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Seatpost Comparison - 1 vs 2 Bolts

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Seatpost Comparison - 1 vs 2 Bolts

Old 12-20-11, 01:30 PM
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amgarcia
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Seatpost Comparison - 1 vs 2 Bolts

Are 2 bolt seatposts recommended greatly over 1 bolt?

This question stems from the comparison of these seatposts:

ORIGIN8 - Classique Sport Seat Post

Kalloy Uno SP-248 Seat Post

Sheldon seems to recommend the ORIGIN 8, but I have a built-in low opinion of the brand for no good reason.

Basically, I'm looking for a 27.2 polished seatpost. Other ideas are welcomed.
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Old 12-20-11, 01:45 PM
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I think when folks typically compare single bolt to double bolt posts they are referring to more than simply the addition of a second bolt, but of a completely different clamping design.

The type of two bolt design that is widely praised and known to be reliable is one where the two bolts are oriented front and back, and are used for BOTH clamping and adjusting. A good example is seen HERE, and HERE. The two bolt design that you show uses those two bolts only for clamping the seat into position, but doesn't allow for controlled micro-adjustments of the angle.

Both of your linked options would be less desirable for this reason. You have to hold the saddle in position and rely on the clamping force to keep the saddle from rotating in the cradle. In the Thomson and 3T examples, the cradle cannot slip because one or both of the bolts would have to be loosened in order for it to shift, something that just doesn't happen. This works because the two bolts are pulling against each other. Because of this you can make minute adjustments by very slightly loosening one bolt, and tightening the opposite bolt by the same amount. Hope this helps.

-Jeremy

Last edited by Tunnelrat81; 12-20-11 at 01:54 PM.
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Old 12-20-11, 01:59 PM
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the 2 bolt you link to is not more than a Dual 1 bolt, Richey does that too..

Thompson, and the old Campagnolo ones, is an example of a 2 bolt type , working in a combination.

Race Face has another design.. 1 bolt clamps the rails, from the side ,
a linkage to the 2nd bolt, the angle adjustment, clamps around the seatpost itself.

very useful for some of the newer low profile saddles , when the clamp mech hits
on the saddle shell when it flexes and bottoms out on the top of the seat post.
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Old 12-20-11, 02:17 PM
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Originally Posted by Tunnelrat81 View Post
The type of two bolt design that is widely praised and known to be reliable is one where the two bolts are oriented front and back, and are used for BOTH clamping and adjusting.
Even if this design is superior, I can't stand using the darn things. It takes at least twice as long to change a saddle. I've never had a problem with a 1 bolt post such as the one the OP posted.

OP: there are millions (almost) of choices for a 27.2 post. Get whatever strikes your fancy. I usually buy based on weight and cost, and of course the appropriate length.
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Old 12-20-11, 02:28 PM
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Another fine 1 bolt was made by Brompton, recently,
there are a stack of friction plates for the angle.
goes on top of plain posts.
made mostly of aluminum.

If I were riding Cyclocross I would want a solid 2 bolt seatpost, to jump on repeatedly
as you will, after barriers.
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Old 12-20-11, 02:38 PM
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Originally Posted by fietsbob View Post
Another fine 1 bolt was made by Brompton, recently,
there are a stack of friction plates for the angle.
goes on top of plain posts.
made mostly of aluminum.

If I were riding Cyclocross I would want a solid 2 bolt seatpost, to jump on repeatedly
as you will, after barriers.
I'm certainly not a CXer, but I do ride Cross-Check. It's a versatile bicycle, mostly. Rides like a Cadillac.

Also, thanks for the advice, FastJake. It seemed like I was going to be doomed to crooked saddles if I didn't get a $100 seatpost. I'm really only looking to shell out $50 at the very most.
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Old 12-20-11, 02:49 PM
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There are tons of two-bolt seatposts under 50 bones. I usually like them better because of the infinite adjustability and most are zero (or low) setback, which I also like.

I currently have fewer good saddles than I have bikes so I have been cursing at them of late since I'm swapping saddles a lot. Gotta stock up on saddles when I get some extra dough.

Here's a sampling of sub-$50 two bolt posts: ( I hope I only snagged 2-bolters, I didn't zoom every pic to make sure, they looked two bolt in the small pics tho)

https://www.universalcycles.com/shopp...2&category=618

https://www.universalcycles.com/shopp...9&category=618

https://www.universalcycles.com/shopp...0&category=618

https://www.universalcycles.com/shopp...6&category=618

https://www.universalcycles.com/shopp...0&category=618

https://www.universalcycles.com/shopp...2&category=618

Last edited by LesterOfPuppets; 12-20-11 at 03:01 PM. Reason: bolt, not bold
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Old 12-20-11, 02:52 PM
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Lester and I had the same idea..
NB: Anything thru QBP can be ordered locally too, same price , less shipping.
though here are examples..
https://www.universalcycles.com/shopp...4&category=618
https://www.universalcycles.com/shopp...3&category=618
https://www.universalcycles.com/shopp...5&category=618
https://www.universalcycles.com/shopp...9&category=618
https://www.universalcycles.com/shopp...9&category=618

This one is just $31
https://www.universalcycles.com/shopp...9&category=618

Last edited by fietsbob; 12-20-11 at 02:57 PM.
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Old 12-20-11, 03:11 PM
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One bolt seatposts, usually of the LaPrade type, can be secure but have rather coarse adjustment steps and you may find you can't get your saddle angled exactly the way you want it. A proper two-bolt design is infinitely adjustable. The Thomson is the best I've found but Easton also makes some very solid two-bolt designs and their aluminum posts are reasonably priced.

