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PostPosted: Wed Nov 06, 2013 9:02 pm 
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Joined: Thu Sep 01, 2011 5:11 pm
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Location: Left Coast of Canada
So I took my new Rampage to work yesterday. I've been worried that the frame is too small for me (it was marketed as a 19 inch which is typically my size, but according to Bikepedia they sold it as an 18.5 and 20 inch BITD). I found the stock uncut seat post was too short - very odd feeling ride with that long stem. Fortunately it has the same diameter post as my Zaskar, so I swapped posts (since the Zaskar is currently awaiting a decision on wheels) and road it in today. Ahhhh, much better. That being said I had to expose a lot of seat post to get relatively comfortable (still have more than the minumum inserted). My buddy put the bug in my ear about seatpost/frame failure due to high seatpost exposure. Are there any rules of thumbs or widsome from the forum on this issue?


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PostPosted: Wed Nov 06, 2013 9:42 pm 
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I'm interested on this one too...main problem with a long post I have found is that it shifts your weight more onto the handlebars, which for me knackers my wrists! Especially with the retro ride style arse up head down!


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PostPosted: Wed Nov 06, 2013 9:52 pm 
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Location: Aberdeen
If you can see the "Minimum Insertion" marking then you've not got enough seatpost left in the frame to be safe.
You can get seatposts in 400mm+ sizes usually (if you need all that seatpost sticking out then either the frame is too small for you or you're some freak of nature :lol: :wink: ).
Sooner or later the post will crack, or snap, or both, and it can also break the welds on the seat-tube (happened to me on a low-end steel Raleigh frame).

Having said that, I see no end of people at work riding about on cheap MTB's that must only have a few centimetres of seatpost left in the frame at best, and no one has died (yet).


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PostPosted: Wed Nov 06, 2013 10:09 pm 
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Joined: Fri Jun 14, 2013 12:02 am
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jimo746 wrote:
If you can see the "Minimum Insertion" marking then you've not got enough seatpost left in the frame to be safe, just go buy a longer seatpost, you can get them in 400mm+ sizes usually (if you need all that seatpost sticking out then either the frame is too small for you or you're some freak of nature :lol: :wink: ).
Sooner or later the post will crack, or snap, or both, and it can also break the welds on the seat-tube (happened to me on a low-end steel Raleigh frame).

Having said that, I see no end of people at work riding about on cheap MTB's that must only have a few centimetres of seatpost left in the frame at best, and no one has died (yet).


The OP said he still has more than min. in the frame so should be good.

My advice is to know your frame. Is it a frame that is known for cracking or failure? If it is then there is a reason to be concerned. If not you might be fine. what does the junction look like? I like the old rockies where the seat stay come in above the top tube and the slot it on the front. This gives the post and junction more support where it is needed, at the back near the seat collar, it's a great design. As long as you post is extending down below the bottom of the top tube by say, an inch, you should have plenty in the frame and you should not have an issue damaging the frame though you could always bend or crack the post is if is a lightweight because there is a lot of leverage on there.


Last edited by cyclotoine on Wed Nov 06, 2013 10:41 pm, edited 1 time in total.

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PostPosted: Wed Nov 06, 2013 10:36 pm 
Gold Trader / MacRetro rider
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Location: Aberdeen
cyclotoine wrote:
The OP said he still has more than min.


Yep, and as rule of thumb the OP "should" be ok with that, it's when you can see the "Min Insertion" mark that you know might have problems.

I don't think there's any one definitive answer, it depends on the post size/shim/seat-tube design/materials used.

I wouldn't let your friends whisperings put you off unduly, maybe post up a pic of the bike to show just how much post is sticking out the frame?


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PostPosted: Wed Nov 06, 2013 10:43 pm 
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Joined: Thu Sep 01, 2011 5:11 pm
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Location: Left Coast of Canada
jimo746 wrote:
cyclotoine wrote:
The OP said he still has more than min.
...I wouldn't let your friends whisperings put you off unduly, maybe post up a pic of the bike to show just how much post is sticking out the frame?


Good idea - I'll get a shot of it when I get home. Not using a lightweight post. Its an Uno - I think the Laprade model. There was a noticable difference in heft between it and the original.


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PostPosted: Wed Nov 06, 2013 10:58 pm 
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Joined: Thu Sep 01, 2011 5:11 pm
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Location: Left Coast of Canada
Here is my thread on the original bike. There are some photos in there with the original post pretty much at max extension. That isn't enough for me - need another two inches or so higher to be comfortable for hammering on the road. Photo from the rear makes it look really high. Photo from front side makes it look not too bad for rolling down the highway.

viewtopic.php?f=6&t=275286

I'll take a shot of it with the longer post when I get home tonight.


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PostPosted: Thu Nov 07, 2013 6:48 am 
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Location: Left Coast of Canada
Ok, here is the seat post around where I'm comfortable riding on the street. So, what do you think? Outrageous or within tolerances?


Attachments:
rampage seat post.JPG
rampage seat post.JPG [ 33.51 KiB | Viewed 400 times ]
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PostPosted: Thu Nov 07, 2013 6:57 am 
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Location: The Home Of Mountain Biking, And All Great Things.
Unless you have unusual body geometry I would suggest a larger frame long term.


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PostPosted: Thu Nov 07, 2013 7:25 am 
Retro Guru

Joined: Fri Jun 14, 2013 12:02 am
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Location: Canada
it's pretty long, but the photo doesn't really help. The rampage is pretty light tubing therefore it could be susceptible to cracking. Watch for crack originating from the the end of the slot on the back of the seat tube. Again it matters what is in the frame. measure how much is in the frame and mark it with a piece of tape and take a photo of that. That will be very telling. Most important thing... how much do you weigh?


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