hint that they alone amongst bicycle manufacturers fully understand the relationship between head angle and fork offset that governs perfect handling. I really don’t buy that.

That they would offer a 370 and 410mm length fork for the same frame, does seem to make a mockery of that idea. 
The rational for not offering the geometry (Though they now publish more than before) is the argument that a little knowledge can be a dangerous thing.  There is some truth in this, I have seen people comparing TT lengths without HT and ST angles, with no understanding how each effects the other. Weight is the other big one of course, if a frame is designed to do a task well, it'll weigh what it weighs. I went to an entertaining talk by a renowned frame builder some years ago, he said that the two most frequently asked questions were wheelbase and weight and that both were the result of design not a part of it.

I’ve never understood why thorn have always been so coy about publishing geometry tables for their frames. Critical numbers that are conspicuously absent include both head and seat tube angles. Thorn claims it’s commercially sensitive information, and hint that they alone amongst bicycle manufacturers fully understand the relationship between head angle and fork offset that governs perfect handling. I really don’t buy that.

In fairness their customer care goes above and beyond, and they do offer extended test rides for Rohloff equipped bikes and a generous 100-day money back guarantee. I was a bit surprised to see that test rides for derailleur equipped bikes are not now available, and the money back guarantee only extends to 14 days. I’m sure this wasn’t previously the case.

My Raven Tour came with a biplane fork with L1 = 410mm but shorter unicrown forks with L1 = 370mm appear to have been an option - reference from Test of Raven Tour on SJS website.  ‘Our Tour came with twin plate 531 ST forks…….a shorter 531 fork is also an option’

If it works for you, it works, I remain sceptical that the designer ever intended for forks of that difference to be fitted. It's the equivalent of a 2 degree head tube angle change, and the resulting difference in trail, I'd notice that.
However, that wasn't my point. Which was the forks were 410mm because that's the length the designer wanted them to be, not because of the crown chosen.  He probably chose that length as it offers the option to swap out for short travel sus forks.
The Raven Sport had considerably different geometry, the shorter fork had the option to be swapped out for an off the peg carbon fork.  When the Tour and Sport merged into the Raven, the 370 cast crown fork was kept and the 410 twin plate dropped.

On a loaded Nomad ( 45 x19 ) I did 46.6km downhill on Ardnamurchan in May. Still love the adrenaline rush and utter folly 😂

I only do the fast downhills on my derailleur bikes, not my Rohloff bike.  Ratio of chainring to sprocket in top gear on my road bike is 50/12.  My two derailleur touring bikes is 46/11, and my rando bike is 52/11. 

But if I am going down a long hill, I let my cadence drop to a slower pace to relax and let gravity do the work. 

The only time I put effort into pedaling on a downhill is if I am going down into a valley and several seconds later I will be pedaling up a steep hill on the other side.  On those occasions I do that to help maintain momentum on the uphill.

Quote from: jul on July 27, 2026, 08:55:06 PM

For information, 36x16  transmission,  aboie 33km/h you can no longer pedal, sometimes it’s frustrating

Depends on your pedaling cadence.

I generally pedal relatively fast at about 90 rpm (tours par minute). With a 36x16 combination that translates into 36 km/h, which is way above a sustainable speed for me on the level, unless I have an exceptionally strong tail wind.

If necessary I can increase pedal cadence for very short periods. With a 36x16 combination at 120 rpm in the highest gear that would be 48 km/h. In practice, that kind of speed is not really useful for me, except perhaps when I negotiate medium size roundabouts, where I feel safer if I am doing roughly the same speed as most of the motor vehicules. 

My current highest gearing on any of my bikes is 42x19 on my Rohloff equipped Raven Sport Tour. I use that bike mainly for day rides with little luggage. Top gear with 42x19 is slightly lower than with a 36x16, the maximum speed I managed recently when pedaling (downhill) was 53 km/h at 137 rpm, just to see if I could still do that at age 69. But normally I would just stop pedaling and coast down the hill.

Yep, i did a mistake, 36x16 transmission, you can ride max at 43 km/h..

At 47km/h you pedal as a salade drainer