Gamut P20 Chain Device – First Look

The first thing I thought on opening the box containing the chain device was, ‘is that it’? A chainring-mounted bashguard, a backplate with guides already attached and a small bag of spacers was all I could see, no parts trees like an airfix model, no big instruction manual. Great! Then…’tidy’. Nicely manufactured, well finished and with subtle graphics on the hollowed-out-as-much-as-can-be bashguard, this thing looks good.

Next thought…’light!’. This little lot is right in the ballpark as far as skinny chainguides go, to be fair the differences between most devices are not huge but of course everyone wants to know how few grams they’re getting for their hard-earned pounds (or dollars or Euros or Tughriks or whatever); in this case, 161 of them. Subsequent neural impulses interpreted the P20 as… ‘simple’. With no rollers to wear out, split or fall off, no holes to thread chains through, and one big simple bolt per guide arm, this thing was about as uncomplicated as it gets.

The guides themselves (which are made of a hard rubber compound that seems pretty slippy without being brittle) can be adjusted for chainline with very simple spacers that sit between the backplate and the guide itself, and of course the backplate can be spaced from your ISCG tabs in the normal way, with the usual type of washers (Gamut offer ISCG, ISCG05 and Flange fit backplates).

The lower guide has a rubber O-ring instead of a roller guide, which is obviously very cheap and simple to replace, and a spare is included from new.  This O-ring is designed to cope with the good old British winter much better than a conventional roller-type design.  A point to note is that on the backplate itself, Gamut have steered away from the commonplace countersunk bolts and instead use low profile flat head bolts to keep the device in place. Why? Well, Gamut reckon that some frame designs can interfere with the guide when mounted normally, and so the backplate itself is reversible, opening up alternative configurations as opposed to getting the Dremmel out and grinding your expensive new device to bits. The guide mount areas are identical on both arms and so the guides can be easily swapped around if you happen to have to ‘flip’ the backplate to get everything lined up well.

Whilst at first this flexibility in configuration seems like good design, there is a compromise in that the bolts that hold the device to your bike don’t have as much material at the bolt head as countersunk bolts do, and they only have room for a 3mm Allen key (presumably to preserve some strength in the bolt head), so those of you with massive forearms or the tendency to think ‘just another quarter turn’ should go lightly. For the super-nerds, and/or those of you with expensive toolkits, Gamut don’t recommend any torque values.

Anyway, these concerns about the bolts may well be unfounded, if they work for Gwinn, Minaar, T Mo, Carpenter, Buchanen, McCaul, Keene and Watts then the rest of us will probably be ok, and only riding fast in proper British conditions will really tell the tale. Luckily an English winter is here, so watch this space!

RRP £99.99

Gamut Components are distributed by Madison

For more Gamut info visit







Words – Anthony Gaskin
Images – Matthew Slocombe

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