jethin

Welp, the title/pics pretty much say it all. I've put some significant torque on this already to no avail, but I stopped short of really going at it so as not to make matters worse. Some details:

- This is a late 80s Simplex seatpost. I'm not sure how replaceable the bolts/nuts are. There is a nice leather seat still attached to it.

- The seat is in a decent position so I don't really need to adjust it. I guess I'd just like to know that the seat is adjustable/removeable if need be.

- I don't have much in the way of chemicals and would prefer not to use 'em, but if need be... I do have some Lock Ease, a graphite solution -- maybe that would help?

- Other option would be to just take it to my LBS. Not sure what mojo they might have to loosen the bolt.

Whaddya think? Recommended treatments? Leave it? Take it to LBS? You tell me. Thanks!

FBinNY 

This is one of those situations where I suggest you may want to leave bad enough alone. From the photo it appears that the frame itself is threaded, as opposed to a replaceable seat band. If so, and you bugger the threads or the bolt in the process of removing it, you're in for some expense and headaches.

I wouldn't give up, and would try some penetrating oil made exactly for this kind of job, such as Kroil, Liquid Wrench or similar, let it soak in 24 hours and have a go at it. If it comes free you're a winner, but otherwise, you have little to gain unless you need to move the addle, and lots to lose with some of the more aggressive methods we might suggest.

mrtuttle04

Your best bet is to use WD40 or similar oil (sometimes called pentrating oil). Thouroghly soak the bolt then wait atleast an hour before trying. A can cost about $3.00 at your local auto parts store. Another option is to drill it out or in which case you would have to replace the bolt. A third option is using a grinder but from your picture this does not look like you can grind a possibility.

HillRider

FBinNY's recommendation for Kroil or Liquid Wrench is far better than WD-40. And waiting over night or 24 hours with repeated applications of the penetrant is better yet.

well biked

We've had some good luck in our shop with this product from Finish Line: https://www.finishlineusa.com/product...cts/chill-zone

dsbrantjr

Repeated applications of Kroil or PB Blaster, periodic firm raps to help loosen things up and time for the agents to wick into the bolt threads, followed by wrenching with a well-fitting tool (cheap and/or worn hex drivers will round out the recess) are your best approaches. A hand impact driver like this one https://www.amazon.com/TEKTON-2905-8-...+impact+driver
may do the trick.

FBinNY 

Remember as you try various methods, that you now have a working rideable bike. You don't want to damage the bolt, or more importantly the threads in the frame with overly aggressive methods. Nothing wrong in trying to get the bolt out, just don't get so caught up in it that you lose sight of the more important objective - a rideable bike, which is what you have now.

urbanescapee

When nothing else seems to work, in cases like these...I use Break Free CLP. I already had it in my shed because it was recommended by the salesman when I purchased my gun. But then I had found a junk bike that the seatpost was rusted into, no manner of pipe wrench, hammering, torching or other lubrication managed to free the badly corroded seatpost from the frame, then someone told me to use Break Free CLP. I left it overnight, and the next day is came out like there was never anything wrong, like butter. I was amazed.

reptilezs

also wire brush the exposed thread

Thumpic

After following FBs method do this. You may also want to run a nut down the exposed threads and give it a significant (but well controlled) blow to jar it loose before trying a wrench. Also be sure your Allen wrench fits well and is thoroughly seated. You can "sharpen" an Allen wrench be carefully grinding the end of the wrench to improve the 90° angles on all six edges; just don't overheat it.

zebede

i'm a pb blaster man myself

SkyDog75

Is this the bolt that secures the post to the frame, or a bolt holding the saddle to the post?

rootboy 

I have a can of PB Blaster. It mostly just sits there now. Since I tried CRC Freeze Off. FWIW

Looigi

IMO, any very thin lubricant or lubricant thinned with solvent works pretty well, but according to some quantitative testing I saw somewhere awhile ago, 50/50 acetone/automatic transmission fluid works the absolute best...if I remember correctly.

FBinNY 

This does work well, as do most of the specific products listed here. IMO it's a coin toss.

However, if using an acetone based home brew, be warned that the acetone can strip some paints.

LesterOfPuppets

Sure looks like a rail clamp bolt to me.

I'd just marinate with PB Blaster weekly for a while. Start trying to loosen when the temptation arises.

jethin

Thanks all, good advice here.

It's hard to tell from the pics, but yep, it's the clamp that secures the seat rails in the seat post. I'll follow your lead and call it a rail clamp bolt.

My plan is to wire brush it, soak it in a Kroil/PB Blaster type product for a day or so and then give it a go. It's a tight spot to spray into, but I'll see what I can do. I'll try not to use too much force if it's just not gonna come free. If it's still stuck maybe my LBS can help me sometime down the road.

Good advice as always FB.

howeeee

I cant get a good idea from the picture what is around that bolt,,but there is nothing like heat to break lose a bolt. No spray of anykind can match heat. So if you can get heat on it, without doing damage to parts around it that always works, never fails. It expands the threads therefore breaking the seal. I just used heat breaking lose the broken frozen cotter pin on the crank of a 59 Schwinn town and country tandem. Somebody gave it to me in peices, you could see where somebody worked on it but couldnt get it out. Heat got it out no problem. Being careful it did no damage to the chrome around it.

jethin

OK, an update and a new question: I wire brushed and saturated the seatpost clamp bolt and was able to get it to loosen it enough to get the seat off. But it's difficult to turn the still rusty bolt and the nut binds at the top of the bolt. I'm not sure if the nut will come off the bolt. In any case, I'd like to have the bolt/nut taken off the seatpost (at my LBS) and replace them. But it's an odd looking design (see beveled nut in attached photo) and I'm not sure if a replacement nut/bolt is available. Anyone?



Alternatively I think I could get the clamp tight on the seat again as is, but the seat would be essentially stuck in place again. Thanks.

Thumpic

I would take it all apart....take it to my bench grinder and wire wheel it into submission.

The threads on the end of the bolt may be peened over slightly (intentionally or from your removal attempts). Try to clean up those damaged threads before you back it out so you won't damage the threaded "nut".

Reassemble with a light coat of grease and forget about it. Unless you plan on leaving it out in the elements or never cleaning your bike; you're good to go.

fietsbob

The bolt itself can be replaced by one of stainless steel Boats at Sea use a lot of stainless hardware,
so Here it's easy to find.

Look for Marine Hardware.

jethin

Thanks for the suggestion, but I'm afraid the bolt will snap before the nut comes off. Sadly I don't have a bench grinder either. I think I'll take it to my LBS and see what they can do. Thanks.

zebede

If you have any movement of the bolt that is substantial progress and would make me believe that you could (with care) get this out yourself. I would continue the soak of pb blaster (or your favorite) and rotate the bolt back and forth. Even though that may be only 1/8 of an inch. Don't over torque it.

Back and forth, spray, walk away, do it again another day. What do you have to loose?

SkyDog75

You could try soaking the rusty parts in something like Evapo-Rust. After removing the rust, it may turn more easily.