TECH: Reduced Fork Offset – Q&A

Shorter fork offsets have been around for a few years now but there is still much disinformation around the tech. As it happens local Enduro shredder Gary Barnard – who is preparing for his 3rd Trans Provence – has been running back to back testing on different offsets. We bought him a beer(s) and got his take on the reduced offset trend.

CAPE TOWN - 9 May 2019 - Gary Barnard on Fork Offset during Bike Network photoshoot on Table Mountain & Signal Hill. Photo by Gary Perkin

BN: Gary, first off, what kind of trails do you spend the most time riding on?

Gary: I live in Cape Town, South Africa which has got to be one of the best cities in the world for riding.  My cycling has seasons over the months of the year.  I usually use the Summer to get in some base miles before amateur road cycling champs AKA the Cape Argus and then transition into trail riding and enduro.  My favourite trails are Jonkershoek, Tokai, Table Mountain and Helderberg between these spots you can get in a massive variety.  My staple, however, is my commute to work which I spice up by never riding exactly the same route.

BN: You have spent many years racing Moto, BMX, DH, and Enduro – break it down for us and then explain why you are so passionate about it.

Gary: So I was born into a motor racing family and spent my formative years chasing my brothers around on whatever bike I could lay my hands on.  That started with their push bike at age 2 and progressed to an Italjet motorbike by 3 and a half. I then raced BMX for 8 years and transitioned to Motocross.  Mountain biking didn’t exist back then so when Mike Hopkins started bringing in Bridgestone MTB’s in the late 80’s my brothers and I jumped onto those.  Back then we used to know every mountain biker, there were no mountain bike specific trails and you could ride anywhere as they hadn’t figured out what these big BMX bikes were all about.

Gary Barnard sending big lines down the Contermanskloof gnar, circa 2010.

BN: What does your ideal kind of MTB race entails?

Gary: So my racing has changed a huge amount over the years.  In the early days we used to race everything, XC, DH and Dual slalom but it was obvious from the start for me that DH was my calling.  The precision and intensity of a race run drew me in and the opportunity to lay it all on the line was what I was looking for.  After my DH racing drive subsided I felt the call of the mountains more and more, I wanted to just get out into nature and get to new trails that I could ideally ride blind (never having seen it before). 

Then I spotted this race that a few friends were raging about and I thought it was for me.  A week riding through the Southern French Alps on ancient trade routes and world war foot-paths.  That was Trans-Provence 2012.  That event changed me, I realised that there was this entire community of people like me out there who thrived in the big mountains and that they were all athletes, not in the head-to-toe lycra and protein-shake kind of way but in the level of conditioning earned from years spent riding and hiking to the top of the biggest mountains in their area just to experience the thrill of the most remote trails. I guess since then I have focused on multi-day mountain bike enduro races.

BN: Cool! What then are the 3 most challenging races you have done and tell us why?

Gary: Trans-Provence 2012, Trans-Provence 2014 and TransBCEnduro 2017.
These are not your normal trans events which are incredibly tough but involve a route that is mostly rideable and you get timed from start to finish. These events are multi-day enduros where you have the whole day to finish the course but are only timed on the Special stages which range from 4 to 18minutes.  That sounds way easier but there is a catch, you often have massive hike-a-bikes to get to the top of the special stages.  The longest hike-a-bike I have done was 4 and half hours carrying a 15kg bike up 1400m of elevation. That was before the first stage even started.  The riding between stages is often exposed hiking trail and mostly single-track, the 40-60k per day distances usually take 4-6hrs and the average speed is around 10km/h.  This all sounds mad if it were not for the incredible trail that you get to ride blind and for me the only time in my life that I will get to ride that trail….thats an intensity that is hard to replicate.

Rallying the rough trails of the Trans-Provence, circa 2014.

BN: So you have had some massive days on some pretty big mountains then – that’s got to be a good way to learn about what products and setups work and which don’t, right? So why did you never work in the bike industry?

Gary: Yea. I studied Electro-Mechanical engineering at UCT and did my thesis on a full-suspension mountain bike.  There was an obvious path to try and work in the bike industry but I decided to not mix business with pleasure.  I have a great job that I find incredibly stimulating and work for a company that have become my family over the past 17 years.  I have always had a passion for the technical side of mountain bikes and have given feedback and input to anyone that would listen to me, that has included Morewood bikes, Leatt, PYGA, Csixx, Swift/Sense.  These have all been a natural process where I would explain how I felt the product was performing and suggest potential reasons for that behaviour on the trail.  As I said, its just a passion of mine to figure out how something works and how that translates into the subjective feel that a rider has on the trail.  Racing downhill bikes gave me a solid reference point for translating a subjective feel into time saved on the course, back in 2002 while racing on a Morewood prototype Izimu I managed a perfect season of wins and I feel that was due to an approach and attitude towards the racing and equipment that was different to the other racers.  I felt that we could always squeeze out some more performance and we tested a lot of things from wheel build and stiffness to tube thickness and brake arms.  It was a lot of fun and in my spare time (this is a passion or hobby of mine, not a job) I have just continued on that path. 

