Moving the saddle forward?

[AnotherEye]

I'm trying to get comfortable on my new build (1960 Carlton frame) & want to move my saddle forward.
I've just looked in Cyclecraft, Franklin says "start with the nose of the saddle about 5cm behind a line passing vertically through the bottom bracket". Mine is currently set at 11cm! that's a massive difference. I need to find a (27mm) seatpost that allows more adjustment forward but that doesn't break the bank. Any suggestions?
thanks in advance.

 

[HLaB]

Thats only a guide, just move your saddle forward in 5mm increments and see if you are comfortable with that before you go to any expense. If it still feels like it needs to go forward you'll get a seat post with less or no set back. Unfortunately if you still feel the need to get forward the bike may be to big for you. IHTH :-)

 

[festival]

That looks a big frame ? how tall are you? how much frame stand over clearance is there?

 

[Holdsworth]

I read this and thought about my own bikes. My tourer with it's compact frame seems to be near enough in line with Cyclecraft's recommendations. My road bike on the other hand has the nose of the saddle right over the BB or thereabouts. It might be the steep angle of the seat tube that is the cause or the long reach stem which means I need to be seated forward in the saddle to reach the brakes because of my relatively short arms. I think maybe installing a short reach quill stem might help if they even make such a thing nowadays.

 

[zacklaws]

I cannot see what is so important about the nose of the saddle, regarding the positioning of the saddle as all saddles are different, some long and some short. I always take my measurements from the part of the saddle upon which your seat bones rest upon to set my bikes up initially which is usually the widest part of the saddle. Once I get the position of my saddle right, then I take a measurement from the center of my headset to the nose of the saddle as a reference as it is easier then to adjust your saddle if you remove it or alter it etc.

I have two road bikes, both with different saddles, both very comfortable, yet the measurements from headset to nose of saddle are completley different, but the widest part of the saddle to headset is identical on both. One bike has a Fizik arione fitted, which is the longest saddle legal for road racing, whereas the other bike has just a bog standard saddle. Two different saddles, two different measurements.

 

[AnotherEye]

That looks a big frame ? how tall are you? how much frame stand over clearance is there?

I'm 5'10", more importantly my inside leg is 33". The frame is 23".
Stand over clearance is 1/2", I guess it would be a little more with thinner tyres!

Richard's Bicycle book says: inside leg less 9" = 34" so 'frame not too big by that,
or; height divided by 3= 23.3, so, likewise, not too big.

I feel I need to bring the saddle forward as it doesn't feel natural right now when I'm right back in the saddle.
I've tried 2 different saddles; both about average in length so I'm wondering if the frame is unusual?

 

[AnotherEye]

You could try a searpost with no layback or even one that can be used reversed and turn it round - I've got the latter on my bodged together TT bike.

I"d like to try that; what is the seatpost you have?

 

[Fab Foodie]

http://www.peterwhit...com/fitting.htm

Early frames have a more laid-back (less vertical) seat-tube, look at old cycling videos and you'll see a different sort of positioning on the bike, nowadays we're slightly further forward.
As mentioned, a 23" frame is probably just too big for you.

 

[amaferanga]

I'm 5'10", more importantly my inside leg is 33". The frame is 23".
Stand over clearance is 1/2", I guess it would be a little more with thinner tyres!

Richard's Bicycle book says: inside leg less 9" = 34" so 'frame not too big by that,
or; height divided by 3= 23.3, so, likewise, not too big.

I feel I need to bring the saddle forward as it doesn't feel natural right now when I'm right back in the saddle.
I've tried 2 different saddles; both about average in length so I'm wondering if the frame is unusual?

Its the top tube length that really matters. Those guides are useless really - what if someone has really long legs, but a short torso and short arms? They'd need a different sized frame to someone with the same length legs that has a long torso and monkey arms.

I was just thinking what Fab Foodie said though - the seat tube is very laid-back so even if the frame were the right size you'd probably want a zero-layback seat post.

 

[HLaB]

I read this and thought about my own bikes. My tourer with it's compact frame seems to be near enough in line with Cyclecraft's recommendations. My road bike on the other hand has the nose of the saddle right over the BB or thereabouts. It might be the steep angle of the seat tube that is the cause or the long reach stem which means I need to be seated forward in the saddle to reach the brakes because of my relatively short arms. I think maybe installing a short reach quill stem might help if they even make such a thing nowadays.

Whats more important imo is the distance to the back of the saddle and where you sit on it, after all saddles are different lengths, some even have no nose ;-)

 

[MacB]

Something easily done on this frame but also applicable to compact frames using the virtual/effective horizontal top tube. Imagine the bottom bracket as a fixed point of a triangle made up of seat tube, horizontal top tube and down tube. Then draw an imaginary line vertically up from the centre on the bottom bracket to where it crosses the horizontal top tube. This gives you a length of TT in front of the BB and a length behind. A lot of manufacturers give the length in front of the BB on their frame specs, allowing riders to choose a frame by 'reach', as they assume the rider will retain the same saddle to BB relationship regardless of ST angle(as long as it's physically possible).

