Having been able to view the development of Brant (Richards) new Ragley brand after he left On-One I thought it would be interesting to look at how he describes the geometry of his frames. With manufacturing being as easy as picking up the phone to a factory in the Far-East you can see why most companies would want to be a little guarded when they quote their numbers.
But it’s not just plagiarism that manufacturers are worried about – it’s the public perception of how their bikes will ride too. They don’t want to scare them off with numbers that appear a bit weird or out of the norm. If you take a peek at the geometry chart for the titanium Ragley it doesn’t seem that unusual:
Maybe the seat angle could be called a little steep but the head angle seems normal – until you read the bit beside which points out the angles are quoted with the fork set at 25-30% sag.
Let’s have a bit of ‘fun with maths’ to work out what the static heights might be. If we take a 140mm travel Fox Float fork, the quoted axle-crown length is 510mm, 25% sag would be 35mm so the length of the sagged fork is 475mm which is when the 67.5 degree head angle is measured.
Running this through the seriously handy geometryCalc we can work out the effect of the sag on the head angle. Rounding up the results we see a static measurement of 66 degrees for the head and 72 degrees for the seat. The other clue to the slackness of the angles is that Brant recommends a 50mm stem with some nice wide bars, which would stop something as slack as that steering like a barge. I think we can safely say it’s going to be stable running downhill.
Head angles need to be matched to stem and bar lengths to keep the steering feel right as the Ragley shows above. For a more usual 68 degree head angle you’d typically pair it with a 70mm stem and a nice set of 26-27″ bars. XC types running a 70+ degree head would be more likely to run a 100mm stem with 22-23″ bars etc. There’s probably something very scientific about this but I’m not sure what it is!
There’s no reason why the Ragley shouldn’t steer well provided it’s setup properly with a good short stem, although ultimately it’s compromised as a ‘do everything’ frame and will probably work best when pointed down the steepest chute you can find. If you’re feeling brave you could even replicate the numbers in your own frame – for about half the price 🙂