Name: RockShox Bluto RCT3 Solo Air 26" Disc Forks
Brand: RockShox

You’ve probably observed more and more riders are on bikes that look “different” on your trails. Bikes that have wheels and tires of gigantic proportion – and we’re not talking about 29ers here. The thing is, even though fat bikes were created to float on top of snow, they’re just too damn fun not to ride on dirt. So how do amplify your fat bike adventures even further? With a supercharged, ultra efficient, first of its kind fat suspension fork called Bluto. We started with the features you’ve come to love from RockShox: Fast Black aluminum upper tubes, stout 15mm Maxle, remote or crown adjustable damping, tapered steer tube, and the infinitely tunable Solo Air spring. Then, the chassis got the fat treatment by reengineering it to meet the unique needs of fat tires and wheels. Everything from crown, to arch, to axle has been optimized to tackle the increased torsional loads of its wide stance. With more traction and control than ever before, you’ll never be happier you went fat.

Key Features:

Available in 80, 100 and 120mm travel options to fine-tune the ride for your style and terrain.
Updated air pressure guides maximize performance for E-MTB applications.
Motion Control™ damping featuring 3-position compression adjustment (open/pedal/lock)
Updated graphic package to complement the RockShox lineup

Specifications:

Wheel size: 26"
Travel(mm): 100mm
Steerer: Tapered
Axle: 15X150mm
Damper adjust: Crown
Spring: Solo Air
Color(FS): Gloss Black
Upper Tube Finish: Fast Black
Maxle included: Maxle Lite
Damping adjustments: Extl rebnd, low speed comp, 3 pos comp (open/platform/lock)
Crown Material: Forged, AL66 TV aluminum
Lower leg material: Magnesium
Minimum Rotor Size: 160mm
Maximum Rotor Size: 203mm
Upper tube type: 32mm straight wall aluminum
Weight Based On: 265mm tapered aluminum steerer, 15x150mm Maxle Light, Solo Air
Weight(g): 1796

Occasionally, without notice, manufacturers change product design and/or specifications.

Suspension Forks Sizing

A new suspension fork is one of the most noticeable and worthy upgrades you can make to your mountain bike. A higher quality fork will be able to deal with more difficult terrain, remaining composed on the trail and keeping your wheel in contact with the ground. This gives more grip, and therefore a more confidence inspiring ride.

Not all forks are made equal, there are some very important size and compatibility aspects to look at first.

Compatibility

Wheel size

There are a few different wheel sizes for mountain bikes. 26”, 27.5” (650b) and 29” are the most common.

There is also plus (+) and fat versions available. If you are not sure it should be written on the side of the tyre.

Whatever wheel size you have, the fork must be designed to suit.

Fork steerer

The fork steerer is attached to the fork crown, this comes up through the frame and headset to be clamped at the top by the stem.

Most modern bikes will have a tapered steerer, this is 1.5” inch wide at the fork and 1 1/8th inch at the stem. Some DH bikes and older mountain bikes will suit a straight 1 1/8th inch steerer.

It is easiest and best if the replacement fork has the same diameter steerer to fit into your frame and headset.

If you are unsure on the size, drop the forks out from the frame and you should be able to see straight away if the steerer is tapered or straight.

Axle size

If you are planning on using the same front wheel with your new fork, the fork’s dropouts must suit your wheel.

The width of the front hub has traditionally been 100mm, with either a 9 or 15mm axle. With a 9mm Quick Release (QR), a fork could be described as 9mm x100mm or QR to fit. A larger 15mm bolt through axle is more common on higher end bikes, a fork could be described as 15 x 100 to suit. This 15mm axle can be a quick release style and can be referred to as 15QR

Over the last few years, a wider 110mm spacing known as “Boost” has become the new standard, this is not available for 9mm QR axles and would be shown as 15mm x 110 or 15mm Boost.

20mm axles have been common on DH bikes for some time. Although DH wheels will be 110mm wide, they are not always “Boost”. There is a new DH Boost for front wheels and forks, this means the hub is still 110mm wide, but the disc rotor/mount sits 5mm out.

For more on MTB wheels see our full guide here

Travel

The amount of distance the fork can move vertically is referred to as travel (shown in mm). The frame manufacturer will have designed the bike around a certain amount of travel. The general rule is to stay with this. Increasing or decreasing the fork travel can result in the geometry being severely compromised, making the bike handle worse than intended and putting more stress on the headtube structure.

*Changing fork travel can void frame warranty from the manufacturer, please check with the manufacturer before any travel increase/decrease.

As fork travel increases so can flex, to combat this a triple clamp design is used for forks with over 180mm of travel. The hub plus the two crowns creates a triple clamp. The forks are for DH use.

A triple clamp DH fork, travel is measured from the lower crown to the top of the fork lower legs

Offset/Rake

The distance the axle is offset from the steering axis. This directly affects the “Trail”. Trail is the distance between the contact point of the tyre and where the steering axis hits the floor. The shorter the offset the longer the trail and vice versa. Wheelsize also affects trail. Larger wheels have a longer trail. With the popularity of 29er MTB’s, there is often an offset choice to be made.

The most common offset for a 29er fork is 51mm, however, fork manufacturers offer shorter offsets to increase trail.

Fitting

Once the correct fork has been chosen there are a few things you should know before fitting.

Crown race – Slid down over the steerer is the crown race, these are usually particular to the headset on your bike. They create a seat for the lower bearings of the headset to sit on, this should be removed from your forks and slid into place on the new fork steerer before installing the new forks.

Star Nut – Inside the steerer tube there is a star nut. This has a wedge design allowing it to be slid down into place but not slid back up. There is an internal thread that takes the top cap bolt allowing the forks to be held in place and allowing adjustment of the pressure on the bearings.

Steerer length – A new fork will have a long uncut steerer, this will more than likely need to be cut to match the length of your original forks, however, it can be cut longer or shorter if you wanted to have more adjustment for stem height.

Setting Sag

See our full guide to setting sag here

Rear shock buyers guide >

IN STOCK SRAM

RockShox Bluto RCT3 Solo Air 26" Disc Forks