52 votes

How to stabilise the bicycle seatpost and saddle when it is all the way up?

Your seat post is not all the way up — it's too far up. If you need the saddle at that height, then you need a longer seat post. As mentioned in comments, there is usually a "minimum insertion&...
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31 votes

How do I place the seat back 20 cm with a full suspension bike?

The only safe answer is to buy a bigger bike frame. When your adaptor fails, you will descend rapidly onto the rear wheel. The remaining original seatpost has an excellent chance of tearing your chest ...
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  • 96.8k
31 votes

How to stop bike renters overextending seatposts?

I assume they are extending the seat post that far because they need it for an appropriate saddle height. So the solution is simple: Offer bikes with larger frame sizes or at the very least equip the ...
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  • 19.2k
23 votes
Accepted

Why are all road bike frames now squashed parallelograms?

Sloping top tubes started with mountain bikes, and were brought over to road bikes by Giant, following a design from Mike Burrows. Partly because a perpendicular joint between the seat tube and top ...
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  • 23.8k
21 votes
Accepted

What are the differences between a seatpost-mounted and frame-mounted rear rack

The advantages of seat mounted racks are that they don’t require rear dropout rack lugs; some of the seat mount racks have quick release levers so you can easily take them off (while racing or ...
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  • 28.4k
18 votes
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Cracked seat post

That seat post is made of carbon fiber tube and metal seat mount that plugs into it. The carbon tube is about to split and the inner part you see is the metal plug. It should be replaced immediately ...
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  • 19.1k
18 votes

How to stabilise the bicycle seatpost and saddle when it is all the way up?

Seat posts are usually marked with a line indicating a minimum insertion point. Extending the seat post past that point poses a risk of the seat post bending, or cracking the frame. While 250-300mm ...
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  • 18k
16 votes

How to make old bike's seatpost slide smoothly when it needs adjustment again?

There are different things that can cause this problem and different tools and techniques that can be used to fix it, depending on the cause and severity. Frame material cannot be left out of the ...
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15 votes
Accepted

Bike comes with frame integrated bolt seatpost clamp - can I cut it off and use QR?

Yes it's possible to hacksaw the clamp bosses off and then file the seat tube round and smooth so that a quick release clamp would slip over it. Before taking such drastic action - which will ...
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14 votes
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Why do some triathlon seatposts go straight up and down instead of at an angle?

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 ...
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  • 2,509
13 votes

Before re-inserting a stuck seat post what should I do to the steel/alloy surfaces?

I would not advise reducing the seatpost, nor widening the frame's ID. A close fit is a good thing for a seatpost. Instead, clean the seatpost using your preferred solvent, and allow to dry. If its ...
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  • 96.8k
12 votes
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How to install a saddle on a seatpost with a top facing bolt

You use the front bolt to set the angle first, then torque the rear bolt. Sometimes a few times to get it right. The front bolt is adjusted with the thumbdial or a lever put into one of the holes in ...
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  • 8,920
11 votes

Is there more than one ideal seat post height based on type of riding?

Yes. However, it varies by type of riding and conditions. All Mountain is probably the extreme example of this (and the main market for dropper seatposts). All Mountain bikes are designed to be ...
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  • 9,858
11 votes

Remove lubricant from seat tube and seat post

A thorough way to do it would be to: Remove the cranks, bottom bracket and seat post. Make sure there is a decent hole between the seat tube and bottom bracket shell (might depend on the frame). Ram ...
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  • 286
11 votes
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Remove lubricant from seat tube and seat post

This is an XY problem. Seatposts should be lubed. While removing all lube may solve your slipping problem, it will likely do so by making the seatpost corrode into place, which isn't something you ...
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  • 11.7k
11 votes
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How to make old bike's seatpost slide smoothly when it needs adjustment again?

Check for burrs (a small ‘lip’ of material) on the inside edge of the top of the seat tube). That’s probably what is scratching the seat post. If you stick you finger carefully in the top if the seat ...
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10 votes
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How can I mount a 25.4 mm seat-post on a frame that needs a 27.2 mm seat-post

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 ...
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  • 2,542
10 votes

What is the minimal seat post depth?

Most seat posts have a "minimum" insert of 3 to 4 inches. But this varies with the material and the thickness of the post, and the weight of the rider means the minimum might still be too little. As ...
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  • 96.8k
10 votes

Safely cutting down a seatpost

I agree with @ojs answer on point (1), you can just cut it with a hacksaw but with the exception of point (2) "the common consensus seems to be at least 5 cm of insertion" - the standard minimum ...
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  • 219
10 votes
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Is it possible and safe to attach this type of seat to suspension seatpost?

Looks like the new one has the same kind of saddle rails so you can remove the attachment from it and try the bare saddle rails in the suspension seatpost. It should work! Undo the two big black nuts ...
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  • 11.4k
10 votes

Bolt holding saddle to seatpost broke

You need to use high tensile bolts for high tensile positions like this. A class 8.8 bolt (metric) or grade 8 (US) or higher is appropriate. Cheese-grade steel from the local discount hardware ...
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  • 96.8k
10 votes

Suggestions for protecting jeans from saddle clamp bolt

I would suggest cutting off the extra threads. If you have access to a Dremel or similar tool it wouldn't be too difficult. Doing it with a hacksaw could be a real pain. Alternatively you could check ...
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  • 18k
10 votes

How do I fix the comfort of my bike?

The first things I look at to smooth out a ride are: Least expensive: Tire pressure. Printed on the tire is the recommended maximum inflation. You can experiment with lower tire pressures to smooth ...
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  • 16.1k
10 votes
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Will grooves on seatpost cause rusting inside frame?

The best thing to do is apply a thin layer of grease to the inside of the seat tube and the outside of the post (only the part of the post inside the seat tube needs grease) and set the seat height ...
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  • 16.1k
10 votes

How to stop bike renters overextending seatposts?

If these are beach cruisers or similar, they'll typically have 22.2 or 25.4mm seatposts (7/8" or 1"). If so, putting longer seatposts in all of them would be cheap. This isn't scummy if what ...
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9 votes

Why do some triathlon seatposts go straight up and down instead of at an angle?

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 ...
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  • 3,227
9 votes

Seat post slipping down

It may seam counter-intuitive, but in the case like you describe a little grease may be the solution. NOTE: If you have a carbon frame or seat-post, carbon specific grease and a torque wrench should ...
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  • 15.7k
9 votes

Bike seat tube is messed up

What’s happened here is that you have expanded the diameter of the top of the seat tube, in the process it looks like you have made some small cracks on the top edge, and created a number of burrs. ...
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9 votes

Why are all road bike frames now squashed parallelograms?

The modern design has one really important feature for the frame makers and sellers: They only need to stock very few different frame sizes, the rest is adjusted by selecting a suitable seat post. ...
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8 votes
Accepted

How to judge comfort when buying a new saddle

This article, The Four and a Half Rules of Road Saddles, from Cervélo Cycles has been really helpful to me when pondering saddles. I think the key points are: The saddle needs to be wide enough to ...
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  • 6,886

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