JRA... Thomson masterpiece seatpost

Discuss light weight issues concerning road bikes & parts.
Raxel
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Joined: Wed Feb 27, 2008 3:41 pm

by Raxel

Many people think that thomson seatposts are stronger than lighter counterparts like KCNC... but I haven't seen any broken KCNC seatpost yet.

Torque wrench was used during assembly, and there was plenty of seatpost in the seat tube.
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tochnics
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by tochnics

i have seen one where the craddle have cracked with this post
the guy who had the bike replaced it with the same model, time for carbon if you ask me

fact is that human error and production mistakes can never be ruled out

also some other guy that was a heavyweight i knew had a record group with centaur crank
because he was afraid the carbon would crack
later the pedal insert came out of his alu crank

seems to me that you can have bad luck with something known to be strong
Join the light side

a light bike does make you go faster unless you are slow

by Weenie


TheBurnOut
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Joined: Wed Dec 16, 2009 10:02 pm

by TheBurnOut

Where did it break?

Maybe you could post a photo of the two pieces together?

Raxel
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by Raxel

It is one of my colleague's, and the post is snapped at the seatclamp area. I can think it is a common user error if the seatclamp is overtighened, but it was installed by a pro mechanic using torque wrench.

Frans
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by Frans

Bummer. But hey, it's a great excuse to shop for a new one, if that's your fancy...

Advise your colleague to use all the warranty avenues open to him/her. But if it wasn't OEM then maybe you'll have to ask the bike shop to contact Thompson directly.

It's a GBP 70 seatpost so on the grand scheme of things no harm done. Not he has to bail out Fanny Mae or AIG or fund the Iraq war.

BmanX
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by BmanX

I have seen KCNC post break and this is the main reason I just changed out two of them for Masterpiece post just recently.

I am not going to modify the post lost likely but at 160g for a masterpiece cut to 250mm, it is a better choice for my big but than the KCNC I used to ride.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

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coloclimber
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by coloclimber

I have no idea why people like thompson posts- they are ugly, a pain to adjust, not light and ....voila
-Deacon Doctor Colorado Slim

rustychain
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by rustychain

Like most "just riding along" stories I am sceptical. Anything can and will break however one antidote with little details...... :noidea: How old was this seat post? Was it ever crashed? Was there any corrosion? How much did your friend weigh? Etc.

" used a torque wrench" covers a wide spectrum of ability. Frankly most pro mechanics would not use a torque wrench on a seat post clamp with an aluminium seat post. Like I said I'm sceptical. Anyway this is just one report from a product that has a good track record as far as I know

First, inspect carefully the seat post clamp and look carefully for any scoring on the seat post that could have compromised it. Second, learn to do be your own mechanic. Just my opinion
WW Velocipedist Gargantuan

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yourdaguy
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by yourdaguy

I agree with RustyChain. If we are doing anecdotal data I know a guy that used to break at least one post a year (a big guy) and he switched all 3 bikes to Thomson and hasn't had a problem in 4 years now.
For certain parts stiffer is more important than lighter.

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djconnel
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by djconnel

The Thomson is nice because it's easy to adjust the angle precisely versus one-bolt systems, although the KCNC is similar.

I put an M5 KCNC clamp, cradle, and bolts on my Thomson, saving 43.0 grams, reducing the mass of my post to 137.4 grams (31.8 mm, cut). Cutting 3.9 cm saved 9.7 grams. The original post was 190.3 grams.

Dan

racerjrp
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Joined: Wed Oct 14, 2009 9:01 pm

by racerjrp

The thomson adjusters are the most precise out there. osmetimes its a PIA but def the most accurate. I like my Elite posts.

uraqt
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by uraqt

It could be the picture or the angle, that post looks much much much thiner than mine. I remember awhile back Thomson said there were fakes/counterfeits out there..............

C

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CharlesM
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by CharlesM

One isn't a trend...

Of all the parts I would call fool proof/durable, Thompson posts are one. The limited info here would do absolutely nothing to keep me from suggesting Thompson product to large guys without torque wrenches.

I know how the posts are made and can tell you without hesitation that there would need to literally be a raw (base) materials issue at hand in order for this not to have been a user created problem. It's a very simple tube stock and the chances of a raw materials issue is pretty slim...

Also. If it were a large batch raw material issue Thompson would likely have a lot of problems on their hands and given there are massive quantities of these posts out there and problems are virtually unheard of, the chances of this being material and not user driven seem even less likely.

Not saying it isnt one of many of not simply a bad post, but the odds don't favor that...


As for "Pro mechanic" being a qualification, I would first carefully define "pro". I have turned wrench on bikes riden by top level pro's... And I am NOT IN ANY WAY SHAPE OR FORM A PRO MECHANIC. There are lots of guys that have worked on a bike used by a "pro" rider (also subject to variable definition). Most are not at the level the staff mechanics of pro tour teams. Techincally anyone working in a shop is a pro mechanic. Some are better than others.


Again, not saying anything posted here isn't accurate, but I would need to see a lot more bad from Thompson before I thought them a poor product...

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djconnel
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by djconnel

PezTech wrote:The limited info here would do absolutely nothing to keep me from suggesting Thompson product to large guys without torque wrenches.


Except for the p.

:)


by Weenie


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