Regardless of the TT length the seat tube angle is the one that's going to dictate how much TT is behind the BB. Older frames with shallower ST angles had more TT behind and vice versa with more modern designs. I believe the length will alter by 10mm for every degree of difference in ST angle, roughly. So two bikes with 570mm effective TT's, but a 70 and 73 ST angles, will have quite different component fit requirements to get the same ride position. If I'm right with the 10mm per degree then putting the same saddle/seatpost configuration in each frame would see the 70 degree one with the saddle 30mm further back, so you'd need a 30mm shorter stem than on the 73 degree to get the same position. But would you want to???? read on

You can do the saddle well back you just need to lower it enough to keep your saddle to pedal relationship right and bring the bars back/high enough to accomodate. Think of it as turning the bike into an upright recumbent the bit that will change is your knee over pedal spindle relationship, aka KOPS, which may be impossible to achieve from this frame. However there are plenty of theories that say KOPS is garbage as an absolute and only happens to work as a starting point by dint of accident. The real test of whether you can do this or not is how your knees/butt feel, they'll soon tell you if it's not working. Also worth bearing in mind that by moving the saddle back and down you're creating a longer/lower posture and may not need to move the bars back/up by as much as you may think, or even not at all. If you look at some of the TdF setups you'll see some of the riders have the saddle right back on setback seatposts, I believe I saw 115mm as a number for Andy Schleck last year. This should mean they can get down to a lower bar position without the upper body taking too much strain. I also read that the cyclists with weedier upper bodies will have the saddle further back than those with more core strength and upper body musculature.

There we are, that should be enough to thoroughly confuse you

 

[Fab Foodie]

Good stuff MacB.
I ride a compact Giant and have the seat right back on the std layback post. Whilst I'm the same size as the OP I can also ride my 23" late 1950s Holdsworth because I prefer to ride back behind the bottom bracket compared to many. It depends also how you ride, I tend to sit back and grind along, but if spinning or sprinting prefer to be on the nose. Watch Fausto Coppi ride to see how they sat back with a lower seat height.
Lemond also liked to sit back, it brings the glutes more into play.
Schlecks a climber too and a rearwards seat position is good for poweriing up climbs.
I also think KOPS is guff (Mike burrows and other have assasinated the theory, but it's a start point).

 

[Fab Foodie]

Whats more important imo is the distance to the back of the saddle and where you sit on it, after all saddles are different lengths, some even have no nose ;-)

Correct, it's the bit you sit on that's important, however the assumption is that most common saddles are roughly the same size and sat-on in approx the same area, so for gross set-up it's reasonable, but the rest should be done by feel.

 

[AnotherEye]

Thanks for all the replies,

There are 2 problems (which is why I've looked at the books):
I seem to be sitting too far forward on the saddle.
And; when saddle is set to highest for me (leg straight when heel is on peddle at lowest) it feels clumsy when I stop and, especially, pull away at lights. I'm familiar with the move ass maneuver so as to get a foot on the ground as I used it on my old bike but this feels very different.

I want to get the saddle right before I move on to, possibly, a shorter stem.
this morning I moved the saddle as far forward as I can, about 1cm and it feels like an improvement.

I just bought some digital calipers;
current seatpost = 26.6 mm
seattube dia= 27mm

I wonder if I could get away with a 27.2mm seatpost?
http://www.wiggle.co...seat-post/#more

Or can someone recommend something else?

 

[MacB]

you can buy seatpost shims which would allow you to bring a thinner post up to 27mm, I would be loathe to try to jam too big a diameter in, particulary as you could be going through a tweaking phase.

I agree with trying what you can first rather than spending, been there, done that and recycled the stuff at 'great' personal loss Don't forget that raising or lowering the bars will alter the reach as well, as a function of the HT angle. As FF says Burrows, and others, have had a good dig at such things as KOPS. Not that they aren't useful but that fits tend to be formulaic and fit you for having a good day, if they include a dynamic component at all. I'd maybe think about dropping your saddle slightly from the highest comfortable point. The saddle height isn't an absolute number it's a small range and the highest point is most effective when you're loosened up, feeling good and pedalling well.

That said, if you get the saddle where you're really happy with it but still not comfy enough on the bars, don't assume lifting/shortening the reach will automatically be the answer. If the saddle is further back than normal then you may need to lengthen the reach. I bought a really short stem to sort this sort of thing once, the problem was very minor, but I'd gone the wrong way. The problem was that my saddle position wanted me longer and lower and I was having to force myself back re the bars. I thought I had it all figured, hence buying the short stem, didn't see the counter intuitive bit re reach.

I had a Surly Xcheck, horizontal geometry and a Giant CRS Alliance, compact geometry, both set up very similar and with only 4mm difference in effective top tubes. But different HT and ST angles and I found the resulting bits around riding, in particular getting a foot down, very different. The compact Giant always seemed easier and more natural than the Xcheck. I don't know if this was just the top tube difference, BB height playing a factor, different saddles, etc...but it was definitely there.