Author Topic: Centre Stand seized pin fix?  (Read 2017 times)

Offline AshimotoK0

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Centre Stand seized pin fix?
« on: November 27, 2021, 03:52:30 PM »
Having just spent several hours, about ten quids worth of Mapp gas, hacksaw blades, blood, sweat, toil  & tears  :( removing a TOTALLY rusted in pin on a CB250K centre stand (suspect bike was left outside for many years) ... has anyone ever tried chopping off the ends of the pipe part/seized pin and at the same time cutting off the outside welds then grinding off the small amount of internal welding, chopping through the centre of the stand tube (and old pivot pin), then  totally remove the old centre tube  and  welding in a new piece of mild steel pipe. Not sure about sizes on other bikes but I have found  suitable mild steel tube on eBay (actually in Hull, near me) suitable for the CB250/350K.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Orcade-Ian

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Re: Centre Stand seized pin fix?
« Reply #1 on: November 27, 2021, 05:38:59 PM »
Hi Ash,
I did exactly that a few years back on our C50 LAC and the advantage in my case was that because the holes in the frame lugs were worn too, I was able to 're-size' those and use a larger O/D tube.  I had to machine that to size and it was a bit tedious getting the old tube out with a Dremel, so as not to inflict too much damage to the stand. It's still as good as new but does get regular greasing.
If you need a piece machining, let me know.

Ian

Offline AshimotoK0

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Re: Centre Stand seized pin fix?
« Reply #2 on: November 28, 2021, 09:15:09 AM »
Hi Ash,
I did exactly that a few years back on our C50 LAC and the advantage in my case was that because the holes in the frame lugs were worn too, I was able to 're-size' those and use a larger O/D tube.  I had to machine that to size and it was a bit tedious getting the old tube out with a Dremel, so as not to inflict too much damage to the stand. It's still as good as new but does get regular greasing.
If you need a piece machining, let me know.

Ian

Great stuff Ian  .. On this occasion, I struggled on and managed to get the old pin out but it didn't even collapse away after two saw-cuts and I had to drill quite a bit of it out.

The next one I do though I will consider the weld-in-a-new-tube method. When I looked into it, the ID of the CB250K tube (and possibly the 400/4) was 17mm and the ID just over 23 mm. You can easily get 25mm x 17mm ID mild steel tube,  so I was going to machine the OD down to the correct diameter. Thanks for the offer of machining .... most kind.. but I have got a small lathe here and loads of machine tools where I still work 1-day/week.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline McCabe-Thiele (Ted)

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Re: Centre Stand seized pin fix?
« Reply #3 on: November 28, 2021, 09:44:41 AM »
Well done Ash that centre pin out - mine took a whole weekend  similar  struggles.

Out of interest is your replacement a nice solid pin - they could do with a grease nipple!
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline AshimotoK0

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Re: Centre Stand seized pin fix?
« Reply #4 on: November 28, 2021, 09:55:36 AM »
Well done Ash that centre pin out - mine took a whole weekend  similar  struggles.

Out of interest is your replacement a nice solid pin - they could do with a grease nipple!

I haven't bought one yet Ted .. I may even make one myself. My friend with a 400-4 tells me the pattern replacement one he bought from David Silver was solid, not tubular.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline McCabe-Thiele (Ted)

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Re: Centre Stand seized pin fix?
« Reply #5 on: November 28, 2021, 10:11:12 AM »
Well done Ash that centre pin out - mine took a whole weekend  similar  struggles.

Out of interest is your replacement a nice solid pin - they could do with a grease nipple!

I haven't bought one yet Ted .. I may even make one myself. My friend with a 400-4 tells me the pattern replacement one he bought from David Silver was solid, not tubular.

Yes I was told that Honda changed the design - a solid bar is easier to remove methinks - you could make one out of SS.
« Last Edit: November 28, 2021, 12:11:45 PM by McCabe-Thiele (Ted) »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline K2-K6

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Re: Centre Stand seized pin fix?
« Reply #6 on: November 28, 2021, 12:38:45 PM »
Ash, if you've got a sds hammer drill with rotary stop facility it can make a really good tool to remove things like this pivot, or at least give one of the best chances of getting them to move.

