Author Topic: Seatpost Nomad mk2 stuck  (Read 1634 times)

joecrewe

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Seatpost Nomad mk2 stuck
« on: January 08, 2019, 09:58:51 PM »
Hi
After having kept my bike in storage for 2 years (in a box), I am now reassembling it. All fine except I am having difficulty inserting the seatpost.  It is clean and greased up and it looks like there may be a *little* rust in the frame's tube. It gets about 7cm in before jamming from tightness (rather than anything blocking it). It needs to go further down for reasonable riding height- as I once had it on a long distance tour. Twisting and pushing the saddle works it to a halt and I don't want to use excessive force/hammers etc. Any ideas what I may be doing wrong or what could help?

Many thanks

mickeg

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Re: Seatpost Nomad mk2 stuck
« Reply #1 on: January 09, 2019, 03:47:46 AM »
I have no ideas, but some clarification might be useful.  My Nomad Mk II has a standard sized (27.2mm) seatpost in a shim that goes in the frame.  Assuming your bike is the same as mine, is your problematic rust inside the frame and that is blocking the shim from seating (bad pun) properly?  Or, is your situation different?  Or did I interpret that incorrectly?


Dave Whittle Thorn Workshop

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Re: Seatpost Nomad mk2 stuck
« Reply #2 on: January 09, 2019, 09:19:25 AM »
Have you had the bike its whole life? We had this recently and it turned out the previous owner had put some spares spokes and a rag down the seat tube (not recommended BTW)

joecrewe

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Re: Seatpost Nomad mk2 stuck
« Reply #3 on: January 09, 2019, 02:46:44 PM »
Thanks for the replies.

Mickeg- yes standard with a shim. Haven't been able to inspect in daylight yet for exact rust damage but it looked minor. That said, even minor rust could be enough friction couldn't it?
Dave- yes I am the sole owner (since 2014) and I stored my spokes elsewhere.

Could it be to do with type of grease? I have the natural stuff that's yellow.
Or If it turns out to be rust in the frame causing it, what would be the recommended action? It's quite far down (starts from about the length of my middle finger after the shim ends).

Thank you
Joe

joecrewe

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Re: Seatpost Nomad mk2 stuck
« Reply #4 on: January 09, 2019, 03:10:17 PM »
Further clarification for  Mickeg- the rust is on the inside of the frame and appears to start after the shim (=the shim is clean)The shim is inserted and has remained inserted, and I haven't tried to move it in any way. The seatpost enters the shim fine and friction probably starts around the point where the seat post encounters the actual frame.  Hopefully that makes sense. Will get further comment on rust once I get to see it in daylight hours when I'm not at work. I packed the bike up in Malaysia's monsoon season in 2016 so humidity may have been present in the box for rust to have found its way there.

taa

bobs

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Re: Seatpost Nomad mk2 stuck
« Reply #5 on: January 09, 2019, 03:39:19 PM »
Bearing in mind the seatpost is 27.2  and the seat tube is 30.9 if I remember,  thats got to be a lot of rust.
Have you tried to insert something narrower than the seatpost  ?

mickeg

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Re: Seatpost Nomad mk2 stuck
« Reply #6 on: January 09, 2019, 07:50:24 PM »
I think first you should take the shim out or see if the shim is stuck in the frame.  I think the shim is non-ferrous, thus could have some dis-similar metal corrosion if there is metal to metal contact long enough.  I think my shim was painted black and my seatpost is also painted so in my case I think I have no metal to metal contact.

If you have a good flashlight with a tight beam, look down the tube to see what is going on. 

When I built up my Nomad, before I built it I used frame saver inside my frame to try to put a good rust inhibiting coating inside.  But I have no idea if that product is available outside USA.
https://www.treefortbikes.com/JP-Weigles-Frame-Saver-Aerosol-Can

If there are comparable products sold in UK, I am unaware of it.

I have also heard of people using linseed oil in a frame to coat it to reduce chance of rust.  But if you try to use linseed oil, do an internet search for linseed oil spontaneous combustion to find out what happens if you dispose of waste rags improperly.

If you have some surface rust, if you could put a long handle on a stiff wire brush, that might be a good idea.  If it was me doing that, i would remove the bottom bracket eccentric from the frame first so anything that goes down it can drop out at the bottom.

If there was water in your bike box over the past couple years, you could have corrosion issues elsewhere, for example rims.  Any chance of water damage in the Rohloff?

Dave mentioned spokes down the seat tube.  I store spare spokes in my seatpost, but they are held in the seatpost with a wine cork.  The cork dried out a bit, so I wrapped tape around it to make it fit tighter.  My cork has never fallen out.  Thus, nothing is stored in my seat tube.

joecrewe

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Re: Seatpost Nomad mk2 stuck
« Reply #7 on: January 09, 2019, 08:40:37 PM »
Thanks for that. The shim is stuck. Pliers not moving it. So I assume it's supposed to come out relatively easy then? I'm now wondering if I had it stored with the Allen screwed in tight (without seatpost) which could explain a tight shim. I guess I should wd40-it loose?

