Ratcatchers Review
July 2004

Here's a comparison between Nike (accelerometer) and Timex (gps) systems from Ratcatcher of Runnersworld fame.

Iíve got the Nike SDM and the Timex Ironman GPS. I love the Nike one because it is absolutely perfect and provides everything I want in a gadget like this. The Timex one is usable but horribly disappointing after having got used to the Nike. Iíll try and summarise my experiences with each:


Works on an accelerometer so always accurate and always reproducible.

Consists of a foot pod and a watch.

Had a teething flaw in that the foot pod kept breaking. Nike replaces the foot pod each time but this has given the gadget such a bad name that most UK suppliers donít sell it anymore. I spoke to a Nike rep at the Rotterdam Marathon expo and he said they have now fixed the problem and were about to release the latest model. Sadly I think the damage is done and UK stores arenít going to risk it. Iíve been refusing a refund for mine because I really do want one so I think Iíll take the money and get a new one from outside the UK.

Because it is always accurate with real-time information can be used for overall distance, real-time pace/speed, average pace/speed, pace/speed alerts and intervals. When itís working I use it most days Ė if it is a straight run I use the pace alert to make sure I am running the correct pace without thinking about it, if I am doing intervals it measures out the intervals for me so I donít need a track or a set route at all but can just run where I like.

Needs to be calibrated, preferably on a track but I did mine on a 10km race. Thereafter itís fine regardless of the pace or terrain you run on.

Can be used indoors, outdoors, anywhere.

Cost £220 when first introduced, cheaper now.


Works on GPS so has all the problems of fluctuations and inaccuracies inherent associated with GPS.

Consists of an arm piece and a watch.

Because the satellite sightings vary and there are patches without coverage it is OK for overall distance but canít be used for real-time pace/speed or pace/speed alerts. They offer the functionality but it is unusable. Iíve tried running with the pace alert on and my pace is either above or below the margin every step so the watch just beeps continuously. It really isnít an option. Average pace/speed is just as bad Ė one rogue reading and everything is out. The last time I tried to use it I was running along the Thames and had set out to run 5:30 pace for the route. I crossed at Southwark Bridge but the device lost coverage and assumed I had just walked over the water so had me down for a shorter distance and a slower time. I had to run flat out for the rest of the route, another 8km, probably doing consistent sub-5 min/km, just to get my average back to what I wanted. So nothing like the consistent easy run I had planned. Itís also useless for intervals because it may lose the satellite for 200m so by the time itís registered that you are onto your recovery youíre already onto your next interval. Absolute nightmare.

What it is good for, and what I do use it for while waiting for my Nike replacement, is distance readings. These arenít reproducible over the same course as the Nike ones are, but are good enough for long runs. All my long runs now are done to an exact pace. The watch beeps every 1km (or whatever distance itís been set to) so I just check my time each kay and calculate my average pace myself to keep on track. Good enough, but hardly the same as a constantly correct pace reading with alerts.

Doesnít need calibrating.

Canít be used indoors or under heavy tree coverage or in very built-up areas Ė most Sundays will find us belting it down Baker Street because the device always goes wrong there and we seem to lose huge chunks of distance that we then need to make up the time for.

Cost £220 when first introduced, cheaper now.

So, in a nutshell, the Nike is the dogís b*ll*cks and the Timex is sh*te but Nike has a design flaw so Timex seems to be the best option currently available in the UK. Once youíve used a Nike one youíll never want to touch the Timex but at the moment I am saddled with it. I think Iím going to try and get a new Nike even if it does mean importing one.

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