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Set back seat post perhaps?

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Set back seat post perhaps?

Old 06-14-24, 07:24 AM
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Set back seat post perhaps?

On one of my bikes in particular, a Surly LHT in 60cm. I'm 6'2, I find myself constantly sitting too far back on my saddle for comfort. My sit bones are riding mostly on the back edge of the saddle. I can ride in fair comfort for a while but eventually I will find that I have adjusted myself to be sitting too far back. My saddle is adjusted as far back as it can go, and I've confirmed the same situation with multiple saddles

My question is, will a set back seat post be my best option? I don't know enough about fit to know if I should also be considering handlebar height, stem length, and even possibly crank length to fix my position. Getting a proper fit from a fitter is not going to happen. Even if I wanted to pay for it, the distance necessary to travel for it is too extreme.
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Old 06-14-24, 09:10 AM
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Do you sit very upright on that bike? At your height, I'd think the frame size a tad large for you. But falling off the back of the saddle doesn't lend any credit to the bike being too large.

Is your saddle at the proper height? If you have it too low for your leg length in a wrong attempt to have your bars seem higher for you then I might can see the falling off the back of the saddle. On road bikes of the various categories, including touring and gravel, proper saddle height is one of the first things you have to get correct within a CM or so before ever trying to figure out the rest of your fit, IMO.

But for the direct answer to your question, if you are happy with everything else, then a seat post with more setback will be the correct thing to do. Get one with enough offset that will put the saddle clamp about the center of the rails. However if your bike is mis-sized or you are keeping your saddle too low, then I suspect there'll be some more issues you'll post later on when you get more mileage and longer ride times behind you.
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Old 06-14-24, 09:14 AM
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Set back seat posts are the norm for road bikes. I don't know why zero setback posts ever became common on them.
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Old 06-14-24, 09:58 AM
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As Iride01 suggests, I'd look at your saddle height first to ensure you have a proper leg extension. Once set, record the saddle to BB axis distance as it shouldn't change no matter what else you do. This doesn't mean that you won't play with saddle height, just that it'll be because you moved your saddle forwards or backwards and you wan't to preserve the saddle to BB distance. If you move the saddle back, you have to lower the saddle and if you move it forward, you have to raise it. Maybe all you need right now is to raise your saddle (if it gives your legs a proper extension) which will move you forward on it.

Then you worry about reach as this will affect your aerodynamics, the weight on your hands (reach affects your center of gravity) and the comfort/control of your arms/hands. Up to you to pick some combination of stem, handlebars and their adjustment to give you what you want. Moving the saddle back (and down) will take weight off your hands, as will moving your grips up and back (for the same arm extension).
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Old 06-14-24, 12:19 PM
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Right now you just need to move the saddle to where you are already trying to sit on it, rather than a new position.
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Old 06-17-24, 08:50 PM
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Originally Posted by Kontact
Set back seat posts are the norm for road bikes. I don't know why zero setback posts ever became common on them.
Because that's what the pro racers with 5 percent body fat and chicken-wing arms and shoulders use. But, yeah, a seatpost with moderate setback should help. And ignore that comment about the bike being too big. Unless you have short stumpy legs (and the fact that you can hang your ischium off the back indicates that you don't), 60 cm is on the money.
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Old 06-17-24, 08:54 PM
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Originally Posted by oldbobcat
Because that's what the pro racers with 5 percent body fat and chicken-wing arms and shoulders use. But, yeah, a seatpost with moderate setback should help. And ignore that comment about the bike being too big. Unless you have short stumpy legs (and the fact that you can hang your ischium off the back indicates that you don't), 60 cm is on the money.
I think racers were had better fits when this trend started. I really think it was just that they became common on MTBs and were often lighter.
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Old 06-18-24, 08:50 AM
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Originally Posted by oldbobcat
Because that's what the pro racers with 5 percent body fat and chicken-wing arms and shoulders use. But, yeah, a seatpost with moderate setback should help. And ignore that comment about the bike being too big. Unless you have short stumpy legs (and the fact that you can hang your ischium off the back indicates that you don't), 60 cm is on the money.
Not according to Surly.

https://surlybikes.com/uploads/downl...hart_OL_VF.pdf

If you look at their geometry, then you'll see that a 60 cm in a Surely is more comparable to a 62 cm bike or larger of most other manufactures. The reach on a 62cm Domane is still about 16 mm shorter than a 60cm SLHT. Seat Tube angle is the same so effective top tube length should be close enough the same although the head tube angle is 0.6° different.


