The Cranktank4 is a uniquely shaped food grade polyethylene container designed to sit low into  the space between the down and seat tubes of conventional double triangle frames.

The “V” profile indents in the front and rear facets allow positive location into most frames without any additional hardware and it secures quickly and simply with two hook and loop “D” buckle straps.

A broad range of tube profiles and sizes and frame angle variations are accommodated by the design. Rounded profile down tubes up to around 50 millimetres are fine and even some squared off profiles work well also. Really broad squared off tubes may require use of the optional Wedgie mount which simply bolts to standard bottle cage bosses. Cranktank4 then locates onto the Wedgie.

The insulated drinking tube with bite valve includes a quick disconnect fitting to allow rapid release from the tank cap so the tube can stay on the bike while you refill. The tube is supplied at 120cms (47 inches) in length for taller riders and is easily made shorter if required.

Also in the kit is a tube keeper which can be fixed in your desired position (handlebar for me) using the included zip ties. The tube is easily accessed while on the move and held securely when not drinking.

The tank has been designed with a relief to the lower section of the seat tube face which provides clearance for most cable operated derailleur mounts. Use of an electronic derailleur will most likely require the use of the optional Wedgie mount fitted to the seat tube cage mounts.

The Cranktanks have been designed with the aim of fitting as many double triangle frames as possible. So touring bikes, gravel bikes, road bikes all the way through to mountain bikes. You’ll find photos on our Instagram page giving you an idea of the broad range of frames it is suited to. The main limitations are small mountain bike frames with heavily dropped top tubes.

It is designed to sit flat along its length against the down tube and slide down (and back) to locate on the seat tube. (Most curved seat tubes are fine.) This provides for very secure location in the frame.

To make sure it fits your frame, take a measurement at 90 degrees to the down tube across to the junction of the seat and top tubes. ( See diagram. The red line is the measurement position.)

Cranktank4:

For down tubes around 38 mm in diameter, the measurement should be 240 mm minimum. For down tubes around 50 mm in diameter, it should be a minimum of 245 mm. For broader, squared off tubes often utilised on carbon or aluminium frames or for use with the Wedgie mount, the measurement should be minimum 250 mm.

Cranktank3:

For down tubes around 38 mm in diameter, the measurement should be 215 mm minimum. For down tubes around 50 mm in diameter, it should be a minimum of 220 mm. For broader, squared off tubes often utilised on carbon or aluminium frames or for use with the Wedgie mount, the measurement should be minimum 225 mm.

Care has been taken to make the inside diameters of the various components as large as possible to remove any restrictions. Comparing the required effort for the Cranktank4 to various backpack style hydration packs, tests show it fits in mid range effort.

When used correctly, water remains in the tube once primed, even when the tube is disconnected from the tank for refilling. (Catch the disconnected end somewhere around the handlebar to make sure.)

The weight ready to fit is around the same as three standard 750 ml bottles and their cages. Taking into account that the Cranktank4 has the capacity of more than five standard bottles it has the potential to save weight.

Being situated low in the frame, even when full Cranktank4 has little to no effect on the handling of the bike and the hook and loop retaining straps ensure it is very securely fixed in position and remains in place even in the roughest terrain. No more lost bottles and their contents.

Lost a component or need a replacement? You’ll find spares in our store and if it’s not there just get in touch. We’ll be happy to help you out.

View our PDF document on how to fit the CrankTank4 to your bike.