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Technical & Reference Section => Tech and Restoration => Topic started by: ammacopij72 on July 08, 2018, 04:04 PM

Title: Bent seat tube
Post by: ammacopij72 on July 08, 2018, 04:04 PM
Just noticed I might have a bit of a disaster here, can't get the seatpost into the tube as there is a slight bend/kink in it. Any ideas on how to resolve this without destroying the (new) powder coat lads??  "help" "help"

Title: Re: Bent seat tube
Post by: oldschoolace on July 08, 2018, 04:15 PM
 difficult to put right.  Easiest option is to find a slightly narrower post( they do vary in diameter from make to make)  and live with it. Without cutting it out and fitting a new mast all I can think of is a well greased post knocked down which may straighten it a bit.... Or get stuck :/
Title: Re: Bent seat tube
Post by: ammacopij72 on July 08, 2018, 05:22 PM
difficult to put right.  Easiest option is to find a slightly narrower post( they do vary in diameter from make to make)  and live with it. Without cutting it out and fitting a new mast all I can think of is a well greased post knocked down which may straighten it a bit.... Or get stuck :/

Cheers fella, can't believe I didn't see it before getting it powdered.. The problem is compounded by the fact that I've had the layback powdered too..

Might try running some sandpaper down the tube to see if it makes it any better and then try the grease and rubber mallet technique, fingers crossed!!
Title: Re: Bent seat tube
Post by: Jon1971 on July 08, 2018, 05:43 PM
difficult to put right.  Easiest option is to find a slightly narrower post( they do vary in diameter from make to make)  and live with it. Without cutting it out and fitting a new mast all I can think of is a well greased post knocked down which may straighten it a bit.... Or get stuck :/

Cheers fella, can't believe I didn't see it before getting it powdered.. The problem is compounded by the fact that I've had the layback powdered too..

Might try running some sandpaper down the tube to see if it makes it any better and then try the grease and rubber mallet technique, fingers crossed!!

I would try that first mate, fine sand paper or wire wool then like you say grease and a rubber mallet. Should sort it :daumenhoch:
Title: Re: Bent seat tube
Post by: Taipan on July 08, 2018, 06:37 PM
I had an old seatpost taken off a GT pro stickered up as a GT post,I stripped it of its powdercoat it didnt have a GT stamp? but the post is deffo thinner (still strong) than the ones available today,so bitd they must have been a lot thinner,so look around for an older post maybe?
Title: Re: Bent seat tube
Post by: oldschoolace on July 08, 2018, 06:59 PM
I have a couple of these



https://m.ebay.co.uk/itm/19mm-To-62mm-Car-Engine-Flexible-Shaft-Brake-Cylinder-Hone-Bore-Honing-Tool-2756-/263481728748?nav=SEARCH

The stones are too fine a grit to do anything but polish tubing but I fook them off and glue small strips of emery cloth to the 3 feet.
Work great on seat masts, quick, easy and reach further than you would ever put a post  :daumenhoch:
Title: Re: Bent seat tube
Post by: ammacopij72 on July 08, 2018, 08:06 PM
I have a couple of these



https://m.ebay.co.uk/itm/19mm-To-62mm-Car-Engine-Flexible-Shaft-Brake-Cylinder-Hone-Bore-Honing-Tool-2756-/263481728748?nav=SEARCH

The stones are too fine a grit to do anything but polish tubing but I fook them off and glue small strips of emery cloth to the 3 feet.
Work great on seat masts, quick, easy and reach further than you would ever put a post  :daumenhoch:

Fantastic mate, thanks for that!  :daumenhoch:
Title: Re: Bent seat tube
Post by: deeman on July 09, 2018, 08:12 AM
What a fooker! I had the same on a RL-20 once.....it's nigh on impossible to spot! I ruined 1 seatpost before I realised what was up. I resorted to grease and mallet technique to get another one in. It never went down as far as I would have liked.....Hope you sort it somehow  :daumenhoch:
Title: Re: Bent seat tube
Post by: Retrodan72 on July 09, 2018, 08:40 AM
Gutted for you Neil especially as you’ve taken so much time to make sure every detail is spot on with this build, but like Damo said, these things are virtually impossible to spot.

