Seatpost with a bit more setback

General cycling advice ( NOT technical ! )
Gee
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Seatpost with a bit more setback

Post by Gee »

I’ve got too much weight on my hands (a little). But my saddle (C17) only had about 5mm movement left.

I’ve got a 20mm setback post. Is one with a bit more setback available anywhere?
hemo
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Re: Seatpost with a bit more setback

Post by hemo »

If you have about a ton to spare Nitto s84 has 37mm max set back but only in 27.2 mm.
SJS has a cheaper J tek one with 30mm sb for £30 again in 27.2mm.
pwa
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Re: Seatpost with a bit more setback

Post by pwa »

https://www.sjscycles.co.uk/seat-posts/ ... er-272-mm/

Also available in black. And is sold elsewhere under different branding. The quality is higher than the price suggests. About 30mm setback.
yostumpy
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Re: Seatpost with a bit more setback

Post by yostumpy »

Try pushing the saddle back that extra 5 mm, it can make a BIG difference, before you buy another post. :wink:
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Cugel
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Re: Seatpost with a bit more setback

Post by Cugel »

Gee wrote: 14 Aug 2022, 11:05pm I’ve got too much weight on my hands (a little). But my saddle (C17) only had about 5mm movement left.

I’ve got a 20mm setback post. Is one with a bit more setback available anywhere?
How is pushing the seat back going to take weight off your hands? Surely it'll do the opposite as you'll have to lean forward more .... ?

Your seat position is best determined by how it positions you above the bottom bracket & pedals for efficient power delivery. You generally alter the degree of your lean-forward (and hence the weight on your hands) by altering the stem length and rise.

It helps to start with a frame having the size and geometry that suits the position you want to achieve given your body's dimensions. But if you have to adapt an existing bike the stem is the most likely component that can change your "uprightness".

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
Gee
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Re: Seatpost with a bit more setback

Post by Gee »

Cugel wrote: 15 Aug 2022, 8:39am
Gee wrote: 14 Aug 2022, 11:05pm I’ve got too much weight on my hands (a little). But my saddle (C17) only had about 5mm movement left.

I’ve got a 20mm setback post. Is one with a bit more setback available anywhere?
How is pushing the seat back going to take weight off your hands? Surely it'll do the opposite as you'll have to lean forward more .... ?

Your seat position is best determined by how it positions you above the bottom bracket & pedals for efficient power delivery. You generally alter the degree of your lean-forward (and hence the weight on your hands) by altering the stem length and rise.

It helps to start with a frame having the size and geometry that suits the position you want to achieve given your body's dimensions. But if you have to adapt an existing bike the stem is the most likely component that can change your "uprightness".

Cugel
Because it moves your centre of gravity further back. Just try it while you’re stood up. If you bend right over you naturally push your butt out behind you - or put your hands on the floor so you don’t topple forward. It’s the same (similar) on a bike. Butt back means less weight on hands.
Gee
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Re: Seatpost with a bit more setback

Post by Gee »

yostumpy wrote: 15 Aug 2022, 6:39am Try pushing the saddle back that extra 5 mm, it can make a BIG difference, before you buy another post. :wink:
👍👍

Just moved it back that 5mm. Quick ride around the block suggests it’s done it. I’ll try it for a few miles later if it cools down.
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Cugel
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Re: Seatpost with a bit more setback

Post by Cugel »

Gee wrote: 15 Aug 2022, 9:15am
Cugel wrote: 15 Aug 2022, 8:39am
Gee wrote: 14 Aug 2022, 11:05pm I’ve got too much weight on my hands (a little). But my saddle (C17) only had about 5mm movement left.

I’ve got a 20mm setback post. Is one with a bit more setback available anywhere?
How is pushing the seat back going to take weight off your hands? Surely it'll do the opposite as you'll have to lean forward more .... ?

Your seat position is best determined by how it positions you above the bottom bracket & pedals for efficient power delivery. You generally alter the degree of your lean-forward (and hence the weight on your hands) by altering the stem length and rise.

