Energy Loss With Sprung Saddle

[Mick F]

We disagree here!

In flat areas, you keep going and don't freewheel much, and you have to cope with a possible headwind.

In hilly areas, the time taken to go down a hill is over in a jiffy at circa 35mph, but climbing them takes ages at circa 5mph. Hills come thick and fast. Average speed is low despite the 35mph freewheeling. Come to Cornwall and try and experiment in average speeds.

As for sprung saddles, when you press down, the side with you leg going down, goes down with it, not upwards. Consequently, the spring absorbs some of the power-stroke.

[Roadster]

As for sprung saddles, when you press down, the side with you leg going down, goes down with it, not upwards. Consequently, the spring absorbs some of the power-stroke.

This can occur if the sprung saddle is set too high, forcing the rider's pelvis (and with it the sprung saddle) to sway from side to side with each alternate pedal stroke. The solution, however, is not a switch to an unsprung saddle, but adjustment of the sprung saddle to the correct height for the rider.

[Mick F]

I can agree with that.
A sprung saddle, therefore, would be lower than an unsprung saddle - all else being equal.

[Roadster]

No, that doesn't follow. On the contrary, a sprung saddle like the Brooks Flyer would be set slightly higher than an otherwise identical unsprung saddle like the Brooks B17, to allow for the compression of the springs under the rider's weight.

[Brucey]

I think you can bounce in all kinds of strange ways if you pedal slightly differently. This might be rather inefficient, and it might vary strongly with the rider; hence the suggestion of tests to see.

However when riding on rough surfaces, a sprung saddle might well be a significant advantage; I'd like to see trials of that, too.

cheers

[Roadster]

With regard to the weight issue, a significantly fatter rear tyre could easily add more unsprung weight to the machine than saddle springs do in providing a similar level of comfort to the rider.

[531colin]

When riding on tracks, its a considerable advantage if you set up your bike so that you can distribute your weight properly. If you sit on the saddle like a sack of spuds, you will one day find a bump and a speed that fires you up in the air.
Personally, I hate sprung saddles.....I'm driven to adjust the saddle height by a few millimetres when changing between winter boots and shoes, the last thing I want is the damned thing moving about.

[Brucey]

I'd tend to agree but there's clearly more than one way of skinning a cat though; according to those who ride them, Pedersens are comfy in their own way, and so are Geoff Apps designed bikes, despite the fact that you are sat bolt upright on both types of machine.

I don't like variations in saddle height much either, not on bikes with dropped bars; but on upright machines (lower intensity of effort and shorter rides) I tolerate it better. I have occasionally ridden an upright bike with a sprung saddle for thirty or forty miles and clearly I could have gone faster on a touring bike, but it wasn't a complete disaster; the main thing I noticed was aerodynamic drag and the fact that the bike weighed a ton.

It isn't quite the same but full suspension doesn't suit every circumstance and pedalling style either. On some FS machines those who are able to pedal nice smooth circles when it is difficult (eg when climbing) get more out of such machines than those who stamp on the pedals briefly once every time round... I'd imagine that the same sort of thing is true of sprung saddles, but there is a need for tests as there is a lack (ahem) of firm evidence....

cheers

[Roadster]

When riding on tracks, its a considerable advantage if you set up your bike so that you can distribute your weight properly. If you sit on the saddle like a sack of spuds, you will one day find a bump and a speed that fires you up in the air.

If you're sat on an unsprung saddle like a sack of spuds, then yes of course you will, and not just one day but very soon and on a regular basis thereafter. On a sprung saddle, however, you won't because the springs will absorb the shock.

That's actually what sprung saddles are for, so that those who prefer riding in an upright position can do so without being repeatedly fired up in the air by bumps in the road. For those who prefer a less upright position, this advantage is either reduced or, as in your case, completely lost.

[mjr]

Actually, I'd suggest them for all except the most aggressive road bikes. It just takes the bum drumming out of cycling.

I've no hard data, but sixty miles into one sportive, me on a hybrid with sprung saddle and 28s and most riders on typical sportive road bikes, plus me in pieces following a close encounter of the pothole kind (bruised thighs, I later discovered), we turned onto a truly rotten fen road: it was concrete panels originally, so had those joints, then tarmac on top which had failed and then they'd surface dressed it without repairing half the holes. It was like everyone else was suddenly on flat tyres! Normal service was resumed after about ten miles, though.

[thirdcrank]

With regard to the weight issue, a significantly fatter rear tyre could easily add more unsprung weight to the machine than saddle springs do in providing a similar level of comfort to the rider.

Springs may not add much weight to a traditional leather saddle, but a leather saddle is a fair bit heavier than a man-made one.

[mig]

i always think that a rider will 'go' best on a saddle that they are well used to riding - for both comfort and power reasons.

[simonhill]

Thanks for the replies. Sorry Brucey, but conducting your experiment would have me doing more bike tinkering than I normally do in a couple of years (God bless my LBS).

I will try swapping seatpost and saddles(easy). In fact the reason I chose a B17 for my latest saddle was with the possible intention of using it for touring once it was broken in.

I had hoped that there might be a saddle-spring-resistance-ometer and someone would have a raft of figures to hand - but as so often in cycling, knowledge is subjective rather than objective.

By the way, the weight difference is 520 gms for the B17, 860gms for the Flyer (it is a Flyer, not a Conquest, that was my original one).

Anyway, thanks again.

[thirdcrank]

Picked at random from ads
Fizik Arione R1 (I don't know if they do an R2 )

165gms
https://www.westbrookcycles.co.uk/fizik ... %20-%20(SC)%20All%20Products&utm_term=4575548919879547&utm_content=Brand_

[reohn2]

Picked at random from ads
Fizik Arione R1 (I don't know if they do an R2 )

165gms
https://www.westbrookcycles.co.uk/fizik ... %20-%20(SC)%20All%20Products&utm_term=4575548919879547&utm_content=Brand_

If they do,at those prices I won't be buying one