Fatbike - mountain bike designed with tyres between 3-4.6 inches, for riding on snow, sand, mud and also quite excellent on loose rock. They look a bit mental and get far too much attention.
But there are two way more important facts: they are damn fun, maybe the most fun you can have with your pants on and are extremely versatile (maybe the next big thing in all mountain biking, with some of the geometries appearing at present and weights going down).
So after lots of research and very little riding of fat bikes I asked cycleworks.co.uk if they could help out and Chris the owner was very happy to help me out with the purchase of the Specialized Fatboy Expert and after a little wait due to some wheel production issues (issues all resolved) it arrived.
The factory spec is not too bad at all, but I had plans, so off came all the SRAM replaced with Shimano and it went 1x10 with a Wolf Tooth Components non-drop 32t chain ring, I added carbon bars, a gravity dropper I had laying around, Shimano M530 pedals and my preferred Ezi Grips with Hope Lock Dr caps.
What remained, is the brilliant frame and fork combination, extremely light and robust Specialized wheels, Specialized 4.6" Ground Control tyres, E13 crank and BB, seat stem and the Shimano OEM brakes. The bike pictured below is my build (minus the seat post change).
So the first thing you notice about the Fatboy Expert is the size of those tyres and wheels. They are wide and look a bit on the heavy side, surprisingly they are not too bad at all, although I haven't weighed this build the whole build must be under 28lb. Not too bad when you consider all that rubber.
Specialized had the wheels and hubs commissioned, so they carry the Specialized name. They have quite an impressive cutout in the rims (90mm wide) that are laced to the Specilaized branded hub with sealed bearings and Hi Lo flange, so far after over 3 months use in all sorts of conditions, seem very solid and reliable. Attached to the rim is the 4.6" Ground Control, Spesh made an very good call here, these tyres at this size on these wheels are an amazing combination and the wheels use stock (but obviously wider for the rear) QRs, maybe a future version could have bolt through front and rear, but if I am honest for what I plan to use mine for I could see quite a number of issues with that change, not least it being a massive pain in the butt in freezing conditions.
Positive, responsive and more grip than you will ever need, that is what the massive 4.6" Ground Controls give you. I am still trying to find the limit and in doing so going faster and faster, which is testing the brakes and my nerve. They have a 120TPI count which maps closely to Spesh's 2Bliss tyre construction and should tubeless well (stay tuned for more on that). The tyres provide loads of float on soft sand, amazing grip on hard pack and transition between the two seamlessly, even at speed. They chew through rocky terrain up or down, like it is a towpath all at a moderate 12psi inflation.
The brakes are a Shimano OEM BR-505 front and rear, with a 180mm rotor at the front and a 160mm at the rear stopping the Fatboy and my 82 kilo from speed extremely well. I was a bit dubious at first as I am a Hope fan boy, but these brakes provide loads of modulation and control, and really stop you fast when you need them to. The decision to put a 180mm on the front is a good one as you do seem to motor downhill on this bike.
The drive train it comes with has SRAM OEM 2 and 10 speed grip shift, which I replaced with XT (1x10) and the X0 rear mech with XT also. The X7 front mech was just removed. All this is just personal preference as I find Shimano more reliable. The Praxis Works chain rings I replaced with a 104 32t Wolf Tooth Components non-drop as they just work so well and the red one looks pretty. Attached to the eThirteen cranks you get a very positive and robust drive train. Which has stood up to quite a battering in my local hills and The Lakes District.
I wont bore you with details of bars, stems saddle etc.. I will just give you a quick list:
But there are two way more important facts: they are damn fun, maybe the most fun you can have with your pants on and are extremely versatile (maybe the next big thing in all mountain biking, with some of the geometries appearing at present and weights going down).
So after lots of research and very little riding of fat bikes I asked cycleworks.co.uk if they could help out and Chris the owner was very happy to help me out with the purchase of the Specialized Fatboy Expert and after a little wait due to some wheel production issues (issues all resolved) it arrived.
The factory spec is not too bad at all, but I had plans, so off came all the SRAM replaced with Shimano and it went 1x10 with a Wolf Tooth Components non-drop 32t chain ring, I added carbon bars, a gravity dropper I had laying around, Shimano M530 pedals and my preferred Ezi Grips with Hope Lock Dr caps.
What remained, is the brilliant frame and fork combination, extremely light and robust Specialized wheels, Specialized 4.6" Ground Control tyres, E13 crank and BB, seat stem and the Shimano OEM brakes. The bike pictured below is my build (minus the seat post change).
She does grab the eye, so be prepared for a lot of attention.
So the first thing you notice about the Fatboy Expert is the size of those tyres and wheels. They are wide and look a bit on the heavy side, surprisingly they are not too bad at all, although I haven't weighed this build the whole build must be under 28lb. Not too bad when you consider all that rubber.