It helps to start with a frame having the size and geometry that suits the position you want to achieve given your body's dimensions. But if you have to adapt an existing bike the stem is the most likely component that can change your "uprightness".

Cugel
Because it moves your centre of gravity further back. Just try it while you’re stood up. If you bend right over you naturally push your butt out behind you - or put your hands on the floor so you don’t topple forward. It’s the same (similar) on a bike. Butt back means less weight on hands.
Somehow this seems wrong.

Firstly, one isn't standing but sitting on the bike seat. If you sit vertically, there's no weight acting through your hands. If you could grasp the bars in that position then lean gradually forward (with the bars) more and more of your weight would be acting through your hands. The greater the lean, the more weight acts through your hands.

In practice, moving the seat back means you need to lean more forward to reach the handlebars, which are in a fixed position in front of you. Surely this will transfer more weight to your hands. It's the centre of gravity of your upper body that moves forward. Your bum is sitting on a supporting seat so moving it back and forwards won't alter the centre of gravity of your upper body in the same way as it would if you were standing only on your feet. ....... ?

Secondly, the seat position should be determined by how it arranges the position of your legs for pedalling at best efficiency. (Power but also sustainability). If you move the seat forward or back from the ideal position to change your reach to the bars, you're going to end up in a less than optimum position for pedalling. So why not alter the stem length/angle instead?

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
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Cugel
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Re: Seatpost with a bit more setback

Post by Cugel »

Gee wrote: 15 Aug 2022, 10:01am
yostumpy wrote: 15 Aug 2022, 6:39am Try pushing the saddle back that extra 5 mm, it can make a BIG difference, before you buy another post. :wink:
👍👍

Just moved it back that 5mm. Quick ride around the block suggests it’s done it. I’ll try it for a few miles later if it cools down.
So was it "the weight on your hands" or the position of your legs for pedalling that was the problem?

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
bikepacker
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Re: Seatpost with a bit more setback

Post by bikepacker »

Cugel wrote: 15 Aug 2022, 2:13pm
Gee wrote: 15 Aug 2022, 9:15am
Cugel wrote: 15 Aug 2022, 8:39am

How is pushing the seat back going to take weight off your hands? Surely it'll do the opposite as you'll have to lean forward more .... ?

Your seat position is best determined by how it positions you above the bottom bracket & pedals for efficient power delivery. You generally alter the degree of your lean-forward (and hence the weight on your hands) by altering the stem length and rise.

It helps to start with a frame having the size and geometry that suits the position you want to achieve given your body's dimensions. But if you have to adapt an existing bike the stem is the most likely component that can change your "uprightness".

Cugel
Because it moves your centre of gravity further back. Just try it while you’re stood up. If you bend right over you naturally push your butt out behind you - or put your hands on the floor so you don’t topple forward. It’s the same (similar) on a bike. Butt back means less weight on hands.
Somehow this seems wrong.

Firstly, one isn't standing but sitting on the bike seat. If you sit vertically, there's no weight acting through your hands. If you could grasp the bars in that position then lean gradually forward (with the bars) more and more of your weight would be acting through your hands. The greater the lean, the more weight acts through your hands.

In practice, moving the seat back means you need to lean more forward to reach the handlebars, which are in a fixed position in front of you. Surely this will transfer more weight to your hands. It's the centre of gravity of your upper body that moves forward. Your bum is sitting on a supporting seat so moving it back and forwards won't alter the centre of gravity of your upper body in the same way as it would if you were standing only on your feet. ....... ?

Secondly, the seat position should be determined by how it arranges the position of your legs for pedalling at best efficiency. (Power but also sustainability). If you move the seat forward or back from the ideal position to change your reach to the bars, you're going to end up in a less than optimum position for pedalling. So why not alter the stem length/angle instead?

Cugel
I am with you Cugel on this theory and it is a theory which has been discussed in a previous thread. IMO it is a theory of an American guy who just wants to make himself different to other bike fitters and in practice it does not work. As you state, get you saddle position correct and measured from a vertical datum from the centre of the BB if you arms do not feel right alter stem length.