You can buy a sds to square socker drive adapters for them, onto which you can use an old socket then make a drift mandrel to go inside the tube to centre it, with a step to locate on the pivot tube plus a hex to go inside the socket, then use the hammer action to drift it out.

It's usually far more targeted and persistent than a hammer and trying manually. 

I buy old sockets from car boot sales to use for making bespoke tools in this fashion as I don't mind cutting them to customize a drift.

Offline AshimotoK0

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Re: Centre Stand seized pin fix?
« Reply #7 on: November 28, 2021, 01:24:56 PM »
Ash, if you've got a sds hammer drill with rotary stop facility it can make a really good tool to remove things like this pivot, or at least give one of the best chances of getting them to move.

You can buy a sds to square socker drive adapters for them, onto which you can use an old socket then make a drift mandrel to go inside the tube to centre it, with a step to locate on the pivot tube plus a hex to go inside the socket, then use the hammer action to drift it out.

It's usually far more targeted and persistent than a hammer and trying manually. 

I buy old sockets from car boot sales to use for making bespoke tools in this fashion as I don't mind cutting them to customize a drift.

Interesting Nigel. I have got an SDS impact drill, albeit  it's only an 18v cordless one but nevertheless I will try it on a seized CB250G5 stand I just found in my stash. I  just need to make suitable adapters like you say... I will try it and report back.

Another method might be to get a close fitting bar down the pin to aid  centralising mounting in the milling machine at work and drill it out, leaving a thin sleeve, which can be removed with, a bit of effort.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline K2-K6

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Re: Centre Stand seized pin fix?
« Reply #8 on: November 29, 2021, 11:37:47 AM »
It's obviously a problem that owners of these bikes have a good chance of meeting at some point when taking on one that's been left for some time.

In engineering terms, drilling into an existing hole is always going to be a fraught experience and especially so if theres any flexibility in machine, clamping or the cutting tool that raises the degree of difficulty.

Adapting a drill bit by grinding off the initial flute exterior diameter for the first 20mm or so may give a "plug" lead to let the drill guide itself through the bore,  but you'd need to hand sharpen the points at which the flutes need to start cutting again to get it to machine the pivot as it drives through. Done that years ago with cutter grinding machinery to recover patchy situations. 

The sds method if you can get competent drive onto is quite easy,  but you'll soon know if it's going to do anything.  I've been adapting this for things like car front suspension links that seize steel bolts in aluminium uprights such that they seem as one piece with any conventional approach. 
Also successful in getting cycle seat posts (more common than you'd think) that resist virtually any other method in extracting them. Made a tool out of rebar steel with a carefully ground hook that can be pushed down inside the tube to latch under the bottom lip and drive it out of the frame to recover badly corroded stuck components.
One characteristic is that at first they don't move but start shedding corrosion dust, persistent application usually gets them going but counter intuitive action to knock it back in as it starts to fidget can get better release conditions between the two parts.

Oh, and you'll definitely need ear defenders  ;D

Offline AndyD

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Re: Centre Stand seized pin fix?
« Reply #9 on: November 29, 2021, 03:39:28 PM »
Ash,
Had this problem on the CJ250 but luckily found a NOS stand cheap on eBay to replace it - the new DS pivot pin to go with it is indeed solid.

I now have the same thing on the CJ360 and have tried all sorts of banging and squeezing (10 tonne press) but no sign of movement so far.
Have got a big old SDS impact drill in the garage so I'll give that a go as well.

I also thought about leaving the old pipe in place, cut neatly at each end, then using a bolt as the new spindle and make up a bush (or rather 'have' made up as no lathe / mill or idea how to use one!) at each end to fit in the frame lugs. I thought this might be an easier option and guess the bolt pivot would work OK for the remaining life of the bikes.
Probably a bit of a bodge but I might try it out and luckily I've now got 2 CJ250 cut off stands and the one on the 400 is also seized and has been bodged up in the past so plenty to try out on!
Cheers,
Andy

Offline McCabe-Thiele (Ted)

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Re: Centre Stand seized pin fix?
« Reply #10 on: November 29, 2021, 04:50:53 PM »
When I was removing my old pin I also made use of my mains impact drill - in my case I had an SDS masonary bit that was just about the right size it  helped shift it - once it had started to move it became increasingly easy to get it to drive out. This was after two horizontal saw cuts as I recall.
« Last Edit: November 30, 2021, 09:52:05 AM by McCabe-Thiele (Ted) »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline AshimotoK0

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Re: Centre Stand seized pin fix?
« Reply #11 on: December 01, 2021, 03:44:25 PM »
Well my SDS adapters haven't arrived yet,  so soldiered on drilling the seized pins out.