On the plus side, you’re an experienced bike builder and you’ve put it out there on  :radbmxsmilie: where others can offer advice from their experiences.

I think you’ll know what to do without damaging the powder.

Good luck fella
Title: Re: Bent seat tube
Post by: ammacopij72 on July 09, 2018, 08:54 AM
Cheers Lads, fingers crossed it turns out okay.....  :-\ "nono"
Title: Re: Bent seat tube
Post by: ammacopij72 on July 09, 2018, 12:09 PM
I have a couple of these



https://m.ebay.co.uk/itm/19mm-To-62mm-Car-Engine-Flexible-Shaft-Brake-Cylinder-Hone-Bore-Honing-Tool-2756-/263481728748?nav=SEARCH

The stones are too fine a grit to do anything but polish tubing but I fook them off and glue small strips of emery cloth to the 3 feet.
Work great on seat masts, quick, easy and reach further than you would ever put a post  :daumenhoch:


Any specific grade of emery cloth mate?
Title: Re: Bent seat tube
Post by: oldschoolace on July 09, 2018, 12:19 PM
Depends on whats down there. A phone torch is handy to shine down the mast. I have used 120 grit in the past when i had a stuck glasfibre post but would say 180-240 would be a good starting point. Aim to go down the grades so the mast is nice and smooth then you are done
I used a 90 second araldite to bond the emery cloth, holds it well enough but is brittle enough to get off when you are ready for the next grade  :daumenhoch:

Will bung a pic of mine up
Title: Re: Bent seat tube
Post by: oldschoolace on July 09, 2018, 12:45 PM
Here you go  :daumenhoch:


Title: Re: Bent seat tube
Post by: ammacopij72 on July 09, 2018, 12:55 PM
 :daumenhoch:
Title: Re: Bent seat tube
Post by: WINI on July 09, 2018, 01:13 PM
Wait till you see my snapped off renthal in an early unstamped GT performer frame  :10_2_12:
Title: Re: Bent seat tube
Post by: ammacopij72 on July 10, 2018, 11:15 AM
Wait till you see my snapped off renthal in an early unstamped GT performer frame  :10_2_12:

 :crybaby: :crybaby: "nono" "nono"
Title: Re: Bent seat tube
Post by: chubby on July 12, 2018, 11:08 AM
That snake post fitted fine, didn't notice a bend in there either Neil ???(https://uploads.tapatalk-cdn.com/20180712/1fce449aa6319949ea3ac3d47a0870f5.jpg)

Sent from my HTC One M9 using Tapatalk

Title: Re: Bent seat tube
Post by: MartyC on July 12, 2018, 01:05 PM
Wait till you see my snapped off renthal in an early unstamped GT performer frame  :10_2_12:

A strong mix of caustic soda will have that out in about a week!
Title: Re: Bent seat tube
Post by: ammacopij72 on July 12, 2018, 04:14 PM
That snake post fitted fine, didn't notice a bend in there either Neil ???(https://uploads.tapatalk-cdn.com/20180712/1fce449aa6319949ea3ac3d47a0870f5.jpg)

Sent from my HTC One M9 using Tapatalk

That's cos the snake post is bent too mate!  :'(

Fingers crossed Clint's idea will sort it out...  "help"
Title: Re: Bent seat tube
Post by: chubby on July 12, 2018, 04:44 PM
Ahhhhh fook
Honestly didn't notice either were bent ..

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Title: Re: Bent seat tube
Post by: ammacopij72 on July 13, 2018, 07:57 AM
Ahhhhh fook
Honestly didn't notice either were bent ..

Sent from my HTC One M9 using Tapatalk

not your fault mate, only a slight kink in the seat tube and never intended to use the snake post so didnt look at it that closely. I think the issue is being compounded by the new nitto seat post being powdered too...

Fingers crossed it's all okay after a bit of fettling  :daumenhoch:
Title: Re: Bent seat tube
Post by: ammacopij72 on July 17, 2018, 06:33 PM
Gonna make an attempt on the seatpost tomorrow, but have now found another problem when putting the stem in. It looks like the casting on the inside of the fork is not very round and the stem post just jams up about 40mm from where it needs to be...  :crybaby: Thumbs down

I'm thinking maybe reaming out the forks might sort it?

