to let you know what’s been going on.
Short-version: British Columbia.
But I broke something else too. Here’s a quickie post about my…well…post?
Sidenote: all bike marketing-geek-speak rather misleadingly describes this bike design as “long, low and slack”, and usually this is accompanied by descriptions of seat-tube and top-tube dimensions, which just muddies the water. I will come back to comment on this whole debacle later in this post.
My 9point8 FallLine dropper post has been (almost) as flawless as the original Pulse post. I think I have placed over 5000km of pretty serious riding on the Pulse with nothing required except lubing the pins 3 times and bleeding the hydraulic stepper once in a parking lot, in the rain, in Montrose Colorado.
(On the Pulse, the hidden internal hydraulic stepper looks like a hand grenade, which is a cool easter egg.)
I really like the company and they have been great to deal with.
On my final ride in BC I had a silly bike failure, see the photo. That’s the control cable for the seatpost. Ka-zing!
The trigger actually has a radius’ed corner and there is no obvious stress point on the cable. For a while I’ve been claiming that I use the post as much as a shifter, and now I’m pretty sure that’s true. That cable was flexed back and forth so much it snapped.
I felt the initial twang early in the ride and the final 3 or 4 strands let go about three quarters of the way through the ride. This went from “perfect” to “crap” in under one ride. Once I noticed that the cable had started popping, I was pretty cavalier about the situation until I recalled (rather too late) that you cannot activate the post by hand since it has the “stealth” routing that buries the whole gizmo deep inside your bike frame.
When this guy broke, my seatpost was therefore stuck wherever it was. I got lucky, it was pretty much a goldilocks height.
I might look for a different trigger. Given the abuse it gets, I think a trigger arrangement that pulls the cable axially would be much better than one that hinges the cable.
Getting back to the idea of “modern bike geometry”. Some ruminations.
Bike companies are dropping big money into carbon molds. I guess the development costs for a mold are around $50-100k per bike model, per size. To rationalize these costs (this is my take on it), they are pushing out bikes that are basically a “hybrid”. Up until recently, the MTB business was busy fragmenting and categorizing products into different riding disciplines like “cross-country”, “all-mountain”, “freeride”, “slopestyle”, “downhill” and so on.
Suddenly, there’s the re-emergence of the “one-bike” quiver killer. You don’t need all those bikes, you need just this one über-machine.
One of the key ingredients to making the “one-bike” has been bolting together two elements…slack head tubes (downhill) meet steep seat tubes (cross-country). A bike designer from England called “Brant Richards” might be the originator of this concept.
All previous iterations of the MTB have run (virtually) parallel seat post and head tubes for one important reason…bikes have to work in both sitting and standing modes.
With the original geometry concepts, it happens that when a rider stands up, s/he shifts about 6″ forward to balance above the pedals, and the act of parallelizing the frame angles makes that relationship come together for any and all head tube angles. And likewise, when sitting, there’s enough room between the seat and the bars.
We typically needed just enough fore-aft clearance to make it where we don’t end up hovering right above the saddle when standing up hovering right above the pedals. The parallel-y bikes of yesterday magically offer up the right relationship, where the the balance points between pedals and seat were shifted about 6″ (or more) in space from one-another.
There’s no conceptual reason why this is the case, but it just happens to work out given the size of adult humans. If you extend a line at 73 degrees, at the height of a saddle, it’ll be about a foot away from vertical, and 6 inches away from a 6″ saddle nose…voila, everything sort of lines up nicely.
However, the slacker head tubes needed for steeper terrain weren’t a tidy 6″ of shift. They were more like 12″ of shift back from vertical. Getting from sitting to standing was like jumping out of a hammock – impossible to do with any finesse. Freeride bikes were hard to ride uphill and the “travel-adjust” fork was innovated as a way to let you climb while sitting on these type of bikes. There were all kinds of knock-on effects when these bikes began to be ridden on trails that were other-than downhill.
The “über-machine” bikes of today riff on this whole set of design issues in another way. Now, if you stand up on a new-wave MTB, you don’t shift forward, you only move up. The saddle is right in the way, straight underneath you. Or put another way, perhaps more accurately, there’s no fore-aft shift, standing versus sitting. The bottom bracket now is straight under your center of gravity as it locates when standing. This pitches the rider into a position where (balance-wise) it’s almost like standing up and leaning forward all the time.
Enter the dropper post. The problem that the dropper post fixes is effectively the problem caused by the costs of carbon fiber molding, which is that we want a way to make the universal bike rideable. How to ride slack head tube angles on all terrain? Instead of shifting in front or behind the saddle, we now telescope the saddle down out of the way and ride always in the same position.
The words that are used to sell this to the public are confusing. What happens if you just compare old bikes with new ones, graphically? If you took an old freeride bike as a starting point, the only thing that has truly happened is that the bottom bracket has moved rear-ward relative to all the other points on the bike, and everything else has been more-or-less maintained.
As a rider, you can intuit it this way: if you try to balance on a skinny, you naturally shift your balance forward, because this makes the steering more reactive (since your center of gravity is right over the front wheel). Now a tiny turn on the front wheel rebalances your bike, and you lose the sawing or wide-swaying weight swings which would drop you off the edge of the skinny.
We need to do this all the time on a modern trail bike. If you have a freeride head angle, you need to push your weight over the front wheel or the bike will ride like a chopper, and you’ll feel front wheel flop (like on the free-ride bikes of yore).
This geometry forces riders into the right “position”. Magically, this un-rideable bike becomes rideable.
What this wave of design reminds me of is the emergence of the “intermediate” freeride bike. Some bike designs that come to mind are the Transition Bikes Syren and BottleRocket and the Santa Cruz Bicycles Nomad 1. What these bikes all had in common was a weird spring-curve on their back suspension. They went regressive-flat-progressive. Not many bikes before or since had any regression.
What this regression was there for is to pump the terrain for the rider. The lack of stand-up ride-ability on these slack bikes was super hard to work right. The bike naturally went to about a 30% sag point and had a built-in, designed-in ability to work through drops in the terrain, even if a rider was just sitting there acting like they don’t have back legs. Check out some old videos of riders sitting down through the chunky terrain and you can see what the deal was. The bike was designed to be ridden from one position, sitting.
Want to know a modern bike that has this exact thing? The Santa Cruz Nomad C. They went all the way back to the VPP1 patent and the bike has a regressive spring rate that naturally sags the bike at 28% of travel. Because it’s pretty hard to pump terrain with the seatpost stacked above your bottom bracket. Now it’s less about skill and more about being boxed in by the geometry. These bikes are designed to be ridden from one balance location too.
The re-cycling of the VPP1 patent is a telling solution to this similar set of problems. What goes around comes around. Evolution or revolution? 😉 In the first wave of the freeride bike, the standing/sitting positions were too different. Now, in this second wave, they are too the-same. And both ways fundamentally impair our ability to selectively weight-unload the back wheel properly.
Basically, to summarize, the modern trailbike overlaps the sitting and standing cockpit, and that’s why I busted my cable.