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Discussion Starter · #1 · (Edited)
I have a new 2007 Azure and the 27.2 seat post kept slipping. I brought it to the dealer and the tech says the seat tube hole is 2 to 6 tenths of a mm too wide. ( not just at the seat collar but all the way down the tube). My 27.2 seat post and another off a new showroom bike is loose all the way down the tube. I asked about another frame but in another 19in Azure both seat posts were loose all the way down the tubes. Does my seat post need male enhancement or just a tighter tube?
 

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Poser said:
I have a new 2007 Azure and the 27.2 sea tpost kept slipping. I brought it to the dealer and the tech says the seat tube hole is 2 to 4 mm too wide. ( not just at the seat collar but all the way down the tube). My 27.2 seat post and another off a new showroom bike is loose all the way down the tube. I asked about another frame but in another 19in Azure both seat posts were loose all the way down the tubes. Does my seat post need male enhancement or just a tighter tube?
I hope you are joking about your LBS not knowing this...
There is more than one size seattube/post. If fact there are many sizes.
The Azure most likely needs a 30mm seatpost not a 27.2. Most IH's are 30mm. You will need to get a seattube shim that goes from 27.2 to 30mm or get a new seatpost.

And never go back to that LBS again.
 

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Discussion Starter · #3 · (Edited)
Actually the bike came with a 27.2 seat post

I bought a complete bike not just a frame. The Specs at Iron Horse for the bike says 27.2. The Seat post test on both frames came from a bike sent complete from Iron Horse.
Yes you are correct, I should have said 2 to 6 tenths of millimeter instead of 2 to 6 mm. I will changed that in the beginning thread.

Thanks
 

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aluminum or carbon fiber?

you don't say what seatpost is giving you grief. the azure specs. all call for 27.2 mm. seems unlikely that you should having so many problems. call iron horse?

the usual steps include roughing up the inside of the seat tube, texturing the seatpost (Thomson elite should need no attention) and make sure you are getting adequate clamping force.

Tacx Carbon Fiber Assembly Compound on a clean post.

you might pop off the collar and grease the top of the seat tube (exterior; b/w seat tube and collar). this will let the collar move a bit as you tighten things down.

if you're still having problems, then get the dealer to slam on a QR clamp like a Hope or Salsa that may get you some extra strength. 34.9 mm, except for U.S. made frames which are 31.9 ( i think; search this forum ).

many rides this past winter at 230 lbs. and more w/o ever having the thomson post slip.

there is something wrong in the state of denmark.
 

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Poser, just a thought... The folks at Thomson are really helpful. Not all posts come out with the same tolerances. The machine tooling wears over time, etc, and they stay within certain specs, but there are slightly larger and smaller OD seatposts within a given size. If you can get an accurate measurement of the post, Thomson will search their stock for a bit larger 27.2 for you. At least they did the same for me once.

Oh, and compensating for the undersized post by getting a beefier clamp is a no-no. It results in the seat tube edge putting stress on the post in a way that can weaken it.
 

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If you're supposed to be running a 27.2, then it sounds like you ended up getting a 26.8 post. Just my thoughts.

My MkIII and my 7point both use 30.0mm posts. I've tried the factory post that came with the bike, a Race Face Diablous, and a Thomson. All work wonderfully at 30.0mm.
 

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Discussion Starter · #8 ·
Yeah. it just a slightly wide hole

Both posts were marked 27.2. I did buy a salsa seat collar because I thought it was inexpensive factory collar causing the problem. Fully tightened it only slips a little, about an inch a mile. It is not just wide at the seat collar but throughout the tube so overtightening the collar may cause seat post failure as Chris2fur stated. I will be trying a 27.4 seatpost so I can get a better idea of just how wide. Thanks for the ideas. Once I know exactly how wide is the seat tube, the frame may be warrantied. But no new frames for at least a month.
 

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Poser said:
Both posts were marked 27.2. I did buy a salsa seat collar because I thought it was inexpensive factory collar causing the problem. Fully tightened it only slips a little, about an inch a mile. It is not just wide at the seat collar but throughout the tube so overtightening the collar may cause seat post failure as Chris2fur stated. I will be trying a 27.4 seatpost so I can get a better idea of just how wide. Thanks for the ideas. Once I know exactly how wide is the seat tube, the frame may be warrantied. But no new frames for at least a month.
Sorry man, That sucks.

Maybe let the dealer deal with the bike and get an Azure from someone else?!
 

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Me too!

I have the exact same problem with a 2006 Azure.

I bought it for my girlfriend, luckily she's not heavy so it doesn't slip very fast. She has to stop and lift it once or twice per ride.

I've also noticed that when I'm washing it the water runs straight in (I use very low pressure) because the fit isn't perfect. So after every wash I have to remove the post and tip the bike and leave overnight.

The best solution I've found so far is to keep the post greased up, seems to reduce the slippage. But I'm thinking a shim might be the way to go.

I have a 2008 MKIII with a 30.0mm post and have no issues at all. Loving riding and loving both of the bikes :)
 

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Poser said:
Both posts were marked 27.2. I did buy a salsa seat collar because I thought it was inexpensive factory collar causing the problem. Fully tightened it only slips a little, about an inch a mile.
The seat tube mush have been reamed a little too much. That should be warrantied.

Also, Thomson made a batch of 27.4 posts a few years back, maybe you can get a hold of one of those.
 

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Discussion Starter · #14 ·
Thanks to all and to Iron Horse warranty to the rescue

I took the bike to my local shop and they measured the seat tube. It fits a 27.4 with a small amount of work. As SenorSlacker recommended I called Iron Horse warranty and they kindly are letting me use the bike until their 2008's arrive. They have even offered to send the replacement before they receive the 2007. So thanks to all of you and thanks to Iron Horse.

Scubapro Once I knew it was okay with Iron Horse, I bought the only Thomson post at 27.4 x 410 I could find. I will be selling it when I get my new frame. Steven should buy it.

Steven, I'm sure my post wouldn't slip as much if I was in similar in weight to your girl friend, but then my post might be even thinner. I guess I could use the idea of less slippage as motivation to get into good shape.;)
 

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Good idea Poser :)

Hey that sounds interesting! I think I might see my LBS about a warranty job too :thumbsup:

If all else fails I'll measure the seat tube and see if it's 27.4mm. I'll be in touch if the warranty is a no go or if the tube is 27.4mm :)
 

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Discussion Starter · #18 ·
Complete shops can ream the 27.2+ seat tube to 27.4

<Steven> said:
Hey that sounds interesting! I think I might see my LBS about a warranty job too :thumbsup:

If all else fails I'll measure the seat tube and see if it's 27.4mm. I'll be in touch if the warranty is a no go or if the tube is 27.4mm :)
Certainly a frame builder. 2/10 ths of a mm is not much.
 
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