If the theory was remotely correct everyone who rides and upright bike would be suffering with very tired or painful arms.
There is your way. There is my way. But there is no "the way".
Gee
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Re: Seatpost with a bit more setback

Post by Gee »

Cugel wrote: 15 Aug 2022, 2:14pm
Gee wrote: 15 Aug 2022, 10:01am
yostumpy wrote: 15 Aug 2022, 6:39am Try pushing the saddle back that extra 5 mm, it can make a BIG difference, before you buy another post. :wink:
👍👍

Just moved it back that 5mm. Quick ride around the block suggests it’s done it. I’ll try it for a few miles later if it cools down.
So was it "the weight on your hands" or the position of your legs for pedalling that was the problem?

Cugel
I can’t comment about pedalling efficiency yet as I’m sweating like crazy and daren’t go for a test ride!!

I quite get where you’re coming from in your analysis but, and I’m no expert on this, but even on the cycle quite a lot of your weight, probably most of it, is carried by your legs, on the pedals, if you pedal hard enough you can take all the weight off your arms (and butt), it’s hard to sustain that for long. In short, and I don’t quite know how, i think there is a complex relationship between spine angle and weight on arms.

I have in the past gone for bike fits and I probably will again, and they always start with the cleats, then the saddle, I don’t really want to with this bike though. 2 reasons, I’m a bit concerned about the frames safety (Google bowman frames), secondly I quite like learning stuff and working it out for myself. I’m fairly sure it’s not height of the bars (they’re only slightly lower than the saddle, I swapped the stem from a 90mm to a 110mm because I felt too much pressure on the web of skin between thumb and forefinger. The 110 mm stem really helped with that and even with that extra 20mm I don’t feel like I’m stretching for the reach.

It is a bit of experimentation and try as I go though. On the plus side - by the time I’ve finished I might not ever need to pay for a bike fit again😀😀😀

The other thing is if you watch even the extreme racing pro’s, they’re bent right over but nonetheless have very little weight on there hands. Though, to be fair, their bodies are quite a bit different to mine😂😂😂
Last edited by Gee on 15 Aug 2022, 3:53pm, edited 1 time in total.
Gee
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Re: Seatpost with a bit more setback

Post by Gee »

I am with you Cugel on this theory and it is a theory which has been discussed in a previous thread. IMO it is a theory of an American guy who just wants to make himself different to other bike fitters and in practice it does not work. As you state, get you saddle position correct and measured from a vertical datum from the centre of the BB if you arms do not feel right alter stem length.

If the theory was remotely correct everyone who rides and upright bike would be suffering with very tired or painful arms.
[/quote]

Yes, but what is the correct saddle position? Up and down, as well as for and aft? Maybe I’m not in it. The C17 is a relatively new saddle for me. What we do know for certain is that moving the saddle backwards or forwards can have a really marked effect on our weight distribution on the bike. There is lot of information from experienced and knowledgable people (531Colin of this site), much more than myself, about this.

When you go for a bike fit they never even begin to think about your handle bar position until they’ve got you ass in the right place. I’m sure I don’t need a higher stem (or bars will be above saddle). I have already tested and found a longer reach beneficial.

I’m hoping to get a ride later for further checking but it does feel that moving the addle back that extra few mm’s as made a fair difference. I might even be able to lower the bars😂😂😂

I don’t want to end up in a very upright position as I like this bike to be sporty but okay for up for audax type riding.
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freiston
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Re: Seatpost with a bit more setback

Post by freiston »

Cugel wrote: 15 Aug 2022, 2:13pm
Gee wrote: 15 Aug 2022, 9:15am
Cugel wrote: 15 Aug 2022, 8:39am

How is pushing the seat back going to take weight off your hands? Surely it'll do the opposite as you'll have to lean forward more .... ?

Your seat position is best determined by how it positions you above the bottom bracket & pedals for efficient power delivery. You generally alter the degree of your lean-forward (and hence the weight on your hands) by altering the stem length and rise.

