At the end of last year, the suspension company X-Fusion released their new 100mm-travel adjustable seatpost called the HILO or HIgh-LOw. The hydraulic seatpost is infinitely adjustable in its 100 mm range, and can be set up to be either cable actuated from a remote on the handlebar or from a lever under the seat. It weighs approximately 620 grams, and is available in 27.2, 30.9 and 31.6mm diameters. The HILO is hydraulically controlled, and pulling the cable or lever allows oil to pass freely through the post's chamber, allowing it to move up or down. When released, oil can no longer move, so the post is held in place, holding its height. It uses an air spring to extend the post, which is adjusted by the valve located on its bottom. Lateral twisting at the saddle and clamp interface is alleviated with their Double key-way design. X-Fusion was kind enough to send along a HILO for a quick four week test on my Ibis Mojo HD steed.

Impressions
Installing the seat lever was very simple, and it was easy to make seatpost height adjustments while riding on moderate trails, but when anything remotely technical or tough was encountered it was difficult to reach back and pull the lever. Pulling the lever under the seat provided very smooth operation, and a simple seated downward pressure (push with the butt) put the saddle into whatever height was desired, while upward motion entailed not weighting or sitting on the saddle. The upward movement was also greatly assisted by the subtle hand pull while using the lever. The system's up and down propagation felt even and occurred at the same relative speed, although it had a somewhat viscous sensation while in motion. The lever system is also handy since it allowed the entire seatpost to be easily swapped between different bike.

I next installed the cable actuated remote system using the instructional drawing that came with the kit. I was finally able get it in place, but the simple pictorial installation guide included with the seatpost wasn't very useful (they do have a HILO setup guide online). Even though I lubed the cable, and had everything working properly, the remote system seemed a bit stiff and awkward, and it never gave the smooth control like the seat lever provided? I did like the hinged remote clamp, which makes it easier to install on a variety of handlebars, and did not require removing brakes, grips or shifters.

I had some issue with it not raising or lowering fast enough to any position (seat lever and remote based), and neither bumping up the air pressure nor playing with cable barrel adjuster underneath the saddle made much difference. I ride very technical trails, and I want the post to react quickly, and it was too slow for my tastes, although it was fine when I was doing stuff on the normal x-country trails, and easier rock gardens.



I had recently been using a 125mm adjustable seatpost for All Mountain riding, so it was tough to shorten back to 100mm, and I really missed that extra 25mm or 1 inch of height when dealing with steep terrain and ledges, and I found myself getting caught on the back of the saddle on occasion. If you pull up on the saddle when the seatpost is in any lowered position, it moves to its highest position, meaning it's not locked and is free to move upwards (due to the single volume chamber design). It does return to the original position when you let it go, but I found the movement annoying, as I do lot's of nasty hiking to get to my favorite sick terrain, and I sometimes need to grab the saddle to pull the bike upwards.

When grabbing the saddle, it didn't twist much due to the Double key-way design, making it have a very solid feel, without any noticeable slop, and they have one of the tighter systems in this regards. The saddle was really easy to install since it uses a single bolt clamp system, so fore and aft, or tilt is extremely simple to adjust, but you do need to lube the bolt and tighten the heck out of it (17 NM) to prevent slippage, and on rare occasions the saddle still tilted on me when I slammed into a big hit.

Measured Specs:
  • Post - 646.9 grams
  • Remote system - 77.7 grams?
  • Lever 11.8 grams

Next » Bottom Line

Here is a short video that MTBR.com's Francis Cebedo did on the HILO:

[youtube width="640"]httpv://www.youtube.com/watch?v=xZ-L3wQu8AE





Bottom Line
The X-Fusion HILO is a nice infinitely adjustable hydraulic seatpost, and it provided very smooth operation throughout its 100mm of travel. The HILO seemed more applicable to X-Country than All Mountain riding, due to the height limitation of its travel and viscosity (slowness) of the movement. The seat lever system worked extremely well, especially on easy to moderate terrain, and it provided excellent operation and precision in its usage, and made the post swappable between bikes. The remote worked adequately, but was stiff and awkward to use. When the HILO was lowered, and you grabbed the saddle, it would rise to the highest position, and made a hike-a-bike portaging more difficult.

Strengths
  • Seat lever system was simple, easy to use and made it swappable between bikes
  • Tight
  • Smooth operation
Weaknesses
  • Remote system was stiff and awkward
  • Needs more sizes - 125mm and maybe 80mm
  • Saddle clamp can slip
  • Raises in lowered positions when the saddle is grabbed
  • Viscous (slow) in movement
MSRP: $250

Overall Rating: 3.5 Flamin' Chili Peppers


X-Fusion Company HILO 100 Specs and Features:
Adjustments height seatposts are improving the way that mountain bikers ride everywhere. All riders can benefit from moving the seat down for added stability on descents or increasing the seat height for climbing. X-Fusion has been manufacturing hydraulic systems for over 10 years so it was natural for us to jump into this emerging product segment. Our goal is to create the most durable, most reliable adjustable height seatpost on the market.
  • Visit the X-Fusion HILO 100 website
  • Hydraulic design allows for smooth adjustability
  • Double key-way design prevents lateral twisting
  • Passes CEN testing for fatigue and impact
  • Wide range of seatpost angle adjustment
  • Optional handlebar remote
  • Easily convertible from lever-actuation to remote handlebar actuation or vice-versa
  • Travel - 100mm
  • Weight - 620g
  • OD - 27.2 / 30.9 / 31.6 mm
  • Options - Seat Post Angle Adjustable Infinitive Travel Adjustable Remote Control
  • Colors - mat silver, black