saddle fore/aft position

[darrenf]

Hi, Have just joined this forum and thought I would open up something which has been annoying me for a while about my bike.

It's a road bike which I have had for a few years and I used to ride an MTB. I have never been able to get the saddle in a position which feels perfect for me.

It either feels too forward in that my natural riding position feels like it should be slightly further back, but if I move it further back, I end up riding off the front of the saddle and sitting on the old perinium area which causes pain/ tingling after even a relatively short ride. I have tried tilting the saddle forward (then I slip forward and have the same problem) and tilting back (nose of saddle sticks up and causes same problem.

I am happy with the reach of my bike (saddle to bars) and also I dont think the saddle over bars distance is too high (9.5cm).

I've started to wonder if the more forward position of the seat is in fact the natural position on a roadbike despite the fact that it still doesn't feel quite right after a few years of riding the bike. I would therefore like to open the question:-

"how far behind the bottom bracket is the tip of your seat"?

for the record, mine is vertically in line with the small (39) chain ring. My frame is a 57cm centre to top of seat tube. My pereived ideal position would be further back than this but that is when the saddle causes me pain!

Also, for the record, I am 6ft tall to give you an idea of frame size suitabilty (I was actually measured for the bike though so relatively happy it "fits".

So, any feedback about saddle position or any other ideas that may help would be much appreciated.

PS great forum, glad to find somewhere I can finally pose these questions.

 

[dhk]

The standard fit method is to position the saddle so that when you are comfortably seated your knee is directly over the pedal spindle (with the crank arm horizontal).

You can check this with a plumb bob (or weighted string) held onto the bony projection under the kneecap. This set up will give you the KOPS (knee over pedal spindle) or neutral position....a good start point.

I like the seat in this neutral position. I've heard that sliding the seat back a cm or two from neutral will give more power for hill climbing, and that moving it forward will allow for more high-speed spin power. But, haven't really tried either of those.

 

[davef]

Haven't seen it mentioned in the books I have read, BUT I would assume you are suppose to keep your foot parallel to the ground. I have noticed this "measurement" can vary a bit with different foot positions.

Also, when you are seated comfortably where is the front axle in relation to the handlebar?

9.5 cm . . . can you easily touch your toes?

 

[Aztec]

On both my road bikes, I ride with the saddle as far forward as it can go on its rails. That puts me close to the KOP position above.

The length of the saddle can throw off a measurement based on where the tip of the saddle is. Skip that.

As for the 9.5cm, that's a lot. At 6' tall, it's not monstrous, but you'd better have some decent hammy and glute flexibility for that.

 

[darrenf]

Hi, thanks for the replies.

The 9.5cm saddle to bar drop seems to have drawn a bit of attention! Is it really that much? Another thread on here on this subject would seem to suggest an average of 10 to 12cm? (thread entitled "what is your seat to handlebar drop" or words to that effect).

I have done the knee above spindle test before but I will give that another go as well.

Also, h/bar in line with front axle test is about right too.

The only conclusions I can draw are:-

1) I just don't get on with the saddle (have just ordered a new selle italia flite genuine gel- so will see with this)

2) My frame may be too small (ie by having a 9.5cm drop, I am bent too far, causing the saddle pain?) I have just had some new forks fitted and my stem has 3, 1cm spacers below it at the moment to give the 9.5cm drop. I have one more spacer availalable so could raise the bars another 1cm but 4 spacers could look a little excessive. Could it be that I need a larger frame, with a longer head tube?

I'm not going to run out and buy a new frame just yet (although I'm really tempted to upgrade my trusty steel gios frame to something a little more lightweight anyway) as I want to continue fine tuning the position until I get it spot on.

The annoying thing is I was fitted for the bike in the first place but here I am, several years on, still fiddling about with the position.

What do you guys reckon, does a 57cm centre to top frame (traditional, horizontal top tube) sound about right for 6 foot tall?

 

[dhk]

Your frame issues sound a lot like mine were. I'm 6', with an 86 cm inseam. My old bike was a "56", measured from the BB center to the top of the top tube. I had my seatpost all the way out to the marking line to get the 76 cm center-to-seat top measurement I prefer. As a result, my drop from saddle to the bars was 10 cm.

This isn't bad for a crit race position, which is what I bought the bike for in 1992. Believe lots of LBS will try to fit you in a race position like this, regardless of the type of riding you do. I don't race anymore, and wanted a bigger bike for comfort on Century and cross-state rides.

My new frame is a 58, which gives me a longer TT, a higher head tube, and plenty of range of seatpost adjustment. With two cm's of spacers under the stem, I have a 5 cm drop to the bars. It's more comfortable, particularly in the drops, and easier to get out of the saddle.

 

[darrenf]

DHK

Did the longer top tube/ reach cause any issues or did you just spec a shorter stem to counter act the longer top tube?

 

[Aztec]

Darrenf, 9.5cm could be a lot. Depends on your flexibility and relative proportions. I tend to like a decent amount of drop because it shifts a bit more weight onto my arms and off of my rear (which is the more uncomfy of the two on longer rides). I'd rather toss some of the hurt onto my triceps and neck, in exchange for some relief where saddle meets body.

57cm, ctt, sounds really small for a 6' rider. That's a 55-56cm ctc. 3cm of spacers and you're still 9cm below the saddle? Are you using a stem that angles up? Try that. 4cm of spacers is really getting too high, per others who I've spoken to on the topic (can't say for myself whether it's a big deal, other than the aesthetics).

Being bent more could be making saddle pain worse (that is, if the pain or numbness is up front -- if it's just general rear end pain, then maybe not). Like I said, for me, more upright tends to mean more pain.

 

[dhk]

DHK

Did the longer top tube/ reach cause any issues or did you just spec a shorter stem to counter act the longer top tube?

No, I particularly wanted a 2-3 cm longer TT in the new bike. Effective length is 57.5 cm now, 2 cm greater than my old bike, plus a 110 stem.

The right reach would depend on your arm length and flexibility. My arms are fairly long, and flexibility is decent, so the reach is not a problem. I like the increased room for climbing, and the higher head tube for less drop.

The larger frame feels more like I'm sitting in the bike rather than on top with my nose sticking over the front. Can still get low by bending the arms, but I'm not stuck in the low position all the time like on the old ride.

 

[darrenf]

Are you using a stem that angles up? Try that. 4cm of spacers is really getting too high

Stem angles up only v slightly, however It is a "flipable" stem so I may try that as it will be a riser stem the other way up. You are right though, I have moved the bars up using the 4th spacer and it does look a little odd. (and still 8.5cm drop)

I am rapidly coming to the conclusion that my frame is too small but I will keep fiddling with the position until I get it right, and then probably look to get a new frame/ bike ready for next summer. (That's what I keep telling myself although now I've got an excuse it's going to be difficult to keep my wallet shut until then- already browsing the bike shops to see what takes my fancy)