The secret length of saddle rails

[horizon]

I was going to post to ask if anyone knew the length of the saddle rails on a Brooks B17 in mm. And then compare them to the length of the saddle rails on a Spa Nidd (and other saddles perhaps). And then I thought that this being a critical measurement, I could find the said information easily on the maker's website.

But it isn't there. Neither Brooks nor Spa AFAIK list the saddle rail length for theirs or anyone else's saddles.

Does anyone know why this is? is there something I am missing? Do all saddles have the same length of rail? Is there an international standard?

[pwa]

Time to start a new repository for this information? We could all measure the usable straight clamping section on our saddle rails and post result here.

[wirral_cyclist]

Time to start a new repository for this information? We could all measure the usable straight clamping section on our saddle rails and post result here.

Does it need to reflect position relative to nose/tail? I have a Spa (Nidd I think) somewhere 'safe' - OK in the may come in pile.

[pwa]

Time to start a new repository for this information? We could all measure the usable straight clamping section on our saddle rails and post result here.

Does it need to reflect position relative to nose/tail? I have a Spa (Nidd I think) somewhere 'safe' - OK in the may come in pile.

Maybe the position relative to the rear edge could be helpful.

[horizon]

Yes, one of the things I reflected on after posting is that it seems quite tricky to measure the exact length of the rails as they are curved at each end.

Another reflection was that the rail length shouldn't matter. In fact the saddle, theoretically, doesn't need any adjustment at all as it is positioned by the frame which is suited to the rider. Then if the worst comes to the worst, the adjustment can be provided by a different type of seatpost.

Another point is that there has to be a limit on rail length to avoid breakage.

Nevertheless I would still quite like to know what's out there!

[rualexander]

Spa Nidd 85mm

[yostumpy]

https://yacf.co.uk/forum/index.php?topic=71796.0

here's a review I did 7 years ago, saddle still going strong. There are some pictures with a tape measure, you should be able to view them.

[peetee]

Another reflection was that the rail length shouldn't matter. In fact the saddle, theoretically, doesn't need any adjustment at all as it is positioned by the frame which is suited to the rider. Then if the worst comes to the worst, the adjustment can be provided by a different type of seatpost.

The problem with that is that there is and always has been a fair bit of adjustment available on the majority of saddles and no unified agreement on what position is right.
It is common for example, for a racing bike to have a lay-back post and mid-rail saddle position, a mountain bike to have an in-line post, a TT bike to have its saddle right forward on the rails and a gents IGH roadster to have a forward-set clamp and post seat pin.

[Brucey]

I was going to post to ask if anyone knew the length of the saddle rails on a Brooks B17 in mm. And then compare them to the length of the saddle rails on a Spa Nidd (and other saddles perhaps). And then I thought that this being a critical measurement, I could find the said information easily on the maker's website.

But it isn't there. Neither Brooks nor Spa AFAIK list the saddle rail length for theirs or anyone else's saddles.

Does anyone know why this is? is there something I am missing? Do all saddles have the same length of rail? Is there an international standard?

there is no standard and the rail length varies. So does where you might sit on the saddle anyway.

FWIW I think the rails on the Nidd are a bit longer than those on the B17. However if you need to use the full length maybe you have the wrong frameset/seatpin.

cheers

[horizon]

However if you need to use the full length maybe you have the wrong frameset/seatpin.

I've always used a VK adaptor to get the saddle back where I want it (other folk have used layback seatposts). The Spa Tourer that I'm building up has a seat tube angle of 72 deg. It's almost a perfect fit and I reckon that maybe with another cm on the rails I could dispense with the VK altogther. AFAICS (I've yet to confirm this) the VK adaptor has a "dead spot" where you cannot reduce its effect any further without removing it completely and I think that is where I want the saddle to be. So there is a bit more trial and error to be had but longer rails might just give me the extra I want with no VK (or new seatpost).

[531colin]

Its deja vue...all over again....https://forum.cyclinguk.org/viewtopic.php?f=1&t=104331&p=1153205&hilit=saddle+rail#p1153205

[pwa]

If starting from scratch, getting the right seat tube angle is step one. Then step two is getting the right seat pin. Hopefully with those two sorted you can get your saddle central on the clamp, but if you can't you are then onto the last resort of choosing your saddle by rail length considerations and having it rammed right back.

Of course we don't always start from scratch.