papaki72

I have a Specialized Allez and I am trying to adjust the tilt of the saddle. It has a two bold system, but no matter what, I cannot adjust both screws evenly. Tightening the rear bolt, then the front, then the rear again, then the front, to a point that when the front feels tight, the rear is too tight already and seems impossible to be done either way. The saddle feels safe in place, but shouldn't both screws feel the same tension? If I want to change anything again, I must undo the front bolt a bit else the rear won't move a bit.

choddo

They affect each other as you zero in on getting it level. In that example you describe, just ease the front off a bit so that you can loosen the back and then re-tighten the front. By doing so, the back will also be tighter again.

You can’t do one, leave it, then do the other.

maddog34

i do the rocker clamps a half-turn at a time, alternating from front to back.... and attempt to avoid them whenever possible.

i have never intentionally bought one that wasn't part of a Big parts buy, or already on a bike.

Iride01 

If you are comparing the force of unscrewing one to the force of tightening the other, those will never match.

Just adjust your saddle to the tilt you want it and make sure both bolts are snug enough so they won't loosen. If they do loosen, then next time you'll know to snug them more. While you snug them your saddle tilt might change a little. If it starts to change, then go to the other bolt and tighten on it. Rinse and repeat till you are happy with how snug both are.

You'll know well before becoming a popsicle if your saddle is getting loose and about to come off. <grin>

79pmooney

I'm not sure what the confusion is. I tighten them. Ride. Want more tilt or less? Stop and back off the rear a lot. Do perhaps a 1/4 or 1/8th turn on the front bolt. Re-tighten the rear. (I always go by neat 1/8th or 1/4 turns so I can undo or fine tune exactly.) I never tighten first the front, then the back then the front again. Front is the "tune". Rear is the clamp. Simple and easy. (Maybe I am totally out to lunch but I've been doing this for 30 or 40 years on (almost) all my bikes.

79pmooney

I always ease the rear and fine tune the front. Rear has easier access so the big rotations and muscle are more easily done there.

FBinNY 

Don't obsess about the tension. Focus on the results. The clamp is on a rocker, and the LENGTH of the bolts fore and aft determine the angle. We all have our own approach, mine is to put light nose load on the saddle, and tighten the rear bolt until the saddle is at the right angle, then tighten the front bolt to secure it there. Usually, there'll be a bit of back and forth to dial it in, buy not always.

Crankycrank

And don't sweat it. Most 2 bolt clamps are a royal PITA. I have 3 different ones and dread changing saddles or changing a saddle/post to a different bike. Be patient and as mentioned go back and forth when tightening the bolts. Truing a wobbly wheel is child's play compared to these.

papaki72

I have been trying to do it like this, but when the front gets a bit tight, the rear is almost impossible to move either direction. It is the first time I did this due to changing the stock saddle of the Allez with a beautiful Selle Italia SP-01 Superflow. (It looks great, I hope my butt feels o.k. on it after three hours non stop on it, or else it is going to be my first total waste of money on this bike.)

FBinNY 

We always start with the assumption that the basics are OK, unless we have a reason not to.

So, take a moment to check that the post and saddle are assembled correctly, and the cradle is properly positioned on the Fulcrum.

These posts are designed to hold saddles level when the post is roughly 17 degrees from vertical.

Level the saddle and tighten finger tight. The bolts should be roughly equal. If not, something is off.

choddo

yeah indeed, that’s what I said or meant to say. He said in the example I was replying to that he’d tightened the front up so much he couldn’t move the rear either way, that’s why I said loosen the front a bit first.

choddo

is it level at that point when the front gets a bit tight?

papaki72

Yes, I tighten it a bit more to get it just firm until I get about 1 degree forward tilt.

choddo

Then I’m not sure you have a problem

grumpus

On two-bolt seat-posts the screws are usually pulling at different angles, so when they're tightened they must be at different tensions, because trigonometry.

SoSmellyAir

I have no problems with two bolt seat posts where both bolts are accessible by hex key / Allen wrench and torque wrench. Center the top saddle rail clamp between the bolts and tighten each bolt evenly (i.e., a half turn at a time) to the same torque allows perfect saddle adjustment. It is usually impossible and not necessary to center the top saddle rail clamp relative to the bottom saddle rail clamp.

But I do not like the ones (e.g., Cannondale C3) where only one bolt is accessible by hex key and the other can only be adjusted via a thumb screw. On these it is pretty much impossible to have both bolts at the same torque or tension.

I prefer two bolt seat posts for their fine adjustment and inherent compatibility with CF saddle rails.

FBinNY 

There's no need to obsess over even tension. The design and Newton's Laws tales care of it for you.

The cradle is like a seesaw, and will reliably equalize the load on both sides. The bolt tension may not be equal, but that's determined by the relative distance from the fulcrum.

Like you, I prefer good wrench to both, but can adapt by setting the wing nut to set the angle, and tightening from the other side.

Bully4

Sounds like easy stuff- try an emonda. Hammer and punch to loose the wedges, then reste the seat from scratch. Two bolt posts are way better!!!

SurferRosa

I have always adjusted my old 2-bolt Campy seatposts with just my fingers on the front bolt to get it in the right position, and then then tighten the rear with a 10mm ratcheting wrench. It's trial and error on the tilt, but works for me.


https://velobase.com/ViewComponent.a...26f2c&Enum=105

79pmooney

+1 I've never tried to tighten the bolt evenly. Never even occurred to me that I needed to. And I've been riding 2-bolt bolts near exclusively since 1977. (Well there were the dark years when I couldn't get my hands on one and rode a Laprade set between clicks for 15 years. And my winter/rain/city bike has had a single bolt aero Chorus on it the past 18 years.)

cyclic_eric

This may be obvious, but hasn't been mentioned. When first installing the saddle, I take all the seatpost head parts apart, then clean, lubricate and reassemble.
Don't lube the saddle rail channel, of course. I've been using a bubble level app on my phone, placing the phone on the saddle.
I really like the 2-bolt or screw system. They do require decent tools though. Maybe you need a longer hex wrench?

choddo

What needs lubricating on a saddle?

cyclic_eric

Sorry - not the saddle, the seatpost head pieces to lube for smooth tilt movement. I edited my post for clarity.

choddo

Defo need cleaning. One of the least cared for parts of a bike :-)

Koyote

I once asked a professional mechanic a question much like the OP's. His response: "Yeah, setting up a two-bolt seatpost takes a couple beers."