2015 Canfield Brothers 27.5 Jedi

Frame Details

The Jedi’s pivots are all noticeably stout, running on 20mm Enduro Max bearings with the bolts running all the way through each pivot. That connectivity through the pivots helps keep everything nice and stiff.

Cable routing is all external and routed under the top tube. Nothing fancy, but it’s clean and functional.

Welds on the frame aren’t the prettiest I’ve ever seen, but the frame is pretty overbuilt, so I’m certainly not worried about anything failing.

The bottom bracket is 83mm and threaded, and the rear end is spaced at 150mm. I would have slightly preferred a 157 rear end just to make throwing the wheel in a little easier, but this is admittedly nitpicky.

One quirk I did come across with the bottom bracket: the threads are cut into the shell, but the center part of the BB shell (that’s not threaded) isn’t machined out at all. This means that the little sleeve / tube that joins the two sides of most external cup bottom brackets doesn’t fit through the shell. I ran into this problem on both SRAM XO and RaceFace Cinch bottom brackets. It’s certainly not the end of the world, but it means that the bearings might get contaminated a little quicker.

Due to the frame’s use of an idler pulley (which I’ll get into below), the frame requires a special “wide angle” chain guide that accommodates the somewhat unusual chain layout. The frame includes a custom MRP guide that worked flawlessly for me.

Finish on the frame is a nice black matte anodization, and the links come in a few anodized color options. My old Yelli Screamy has a similar anodized finish that has held up really well in the 4 years I’ve owned that bike. The decals on the Jedi are all gloss black, which makes for a pretty stealthy look (and lots of people asking what kind of bike it is).

Aside from the frame being pretty porky (11.5 lbs with a Cane Creek shock), my main complaint in terms of construction is just the tire clearance. At the seatstay bridge, the rear tire is pretty tight in there. This is not great for mud, nor is it great for those who are inclined to run bigger tires. Here’s a picture—the tire is a Maxxis Minion DHF 2.5” that’s seen better days.

The Linkage and the Idler Pulley  

I’ve been casually interested in the Canfield DH bikes for quite a while, and I have a Yelli Screamy that’s pretty much my favorite bike ever. But I’ll admit that I’ve always been turned off by Canfield’s use of an idler pulley on the Jedi. The idler pulley is quite simple: it’s just a small cog that the chain loops over in between the cassette and the chainring.

Why was I hesitant? The idler is another source of friction while pedaling, and it’s another part to break. In particular, a lot of force goes into that idler while pedaling, so the bearings have some work to do. Canfield is certainly not the only company to use an idler pulley, but bike history is replete with stories of idler pulleys generally sucking.

So why use an idler? This has to do with the linkage on the Jedi, and more specifically, the axle path. This is going to get a bit technical, so bear with me (and if you don’t really care about this discussion, feel free to skip ahead to the next page).

Most full suspension bikes have some amount of chainstay growth as the suspension compresses. In other words, the distance from the rear axle (around which the cassette spins) to the bottom bracket (around which the cranks / chainrings spin) increases as the suspension compresses. With a few exceptions, this happens on every full suspension bike, and dialing in how this happens is a big part of designing a good suspension system.

The lengthening of the chainstays (and, simultaneously, the compressing of the suspension) is resisted by force on the chain. So the suspension compresses and the chainstay gets longer, but if you’re hammering on the pedals and putting force into the drivetrain, that force on the pedals is resisting the lengthening of the chainstays, and therefore is resisting the compressing of the suspension.

In a lot of situations, that’s a good thing—your pedaling forces firm up the suspension, which makes the bike pedal more efficiently. You might have heard about an anti-squat curve for a bike. The amount that pedaling forces resist the compression of the suspension is part of what the anti-squat calculation is telling you about.

But it’s not quite that simple. The lengthening of the chainstays can also result in pedal kickback. When you smack a bump and the suspension compresses sharply and the chainstays get a lot longer all of a sudden, that’s going to manifest itself as a tug on the chain, and in turn, a tug on the pedals, which, speaking from experience, is really annoying.

And those same forces can also make the suspension less supple; if chain forces are resisting the compression of the suspension, the suspension might not be doing everything it can to absorb bumps. This might be alright from a pedaling efficiency perspective, but it’s not so great for a DH bike.

This is a very generalized discussion that glosses over a lot of important details, and so far I’ve only been talking about suspension kinematics as they relate to the drivetrain. But the whole point of suspension is to absorb bumps on the ground, and that’s where a rearward axle path has some advantages. Namely, a dramatically rearward axle path helps the rear wheel get over sharp bumps without “hanging up.”

Most people have encountered that feeling of their wheel “catching” on an obstacle in the trail. If the wheel is allowed the swing “backward” as it encounters such a bump, it essentially buys itself a bit more time to gracefully roll over that obstacle. Or in other words, the rearward axle path softens the hit when your wheel encounters a bump that it needs to roll up and over. I’ll get into how that translates on the trail down below, but for the moment, suffice it to say it’s a good thing.

So, the guys at Canfield decided they wanted that nice rearward axle path, but having the chainstays grow dramatically creates drivetrain problems, which brings us back to the idler pulley.

By strategically placing the idler pulley, Canfield can effectively eliminate the drivetrain problems associated with the rearward axle path. Depending on where they place the pulley, they can keep pedaling efficiency ideal and avoid having any issues with pedal kickback, all while getting the axle path they want.

The downside: there’s an idler pulley. (Note: that’s arguably not the only downside, more on that below.)

The idler that Canfield uses is pretty obviously something that they’ve done a lot of refinement on (since they’ve been working with idlers for over a decade). It’s titanium, it runs on high quality bearings, and it’s integrated with the frame to manage the chain as cleanly as possible.

I’m happy to report that, despite my considerable skepticism, I don’t mind the idler at all. There’s a tiny bit of added friction in the system, but it’s far lower than what I expected. It’s tough to quantify, but it certainly doesn’t bother me, although it might if this was a bike that I was going to have to pedal uphill. I’d say it’s roughly akin to the added friction you get when you add a chainguide.

I haven’t had any durability issues, and the idler does a good job of keeping the chain situated. Even while pedaling through rough, choppy crap, I haven’t had any chain skipping or jamming issues. Literally the only issue I’ve had thus far is that my jeans got sucked into the idler once while I was pedaling around the driveway.

Also, a frequently asked question about the idler pulley is chain length. Normal chains usually come with between 114 and 120 links, and I’m running 110 links on my Jedi. So no, you don’t need to purchase extra chain

NEXT: On the Trail, Riding Situations, Etc.