 As for rust I really can't see much at all, if any and as bob pointed out it would have to be thick, which it isn't.
Thanks again

lewis noble

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Re: Seatpost Nomad mk2 stuck
« Reply #8 on: January 09, 2019, 09:35:07 PM »
I'm not familiar with the Nomad frame and fittings, not at home and hard to look at things on phone, but I wonder . . . Is the seatpost distorted in some way, so problem not in the shim  /  frame? Do you happen to have another 27.2 seatpost you can try in there? Lewis
 

joecrewe

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Re: Seatpost Nomad mk2 stuck
« Reply #9 on: January 09, 2019, 10:20:09 PM »
Inserting another post the same diameter produces the same result.

I have now removed the shim with a bit more force and wd40 to reveal a filthy contact between shim and frame.  Rust, white solid extruded particles on both frame and shim.  Bottom eccentric bracket removed, I have wire brushed some of it off so far and the shim is currently soaking in coca cola for 20 mins.  I have a handful of rust removers and converters - what's the advice on using these ?

Cheers guys

joecrewe

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Re: Seatpost Nomad mk2 stuck
« Reply #10 on: January 09, 2019, 10:34:03 PM »
Ps. Rims intact. Some rust on frame when I took out bottom bracket.

mickeg

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Re: Seatpost Nomad mk2 stuck
« Reply #11 on: January 10, 2019, 06:55:44 PM »
I have no idea what the white stuff would be but I suspect it is a product of dissimilar metal corrosion or perhaps aluminum oxide.

Do you have plans to use the bike in the near future that would require that you expedite anything you do?

For the future, if you try any rust preventative measures such as the frame saver I used, it is best to apply to a dry surface.  I have no idea how permanent it would be if applied over a surface that is coated with WD 40.  I also do not know if the WD-40 would dry to accomplish a similar solution, but since the rust and corrosion has started, you want to arrest that.  Dave in the Shop might have thoughts on the best treatment.

Grease on a seatpost and in this case also on the shim is a standard recommendation to avoid dissimilar metal corrosion and also reduce or prevent water entry into the seat tube.  That is one option. 

I readily admit that I do not grease those parts on my Nomad Mk II.  But I applied a rust inhibitor before I built up the bike, I am in part relying on that.  And with the eccentric designed the way it is, any water that gets in the seattube should drain out at the bottom instead of allowing it to accumulate like could happen on a normal bottom bracket. 

The reason that I choose to avoid greasing mine is that when I pack up the bike for transport, I am trying to avoid having more greasy parts than are absolutely necessary.  And as I mentioned above, I have a painted seatpost and painted shim to prevent metal on metal contact.  (I now am thinking I should put another layer of paint on my shim.)

My other bikes without a shim and without a painted seatpost, I always grease those.  The ones with a painted seatpost, I grease those too, mostly to limit water ingress.  But with a painted seatpost, I admit that I am more careless than I should be.

Before you do any serious traveling on the bike, re-lubing everything that should have lube on it might be a good idea.  I am assuming your headset and bottom bracket has sealed bearings, thus nothing to do on them.  But just about anything else likely could use some lube.  And an inspection for any corrosion.

You probably should change the oil soon on the Rohloff, but if I was doing that, I would go for a bike ride of several km first and use it in every gear to try to get any particles into suspension in the oil immediately before I drained the oil.

joecrewe

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Re: Seatpost Nomad mk2 stuck
« Reply #12 on: January 13, 2019, 05:00:39 PM »
Hi Mickeg

Thanks for your advice. I have been in the process of slowly cleaning it up and checking for rust and scratches. I took it for its first test ride today in 3 years and it's all good.  I plan to change the oil in a coupe of weeks once I have done a short 2 day tour locally. The eccentric bracket was more or less intact, just a touch of red stuff that easily wiped off. The seatpost now goes in nicely after having brushed it and the shim up and greased.

The biggest issue I have is plenty of scratches on the frame and racks that have turned rusty.  I have cleaned it up using brushes, a rust sponge and anti rust liquids.  The supplied little bottle of black paint is gloss I think so I will probably find some matte to match the rest of the frame and racking. Not sure if I should prime these little clean bits before painting. Probably!

mickeg

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Re: Seatpost Nomad mk2 stuck
« Reply #13 on: January 13, 2019, 06:23:56 PM »
My Thorns came without any touch up paint.

My racks and my Sherpa are matte black.  I use some black finger nail polish that I found in a store for touch up on little worn spots.  The finger nail polish bottle has a tiny brush built in to the cap, so that is very convenient.