As noted the ORIGIN8 post you referenced isn't a real 2-bolt design at all and has no advanatage over most 1-bolt designs. FastJake is right that real 2-bolt posts make saddle changes slower but, really, how often do you change saddles?
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Old 12-20-11, 03:48 PM
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Originally Posted by HillRider View Post
As noted the ORIGIN8 post you referenced isn't a real 2-bolt design at all and has no advanatage over most 1-bolt designs. FastJake is right that real 2-bolt posts make saddle changes slower but, really, how often do you change saddles?
Not very often.
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Old 12-20-11, 03:49 PM
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Does anyone ride a Thomson? What is the benefit over a $50 two bolt with micoadjust?
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Old 12-20-11, 04:30 PM
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Some 1 bolt posts do not have the notches and are infinitely adjustable, but more do have the notches. It will probably be impossible to tell either way buying over the internet.

Originally Posted by amgarcia View Post
It seemed like I was going to be doomed to crooked saddles if I didn't get a $100 seatpost. I'm really only looking to shell out $50 at the very most.
I've bought quite a few posts on ebay, and never paid more than $25 even for oddball sizes. $50-$100 could get you a nice carbon post if you wanted to go that way.
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Old 12-20-11, 04:33 PM
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I'm a sucker for shiny things. I'm shopping around for a silver seatpost now!
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Old 12-20-11, 04:39 PM
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Originally Posted by amgarcia View Post
I'm a sucker for shiny things. I'm shopping around for a silver seatpost now!
Actually now that I think of it... What color is your bike? I have one of these "gold" seatposts on my bike and IMO it looks pretty sharp. It's the one thing people actually comment on https://www.ebay.com/itm/BIKE-BICYCLE...item2c61ab8141

They make several other colors. I just searched "27.2 post" and did lowest price to find that one.

That K-Alloy one you posted in the OP is nice too. I have one on another bike.
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Old 12-20-11, 04:44 PM
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Originally Posted by FastJake View Post
Actually now that I think of it... What color is your bike? I have one of these "gold" seatposts on my bike and IMO it looks pretty sharp. It's the one thing people actually comment on https://www.ebay.com/itm/BIKE-BICYCLE...item2c61ab8141

They make several other colors. I just searched "27.2 post" and did lowest price to find that one.

That K-Alloy one you posted in the OP is nice too. I have one on another bike.
Black with silver. Although the gold actually looks awesome, it would clash with the silver. Which one of your bikes has it?

Thanks for the comment on the one I originally posted. I might buy it just to take advantage of VO's free shipping. I'm looking at some other items as well.
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Old 12-20-11, 04:53 PM
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Originally Posted by amgarcia View Post
Which one of your bikes has it?


1984 Trek 610. Goofy mess of spare parts. Too small for me, that's why I needed the new seatpost as the original wasn't long enough. Currently sitting on my race wheels.
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Old 12-20-11, 07:37 PM
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That's a nice looking "goofy mess of spare parts".
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Old 12-20-11, 09:21 PM
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Does anyone ride a Thomson? What is the benefit over a $50 two bolt with micoadjust?
Someone is Bound to , they keep selling them..
Thompson is a US company, the bike parts are a small sideline .
Best materials used, all spare parts are available if you lose any..
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Old 12-21-11, 03:16 AM
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A request for Thompson reviews would likely yield much response in the Road Cycling and Single Speed Fixed Gear subforums. I'm sure a google search would return many results as well. I think the only bike parts I've spent that much money on has been wheels
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Old 12-21-11, 06:31 AM
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If your looking for Thompson, you won't find any seatpost, it's THOMSON.

For their quality, their great seatposts, they also hold their value (at least in the UK) so if you change your frame an it has a different sized seatpost, you will get most of your money back when you come to sell it.
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Old 12-21-11, 06:41 AM
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I think thomson has a patent on their rocker clamp or something, because no one else uses it.

If only thomson made a 25mm set back seatpost with that clamp...
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Old 12-21-11, 08:32 AM
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I prefer the 2 bolt seat post like Thomson, I do own one Thomson and it is a very nice seat post. I like the cheaper Easton EA30.

The reason I like the 2 bolt style is that it is easy to micro adjust when fine tuning a new setup.
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Old 12-21-11, 08:40 AM
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I have a Thomson on my single speed, and would certainly buy another one. I've had a Syncro that was very similar, and cheaper. I really like the infinite adjustability. When using a [notched cradle] Kalloy type, it seems I'm always wanting to be right in between two notches. But what's really annoying - most of them change angle slightly when you tighten them down. So you think you've got it right, tighten down, and it's moved.
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Old 12-21-11, 08:58 AM
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Originally Posted by FastJake View Post
Even if this design is superior, I can't stand using the darn things. It takes at least twice as long to change a saddle. I've never had a problem with a 1 bolt post such as the one the OP posted.

OP: there are millions (almost) of choices for a 27.2 post. Get whatever strikes your fancy. I usually buy based on weight and cost, and of course the appropriate length.
I agree that 2 bolt posts are a pain when it comes to saddle changes but single bolt posts are a pain when it comes to changing saddle tilt.

The Raceface post (and Salsa's similar offering), decouple the tilt and clamping feature. It takes the best feature of the single bolt posts, i.e. a single bolt to clamp the saddle rails, and combines it with a separate mechanism for tilt. Dead simple to change a saddle and dead simple to change tilt if you need to.
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Old 12-21-11, 09:58 AM
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Originally Posted by amgarcia View Post
Does anyone ride a Thomson? What is the benefit over a $50 two bolt with micoadjust?
Yes, I have a Thomson, and it is a wonderful seat post. Note, I did not buy it, it came with a bike I bought (I am too cheap to pay more than $20 for a seatpost, complete bike cost slightly more than what the Thomson seatpost sells for..).

+1 I never change saddles, so the adjustability of a two bolt seatpost trumps the extra time it takes to install a saddle.
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