Frustrated by Seatpost

Shop deals on ebay
BOXKARS
shop deals on amazon
Bike Wall
Rat Rod Bikes Bicycle Forum

Help Support Rat Rod Bikes Bicycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Bicycle808

Bicycle808

Joined
Feb 19, 2011
Messages
5,297
Reaction score
3,302
Location
NJ USA
Rating - 100%
28   0   0
I have an old schwinn DX frame, and I needed to get a new seatpost for it. The DX should take a 13/16" post, so I orcered a nice cromoly one from porkchop. Thing is, the post won't fit in the frame. goes in maybe 1/2" and gets jammed up. I tried to gently pry the groove in the seat-tube apart a bit, but to no avail. I don't wanna do anything to drastic, b/c i don't wanna do any permanent harm to the frame. Does anyone know any tricks I can try? Is it possible that there's an even thinner seatpost out there on some of these ancient schwinns? Before anyone asks, I liberally greased the post ond inside of the tube, and checked for any bizarre blockages in the seat-tube. I'm just hoping for some other possible tricks of the trade.

thanks in advance,
-rob
 
try some sort of Honing Brush, Brass Brush or something like that. Lube or Wd40 to help cut the crud. You can even take a dowel , cut a slit or two and insert sandpaper and turn by hand.

909.jpg
 
Do you have another frame that should be the same size? Maybe the post is a tiny bit too big.
 
troop down to the local auto parts store and buy a small master cyclinder brake hone. Ball hones are more 50 bucks each thanks to the new EPA rules on the grit dust.
 
+1 on the split dowel and cheap samdpaper; cant beat the cost and can change the paper grit to suit. The brake cyl. hones are nice, but really fine polishing grit stones that plug up quick on dirty, rusty work.
I use a metal chisel on seat tube slots, the wide bluntish taper spreads the slot with only a careful hammer blast or two. Im also lucky enough to have some coarse files with flat/curves sides that fit into tubes like that; it has not been unusual to find a burr or such in there, especially at the slot sides or bottom that can hang you up.
 
Thanks for the advice, everybody. I'm likely to try most of the suggestions, starting with the cheapest. Ha.

If it doesn't work, i'll probably just try'n sell the frame (with full disclosure of the issue, of course.)

-rob
 
Keep your eye open for a set of adjustable reamers. They are worth there weight in gold for any shop. You can use them to clean up the seat tube and steer column of every bike you work on. I picked up two sets of very nice but old American made reamers off of eBay for cheap.
 
I had the same problem with a chromed cr-mo seat post I bought off eBay. I used sand paper till my hands were sore, then it went in maybe a 1/2" further, then I bought a 13/16 drill bit that was 9" long from a construction supplier and drilled it out. It was a little hairy getting it started but it worked. I wished I had started with that...
 
Glad that worked for you, but after a lifetime of wrenchin' (prof and hobby) Ive seen power equipment make big mistakes way fast. The old adage,"you can take it off easier than you can put it back on" is very true.
There is a 'rule of halves' that most dont know about, and it works really well.
Do your measurements and take off half of what you think needs to come off. Check again, and take of the next 'half', etc. etc. Dont be surprised if, when you get to a nice fit, that you took off a bit less than you had first figured.
 
You got lucky. Large twist drills like that are bad juju. I have seen the flutes catch on the frames seat post expander slot and rip the bike apart. In retrospect doing that again I would have the seat post clamp installed before drilling.
 
I'm a contractor and I use those tools all the time so I have many years of experience using big drills. I just used one with variable speed so I slowly drilled out what ever was causing the post to get jammed. I was mad at my self for not doing it sooner... But you do have a good point if you've never used larger drills (mine was a 1/2" Milwaukee pistol) know as a wrist breaker, you have to be careful!!! like anything else use you have to be focused on safety or you will get hurt.
 
yep, 13/16 drill bit will clean up the inside of the seat tube for you.

seattube1.jpg


do pay attention to the safety advice already posted.

if the drill hangs up, make sure you have a firm grip on the drill motor so that you don't get hurt.

variable speed drill motor, and slow speed drilling is the best way to approach it.
 
update: i got it handled, just using handtools and other caveman sensibilities.i'm incredibly stoked. i got the frame kind of cheap, so dealing with these issues wasn't too unexpected. now, i just gotta build some wheels and finish this pig... pick out asaddle, too.

thx for the advice, everyone
-rob
 

Latest posts

Back
Top