SRAM AXS & Quarq Short Crankarms

£460.00
Compatibility Guide & Technical Resources

NEW STOCK DUE THE WEEK COMMENCING THE 29.09.25.

SHORT VERSION 145-160mm. 

Bringing maximum aerodynamics to your SRAM AXS and Quarq spiders through a narrower Q factor, CFD optimised crankarm profile and adjustable length crankarms.

Available in both short and long versions, allowing adjustment in 2.5mm increments between 145-160mm and 160-175mm respectively.

As part of the package a DUB spindle is supplied (narrow or standard), as such you will be replacing your crankarms and spindle. Retaining only the spider/direct mount chainring. Please consult our Dimension Guide for more information on spindle length and compatibility:

 

The standard-length spindle when paired with our crankarms offers a 137mm Q factor while the narrow-length spindle offers a 129.5mm Q factor.

If required additional pedal insert sizes are available to purchase separately.

Spider and/or direct mount chainring is not included. 

Product Description

SRAM AXS and Quarq cranksets are market-leading cranksets with various powermeter, BCD and direct mount options to suit your needs. With a Q factor of 145mm; installing the Cratus crankarms will reduce the Q factor, depending on the spindle option selected; narrow to 129.5mm or standard to 137mm. A 15.5mm and 8mm reduction in Q factor respectively.

Manufactured from 7075-T6 aluminium, anodised black and subtly laser etched with WattShop branding.

These crankarms are only compatible with 8 bolt SRAM and Quarq interfaces. Due to the design of the crankarms, a spindle is required and is included in the price. Therefore keeping only the spider or direct mount chainring in place. The spindle is a DUB spindle, allowing you to continue using the same bottom bracket.

If you intend to purchase the narrow spindle please check you have sufficient clearance. There is a 7.5mm reduction in spindle length. You can check clearance by measuring your existing spacer/s + preload ring setup. You may also need to check chainstay clearance.

Additional pedal insert lengths can be purchased separately.
Technical Specifications

TEST DATA

The 15.5mm reduction in Q factor equates to a rider dependent saving of 0.0015 to 0.0030m^2. Assuming a standard air density of 1.225kg/m^3 this results in a saving of:
- At 50kph = 2.5-5w
- At 60kph = 4.5-9w
Whereas an 8mm reduction in Q factor equates to a rider dependent saving of 0.0008 to 0.0016m^2.
- At 50kph = 1.5-2.5w
- At 60kph = 2-4.5w

FITMENT CONSIDERATIONS
Crankarm clearance is an important consideration. Reduced Q-factor is initially achieved through narrowed crankarms, in turn, this reduces the clearance. There is an increased risk of chain strike (between crankarm and chain) when in the smallest sprocket of your cassette. Specifically with the long crankarms, the issue is less likely to be present with the short crankarms. Please refer to the dimension guide and check your fit dimensions.
If you have chain strike we recommend moving spindle spacers to the drive side to reduce the chain angle.
The narrowed crankarms also eliminate 2x compatibility. The space needed for the front derailleur to shift laterally is removed. In some rare instances, you may be able to setup a front derailleur, but generally we suggest the crankarms are used in a 1x arrangement.

WEIGHT

- 160-175mm Arms = 506g
- DUB Spindle (narrow) = 73g
- DUB Spindle (standard) = 77g
- Pedal Inserts (inc plates) = 35g/pair

HARDWARE

- DS & NDS crankarms
- 1x spindle (narrow or standard)
- 2x retention bolts
- 1x pair of pedal inserts and plates
Customisation Options

Spindle spacers, wave washers and spindle-to-spider bolts are not included. We can provide the spindle spacers and wave washers upon request.
Fixed length options can be made to order. Please email info@shopforwatts.co.uk with your custom requirements.