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General Technical / Re: Brooks saddle
« Last post by Andre Jute on Today at 07:47:16 AM »
I'm curious to know if a used Brooks saddle have to be replaced by a new one..

If yes, how can we know ?

There's a tensioning bolt under the nose of the Brooks saddle. You take a one-eighth turn on it when the saddle starts looking hollow (the proper English is swaybacked -- don't ask me why: English isn't my first language, by half a dozen or so, so I would have said that if we have to have a horsey metaphor it should be lordosis, an equine spine symptom). In your case maybe a quarter-turn. When you've used up all the thread on adjustment bolt, you take the bolt to a welder and ask him to weld on a longer piece of threaded rod, same diameter and thread count per inch. If you're worried about the appearance of your clearly neglected saddle, buy some neat foot oil from your local saddlery (more £$%^&* horses), pour the contents of the can into a baking dish or a bowl large enough to take the saddle and soak first the top and then bottom in the neat foot oil, 10-20 minutes per side. You do that only once, then a thin layer of Proofide once a year only on top. After the short soak in neat foot oil lay the saddle aside for a few days to dry out a bit, then polish only the top with a soft cloth. Tension with your longer bolt and you're good to go for several more years.

A Brooks saddle is like a Catholic wife, you marry it for life, no divorce.
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General Technical / Re: Brooks saddle
« Last post by jul on Today at 07:37:13 AM »
Good th know all this information ..

If the C17 fit me, the big advantage it is not afraid of humidity..

But if i have to buy a new B17, it will be with brass rivet ! Mine are rusty it is not  pretty
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General Technical / Re: Brooks saddle
« Last post by Moronic on Today at 06:35:42 AM »
I'm curious to know if a used Brooks saddle have to be replaced by a new one..

If yes, how can we know ?






Thanks in advance

You'll know when the one you have gets uncomfortable.

Except it's likely a boiled-frog thing. It might be hard to remember how much more comfortable the saddle was when in better repair.

When I bought my Mercury, I fitted an ancient Brooks Professional that I had acquired from a bike purchased used 40 years earlier. I'd revived it with a soak in neatsfoot oil and had used it happily enough on several multi-day tours. I had preferred it to various plastic saddles I'd tried.

With the Mercury purchase I was in the saddle much more frequently and for longer periods. I started to wonder whether a new B17 might be better. Took me a while to male the jump because I'd heard the horror stories about the discomfort of a new Brooks and the need to accommodate that for a thousand miles or more while it broke in. If it broke in.

Bit the bullet and on went a standard B17. First ride it proved exactly as comfortable as the ancient Professional it replaced, and hurt in just the same places.

It's now been under me for a couple of thousand miles (guesswork as I don't use a cyclometer) and it's fabulous. Way better than the old one, which is the point of this anecdote.

It's a real pleasure setting off on a ride and feeling the comfort of the broken-in Brooks underneath me. For the next couple of hours I don't even think about it. At that point if I've not been off the bike or much out of the saddle I may want to stand on the pedals for a bit of relief. I'll only need a few seconds.
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it's questionably how much benefit is derived from any extra stiffness [in the fork] beyond what's required.

The part-sentence quoted from your otherwise admirable post is debatable. Nobody in his right mind designs a touring bike down to some minimum, like a race-and-trash carbon bike. And if you follow that thought through, the strength* "required" for a touring bike should exceed the worst that can happen to it. The cyclist should be able to pick up his bike and continue the journey even after the earth parts and swallows him up.

* A bike or component like a fork that is stiff enough isn't necessarily strong enough: for instance the tube walls might be thin enough to dent, while a conservatively designed bike that is strong enough is usually also more than stiff enough.
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General Technical / Re: On the biplane crown: what does it add to the bike's stiffness?
« Last post by PH on August 14, 2026, 11:48:10 PM »
Not sure I understand all of that…..but the basic problem with the longer biplane fork for me was that it raised the bottom bracket height too much.  The alternative 40mm shorter Thorn fork I now use allows me to have the correct pedal - seat distance and still be able to get a foot safely down when stopping.  Essential on sloping ground and when carrying luggage.  I am sure both fork types are well strong enough for my riding speeds and style!
Forks are measured crown race to axle (C>A) that's the only length that effects geometry, it makes no difference how much of that is crown and how much blade.  I think there must have been some misunderstanding with your bike, I doubt Thorn has ever offered forks with a 40mm difference intended for the same frame. A twin plate crown fork may need to be slightly longer to maintain the same tyre clearance, a few mm, but as this link shows they don't take up much more room than any other design.
https://www.framebuilding.com/NEWPARTSPAGES/Cast%20Fork%20Crowns.htm