It helps to start with a frame having the size and geometry that suits the position you want to achieve given your body's dimensions. But if you have to adapt an existing bike the stem is the most likely component that can change your "uprightness".

Cugel
Because it moves your centre of gravity further back. Just try it while you’re stood up. If you bend right over you naturally push your butt out behind you - or put your hands on the floor so you don’t topple forward. It’s the same (similar) on a bike. Butt back means less weight on hands.
Somehow this seems wrong.

Firstly, one isn't standing but sitting on the bike seat. If you sit vertically, there's no weight acting through your hands. If you could grasp the bars in that position then lean gradually forward (with the bars) more and more of your weight would be acting through your hands. The greater the lean, the more weight acts through your hands.

In practice, moving the seat back means you need to lean more forward to reach the handlebars, which are in a fixed position in front of you. Surely this will transfer more weight to your hands. It's the centre of gravity of your upper body that moves forward. Your bum is sitting on a supporting seat so moving it back and forwards won't alter the centre of gravity of your upper body in the same way as it would if you were standing only on your feet. ....... ?

Secondly, the seat position should be determined by how it arranges the position of your legs for pedalling at best efficiency. (Power but also sustainability). If you move the seat forward or back from the ideal position to change your reach to the bars, you're going to end up in a less than optimum position for pedalling. So why not alter the stem length/angle instead?

Cugel
Shirley it's a bit more complicated/dynamic than that. The more forward your centre of gravity, the more you will need to push back on that weight with your arms (or "brace" your arms) to maintain balance. If you try to ride "no-handed" forward on your saddle & leaning forward, it is harder than being back on your saddle and upright because it is harder to balance with the forward centre of gravity unless you take the weight on your hands.

The more forward the centre of gravity, the more the share of weight goes to the hands, the further back the centre of gravity, the more the share of weight goes to the saddle.

There are many "correct" saddle positions for a specific rider - the seat tube is (usually) angled backwards and so as a saddle is raised, it is also set back more (without changing rail clamp position). Using the rails & varying setback values of seat posts, the saddle can be in the "correct" position throughout a range of positions in an arc relative to the BB (subtle but significant), shifting the centre of gravity as it travels through that arc.

Core strength and leg power will enable a rider to maintain a forward lean without putting so much weight on the hands by taking the weight through the pedals - so a stronger rider can maintain balance with a forward saddle and longer reach without putting so much weight on the hands than a weaker rider by using the third contact point of pedals to take a share of the weight from the hands and saddle - so a road racing cyclist can put less weight on the hands with a higher, more forward saddle and a longer reach than a slow utility cyclist would on the same bike, even if they're identically proportioned.

So a cyclist can reduce the share of weight being supported through the hands by increasing the saddle setback. Imho, reach should be addressed (via stem/stack/bars) after optimal saddle position (including set-back) has been arrived at for a particular rider, given their strength, size and cycling style, so that balance can be achieved with little weight on the hands in the most relaxed or usual position the rider is likely to be in (such as on the tops or on the hoods) - then the bar position can be set to meet that position.
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute. ;)
PH
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Re: Seatpost with a bit more setback

Post by PH »

Cugel wrote: 15 Aug 2022, 8:39am How is pushing the seat back going to take weight off your hands? Surely it'll do the opposite as you'll have to lean forward more .... ?
Cugel
I think there's some sort of misunderstanding here, I doubt anyone ever suggested moving a saddle to adjust reach, but rather too much weight on your hands is often a symptom of the saddle not being far enough back. I know it may seem a subtle difference, but it's an important distinction, I doubt there's much disagreement about it among bike fitters or sports physios.
yostumpy
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Re: Seatpost with a bit more setback

Post by yostumpy »

Trust me, it works. The sekrit to the dilemma is in the op’s choice of saddle. I use a Spa Nidd (B17 clone) and as such it has a metal horseshoe at the rear, meaning the saddle has to go back 10mm ish further than a plastic padded saddle, otherwise sitting on the rivets gets painful. Ditto C17, different material and cantle plate, but same design. All those doubters,… move your saddle forwards by 10-12mm then try.
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