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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: ...


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

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

Triathlon bikes are about one thing, and one thing only. Aerodynamics. Dan Empfield, the creator of the Quintana Roo brand, recognized this early on. Cervelo came along soon after, and their designs basically changed how time trial bikes are viewed, with their breakthrough design of the P3 in 2001 (Company history here.) This P3 design evolved, and there ...


5

There isn't always one size frame which fits a person well in a given model line of bikes (there may be 2 or more - probably 2 if someones on the border of sizes). In some cases, you can get multiple models to fit by swapping out stems and seatposts and saddle and handlebar adjustments or swaps. However, this is highly dependent on the particular model of ...


5

Just buy an inexpensive metal seat post, and if eventually it wears out it wears out. That seems to be your least expensive option. Especially if it's just a trainer bike. Just lube it up with either a little bit of oil or odorless teflon grease.


5

Typically, for an aluminum post you align the gaps. For a carbon post you turn the clamp 180 degrees from the gap in the seattube to minimize the chance of crimping the seatpost. Some manufacturers have their own recommendations, but they're typically in line with what the aforementioned guidelines.


3

(this is more of a supplemental answer to Pete's one) The answer is somewhat different if you already have back pain vs if you don't. Simply, if you already have pain it's much easier to make it worse, but if you don't an upright bike is fairly unlikely to cause it. The main factor is likely to be how far forward you lean while stilling on the bike, with a ...


3

The number of comments to your question is becoming quite large, so I thought I'd roll my comments up into an answer (of sorts). You ask whether the seat postures could cause back pains, and whilst I have no specialist knowledge in this area, I'd have to say from a purely empirical viewpoint that the answer must be "no". A lot of people ride a lot of miles ...


3

Penetrating oil (Liquid Wrench). It may take a few days as it needs to work its way down. Or it may free it up in a few minutes. The risk you take with a lot of force with a pipe wrench is you bend the bike or brake off the post or get the post out of round. You should grease the seatpost to help prevent this. If you don't bend the post then I ...


3

Aligning the gaps will allow the clamp to compress the tube a little better, therefore reducing the amount of tension needed from the clamp to hold the seat post in. And less tension means a longer life for your seat post clamp. Now, there's the issue of which way your clamp lever faces if you use a quick release clamp. Most have it facing backwards so it ...


2

According to a forumer working in bike building industry (SUNN, France), mounting the seat post clamp with its gap on top of the seat tube gap is important to ensure an equal and secure gripping.


2

Get 2 spanners that fit. Hold the bolts on both sides with the spanners and turn any one side to remove easily. To put it back alternately rotate each side 1 or 2 turns. Be careful with the tightness, if it's slightly loose you'll experience slight play in the saddle and the micro adjust assembly will soon get worn out. Too tight and you might deform your ...


2

The only disadvantage I can think of (that you haven't already listed) is the remote control: It's yet another control sat on the handlebars. This is fine if you're running a single chain ring (1×10 or similar), because it can sit where the front shifter would normally go. Less than ideal if you're running 2 or 3×10, have remote lockouts, a bell and so on. ...


2

The easy method is to use cable ties and route it where you like. Remember to add Biketape (transparent frame protection tape, aka helitape) to prevent the cable rubbing the paint off your frame etc.


2

It partially depends on where the cable comes out of the post. If it's from the top you can route the cable across the bottom of the top tube and up to the handle bar or down the seat tube and up the down tube. On the other hand, if the cable comes out of the bottom of the post, you can try to go out the bottom of the seat tube and up the down tube. What is ...


2

If the bike is a cheap one, then a really cheap seatpost must exist for it. Cheap Seatposts are usually made of steel or mild steel, which should withstand the wear from repeatedly adjusting the seat height, so my advise here is, don't worry that much. Some bikes use a type of seatpost that doesn't have an integrated seat clamp. If this is your case, it is ...


2

I can't find any other posts, unless they are boutique and don't sell online. However it looks like Thomson, Fox, and Crank Brothers all have posts with 125mm which seems to be the next step down. From there, a few have 110mm and the rest are at 100mm.


1

I had the same problem. I used vise grips and clamped down very tightly. I hit the vice grips with a hammer, repeatedly. This will jar it loose- it took me about 15 minutes. The bad news: when I did this with my bike, it left deep scratches on the post (the vice grips will come loose and need to be clamped down again).


1

You have to make sure that you're actually tightening the quick release down - it should leave an imprint on your hand when you close it down. If you put a product like frame saver in the frame, you'll need to tighten it down extra since that makes seat posts super slippery. See this thread as well.


1

Traveling long distances on a bike seat is almost always going to be uncomfortable when your body isn't used to it. Give it time. But also, consider taking your bike with you to have a professional make sure the seat and the bike fit you. Some people have managed to permanently damage their blood vessels ( I won't go into detail ) by improperly sitting on a ...


1

In addition to aerodynamics, not yet mentioned is the benefit to your running off the bike. By changing the seat angle, you use your muscles differently and can run faster off the bike than a more traditional seat post angle. As noted in this article, test subjects were about 5 minutes faster in a 40k/10k Brick (stationary bike/treadmill run). There was ...


1

My two cents: If you align the gap in the tube with the gap in the clamp, the grip will be much stronger. You'll need less force in the lever to hold the seatpost in place. If you keep them counter-aligned, you'll exert considerably less pressure, and there is a chance that the pressure will be "more evenly" distributed, although I don't "feel" it to be ...


1

I found that the GMC Denali 21 speed uses an HL Aluminum Micro Adjust 27.2 X 300mm, so I assume your seat is very similar to those found on the Denali. In this case you will need a small crescent wrench that will fit between the guts and the side of the saddle. Some bolts are square and will stay put when loosing the nuts, but some are not and might require ...


1

I found this video, and decided to do like him. He puts some kind of extension on his power drill, and on the end he puts a tiny 1 inch steel wire wheel. He drives the wheel up and down in the seat tube for some time until the rust is gone. I tried hard but never found a wirewheel this small in my country, at least not one that would fit on an extension. ...



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