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makes no sense....

The STA angle thing is simple, the saddle on the Tarmac should be about 1.7cm further BACK than the Giant to produce about the same KOP. At your saddle rail height, the difference is a little more than 1cm per degree. From the picture it looks like you have the saddle on the Tarmac way too far forward. It can't be further back than the Giant.

If you want two bikes to fit the same, you should first use the same saddle. I assume you know how to drop a plumb line from the knee to the center of the pedal axle to establish KOP. You can also drop a plumb line from the tip of the saddle to the and see how far behind the crank centerline it is, using the crank arm, set horizontally, with masking tape on it to mark on.. For someone who wants KOP, this is probably 3-5cm behind the crank center, but saddles and femur length vary quite a bit. You don't say how far forward you want your knee, but I'm skeptical that this is the cure for your knee pain. It could just as likely be failing to maintain the proper saddle height and leg extension or a foot misalignment problem that requires cleat shims. I've moved my saddle over a large range of fore/aft position and never caused any knee pain.

It's also smart to use the same handelbars and stem to insure the same reach, but barring that, take a diagonal mesurement from the saddle tip to an identifiable point on each brake hood. Measure both sides and take the average to compensate for having the bars perfectly straight. This give you an idea if the reach is the same.

I'd run a "reach" comparison for these two frames, but it would be worthless, since the frames are drastically different in vertical size and reach comparisons are only valid on frame of the same size. FYI reach is the TT length minus frame setback.

I'd also say you goofed on the frame size. The Tarmac is vertically too small. What possessed you to buy a frame with a 4cm shorter head tube? The flipped stem only makes up for a little over half of the height difference, then you cut the steerer so short that you can't raise the bars any more except by using a +17 stem. The time to figure out how a frame will fit is before you buy it. The Giant could have been setup with at least some of the radical differences on the Tarmac and ridden, before buying the tarmac.

Other observations; was the bike setting on a level surface when the saddle was adjusted for KOP?. I can't imagine it was. Also a saddle tip to center of bar measurement of only 47cm is ridiculously short for someone of your height. My saddle is 1cm higher. With ordinary 85mm reach bars, mine would measure about 51cm and I'm three inches shorter than you. You have to be incredibly cramped up.
 

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Discussion Starter #3
The Giant is the new frame as I knew the Tarmac was too small. So I am on the right track by setting the saddle tip 4cm back from centerline of the cranks. The TCR picture is not as current as I slid the saddle back yesterday to get 4cm behind the crank centerline. So when I was fitted on the Tarmac, I was told to get KOPS that i needed to slide the saddle way forward like pictured. Was I fitted improperly, or was it that the tarmac frame is too small to begin with? Having the saddle that forward, would it produce pain above my knee? With the saddle back further on the TCR now I hope that will rid that pain. The TCR is the current ride, the Tarmac has been sold. Just wondering how to tweak it to get a little more comfort/power.
 

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misunderstood...

I've got the flu this morning, so I'm not all together with it. If a fitter adjusted the Tarmc to look like that, NEVER go back to him. The Tarmac frame is too small. The 54cm probably would have been fine.

Regarding the Giant, it doesn't look bad, but I'm never convinced that saddle fore/aft "causes" knee pain. Where is your knee pain located front, back, both knees? Saddle height, cleat adjsutment and your choice of gears all play a part. Some folks just ride stupid. They pick an overly large gear for all terrains and crank it hard, at 60-70 rpm, thinking that they are applying "power" to the pedals. Dead wrong. Power = torque x cadence. Run a fast 90-110 rpm cadence and you'll probably produce far better power and much less stress on the knees.

To roughly set your saddle height, clip into the pedals and rotate one crank to the bottom of the stroke. Be sure you can at least drop your heel into a level position, with the leg locked at the bottom of the stroke. . This height is pretty high, since it will force you to lift the heel at least 2cm to maintain about a 30 degree bend in the leg at the bottom of the stroke. Slightly higher or lower may be preferred, depending on your "natural" foot angle while pedaling. I run mine a bit lower since I don't pedal with the heel up very much. Once you get the saddle height set, be sure to lower it 3mm for each 10mm that you move the saddle back ( and vice versa) if you make fore/aft changes.

What's the saddle tip to center of bars dimension for the Giant? If it's not at least 51cm, you've got to be cramped, unless you have very short arms. A good test for this is arm to knee clerance, while you're pedaling with the hands in the drops, fingers in reach of the brake levers and the upper back as low as you would normally ride during aggressive cornering or riding the flats. If your arms and knees interfere, then the stem's still on the short side.

My last comment is regarding the bars. If you want/need the brake hoods up fairly high, bars that don't "ramp down" so much from the top setion should be considered. Something like the Deda 215 anatomic perhaps.

I've got a pair of Easton EA-70 bars coming. They have a failry short reach. I'll post a report on the bend in the near future.
 

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who cares about the angles and tube lengths. compact geometry is all about virtual length. For example, measure the distance from say...your saddle to bars in the E5, and try and replicate that distance on the gaint.

and just do that for everything. u should be fine. and as long as you can feel comfortable on both bikes then it's all that matters.
 

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duh...

I guess you haven't followed the discussion. We've been discussing KOP measurements, saddle height, handlebar height and saddle tip to bar centerline.

The poster doesn't like the fit of the Tarmac (no wonder it's all screwed up). Changing the Giant to be remotely similar would be a mistake.

The word virtual is a misnomer. A "virtual" TT length is actually a horizontal TT length, the same as a conventional frame. Without it, it's tough to compare the fit. The only other real important length is head tube length. That's the same as a conventional frame also. A responsible builder will also provide a "virtual" frame size, generally a c-c size, as if the TT were horizontal.