I have now removed 3 pins in 3 off  CB250/350K centre stands,  by drilling out with a really nice quality drill bit that an old guy (now sadly RIP)  left me. I didn't do any saw-cuts at all on the last one.

The good thing is,  the pin is tubular and using a Makita cordless drill, the drill tends to centralise quite well if you take it steady and all three pins are now totally drilled out with no significant damage to the sidewalls of the stand horizontal pivot tubes. Plenty of some fancy pants 'Wurth' drilling compound that Ben Powell gave me last night also helped a lot. We did try 3 Tonnes of force on one seized pin last night in the hydraulic press at work, with no joy, even after heating the centre tube to almost cherry red. Without making suitable adapters,  it was difficult to apply any more than 3 tonnes safely.

Got one more to do for my mate in Beverley tomorrow (again CB250K)  and then that's it for all of my bikes.

I do have totally a spare  seized 400/4 centre stand  somewhere though, so when my SDS adapters arrive, I will dig it out and try the K2-K6 (Nigel) SDS impact method.
« Last Edit: December 01, 2021, 03:46:12 PM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline AndyD

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Re: Centre Stand seized pin fix?
« Reply #12 on: December 01, 2021, 06:33:40 PM »
Sounds a good result Ash
Spent an hour or two today getting one pin out.
SDS drill didn't do much sadly - except make all the house lights flicker as it battled the rusty pin!
Fed a good sawblade through the pin and cut through on two sides after which the pin came out easily so got there in the end.

Cheers,
Andy

Offline AshimotoK0

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Re: Centre Stand seized pin fix?
« Reply #13 on: December 01, 2021, 06:52:09 PM »
Sounds a good result Ash
Spent an hour or two today getting one pin out.
SDS drill didn't do much sadly - except make all the house lights flicker as it battled the rusty pin!
Fed a good sawblade through the pin and cut through on two sides after which the pin came out easily so got there in the end.

Cheers,
Andy

Good result too Andy. The three I just did, two of them I did the two saw-cuts on but the pin was totally rusted to the stand tube along it's whole length and no amount of bashing would shift it. I drilled out from both ends and the last inch or so in the centre did drift out but even then it took a lot of force to shift the final 'plug'
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline taysidedragon

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Re: Centre Stand seized pin fix?
« Reply #14 on: December 02, 2021, 09:33:19 AM »
Well my SDS adapters haven't arrived yet,  so soldiered on drilling the seized pins out.

I have now removed 3 pins in 3 off  CB250/350K centre stands,  by drilling out with a really nice quality drill bit that an old guy (now sadly RIP)  left me. I didn't do any saw-cuts at all on the last one.

The good thing is,  the pin is tubular and using a Makita cordless drill, the drill tends to centralise quite well if you take it steady and all three pins are now totally drilled out with no significant damage to the sidewalls of the stand horizontal pivot tubes. Plenty of some fancy pants 'Wurth' drilling compound that Ben Powell gave me last night also helped a lot. We did try 3 Tonnes of force on one seized pin last night in the hydraulic press at work, with no joy, even after heating the centre tube to almost cherry red. Without making suitable adapters,  it was difficult to apply any more than 3 tonnes safely.

Got one more to do for my mate in Beverley tomorrow (again CB250K)  and then that's it for all of my bikes.

I do have totally a spare  seized 400/4 centre stand  somewhere though, so when my SDS adapters arrive, I will dig it out and try the K2-K6 (Nigel) SDS impact method.

Well done Ash. You have a lot more determination than I do!
Gareth

1977 CB400F
1965 T100SS

 

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