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17

Before you take any more forceful measures, it may be a good idea to think a little about chemistry: 'Rust' is typically the name put on any type of corrosion, but technically & specifically, it is the corrosion of iron (or steel) to form iron-oxides. Although your bicycle is most definitely steel, your seatpost is not -- it's aluminum-alloy, which ...


14

You might find a suspension seatpost to be comfortable, but a suspension seatpost is not a substitute for a full suspension bike. The purpose of a suspension seatpost is purely comfort (though as mikes mentions, not everyone agrees that they achieve this goal), where as the purpose of a full suspension bike is first and foremost control. Suspension on the ...


10

Phil Wood, the owner of the bicycle tool and components company of the same name, once commented that his number one requirement when he was buying barrels of grease for his company, was that it be the exact same green color shade as the previous batch, so that he didn't get too many phone calls asking what he'd changed. Point is that the "bike specific" ...


10

On old steel bikes a good reason would be to prevent the seatpost from rusting onto the frame, thus preventing saddle height adjustment. More recently I understand from my LBS that you do it to prevent water from seeping into the frame along the (imperfectly sealed) seatpost. Depending on your frame you could end up carrying one or more kilo's of water with ...


9

This is a tough one. It's not impossible but you really need mechanical advantage. If you can clamp the seatpost, you will get the best chance at freeing this. You will probably damage/lose the seatpost with this method. Make sure the seatpost is free of grease and oil on the outside. Turn the frame upside down and clamp the seatpost into a bench ...


9

As the person who made that claim, the reason is that allegedly some greases can attack the epoxies found in some carbon fiber applications, causing a breakdown of the CF structure, and causing expansion which will jam the post in place. The epoxy will otherwise not corrode, so it's not necessary for that purpose. The manufacturers also recommend you do not ...


9

To crudely simplify things, a triathlon/TT bike position is much the same as a road position, but basically "rotated forward", so your arms rest atop the very-low-set bars. A consequence of this is, the seat ends up further forward. (source) Using Chris Froome's TT position as an example, noting the hip position versus the bottom-bracket position: ...


8

Carbon parts will cause aluminum to oxidize, as a chemical reaction which is why seat posts wind up stuck in frames. But that isn't why this is necessary. "Carbon grease" is not actually grease. It's a friction compound which increases the friction between your fancy carbon seat post and your frame. Increasing the friction allows a lower torque on the ...


8

Greasing your seatpost will prevent problems like this: "Removing Seat Post rusted into downtube". Don't use chain oil, grease is what you want. As whatsisname pointed out, all fasteners on your bike should be lightly greased. This is what keeps them from corroding and seizing over time, becoming a real pain to remove. If you have trouble with a ...


7

The problem is that there is only one bolt holding the seat at the angle you want. Put enough torque on the back of the saddle and can overcome the friction that's holding the seat in place. A few options: Tighten up that bolt as much as you dare (but you've already tried that). Increase the friction between the seat post and the bottom of the seat clamp ...


7

You should absolutely grease your seatpost (unless it is carbon fiber). It won't slip around if your seatpost clamp is properly tightened. Get a thing of grease from the bike shop, like the park tool grease. Better yet, get the big tub. Then, generously apply it all over inside your seattube. When you think you have enough, add some more. Then put the ...


7

I present you with evidence that seatposts can, in fact, seize! Alloy and steel seatposts are both perfectly capable of seizing to both alloy and steel frames. IIRC, carbon seatpost/frame combinations may need carbon assembly paste for almost the opposite reason: to increase friction and reduce the torque required for a good grip.


7

There are generally two types of dropper seatposts, mechanical (e.g. GravityDropper) and hydraulic (e.g. RockShox Reverb). Mechanical dropper seatposts use a spring to move the seatpost and a bolt to keep it in place. This is a very simple design and there are few things that can break or jam, and the weight is also kept very reasonable since there are few ...


7

There are seatpost shims available for a few dollars. You should get them easily in your local shop or online. I use an aluminum shim in one of my bikes with exactly the dimensions you need, it works flawlessly and looks very clean. I got it for about 3.50 € (5$).


