Suspension and Frame Design
Transition didn’t invent the whole long, slack head angle, steep seat angle thing, but they’re one of the brands that have fully embraced that sort of thinking. And now they’re applying their 'Speed Balanced Geometry' to the all-new Spur, a 29er with 120mm of front and rear travel. This isn't your typical cross-country bike, though, with Transition saying that it's designed to be relatively light and cover ground quickly but, as Transition puts it, “descend anything you may encounter along the way.’’
To underline that capability, the Spur comes stock with stuff that you wouldn't usually see on a 120mm-travel bike. There are 2.4" wide tires from Maxxis with EXO casings, long-stroke dropper posts (my size-large test bike has a 180mm OneUp dropper), and four-piston brakes on all models. Further making the Spur's intentions obvious are the 800mm wide handlebars and 50mm stems across the three-bike range.
• Intended use: Everything?
• Wheel size: 29"
• Rear wheel travel: 120mm
• Fork travel: 120mm
• Frame material: Carbon fiber
• Threaded bottom bracket
• SBG geometry
• Four-piston brakes, long-travel dropper posts, wide tires stock
• Weight: 24.74lb (X01 build)
• MSRP: $4,999 - $8,999 USD
• More info: www.transitionbikes.com
The Spur’s suspension layout is pretty straightforward, with the SIDLuxe shock being compressed from above via a cute little rocker link that’s also carbon fiber. Like some other short-travel bikes, Transition has skipped using a pivot at the axle, with a “carbon-tuned pivot-less flex stay
” doing the job instead. Engineered flex pivots always seem to get a bit of heat from people who are wary of such things, be it for a good reason or not. They’ve always been reliable in my experience, though, and I’ve owned and ridden a bunch of different bikes that use flex pivots. Remember, there are barely a few degrees of movement down at an axle pivot, especially on these short-travel bikes, and engineered flex can easily do that job.
Transition doesn’t make any weight saving claims about the flex pivot, but other brands have said that they’ve shaved around 200-grams by not using sealed bearings and all the required pivot hardware. Word is that the suspension works well when running anywhere between 25 and 35-percent sag, a relatively wide range for a bike with just 120mm of travel, and the 30-percent progression has a "consistent linear rate of change."
Oh, and if 120mm is way too much suspension for you, Transition says that you can swap out the 45mm-stroke SID shock for one with 37.5mm to convert it to a 100mm-travel Spur.
There are a handful of details on the Spur worth mentioning, starting with the threaded bottom bracket shell and headtube that takes press-in cups to allow for angle-adjusting headsets. It’s almost like these Transition guys read Pinkbike comments or something… Hmmm.
On that note, there’s a ton of room for a bottle inside the front triangle, as well as a mount under the downtube for when you want to suck on a muddy nipple. There’s another set of threaded bosses on the underside of the toptube for some sort of bolt-on tool kit. Other details: Cable routing is internal and pass-through to make repairs easy, and check out the rubber chainstay protection - it sits nearly flush with the frame and sure looks classy.
Suspension travel doesn't define geometry, but the Spur is sporting some forward-thinking numbers relative to its travel. There's a 66-degree head angle - the slackest of the nine bikes in our upcoming cross-country Field Test video series - and my large-sized test bike has a 480mm reach. That's 20 to 30mm longer than many other large-sized bikes that aren't feeling so large these days.
There’s also a 75.9 - why not just call it 76? - degree seat angle that really helps to make the 480mm reach feel not so long, and the rear-end is 435mm on all sizes.
It may have just 120mm of travel, but the Spur didn’t start life as a cross-country bike like the Scalpel and Epic EVO, and that allowed Transition to take a much more aggressive approach in the geo department because they didn’t need to make a bike that was originally born as a racer. Spur Models
There are three different versions of the Spur, all based on the same 2,500-gram carbon frame and shock, and starting with the GX build at $4,999 USD and followed by the bike I'm currently testing, the X01 version that costs $5,999. That gets you a SID Ultimate fork and SIDLuxe shock, a set of DT Swiss’ XR1700 wheels, and guess what kind of drivetrain, all of which adds up to 24.74lb. Want less weight and a wireless drivetrain? The AXS bike costs $8,999, although that does get you a set of carbon rims as well. The frame and shock cost $2,999.
I've been putting in a ton of miles on the all-new Spur, so stay tuned for our upcoming cross-country Field Test video review series where it'll be covered in-depth.