Bronson Alloy 27.5" - AM - 150mm VPP Travel

  • Frame: £1,599
  • Complete Bikes 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.

 

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
  • 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"

Frame Only Available from £1599

Complete Build Options

Bronson Alloy | R1 AM*--BRONSON
Wheelsize: 27.5 - £2,999
ForkFox Rhythm 150 - 27.5"
ShockRock Shox Monarch RT
Rear DerailleurSRAM NX - 11 speed
Front Derailleur
ShiftersSRAM NX - 11 speed
BrakesSRAM Level T
RotorsAvid Centerline - 180mm (F/R)
CranksetRace Face Aeffect Steel - 32t, 170mm (S), 175mm (M-XL)
Upgrade
Chainguide
CassetteSRAM XG1150 - 10-42t
ChainSRAM PC1110
HandlebarRace Face Chester - 35x785mm
StemRace Face Ride - 35mm
GripsSanta Cruz Palmdale
HeadsetCane Creek 10 IS
SeatpostRace Face Ride - 31.6x400mm
SaddleWTB Volt Race
Front HubNovatec D711 - 15x110mm, 32h
Rear HubNovatec D712 - 12x148mm, 32h (XD)
RimsWTB STP i23 TCS - 27.5", 32h
Rim Upgrade
SpokesDT Swiss Champion
Front TyreMaxxis Minion DHF EXO TR - 27.5x2.3"
Rear TyreMaxxis Minion DHR2 TR - 27.5x2.3"
Tubes / SealantStan's Sealant
Bronson Alloy | S AM *--BRONSON
Wheelsize: 27.5 - £3,699
ForkRock Shox Pike RC SA 150 - 27.5"
ShockRock Shox Monarch RT
Rear DerailleurSRAM GX 11 speed
Front Derailleur
ShiftersSRAM GX - 11 speed
BrakesSRAM Guide R
RotorsAvid Centerline - 180mm (F/R)
CranksetRace Face Aeffect AL - 32t, 170mm (S), 175mm (M-XL)
Upgrade
Chainguide
CassetteSRAM XG1150 - 10-42t
ChainSRAM PC1130
HandlebarRace Face Chester - 35x785mm
StemRace Face Turbine Basic - 35mm
GripsSanta Cruz Palmdale
HeadsetCane Creek 40 IS
SeatpostRockshox Reverb Stealth - 31.6x125mm (S), 150mm (M-L), 170mm (XL)
SaddleWTB Volt Race
Front HubNovatec D541 Torque Cap - 15x110mm, 32h
Rear HubNovatec D542 - 12x148mm, 32h (XD)
RimsRace Face AR 27 - 27.5", 32h
Rim Upgrade
SpokesDT Swiss Champion
Front TyreMaxxis Minion DHF 3C EXO TR - 27.5x2.3"
Rear TyreMaxxis Minion DHR2 TR - 27.5x2.3"
Tubes / SealantStan's Sealant

Available Upgrades

Bottom BracketHope Stainless BB + £55
HeadsetHope Headset + £45

Can I mount a chainguide to my bike?

No. We opted against including ISCG tabs, as one-by drivetrains have rendered them mostly unnecessary.

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?

This bike uses an integrated headset with drop-in bearings and integrated bearing races. The SHIS measurement is IS41 (upper) and IS52 (lower).

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/HeadtubeIntegrated; IS41 upper, IS52 lower
Seat Post31.6mm
Eye to Eye length200mm
Fork Compatibility150-160mm
BB ShellStandard
Max Tire Size2.4"
Brake TypesDisc
Water Bottle Mounts2x bottle cage mounts