Saturday, 28 January 2017

Wren Inverted Fatbike Fork | Full Ride Report

If you have been following this review of the Wren Inverted Fatbike Fork you have already seen Introduction and the Install & Setup.  If not you may want to take a peek them first before jumping into the juicy ride details.

So now its time to see how the Wren handles some real world multi seasonal conditions. 


The test vehicle for the Wren was a 2016 Norco Sasquatch 6.1 that sported a Bluto from the factory.  The white Bluto had 100 mm of squish, an axle crown measurement of 511 mm, a 51 mm offset (rake) and an MSRP of $685 - $715.  The specifications of the Wren (WSF150-110ATK) include 110 mm of suspension, an axle crown of 530 mm, offset of 45 mm and MSRP of $999.

Norco sasquatch

On paper the Wren is slightly taller with slightly shorter rake (more trail) which translates into more stability at speed coupled with slower steering when travelling more slowly.  Descents should also be slightly easier. However, in reality the actual difference in geometry between these two forks is minimal.  But the big question is . . . how does the Wren actually feel and handle in the dirt and snow?

Having almost 12 months on the Bluto it saw all varieties of terrain including: snow (pristine to cratered), ice (smooth to fractured), flowy single track, gnarly cross country and downhill, mud and water, gravel grinds, pavement and untouched back country exploration.  The Bluto did what was supposed to do while exhibiting some flex and mimicking a pogo stick from time to time.

Wren Inverted Fatbike Fork

The Wren Inverted Fatbike Fork was mounted up to the Sasquatch and after 6 months (early fall to the dead of winter) it has been exposed to the same terrain and environment.


Simply put, the Wren does what the Bluto was meant to do, but it does it much better.  The design of the Wren makes it much more stable and smooth than the Bluto.  Drop offs can be taken without worry of bottoming out the fork and rock gardens can be taken at whatever speed you are comfortable attacking.
Wren Inverted Fatbike Fork

The Wren not only feels solid . . . it is solid.  No hinting of flex, with the only movement happening within the 110 mm of keyed stanchion travel.  And with the Wren being infinitely adjustable, it can be set up for any rider for any conditions and not disappoint.

Wren Inverted Fatbike Fork

When installing the carbon bash guards I did have some reservations about the durability of the thin guards that felt like brittle plastic.   Boy was I mistaken . . . those suckers are tough.  Repeated whacks by low hanging branches and shrubs, coupled with slight pecks from a rock or two have resulted in only a few scrapes and scuffs.  I have a new respect for carbon.

Wren Inverted Fatbike Fork

The lockout, although no remote, successfully limited the suspension when not needed during gravel/ice grinding on level surfaces.  When heading out bikepacking I did use the lockout for a very short period of time.  Having a pile of gear (4.4 kg/ 10.2 lbs) strapped to the bars I had anticipated that the Wren would be bobbing and weaving like the Bluto had done when I ran a lightly loaded bar bag.  With a tiny tweak of the rebound, and no adjustment to the air chambers, the Wren was actually able to run unlocked while carrying extra gear AND hitting trail humps and bumps. Cool!

Wren Inverted Fatbike Fork Bikepacking

During the winter season many people carry their fatties to the trailhead inside their vehicles to minimize road grit and grime.  This generally means removing and installing the front wheel twice per ride.  While a certain amount of finesse is needed to install the axle, the more practice the easier it gets.  Having removed/installed the axle well over 100 times there is no obvious wear and tear to the axle or fork.

Wren Inverted Fatbike Fork

A big concern for Bluto winter riders is the tendency of it to freeze. The aftermarket has come to the rescue, but why hasn’t RockShox fixed the issue in its design?  The folks over at Wren Sports state that their fork will not freeze up in conditions that would impact the Bluto.  To date the North Atlantic winter cold has had no impact on the Wren’s performance during winter testing . . . even during a two-hour frozen lake circumnavigation hitting several ice heaves along the way.  Wren Sports, in anticipation of some riders taking the Wren into uber-cold conditions are currently doing testing on polar grade temperature modifications.

