RIDEA | Ridea Group Ltd. - MING SUEY PRECISION INDUSTRIAL CO., LTD.

Modular system

Pneuma cranksets are fully modular. The different parts (crank arms, spindles, power meter spiders, spiders and chainrings) can be mixed and matched to suit every rider specific needs. Your crankset can change with you at the same time that you change your riding style or your fitness.

The only limitations are that 29 mm spindles require specific Pneuma crank arms for 29 mm, and vice versa with 24 mm. Also, the BCD and number of bolts for both the spider and the chainrings must be the same. Other than that, you can mix and match Pneuma crankset parts to best suit your needs.

A new concept of hollow crank

All high-end cranks try to reduce weight by reducing the quantity of material used. Most cranks, despite the external appearance, are more or less hollow in the inside. Although in most cases, hollow cranks work flawlessly during the whole expected life of the crankset, sometimes moist and humidity can build up in the interior, leading to corrosion or rust and, eventually, crank failure.

The design of the Pneuma crank reduces the weight while retaining an optimal weight/stiffness ratio, as well as completely eliminates the possibility of corrosion or rust building up in hidden areas.

3 spider-chainring positions for your Powering

Pneuma spiders can be installed in three different angles, with ten degrees of separation between each position. When using oval chainrings like the Ridea Powering, this feature can be used to adjust the position of the biggest and lowest ratio of the chainring in relation to the crank arms, in order to better adapt to you riding preferences and musculature.

24 mm and 29 mm spindles

Ridea designed the first 29 mm diameter spindle back in 2012 with the ES BB29 series. Pneuma cranksets inherit this innovation and are available in 29 mm versions, which are compatible with other 29 mm solutions in the market like SRAM’s DUB™. Needless to say, Pneuma cranks are also available with 24 mm spindles, which again are compatible with other solutions like Shimano’s HOLLOWTECH II.

Available spindles for Pneuma cranks

The following table shows all the available spindles for Pneuma. Highlighted in gray are the spindle type(s) that is(are) standard for this specific crankset model (Pneuma BCSA). Other spindles can be installed to suit specific needs.

Spindle model	Bearing race diameter	Bearing race distance (outer-to-outer)	Bearing race distance (inner-to-inner)	Total length	Material	Weight	Application
R410	24 mm	92 mm	70 mm	126 mm	SCM440 or TI64	111 g (steel) 62 g (Ti)	Road, single speed and track bikes
M411	24 mm	96 mm	74 mm	130 mm	SCM440 or TI64	118 g (steel) 68 g (Ti)	MTB 135-142 mm Brompton Birdy (1x)
M412	24 mm	102 mm	74 mm	136 mm	SCM440 or TI64	124 g (steel) 69 g (Ti)	MTB 148 mm Birdy (2x)
M413	24 mm	105 mm	74 mm	139 mm	SCM440	126 g	MTB 157 mm
R910	29 mm	92 mm	70 mm	126 mm	AL7075	87 g	Road, single speed and track bikes
M911	29 mm	96 mm	74 mm	130 mm	AL7075	92 g	MTB 135-142 mm
M912	29 mm	102 mm	74 mm	136 mm	AL7075	96 g	MTB 148 mm
M913	29 mm	105 mm	74 mm	139 mm	AL7075	98 g	MTB 157 mm

P/N	Pneuma BCSB
Crank material	CNC AL7150 (Sekoan crank arm)
Crank arm length	170 mm
Spider mount positions	Three, in 10° steps
BCD	130 mm 5 arms
Weight	490 g (170 mm; TI64-24 mm spindle; w/o chainring)
Ridea chainrings	LamiFlow R5ST series (2x)
Colors	Black (more colors are available as a customization option)

Spindle diameter	Spindle material	Spindle length	Bearing contact area	Chain line	Q factor
24 mm	SCM440 or TI64	130 mm	96 mm	48 mm	164 mm