Sentinel Alloy GX Bike

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  • Special Offer
  • Regular price £4,499.95
VAT included.

The Sentinel is a bit of a do-everything bike in the Transition range, up for all-dayers in the hills or uplift days.

Out of the box, the bike is set up with a 150 mm shock and 160 mm fork, but the bike will still handle well with a 150 or 140 mm fork, and you can change the rear shock for a shorter one to run the back at 140 mm.

Transition have given the longer-lower-slacker approach a name - "Speed Balanced Geometry" - but effectively it means short stem, slack head angle, short offset fork and a longer top tube, pretty much what you would expect from any modern enduro-orientated bike. On that note, all models can take a water bottle, though you'll need to use a fid lock bottle on the size small frame.

Never ones to shy away from a cheesy name, the Transition's "GiddyUp" suspension has fantastic small bump sensitivity and enough progression to run a coil shock without blowing through the travel. The Enduro Max bearings and additional bearing shields are a huge plus point for UK riding!

This GX spec bike has a great spec, with SRAM Code RSC brakes, Fox Performance Elite suspension and an excellent OneUp dropper post. Dropper size and bar rise vary depending on frame size.

Cycle to Work

UK customers - you can use the Government’s “Cycle to Work” scheme to buy this bike from 20Twenty, and you could save 25-39%. You can buy a bike, bike and accessories, or just accessories through the Cycle to Work scheme. We can even provide you with a custom-built bike through the scheme.

We use Cyclescheme to administer Cycle to Work bike sales. Your employer needs to be registered with Cyclescheme. If they are not, they can sign up here.

There is no £1000 limit any more, though your employer might have a limit. You can use the Cyclescheme calculator to work out what you might save here.

For more information, click here to contact us or call 01330 828562

Sizing & Geo

A. Reach 420 450 476 501 521
B. Stack 613 622 631 640 649
C. Effective TT Length 552 585 613 641 665
D. Seat Tube Length 350 390 430 460 490
E. Effective St Angle 78.2° 77.5° 76.9° 76.4° 76.0°
Seat Height For ST Angle 600 660 720 780 820
Actual St Angle 70.8° 70.8° 70.8° 70.8° 70.8°
Seat Tube Offset At BB 87 87 87 87 87
F. Head Tube Length 100 110 120 130 140
G. Head Tube Angle 63.6° 63.6° 63.6° 63.6° 63.6°
H. Chainstay Length 440 440 440 440 440
I. Wheelbase 1199 1233 1263 1292 1316
J. Bottom Bracket Drop 29 29 29 29 29
K. Estimated BB Height 346 346 346 347 347
L. Stand Over Height 671 688 700 712 722
M. Fork Offset 43 43 43 43 43


FRAMESentinel Alloy 150 mm (compatible with 140 mm), 29" Wheels, Alloy construction, additional bearing shields, Enduro MAX bearings, top tube accessory mount, 73 mm threaded BB, chainstay and downtube protection, Internal Cable Guides, Manufacturers lifetime warranty
REAR SHOCKFox Float X Performance Elite 2 Position
FORKFox Float 36 Grip 2 Performance Elite 160mm Travel/44mm Offset
STEMANVL Swage (40 mm)
HANDLEBARANVL Mandrel Alloy 35 SM/MD (800x20) LG/XL (800x30) XXL (800x 40)
GRIPSSensus Lite
SEATPOSTOneUp Dropper Post - SM (150 mm) MD (180 mm) LG/XL/XXL (210 mm)
ROTORSSRAM Centerline (200 mm)
CASSETTESRAM XG 1275 (10-52t)
CRANKSRAM GX Eagle DUB (30t/170mm)
RIMSDT Swiss M 1900 Spline 30
SPOKESDT Swiss Champion
HUBSDT Swiss 370 Ratchet LN
TIRE/FRONTMaxxis Assegai 3C EXO+ (29x2.5)
TIRE/REARMaxxis Minion DHRII 3C EXO+ (29x2.4)
INCLUDEDTubeless Valves & Stans Sealant (6oz)

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