Specialized had the wheels and hubs commissioned, so they carry the Specialized name. They have quite an impressive cutout in the rims (90mm wide) that are laced to the Specilaized branded hub with sealed bearings and Hi Lo flange, so far after over 3 months use in all sorts of conditions, seem very solid and reliable. Attached to the rim is the 4.6" Ground Control, Spesh made an very good call here, these tyres at this size on these wheels are an amazing combination and the wheels use stock (but obviously wider for the rear) QRs, maybe a future version could have bolt through front and rear, but if I am honest for what I plan to use mine for I could see quite a number of issues with that change, not least it being a massive pain in the butt in freezing conditions.
Positive, responsive and more grip than you will ever need, that is what the massive 4.6" Ground Controls give you. I am still trying to find the limit and in doing so going faster and faster, which is testing the brakes and my nerve. They have a 120TPI count which maps closely to Spesh's 2Bliss tyre construction and should tubeless well (stay tuned for more on that). The tyres provide loads of float on soft sand, amazing grip on hard pack and transition between the two seamlessly, even at speed. They chew through rocky terrain up or down, like it is a towpath all at a moderate 12psi inflation.
Bags fall of grip and float
When they say fat, with a 190mm rear hub they mean FAT. I was interested that this might make the frame bit flexible, but if it does once it is all locked together with the wheel in place you don't notice it, the power goes straight to the ground.
The brakes are a Shimano OEM BR-505 front and rear, with a 180mm rotor at the front and a 160mm at the rear stopping the Fatboy and my 82 kilo from speed extremely well. I was a bit dubious at first as I am a Hope fan boy, but these brakes provide loads of modulation and control, and really stop you fast when you need them to. The decision to put a 180mm on the front is a good one as you do seem to motor downhill on this bike.
The drive train it comes with has SRAM OEM 2 and 10 speed grip shift, which I replaced with XT (1x10) and the X0 rear mech with XT also. The X7 front mech was just removed. All this is just personal preference as I find Shimano more reliable. The Praxis Works chain rings I replaced with a 104 32t Wolf Tooth Components non-drop as they just work so well and the red one looks pretty. Attached to the eThirteen cranks you get a very positive and robust drive train. Which has stood up to quite a battering in my local hills and The Lakes District.
The eThirteen PF30 100mm, means that the overall BB width is kept at a modest 130 when measured cup outer to cut outer and therefore there is not a massive difference between it and my other bikes, but the first few rides will feel odd and I suggest you keep the saddle a bit lower than normal. I have read a few differing reviews about the PF30s but I have to say that mine have not started squeaking or imploding and feel very smooth after quite a bit of use.
- EA70 Monkey Bar;
- Specialized 3D forged stem (OEM);
- Specialized BG Henge (OEM) and my preferred saddle anyway;
- Gravity Dropper seat post;
- Shimano M530 pedals.
The wide elliptic down tube provides loads of stiffness and reduces weight, as the M4 aluminum is clearly light.
The FACT Carbon forks are very sexy and certainly responsive. With such a wide tyre, you really don't need much give in the fork, so the FACT is a great choice.
So what does it ride like, firstly I will say, when I know my next ride is on this bike I start smiling before I even pick it off the rack. If there is one thing no-one can argue about is Specialized know how to R&D and then produce a bike. This is no exception, in fact, they have probably pipped the specialist fat bike builders here, dare I say it, and I tend to ride niche or near enough to.
It is damn fun, you first notice that it is actually quite light to ride, it is nimble, more than you expect. The frame and fork are impressively stiff as are the wheels, with those big tyres giving exceptional grip, control and comfort. So much grip and control, that I have set new PB's on segments the first time I ride them, that I have ridden on All Mountain bikes a few times.
The bike responds well when pushed hard and is easy to ride when you are just cruising. I find it as nimble in the air as it is on the ground and finds it transitions well from one sort of terrain and trail to another.
Those big old tyres and heavy tubes, seem to only really affect you when getting going or on a very long relatively steep climbs. On flat twisty trails the Fatboy Expert buzzes along and will surprise more than a few other riders, but if the surface is hard pack, it is going to hum like a tractor on the tarmac/bitumen. So be prepared and watch yourself with those tyres when commuting to your trail, they really don't like high speeds on the road.
If I was pushed to give the Fatboy Expert some true ratings they would be as follows, out of 5:
Looks: 5
OEM Spec: 3.5
Ride: 4.5 (ignoring the climbing, I would give it 5)
Value for money: 4
Smile Factor: 5+
I really am impressed and this bike has been the one I have spent most time on since I got it.
Too much fun. :)
