Custom seat post
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What diameter?
The first thing I think of is a post with a close to horizontal extension of 7/8. A common/cheap steel seat clamp could then be used. This is much like what bikes had nearly 100 years ago. But back then the post's 7/8" extension ran forward to offset the really relaxed ST angles used back then.
If the ST ID fit diameter is a common 4130 tube size the cost to make will be fairly low. So What diameter? Andy
The first thing I think of is a post with a close to horizontal extension of 7/8. A common/cheap steel seat clamp could then be used. This is much like what bikes had nearly 100 years ago. But back then the post's 7/8" extension ran forward to offset the really relaxed ST angles used back then.
If the ST ID fit diameter is a common 4130 tube size the cost to make will be fairly low. So What diameter? Andy
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AndrewRStewart
AndrewRStewart
#3
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Thanks for replying Andy, 25.6. I'm using one of these but along with the Rube Goldberg seat clamp I fabbed , its slowly bending.
This setback on a cruiser frame is comfortable for me but maybe I should look at a pedal forward frame instead. any feedback on this rans?
This setback on a cruiser frame is comfortable for me but maybe I should look at a pedal forward frame instead. any feedback on this rans?
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TiCycles could certainly make such a post. They aren't cheap. But unusual designs is something they regularly take on and do well. (In-house engineering and machining skills that go well beyond frame building.)
I have two posts with 60mm setback from them. A machined bar of aluminum that the tube is fitted into. Machined to accept the excellent Thompson clamp parts. They regularly use aluminum for the post or titanium if you want to pay the premium. I don't see why they couldn't do steel. Sounds like your post would be a full step beyond mine and require a new approach. Exactly what TiCycles thrives on. But the post might cost more than the rest of your bike.
I have two posts with 60mm setback from them. A machined bar of aluminum that the tube is fitted into. Machined to accept the excellent Thompson clamp parts. They regularly use aluminum for the post or titanium if you want to pay the premium. I don't see why they couldn't do steel. Sounds like your post would be a full step beyond mine and require a new approach. Exactly what TiCycles thrives on. But the post might cost more than the rest of your bike.
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That seatpost looks like it was made for a vintage seat clamp. Some bike shops might have one.
As far as the rans goes, I think people generally like them, if they can stand the position. There are other pedal forward bikes. Rans sued Trek because Trek was making one. I think they lost. In any event, Trek still sells the Electra townie, which is pedal-forward.
As far as the rans goes, I think people generally like them, if they can stand the position. There are other pedal forward bikes. Rans sued Trek because Trek was making one. I think they lost. In any event, Trek still sells the Electra townie, which is pedal-forward.
Last edited by unterhausen; 07-11-22 at 10:19 AM.
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The imaged post with the bracing strut looks to be a mid 1980s BMX one. I don't ever remember seeing one of them min a 25.6 diameter though. Given the large amount of set back I would want a pretty thick wall to reduce the bending. Before I would consider making a seat post I would want to have the frame on hand to both self measure the ST ID and to use as a go/no go gage for the new post. Andy
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AndrewRStewart
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#7
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The current strut is a 25.6 eBay special, its quite thick but soft enough to be slowly bending, might be able to see it in the photo. The bike is an electra, mid-90's Klunker style. Right now it's comfortable for the amount of mileage I'm able to achieve.
Looking at the seat tube, it's incredibly thin walled compared to the seat post. I imagine it would deform if the post was stiffer.
I have trouble riding head down and putting weight on wrists and shoulders but like to able extend legs and straighten my knees on the pedal downstroke. Might be a better idea to try a Townie or a Loft designed for upright posture.
Looking at the seat tube, it's incredibly thin walled compared to the seat post. I imagine it would deform if the post was stiffer.
I have trouble riding head down and putting weight on wrists and shoulders but like to able extend legs and straighten my knees on the pedal downstroke. Might be a better idea to try a Townie or a Loft designed for upright posture.
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"but like to able extend legs and straighten my knees on the pedal downstroke." hevysrf
Well, I'm good with what works for you. However, the usual seat height results in around a 20-30 degree of bend between the femur and the tibia when "fully" extended. I find that more height than this is often preferred by those that have a rather slow cadence, for all the better and worse that this brings with it. If riding by one's self this is a moot point. If riding with others the ability to quicken the pace briefly can be essential to whether you'll be able to be close enough to talk with your fellow cyclists, and a slow cadence generally makes for a slow speed up from stops and such. Andy
Well, I'm good with what works for you. However, the usual seat height results in around a 20-30 degree of bend between the femur and the tibia when "fully" extended. I find that more height than this is often preferred by those that have a rather slow cadence, for all the better and worse that this brings with it. If riding by one's self this is a moot point. If riding with others the ability to quicken the pace briefly can be essential to whether you'll be able to be close enough to talk with your fellow cyclists, and a slow cadence generally makes for a slow speed up from stops and such. Andy
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It sounds like you are a good candidate for a 'bent.
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#10
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I did have a Tailwind for a few years, wasn't very inspiring. I occasionally look for a SWB bent, but they are pretty rare in the used market.