Wren Inverted Fatbike Fork

While scooting the winter trails one day I spied a narrow snow bridge spanning a two-foot wide trench across the trail.  I though it was solid, but the front tire broke through (at speed), dropped into the deep trench and stopped.  After dusting myself off and straightening my severely twisted bars I inspected the fork.  There was no damage and it continues to track well.

Riding the Bluto aggressively in winter, more specifically into a tight downhill turn, the fork dives and sticks making exiting the turn anything but graceful.  As such, when anticipating such terrain I would lock out the fork.  The Wren does not exhibit such quirky behavior, but instead rebounds as you would expect allowing smoother and faster exits.

It’s pretty common knowledge that the Vee Snowshoe 2XL is one massive tire and is only able to fit the frame of a limited number of fatbikes.  Running it on the front is possible with a rigid fork, but good luck running it on a suspension fork . . . until now.  The Wren Inverted Fatbike Fork with its 5.35” clearance between the upper sliders easily clears the 2XLs girth. Super float and squish . . . excellent!

Wren Inverted Fatbike Fork


The Wren Inverted Fatbike Fork is a fine piece of technology and is solidly creeping into the fatbike front suspension market.  Not only have individuals recognized the benefits of the Wren, so have niche fatbike dealers that offer the Wren Inverted Fatbike Fork as standard/optional equipment on bike builds.

Customer service is second to none. You have an issue or question about the fork, or any of the products Wren Sports offer, they are only an email or phone call away. They are super responsive and super helpful.

As the fork is assembled and designed in a modular format all parts can be exchanged for new parts when needed.  If you are unable to get the fork to one of the ever expanding network of service centers, much of the maintenance and adjustments can be done by a competent bike mechanic.

Wren Sports has created a benchmark that all other fatbike suspension fork builders should aim to aspire . . . if they can catch up.

If you are unhappy with your current front suspension, building a fattie from scratch or looking to add squish to the front of your fatbike . . . be sure to check out the Wren Inverted Fatbike Fork by Wren Sports.

Ride on !

Sunday, 15 January 2017

Fatbike Front Suspension | Guide & Comparison

Many people will agree that front suspension is not really needed on a fattie in the winter as the white stuff generally covers the nasty humps and bumps.  The available squish in the aired down tires make most riding quite enjoyable.  However, when riding trails frequented by hikers, front suspension is appreciated when hitting frozen sunken footsteps.

When riding a fattie in the other three seasons the need for front suspension increases significantly.  Is it absolutely necessary . . . not really. You just have to ride a little slower to minimize the front end jarring, or fly down the trail just kissing the crest of each bump.  If your riding style is somewhere in between, front suspension should be in your future.

If you are the kind of rider who craves specifications and details, be sure to check out the chart below.

RockShox Bluto

When people think of fatbike front suspension the first name that comes to mind is the RockShox Bluto. Hitting the market in late 2013 the Bluto was the first mass produced front suspension for fatbikes. Available in 80 mm, 100 mm, and 120 mm variations this fork was well appreciated by those riding fatties outside of the winter months.
Fatbike Front Suspension Guide Bluto Wren Mastodon Renegade
Word around the LBS was that the Bluto does not use the latest and greatest technology, but rather borrows something from the not to distant past.  It was quickly realized by the fatbiking community that the Bluto did not like the cold . . . which is unfortunate since winter is the preferred habitat of the fatbike.  The aftermarket quickly came up with a solution, which oddly enough, when installed could compromise warranty.

Nevertheless, the Bluto has smoothed out a lot of trails.  Its simple to set up with air in the left fork and rebound and manual lockout on the right.  It can run up to a 5" tire and the remote lockout option is quite popular.  And a relatively simple spring swap can change your travel.  Color options include black or white.

MSRP $685 - $715 USD

WREN Inverted

Initially known as the "fork of many names" this inverted fatbike fork came to market around the same time as the Bluto and was initially stamped with an 11Nine and Carver logos. In 2014 Wren Sports started selling its Inverted Fatbike Fork and after extensive testing became exclusive North American distributor of this non-traditional fork. Extensive tweaking & improvements include: keyed stanchions, beefed up crown, stronger bushings, new axle, stock carbon fiber stanchion guards, cable guides and a TwinAir system.