I think their present use is largely aesthetic, they are measurably stiffer, but not as stiff as a unicrown and it's questionably how much benefit is derived from any extra stiffness beyond what's required.  They were popular at one time because frame builders could make their own rather than buying in cast crowns, there was also the idea that they could be used with lighter blades to add compliance. I think it may also be possible to weld the blades in place rather than braze them, which might explain their popularity with Thorn's frame builders.
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Not sure I understand all of that

Sorry about that! Basically I'm just saying that theoretically a shorter fork, all other factors equal, is superior to a longer fork.

On a sturdy frame, like the Thorn touring frames, I sincerely doubt it matters much to the cyclist who stays within the generous load limits of the bike.

It starts to matter when in the search for the marginal gramme of weight-reduction a diamond-frame approaches noodle-like tube diameter and wall thickness.
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General Technical / Re: Brooks saddle
« Last post by JohnR on August 14, 2026, 04:54:30 PM »
I've got a barely-used C17 but know people who are happy with them. Those people weigh somewhat more than my 64kg / 142lb and I think that's a factor. Few saddles have versions to cater for different rider wights.
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The Mercury I bought from Thorn in 2020 had that type of fork but it also had 650B wheels which reduce the bottom bracket to ground distance relative to 700C with the same tyre size.
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Forgive this being probably my first and only post, but I bought this on a whim hoping my wife and I could spend more quality time with each other. When I presented her with the idea along with a jaunty rendition of  “Daisy, Daisy, give me your answer do..”  – her answer was a hard “NO!”
So, ultimately what we have is a very redundant early-generation Thorn Discovery touring tandem, which you’ll doubtless know has a UK-built Reynolds 531 frame, finished in the factory original cobalt/metallic blue. It is a well specified example of one of Thorne’s excellent long distance touring tandems.
I don’t know the correct way of sizing these frames, but the captain’s frame tube is 22 inches from the centre of the bottom bracket to the saddle clamp and the stoker’s is 20 inches. The seats are both in excellent condition, the stoker’s being a sprung post item. The rims are wide Gordo items running straight and true, and both tyres are in excellent condition.
Brakes and shifters are Shimano Deore XT kit, and the chainset/deraillieurs are Deore XT 3×9. Everything works as smoothly and seamlessly as you’d expect. The crankset is Thorne/Talon, with 170mm cranks and TCM04-48 48-tooth outer chainring.
Being a pretty serious touring tandem, it comes complete with front and rear carriers, and the corresponding Ortleib Roller Classic bag system. Everything you need to just pack up, jump on and go. The icing on the cake must be the Mickey Mouse bell though!
The tandem had been in storage for some time but has cleaned up well. The blue tape on the captain’s top tube was to protect the paint from his belly bag – it’s just not been taken off. I’ve given everything appropriate lubrication and adjustment but it must be borne in mind that it’s not new and has been previously used, Please let the pictures tell their own story.
I’m not sure how many photos I can post here, but feel free to message me if you need more, I’ve got plenty of hi-res images I can send by email. Collection only from Wimborne for this one, but I work from home so am always around.
Price wise – I’m looking for around £950 for the whole lot.
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Bikes For Sale / Re: 2004 Thorn Raven Rohloff For Sale
« Last post by Andre Jute on August 13, 2026, 09:24:02 PM »
Joe's photographs remind me how much I loved that biplane fork...
Interesting - why?

I answered Andy's question in new thread "On the biplane crown: what does it add to the bike's stiffness?" at
https://thorncyclesforum.co.uk/index.php?action=post;msg=117250;topic=15757.0
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