The angles have exactly the same effect on saddle location, regardless of whether the frame is a compact or conventional. If you don't know the effect of the large change in the STA, then it's tough to pick a seatpost, except by trial and error.
 

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haha yes, i realised the flaw of my post after i had posted it!!!! because only then did i begin reading the replies! d'oh

my baaaad :D
 

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Discussion Starter #8
Thanks. I'll measure of the tip to bars tonight, as well as remeasure the tip of the saddle versus crank centerline. My knee pain is only on my right leg, above the knee cap and slightly inward. Maybe I just use to much right leg when I pedal.
 

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capt_phun said:
Thanks. I'll measure of the tip to bars tonight, as well as remeasure the tip of the saddle versus crank centerline. My knee pain is only on my right leg, above the knee cap and slightly inward. Maybe I just use to much right leg when I pedal.
paint above the knee cap, slightly inward? as in, at the back of the leg>? if so, sounds like you are over extending ur right leg. adjust the cleat on that side and slide it forwards on the shoe a bit and see if it helps!
 

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Here's the two superimposed with BB's lined up as best I could. There's bound to be distortion from the perspective, but it should still be helpful.

<img src="https://andyshenphoto.com/comp.jpg"
 

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merckxman
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Some info on knee pain

Lots of info on "knee pain saddle position" if you google.
This site had the following:http://www.cptips.com/knee.htm

Knee Pain Location
One way to classify knee pain (and identify possible solutions) is to look at the location of the pain.

Anterior (see chondromalacia below)
Reasons
patellar tendonitis
patellofemoral syndrome
Causes
pushing BIG gears - cadence too low
saddle too low or too far forward
foot too far forward on the pedal
crank arms too long
leg length discrepancy with seat set for shorter leg
Possible solutions
ride at 75 rpm or higher
raise seat (in small increments of less than 5mm) or move seat back
move cleat forward 1 to 2 mm
shorten crank arms by 2.5 cm
set seat for longer, not shorter, leg with correction for the shorter leg

Posterior
Reasons
hamstring/gastrocnemius
neurovacular bundle
Causes
saddle too high or too far back
too much pedal float
leg length discrepancy with no correction for shorter leg
Possible solutions
lower seat (in small increments) or move seat forward
limit float to 6 - 8 degrees
set seat for longer, not shorter, leg with correction for the shorter leg

Medial (inner side)
Reasons
medial collateral ligament
pes anserenus
Causes
cleat position too wide - foot held externally rotated (toes point out)
excessive knee frontal plane motion
too little pedal float
Possible solutions
narrow foot position by moving cleat inwards
orthotic or wedge to correct foot alignment
pedal float should be 6 - 8 degrees

Lateral
Reasons
iliotibial band
degenerative lateral meniscus
Causes
cleat position too narrow - foot held internally rotated (toes pointed in)
too little pedal float
excessive knee frontal plane motion
Possible solutions
widen foot position by moving cleat away from the bike
pedal float should be 6 - 8 degrees
orthotic or wedge to correct foot alignment
 

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Discussion Starter #13
Ok so the tip of the seat is 4.5cm back from centerline of the cranks/BB. Seat tip to center of bars is 52cm. Using the competitive fit, it looks like I may need a 110mm stem versus the 100 to get the 53cm reach?
 

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That's better...

Well, just by coincidence my saddle tip is also 4.5cm behind the BB spindle, so at least you're in the ballpark. The saddle tip to bar centerline is also in the ballpark. FWIW, I use a Fizik Gobi, that has a lot of rail length, like the Arione.

Have you rechecked KOP and noted the many possible causes of knee pain, other than the saddle too far back? You might find that the cleats are not in the correct position, lack float, or even that one leg is shorter than the other. I have one leg shorter than the other, but never realized it until I raised the saddle so high (acting on bad advice) that the shorter right leg was reaching excessively at the bottom of the stroke, causing right side, lower back pain. I used a 4-5mm thick shim for a few years, but later found that using speedplays with unlimited float and a lower saddle solved the problem.

Personally, I'd never place my knee forward of the pedal spindle. Right now, mine's about 1cm back. A saddle that's too far forward will put too much weight on your hands, resulting in the need for a higher stem (raising the torso and taking the weight off).

As for the reach, yes one size longer stem will increase the reach, but you really can't depend on a fit calculator to tell you much about stem length. Most have no clue where your saddle is at, so the same length stem could have a reach that covered a 3-5cm range. Try the practical test that I described. I you don't have real good midsection strength, you may find that the shortest stem that avoids knee to arm interference will feel too stretched out while riding the top of the brake hoods.
 

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I can't help wondering whether KOPS was correctly done on the Tarmac.

Steep seat angle, non-setback post, and saddle pushed all the way forward, that's about 7-8cm more forward than a typical position right there. Your thighs have to be that much shorter than someone of similar stature to yield that result. It's just odd.

Just so you know, KOPS is merely an approximation measure by coincidence rather than having some inherent logic. So you don't have to be religious about it.

It might be helpful to show a picture of you on the bike -- that'll be worth a thousand words.

capt_phun said:
Check out this pick for knee location. I truly appreciate all the responses.
 

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Discussion Starter #16
Ok so one quick question. When measuring from saddle tip to the inside of the bars, do you measure to the area right next to the bars or do you measure to the inside of the bars where your hands would go?
thanks
 

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saddle tip to CENTER of bars...

at the stem is the common measurement used to verify a change in position.
 
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