Fatbike Front Suspension Guide Bluto Wren Mastodon RenegadeKeeping the larger 43 mm stanchions on top allows the lighter 36 mm lower stanchions to be more responsive. The TwinAir system, with two air valves (one on top and one on bottom) allow fine tuning of the fork. The adjustable rebound knob on the right fork keeps the damping in check and the lockout can make the fork rigid when needed. Travel is from 80 mm to a whopping 150 with the capability of running a 5.05" tire.

Another interesting feature of this fork is that practically all the improvements can be retrofitted on older forks. And if you can't get it to a factory service center much of the maintenance can be completed by a competent mechanic.

There are other companies that currently sell similar looking forks, however they do not have the extensive range of improvements that are available in the Wren.

MSRP $999 - $1149 USD

RST Renegade

In 2015 RST (Rapid Suspension Technology) introduced its Renegade to the fat world. In addition to the 1.5" tapered steerer tube, they offer a straight option for those running fatties without the a tapered head. In 2016 the Renegade made its way into the Norco fatbike lineup on its Sasquatch 6.2.

The Renegade offers three travel options (80 mm, 100 mm and 120 mm), has an optional remote lockout, room for a 5" tire and is available in black and white.


Lauf Carbonara

Originating from land of geothermal energy we have the ultralight
Carbonara fatbike fork.  In 2015 these folk introduced the fatbike world to a truly original type of suspension with no moving parts.  By suspending the axle behind the fork and between two sets of fiberglass leaf springs, the Carbonara give riders 60 mm of suspension.
Fatbike Front Suspension Guide Bluto Wren Mastodon Renegade
Weighing in at about 1100g (2.31 lbs) this is the lightest fatbike suspension fork on the market and it has the chops to run a 4.8" tire.  However, the limited travel and lack of rebound damping may limit the fork's usability to the smoother of the gnarly trails.

Lauf can actually supply the Carbonara in a number of cool colors (at a small premium) to compliment just about any fattie.


Manitou Mastodon

Fatbike Front Suspension Guide Bluto Wren Mastodon Renegade
Released early in 2017 this fat offering from Manitou is attempting to take a bite out of the market with it Pro (2210g) and Comp (2430g) models.  The Pro version comes with hi and lo speed damping.

Specs include 80mm - 150mm travel, 34 mm stanchions and "all temperature" performance.

Only time will tell how this beast will perform.

MSRP $TBD (Seen retailed for $700 USD)


While not exactly a fork, the Stafast suspension stem does reduce jarring impacts on the front of a fattie. There may be some resemblance to suspension stems of days gone by, but the technology is all new. The Stafast suspension stem uses an adjustable air shock with 25 degrees of adjustable rise and it weighs in at around 360g.

By replacing a standard bicycle stem with Stafast, strain on a rider’s upper body is decreased dramatically; and unlike other dampening components on the market, StaFast lessens impact without sacrificing performance

The Stafast stem was tested by Fatbike Republic and the stem delivered as promised. Check it out here. It provided 15-20 mm of suspension to take the edge off the rough terrain, its super easy to install and it can easily be swapped between bikes.



In the very early days a few inspiring fatbike engineering ninjas adapted the Cannondale Lefty fork for fatties. There were numerous challenges in getting these babies to work correctly, but people did. Cannondale now offer the Lefty Olaf as a suspension option on their high end Fat CAAD 1.

Finally there are the Asian knockoff fat suspension options that we have all seen on various sites. These forks are generally offered at crazy low prices and the specs seem a little dubious. Some people who have purchased them claim that they are exceptionally heavy and don't live up to the claims. I guess its a buyer beware situation.

And for you detail nuts . . . click on the chart below to enlarge.

Fatbike Front Suspension Guide Bluto Wren Mastodon Renegade

As the fatbike market evolves there may be new players providing front end squish, but in the meantime you do have several options from which to choose.

Ride on!