But I will agree there is something else going on if the OP's butt is wanting the go off the back of the saddle. And being a oversize frame tends to make me think the OP is doing something very wrong that we don't even imagine.

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Old 06-18-24, 06:52 PM
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Originally Posted by Iride01
Not according to Surly.
Yeah, they do run large. But if he's hanging his tailbone off the back of the saddle, he's having no problem reaching the pedals with his legs and feet or the handlebar with his arms and torso. I would want to see him on the bike before I'd tell him to buy a different one.

Last edited by oldbobcat; 06-19-24 at 06:55 PM.
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Old 06-25-24, 04:24 AM
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Originally Posted by Kontact
Set back seat posts are the norm for road bikes. I don't know why zero setback posts ever became common on them.
I use a zero setback post on my Disc Trucker because it has a 72 degree seat tube angle. Then again I use an SMP which is typically mounted 15mm more forward than a typical saddles. But looking at the rails, I still wouldn't need a setback post with a typical saddle.
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Old 06-26-24, 01:51 PM
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Originally Posted by elcruxio
I use a zero setback post on my Disc Trucker because it has a 72 degree seat tube angle. Then again I use an SMP which is typically mounted 15mm more forward than a typical saddles. But looking at the rails, I still wouldn't need a setback post with a typical saddle.
I guess you could call a trucker a road bike. But it has that seat tube angle to get you to sit back and up. A zero post is a good idea if you don't want to.
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Old 06-26-24, 02:29 PM
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Originally Posted by RH Clark
On one of my bikes in particular, a Surly LHT in 60cm. I'm 6'2, I find myself constantly sitting too far back on my saddle for comfort. My sit bones are riding mostly on the back edge of the saddle. I can ride in fair comfort for a while but eventually I will find that I have adjusted myself to be sitting too far back. My saddle is adjusted as far back as it can go, and I've confirmed the same situation with multiple saddles

My question is, will a set back seat post be my best option? I don't know enough about fit to know if I should also be considering handlebar height, stem length, and even possibly crank length to fix my position. Getting a proper fit from a fitter is not going to happen. Even if I wanted to pay for it, the distance necessary to travel for it is too extreme.
Do you have a bike you like? That is fun to ride? That doesn't leave you feeling like something isn't right? If yes, you have a starting point for your Surly. The triangle formed by the bottom bracket, where your hips sit on the seat and the handlebars. This triangle can be rotated back for a more upright sitting position or forward for a more racy and aero position but I use it as the core of my fit on all my bikes. The most important part of this triangle is hip to BB distance which is a little hard to document. One trick is to sit on the bike in say a hallway where you can have the bike so upright it falls over and just reach out to the walls for balance. Do this on the bike that works for you. Without rotating your hips at all, ie keeping them dead square, rotate one pedal down to in line with the seat tube. Now place your barefoot heel on the upside down pedal spindle. Can you reach it without stretching? If not, add slippers or cycling shoes or dress shoes until you can. Now, can you also bend your knee a touch without lifting your heel off? There is exactly one seat height where you can do both with either foot and never rock your hips. Might take a few tries to find that perfect pair of shoes with the just right heel but once done, you will be able to set up any bike's seat height very quickly.

Next, hang a vertical line down to the bottom bracket. (Bike indoors on a level floor, using a carpenter's level or just a string and weight.) Measure how far back the nose of the seat is from the vertical line. (Or better, place a mark or tape half way back on the seat and measure to it. This will vary less in terms of where your hips are likely to seat on different seats.)

And third, decide how you want to use this bike. Cruiser, say, so more upright or racier so aero means more? Adjust the seat of your new bike back or forward a little to reflect that. Last, set your handlebars the same distances from the BB and seat as your of-so-sweet reference. Go for rides. Bring all the wrenches for handlebars, stem and seatpost, both up and down and forward, back and tilt. Do small changes, mark them (bring easy to see tape), keep records.

Yes, real work. But it will steer you to seatposts and stems that put the seat and bars where your body wants them. Now, if none of your bikes is "right", this approach won't work. I'd suggest working first with the bike that is closest; seeing if you can dial it in to before going on a goose chase.
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