6

In general, you've hit the high points yourself. The benefits (and issues) will vary by post model, manufacturer, and design. Carbon fiber is a very versatile material engineering wise. Storck makes 2 carbon posts, which are externally identical. But one is a comfort post, which focuses solely on smoothing out your ride, and the other focuses on being ...


6

While it's true that your hips rocking indicates that the seat is too high, there is a different rule of thumb for knee pain related to the fore and aft position of the saddle. It's easy to remember: If your knee hurts in front, your seat is too far forward. If your knee hurts in the back, your seat is to far backward. The most important thing to ...


6

The best grease is the grease with the least amount of contaminants. Everything else is secondary to that. Naturally grease does not come with contaminants in it, but, in the workshop it attracts any dirt going, as if it were some huge magnet. Therefore, packaging is important. The large tub that you have for the car/motorbike/boat/unicorn cage might not ...


6

Seat post suspension is not designed for efficiency. It is designed to add comfort to a hard tail mountain bike frame. There are only a few really good suspension seat posts, and they are rarely used on hybrid bikes. Almost always, you will find that the suspension post on a basic hybrid is just a spring in a tube. Occasionally, they add the ability to ...


6

After some more searching, it looks like I'm looking for a layback seatpost, and they're available for purchase on eBay.


6

Any frame can support a range of rider sizes by adjusting (among other things) the seat post and stem. However, as you might suspect, there are compromises to be made. And, there are limits to how big of a rider can fit on a given frame. I'll explain a bit more below to illustrate these points. You can adjust the seat post by making it higher (may ...


5

Heavy, water-proof grease is a good idea. Slipperiness isn't the reason for the grease. The goal here is to keep out moisture and oxygen, thereby discouraging oxidation. Aluminum oxide is especially problematic, as its molecules are substantially larger than the aluminum molecules in your seat post. Oxidation will cause it to jam very tightly. In general, ...


5

You can probably use a small wire brush to get the rust out of the frame and for the future use JP Weigle Frame Saver spray. It acts as a rust inhibitor so should slow down/stop any rust forming on the inside of the frame. You can get frame saver at JensenUSA (I'm sure there are lots of other spots too). ...


5

You should check out the 15 Way To Unstick a Seatpost by Sheldon "Unggggghhh!" Brown http://www.sheldonbrown.com/stuck-seatposts.html


5

Untested and at-your-own-risk, but this is what I would try: Soak the rusted join with WD-40 from above and below (ie. flip the frame and spray down the seat tube). Let it sit for a few hours or overnight. Secure the frame against something solid, like a heavy workbench (not a repair stand!). Put an old saddle you don't care much about on the seat post. ...


5

Try to push the seat down slightly.The carbon weave can act the way those finger cuff toys we had as children did (the more you pull the tighter they get).By pushing down you release the grabbing action.Make sure you use something similar to Park Tool Carbon/Alloy Assembly Lube before you reassemble it,check with your local bike shop for their ...


5

I have repaired non structural and surface carbon blemishes with clear nail polish. I had no issues and used the handle bars for several years with no issues.


5

Unfortunately, this is a common issue with more basic seat posts. There are 2 options: Use sandpaper or a Dremel to remove the teeth which fix the angles of the seat post. If you make it completely smooth, then you can use grip tape like that designed for a skateboard deck to add friction without locking you in to specific angles. This approach has ...


5

It seems everyone I know has a love/hate relationship with them.In other words liked it or didn't.My main complaint was while trying to maintain a consistant cadence I could feel the seat height changing.It seemed to interfere with my pedal stroke.Mine was an inexpensive telescope type,with no adjustments.My reccomendation would be stay away from the lowend ...


5

Note that, in theory, suspension of any sort saves energy on a rough surface, since you "burn" less energy moving your own body up and down as you go over bumps. The negative side occurs, however, if the suspension absorbs energy as the pressure changes as you pedal -- ie, it goes up and down with each pedal stroke. Again, in theory, a seatpost is least ...


5

DMR make hinged clamps for mounting chain devices and bottle cages. 3 different sizes and there is a 31.8mm which should be perfect. Easy job to retro-fit an existing QR lever and bolt I reckon? Part Number: DMR-CLP-286 Alternatively here is something from a different application that would probably work. You might be able to contact the company for a ...



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