Just starting to piss me off now as was hoping to have this done for mk and I'm running out of weekends.... :tickedoff:
Title: Re: Bent seat tube
Post by: oldschoolace on July 17, 2018, 09:16 PM
Had the same problem when I was trying to install a linear bearing in a fork once to run a woody style roller cam. Ended up buying a blacksmiths bit with a reduced shank (about 7 quid)
Ran it in a corded drill on half speed with the forks in a vice. Went really slow at it so it didn't grab and it worked a treat if a little scary  :LolLolLolLol:
Title: Re: Bent seat tube
Post by: ammacopij72 on July 25, 2018, 03:11 PM
the good news first....the sea post tube is now sorted!!  :daumenhoch: :daumenhoch: :daumenhoch:  :D :D :D

....and now the bad news....still working to getting material removed from inside the fork steerer tube thingy and it's a right pain in the arse.  Thumbs down Thumbs down

Have been using a pillar drill fitted with a bar wrapped in 80 grade emery cloth in my lunchbreaks at work...taking forever but still hopefull to get this sorted and built for MK! 
Title: Re: Bent seat tube
Post by: Retrodan72 on July 25, 2018, 03:13 PM
the good news first....the sea post tube is now sorted!!  :daumenhoch: :daumenhoch: :daumenhoch:  :D :D :D

....and now the bad news....still working to getting material removed from inside the fork steerer tube thingy and it's a right pain in the arse.  Thumbs down Thumbs down

Have been using a pillar drill fitted with a bar wrapped in 80 grade emery cloth in my lunchbreaks at work...taking forever but still hopefull to get this sorted and built for MK!

Yay for MK Neil mate, keep the faith.  :radbmxsmilie:
Title: Re: Bent seat tube
Post by: chubby on July 31, 2018, 09:48 PM
I hate to ask but..............

How's it coming on Neil???

Sent from my G8341 using Tapatalk

Title: Re: Bent seat tube
Post by: ammacopij72 on August 01, 2018, 12:10 PM
I hate to ask but..............

How's it coming on Neil???

Sent from my G8341 using Tapatalk

Seatpost is sorted  :D and fingers crossed the fork tube thingy will be sorted this week so I can get it built this weekend. Then the big unveil at MK!  "wantit"

you getting there for the Friday mate?
Title: Re: Bent seat tube
Post by: chubby on August 01, 2018, 12:14 PM
I'll be there Friday
Look forward to seeing it dude..

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Title: Re: Bent seat tube
Post by: Retrodan72 on August 01, 2018, 12:21 PM
I'll be there Friday/early hours of Saturday depending on how many times I get lost or stop for a wee
Look forward to seeing it dude.

Sent from my G8341 using Tapatalk


 :shocked:  ::)
Title: Re: Bent seat tube
Post by: chubby on August 01, 2018, 12:22 PM
I'll be there Friday/early hours of Saturday depending on how many times I get lost or stop for a wee
Look forward to seeing it dude.

Sent from my G8341 using Tapatalk


 :shocked:  ::)
Well there is that!!!

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Title: Re: Bent seat tube
Post by: ammacopij72 on August 01, 2018, 12:26 PM
I'll be there Friday/early hours of Saturday depending on how many times I get lost or stop for a wee
Look forward to seeing it dude.

Sent from my G8341 using Tapatalk


 :shocked:  ::)
Well there is that!!!

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 :2funny: :LolLolLolLol:
Title: Re: Bent seat tube
Post by: ammacopij72 on August 01, 2018, 01:15 PM
Forks SORTED!!  explosion
Title: Re: Bent seat tube
Post by: chubby on August 01, 2018, 01:26 PM
Thank fook for that

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Title: Re: Bent seat tube
Post by: ammacopij72 on August 01, 2018, 01:37 PM
Thank fook for that

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Yep, those emojis pretty much sum up the process mate!  :smiley6600:
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