Is it OK to shorten seatpost?

Angusthewestie

Bit of a simple question (and hopefully not too stupid :oops: ), but I'm thinking of shortening my seatpost. I've got an Immobitag that needs to be dropped down the seat tube, and because it's a FS bike, there isn't clearance to the bottom of the tube, as a bolt goes through it. Effectively, this means that I will lose about 3cm of tube depth and this means that the seatpost would not then drop low enough for descents.

I'm thinking about asking the LBS to take 3cm off it for me ... I would still have enough height at maximum extension.

I'm a bit reluctant to meddle, but once I put the Immobitag in, I won't be able to remove it again. Wondering whether not to bother with the Immobitag and use it on my other less expensive bike.

Hope this makes sense.

diy

Is this a standard alu tube? for the cost of getting it shortened by an lbs you could probably buy a short tube and flog the old one. But a standards aluminium tube can be cut with a pipe cutter or fine metal saw/grinder.

Angusthewestie

Yes, this is the alu tube as supplied with the bike (Giant brand). It's 375mm ... and there is an Easton EA50 350mm going for £20 on the classifieds at the mo! Dithered about this, but am not sure whether / how much the LBS would charge me. I got the bike there recently ... is it something that they might do FOC, I wonder.

stumpyjon

As long as you still have enough post inserted then there is no problem cutting a bit off. Pipe cutter, mitre saw etc. to get a neat square finish.

Deputy Dawg

Can't you just remove the offending bolt while fitting the Immobitag so its sitting out of the way of the seatpost?

Angusthewestie

Funnily enough, the exact same thought just struck me! It's an Anthem X4, so you can see the suspension bolt that is in the way:

http://www.giant-bicycles.com/en-gb/bik ... 892/39069/

I'm due a free service sometime soon, so I might ask if the LBS will do it, as I'm not sure I want to start removing bits of the suspension ...

But I do like the idea of the tag if it's stolen (- not a tracking device, but means I'll get it back if it's stolen and then recovered).

Cheers!

stumpyjon

Shouldn't be a big job but they'll probably charge you for it.

GHill

I cut mine with a hacksaw and cleaned it up with a file.

cavegiant

Angusthewestie wrote:

Funnily enough, the exact same thought just struck me! It's an Anthem X4, so you can see the suspension bolt that is in the way:

http://www.giant-bicycles.com/en-gb/bik ... 892/39069/

I'm due a free service sometime soon, so I might ask if the LBS will do it, as I'm not sure I want to start removing bits of the suspension ...

But I do like the idea of the tag if it's stolen (- not a tracking device, but means I'll get it back if it's stolen and then recovered).

Cheers!

Don't count on getting it back, the police are so lazy checking that bike with tags in have been sold at auction.

wilko193

Fine to cut posts - just make it straight and make sure that you have enough post left in the frame

Thread8

Dont do what my mate did and get bored halfway through cutting it and snap the rest off :roll: , cut it straight through or you'll weaken it

Robowns

GHill wrote:

I cut mine with a hacksaw and cleaned it up with a file.

Same, extremely easily done. By the time you wrote the thread you couldve already had it back inserted.

JamesBrckmn

i just used a hacksaw with a blade for metal, and sanded it down afterwards

xCatch22x

I did one on my old bike to save weight really. A diet would have been better, but you know what it's like after reading a feature in a biking magazine!

I cut off the bottom to allow the minimum insertion at my max saddle height. I also did this at a 45 deg angle so that the front is longer than the back but it still retains its strength. Chamfer all the edges too.

Wayne.