BN: Rad. That brings us nicely to fork offsets. Tell us why you have been testing various offsets?

Gary: I have entered another Trans-Provence which Ash Smith the race organizer has said will be his last. It’s going to be bigger than anything he has done before with over 20,000m of descending over 6 days.  I want to be on the best equipment and that meant jumping onto a new school enduro bike.  Bike geometry is going through a step-change in evolution with reach and wheelbase increased massively on prior versions of bikes.  The increased reach allows the rider to be more centered on the bike over most terrain including steep trails where the riders weight never moves to a point that would cause an OTB.  With this increase in reach the bike needs to be ridden more off the front wheel. 

“I immediately experienced a more precise turn-in on the tight switchbacks.” – Gary

If a traditional (or an old school geo bike) position is adopted the front wheel does not have enough traction and the bike can feel incredibly sluggish and will “push” in turns meaning it will slide straight forward as the rider attempts to make a tight turn.  Whilst it sounds counter-intuitive the remedy for pushing the front wheel is to put more weight onto it and that is where fork offset comes in. When the fork offset is reduced there is naturally more weight on the fork and when combined with a long reach and slack head-angle can give you best of all situations.  You can get a well-balanced bike which positions you nicely between the wheels, good roll-over on obstacles and a great turn-in on tighter corners.

BN: How would you explain what offset is, I mean in your own words?

Gary: Offset is the perpendicular distance that the axle of the fork is in front of the center-line of the steerer tube.

A bigger offset number would be 51mm and a shorter number would be something closer to 44mm, or less.

BN: Which genre of bikes is it more important on?

Gary: I feel it is a factor for all bikes.  In motocross, racers test fork offset all the time.  Its always been important, mountain bikers have just seldom realized it was a factor. 

BN: What have you found to be true for you when riding the different offset numbers – like how does the offset impact on the way the bike rides?

Gary: Ok so here is the reality!  I am incredibly lucky to have been able to ride 2 forks back-to-back on the same bike with the same travel.  I bought two Fox36 Factory grip2 forks, one in 51mm offset and the other in 44mm offset.  I did this for myself as I needed two forks, one for the E-Bike and one for the enduro bike and I was really trying to understand the trade-offs.  
I can honestly say that I noticed the difference immediately, a 51mm offset fork is currently the ‘standard’ for a 29er so I will give all my feedback relative to that benchmark.
I was riding a Sense Exalt with a reach of 460mm and with the 51mm offset 160mm fork.  At 173cm tall, that is a big bike for me and I was battling in tight steep switchbacks to move far enough forward to weight the front wheel without feeling like I was dragging a long trailer behind me.  A centered position would push the front and a forward position would cause alarming rear-wheel events as it was not tracking the front wheel.  
Once fitting the 44mm offset fork I immediately experienced a more precise turn-in on the tight switchbacks with intuitive weight distribution and less micro-management of the handlebars to keep the bike tracking through the turn.  Whilst before I kept fighting to maintain flow through the turn the bike had an ‘on-rails’ feeling and I was out the turn without any fuss.
I was worried that this “tighter” turning bike would feel unstable at speed and while there is a more direct steering I haven’t had any problems holding a line at speed.
The sensation of the reduced offset is similar to reducing stem length.  In my subjective opinion, a reduction in fork offset of 7mm feels like a reduction in stem length of 30mm.  The bike feels more precise and nimble.

BN: Would you say reduced offset for everyone? 

Gary: I don’t think it is about the person but rather the bike.  I choose to ride a bigger bike than recommended as I enjoy the bigger sweet-spot one gets with an increased reach and wheelbase in order to compensate for the extra length the reduced offset helps make the bike feel more nimble through the tight stuff while not losing much in terms of high-speed stability.  I far prefer that to a shorter wheelbase and reach bike where body position becomes more critical. 

BN: What kind of conclusions are you at with offset? 

Gary: I’d like to ride reduced offset, longer reach and wheelbase bikes across all genres of mountain bikes.

Keep on shredding Gary!

Images: @garyperkin and @ewaldsadie and others supplied by GB

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