How to Tighten Bike Seat and Why the Seatposts Slip

O.k., you ‘ve been riding this bicycle for a few days. possibly you bought it modern, possibly it ‘s used, possibly you stole it from your brother. But you notice over the course of a few rides that the induct post tends to creep down. “ What the % $ # & ! ? ” you say to yourself and possibly a bunch of other folks as you begin to get a little hot under the hood. “ Why is this thing slipping ? ! ” Why do seat posts slip ?
The fundamentals :
A post that fits a frame well slides smoothly into the seat tube of the frame without any lateral pass play ( side to side motion ). This means that the seat station out diameter needs to be very close up to the inner diameter of the ensnare ‘s seat tube. The seat tube of the skeletal system has a short-change slot hack lengthwise at the top of the metro. The buttocks post clamp goes around the top of the pipe. When the clamp bang is tightened, the frame material flexes slightly ( the slot allows this bend to occur ) and tightens against the seat post. This, of course, is what holds your post in put. If the clamp ca n’t tighten enough for some reason, your station will slip under load .
Expanding on the basics :

Manufacturer specifications for any component, be it a seat pipe diameter, seat post diameter, or what have you, allow a small margin of erroneousness. This means that the buttocks tube of even a new frame may have an actual inner diameter a spot larger or smaller ( we ‘re talking 10ths to 100ths of a millimeter here ) than it lists in its specification. same goes for the post. then if you have a frame that has a seat tube hole slenderly larger than specification. ( for model : 27.2mm specification, 27.29mm actual ) and the seat post is slenderly smaller than spec., the post will be likely to slip. Assuming both tube and post are within manufacturer margin of variance, this wo n’t be considered a guarantee. In fact, some mail manufacturers ( we ‘re not mentioning any names ) actually machine their posts smaller than their print size to accommodate seat pipe discrepancy ( print 27.2mm, actual 27.1mm or thereabouts, for case ). These posts are always more likely to slip, even though the post may be brand newfangled, expensive, and marked at the adjust size for your frame. Up to this point we are working under the assumption that everything — mail, frame, etc. — is newly. If your human body or post or both are used, this division may be further amplified by wear and tear. Adjusting post height many times over the years can wear down the frame and post a morsel, peculiarly if you do not clean them both regularly ( and who does ? ). Grit and dirty tend to act like emery paper, specially in such tight places. Again, we ‘re talking about very little amounts of material, but enough to possibly cause some slippage. Or possibly person who owned the bicycle before you Flex-honed the seat tube and it is now a act larger than it started out. sometimes a bad post or frame is pretty obvious ; in other cases, you may not be able to tell with the naked eye.

Read more: False Flats

junior-grade causes of slippage : other, less likely culprits behind post slip include extreme over-greasing of the post, particularly using a Teflon lubricant on the post, heavy rider weight, and exceptionally approximate trails. These are junior-grade causes, however, which alone exacerbate the elementary causes and should not alone cause slippage. none of these reasons, however, whether primary or secondary coil causes, are the most coarse trouble .
All that aside, however : The most coarse rationality for post dislocate we have come across is the use of the improper type of buttocks post clamp for your size and type of riding. A cute little clamp that tightens with a 4mm Allen samara may work o.k. on your road bicycle, but it wo n’t cut the mustard on your batch bicycle. For heavy riders, rough trails, and most other things that continue to cause your post to slip, you need a beefier clamp. We make a model called the Constrictor, which has a large frame contact area and uses an enormous 8mm bolt ( tightened with a 6mm Allen key ) so you can apply plenty of torsion, plus it has lots of thread to draw against. The Constrictor was designed specifically to address the topic of post mooring, but even when using a beefy clamp there are some things to know to ensure it will work .
How to install a seatpost : First off, you want to grease the post and seat tube inside surface. Just a flimsy movie to help things swoop. You do n’t need a light, but enough to inhibit corrosion and advertise easy insertion and removal of the post. Next, apply a light film of grease to the inside of the clamp ( the part in contact with the frame ) and the clamp bolt threads. You ‘re putting a distribute of pressure on that abscond and grease helps keep everything from binding, allowing the clamp to tighten to its full moon potential. Although most of the clock you can use just about any dirt, certain situations may call for a specific grease. The run off on our stainless steel steel stake clamp will work best if you use an all-teflon grease on the bolt threads. finally, torque the gobble to manufacturer specification. If you ‘re using a clamp besides wimpish for your application, you ‘ll break the clamp thunderbolt or round out the flats before it can tighten enough to keep your stake from slipping. And estimate what : that ‘s not a guarantee. If you ‘re using our constrictor or another appropriately heavy duty clamp, and you ‘re pretty indisputable your post and frame of reference are compatible, and your post is still slipping, then you have what we call a position, cowboy, and you need to consult your local bicycle mechanic .

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Category : Cycling
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