Bronson Alloy 27.5" - AM - 150mm VPP Travel

  • Frame: £1,599
  • Custom Builds from £2,999

When we introduced Bronson, it took the market by storm, redefining what people expected from a 150mm trail bike.

Equally at home in the Trans-Provence as it was on The Ridge, updating and improving it was going to be no small feat.

The most visible upgrade is the completely new VPP® link arrangement. The lower link tucks neatly above the bottom bracket, fully-recessed and protected from impacts. Meanwhile the box-section upper link now mounts cleanly to the top- tube and enhances lateral stiffness as a result.

Shock rate’s been in refined in the process too, delivering greater small bump sensitivity and a more progressive mid-stroke.

Geometry has also evolved subtly to meet demand from riders for a bike of this ilk. The seat tube angle’s been steepened, placing the rider right above the cranks and perfectly in position to lay down the power. Meanwhile a one-degree slacker 66 degree head tube angle combines with a 20-25mm longer top tube and shorter chainstay length to create an evermore rally-ready geometry than its predecessor.

This CC-level carbon frame is every bit as stiff and strong as our C-level frame, but weighs about 280 grams less, due to the use of some lighter, stronger, and more expensive carbon fiber. Using this material in key places allowed us to use less material overall, which is what shaves off more than half a pound from the frame.  

 

Frame Features

  • 148mm Rear Axle Spacing
  • 150mm (6") VPP™ suspension
  • 27.5" wheels
  • Double sealed pivots for long bearing life
  • Angular contact bearings maximize stiffness
  • Collet axle pivots lock in place without pinch bolts
  • Bottle cage mount within front triangle fits piggyback shocks
  • Molded rubber swingarm and downtube protection
  • Stealth and external seatpost cable routing
  • Threaded Bottom Bracket
  • ISCG-05 tabs for chainguide compatibility
  • Direct mount rear derailleur option

Shock Setup

Shock: Fox Float Performance

Rider WeightAir PressureShock Sag
100lbs (45.5kg)100 psi15-17 mm
120lbs (54.4kg)125 psi15-17 mm
140lbs (63.5kg)150 psi15-17 mm
160lbs (72.6kg)175 psi15-17 mm
180lbs (81.8kg)200 psi15-17 mm
200lbs (90.7kg)225 psi15-17 mm
220lbs (99.8kg)250 psi15-17 mm
240lbs (108.8kg)275 psi15-17 mm
260lbs (117.9kg)300 psi15-17 mm
280lbs (127kg)325 psi15-17 mm

Shock: Fox Float X Factory

Rider WeightAir PressureShock Sag
100lbs (45.5kg)120 psi15-17 mm
120lbs (54.4kg)145 psi15-17 mm
140lbs (63.5kg)170 psi15-17 mm
160lbs (72.6kg)195 psi15-17 mm
180lbs (81.8kg)220 psi15-17 mm
200lbs (90.7kg)245 psi15-17 mm
220lbs (99.8kg)270 psi15-17 mm
240lbs (108.8kg)295 psi15-17 mm
260lbs (117.9kg)320 psi15-17 mm
280lbs (127kg)345 psi15-17 mm

Geometry

All measurements reflect installation of a fork with a 544.4mm axle-to-crown height.

Bronson Geometry
  S M L XL
Top Tube Length 573mm - 22.5" 596mm - 23.4" 618mm - 24.3" 651mm - 25.6"
Seat Tube Length 395mm - 15.5" 420mm - 16.5" 460mm - 18.1" 495mm - 19.5"
Head Tube Angle 66° 66° 66° 66°
Seat Tube Angle 74° 74° 74° 74°
BB Height 341mm - 13.4" 341mm - 13.4" 341mm - 13.4" 341mm - 13.4"
Wheelbase 1141mm - 44.9" 1165mm - 45.8" 1189mm - 46.8" 1223mm - 48.1"
Head Tube Length 90mm - 3.5" 100mm - 3.9" 110mm - 4.3" 120mm - 4.7"
Chainstay Length 433mm - 17.0" 433mm - 17.0" 433mm - 17.0" 433mm - 17.0"
Standover Height 727mm - 28.6" 731mm - 28.8" 734mm - 28.9" 748mm - 29.4"
Reach 405mm - 16.0" 425mm - 16.7" 445mm - 17.5" 475mm - 18.7"
Stack 586mm - 23.1" 595mm - 23.4" 605mm - 23.8" 614mm - 24.2"

 

 

 

* Effective top tube
** Seat Tube length measured from center of BB to top of seat tube

Size Guide

S
5'0"5'5"
M
5'5"5'10"
L
5'10"6'1"
XL
6'1"6'6"

Complete Bikes

All upgrade prices are relative to the standard component price.

Stock Colours:

Build Kit:

Shock:

Fork:

Additional Upgrades

788

Can I mount a chainguide to my bike?

Yes, this bike is equipped with ISCG-05 tabs for easy chainguide mounting.  Most chainguides on the market that are made for this standard should work.

Is the 148x12 derailleur hanger the same as the 142x12 hanger?

No, it's not. We had to make a new derailleur hanger to go with the new dropout. They look similar, but the easiest way to tell them apart is the finish. Our 142x12mm hangers have a bead-blasted finish, while the 148x12mm hangers have a smooth, machined finish. 

Should I grease the headset cups when I install them?

Yes, we recommend this. Do not use the Carbon Assembly Compound on the headset, as it will make it more difficult to remove from the frame.

What is the torque spec for the seat collar?

We don't provide a torque spec for the seatpost, because it really depends on what seatpost you are using. Some seatposts are slippery, and require more torque to stay put, and others are very thin- and can be crushed by overzealous tightening. Some are both slippery and thin... Make sure you use the Carbon Assembly Compound included with your frame, and use some common sense.

You will not damage your frame by overtightening the seat collar, assuming you have a 31.6 seatpost in there.

What Kind of Front Derailleur do I Need?

The updated versions of the Bronson, 5010, and Tallboy use Shimano side-swing front derailleurs. The names and part numbers are: 

Shimano XT M8020 Side Swing
Shimano XTR M9020D Side Swing

What kind of headset does this bike use?

We use a headset generally referred to as "mixed tapered". This is a 44mm internal upper cup, with an external 49mm lower cup. The SHIS name is ZS44/28.6 EC49/40.

What kind of rear brake adaptor do I need?

This frame uses a standard IS rear brake mount. Just pick your rotor size and order the correct adaptor to go from IS to post mount (all modern brakes).

What size bottom bracket shell does this bike use?

We use a standard 73mm threaded BB. Nearly any crank on the market (besides BB30 cranks) will fit.

What size seatpost do I need?

This bike uses a 31.6mm seatpost.  Always ensure it is inserted into the frame a minimum of 4" (100mm).

Suspension SystemVPPTM
Front DerailleurDirect to Frame
Headset/Headtubemixed taper 1.5" Lower, 1'1/8" upper
Seat Post31.6mm
Eye to Eye length200mm
Fork Compatibility150-160mm
BB ShellStandard
Max Tire Size2.4"
Brake TypesDisc
Water Bottle Mounts2x bottle cage mounts