Zero offset seat posts
#1
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Zero offset seat posts
I was about to sell my Breezer Venturi when a fellow member suggested I try a zero offset seatpost. The change in comfort and power were drastic. I'm wondering whether it would be even better with something more than a zero offset. Does such a thing exist?
#2
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Isn't the effect of a zero offset seatpost just to move the saddle forward? Couldn't you just move your saddle forward on the zero offset post, unless it's already as far forward as it can go?
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Yeah. Just turn your setback seatpost around.
But that looks super, super ugly.
And it might position you so far forward that you fall over the first time you try to take a corner at speed.
But that looks super, super ugly.
And it might position you so far forward that you fall over the first time you try to take a corner at speed.
#4
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Yeah
A zero offset supposedly increases the seat tube angle by 2 degrees. The saddle is already as forward as it can go. Recall this bike has a very long ETT (57.5cm) for a size 54cm.
#5
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That's what I thought, but it turns all the seat posts I have can't level a saddle when turned around the other way. Are there seat posts designed to level saddles no matter the direction?
#8
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Thanks
#9
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Pro bike fitters would not recommend this. The saddle should be back far enough to keep the weight off your hands. The exception might be a bike with a 72.5 STA. I've always used a 25mm setback post. If I moved the saddle 20mm forward, the stem should be made 20mm longer, otherwise you're moving the saddle to correct a reach problem, which also wrong.
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Pro bike fitters would not recommend this. The saddle should be back far enough to keep the weight off your hands. The exception might be a bike with a 72.5 STA. I've always used a 25mm setback post. If I moved the saddle 20mm forward, the stem should be made 20mm longer, otherwise you're moving the saddle to correct a reach problem, which also wrong.
#11
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I have one bike with a zero setback seatpost, but it's got a 72.5 STA and I have shortish thighs, so that's a bad match. My bikes with 73 or 73.5 STAs, the saddle's all the way forward on setback posts.
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#12
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To what end? Knee over pedal, or some other criteria? I pay no attention to the idea of knee over pedal and neither do some of the most respected fitters, like Steve Hogg. I ride a fairly small frame and those tend to have 74-74.5 degree STAs, Each degree is only about 10mm.
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To what end? Knee over pedal, or some other criteria? I pay no attention to the idea of knee over pedal and neither do some of the most respected fitters, like Steve Hogg. I ride a fairly small frame and those tend to have 74-74.5 degree STAs, Each degree is only about 10mm.
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Keep in mind this is the notorious Breezer Venturi OP is trying to make rideable. Nothing "normal" applies....
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I ride a 56 at 177cm due to a long torso.
My fitter also has me setup on a 0 offset post with saddle forward. I have a gorilla frame with very short femurs. This setup is required to get me close to KOPS.
I feel fine on it.
My fitter also has me setup on a 0 offset post with saddle forward. I have a gorilla frame with very short femurs. This setup is required to get me close to KOPS.
I feel fine on it.
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#16
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Your knee could be 2cm behind KOP and it wouldn't hurt a thing.
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KOPS is just a starting point for weight distribution between hands, saddle, & feet. There are countless examples of other fits where KOPS doesn't apply either because of the bikes intended use, be it maybe a couple of miles at a time like a dutchie, or some styles of mountain biking, or because the weigh is not bourne by the sit bones like the fit on a recumbent or by elbows & shoulders like a TT bike.
But there are also countless examples of where it *is* an appropriate starting point. Road bikes.
In any case, to get back on the OP's question: RedShift Sports makes a dual position seat post that will move your seat 5cm forward to a TT position & up an appropriate amount for proper distance to maintain the same leg extension. Effectively it temporarily converts your bike to a TT bike & back again in an instant.
Most people pair the dual position seat post with aero bars because that is what it is designed to mate to. But I just use it to strongly stay in the drops for extended periods or to fight wind & can stay there until my neck, shoulders/arms get tired of holding up my torso. Then I flip back to the standard KOPS road position & carry on further on down the trail & faster on that segment than I was before.
But there are also countless examples of where it *is* an appropriate starting point. Road bikes.
In any case, to get back on the OP's question: RedShift Sports makes a dual position seat post that will move your seat 5cm forward to a TT position & up an appropriate amount for proper distance to maintain the same leg extension. Effectively it temporarily converts your bike to a TT bike & back again in an instant.
Most people pair the dual position seat post with aero bars because that is what it is designed to mate to. But I just use it to strongly stay in the drops for extended periods or to fight wind & can stay there until my neck, shoulders/arms get tired of holding up my torso. Then I flip back to the standard KOPS road position & carry on further on down the trail & faster on that segment than I was before.
Last edited by base2; 07-26-20 at 09:51 AM.
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Maybe these can be merged. https://www.bikeforums.net/road-cycl...r-venturi.html
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If you need the saddle further forward than what you can get with a zero setback post something is wrong.
What is your saddle height and set back from the BB?
What is your saddle height and set back from the BB?
#21
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At 5'-6" or 168cm, with an 83cm inseam and 73cm saddle height, I have long legs and short torso. I use a 25mm setback post with the saddle further back than the midpoint. I also use a fairly large saddle to bar drop of 10cm. That requires no steering tube spacers and a -17 stem. If I have a frame with a reach that's in between stem sizes, I choose the shorter 100mm stem and push the saddle back further rather than use a 110 with the saddle further forward. I do a lot of climbing and the further back position works better for climbing, IME. Part of the post setback is due to the steeper STA of 74-74.5 degrees, used on smaller frames. I could even use a frame with a 75 degree STA, in some brands. That would require a 32mm setback post for me.
The forward positions on the pro bikes are accompanied by a large saddle to bar drop and long reach, similar to that of a time trial bike, but without the aero bars. With the vast majority of cyclists not competing, pro positions aren't all that relative to the average Joe cyclist. Most would find the position to be uncomfortable.
The forward positions on the pro bikes are accompanied by a large saddle to bar drop and long reach, similar to that of a time trial bike, but without the aero bars. With the vast majority of cyclists not competing, pro positions aren't all that relative to the average Joe cyclist. Most would find the position to be uncomfortable.
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you have the wrong fit. Get yourself a new bike.
#23
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I suspect that if you're between two sizes, both of them are smaller than this bike.
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Pro bike fitters would not recommend this. The saddle should be back far enough to keep the weight off your hands. The exception might be a bike with a 72.5 STA. I've always used a 25mm setback post. If I moved the saddle 20mm forward, the stem should be made 20mm longer, otherwise you're moving the saddle to correct a reach problem, which also wrong.
Now I am long limbed. A 73 ST and traditional setback post would have the seat pushed back a bunch. But I would also be riding a slammed 140 stem to get the reach. And I'd have real weight on my hands. (Since my bike is custom I get to do what I want. 74 st, 60 mm setback post and the rails centered. 120 stem simply because that is what Eddy and God ride. The ST angle and post setback are to 1) get the rear wheel forward for my forward weight and 2) centered seat rails means the ti rails go forever. Ti rails = butt comfort for me.)
To ride without hand issues I have to pay real attention to details like handlebar shape and rotation and lever size, shape and rotation. But that is (at least still, at 67 yo) doable, I get to ride a low, powerful position without issue and not work a lot harder than I have to to go upwind.
Edit: I am in mo way badmouthing zero offset posts. They do not work for me unless I do some pretty unusual things with frame geometry, but the goal is to get what works for that rider. I know probably no one I would put on my setup!
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Saddle position also has a lot to do with the type of riding that you are doing. For example saddle position for time trialing or the track racing. A zero setback post might be completely appropriate for events other than road riding.