Other Stuff > Misc / Open
Centre Stand seized pin fix?
McCabe-Thiele (Ted):
--- Quote from: AshimotoK0 on November 28, 2021, 09:55:36 AM ---
--- Quote from: McCabe-Thiele (Ted) 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!
--- End quote ---
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.
--- End quote ---
Yes I was told that Honda changed the design - a solid bar is easier to remove methinks - you could make one out of SS.
K2-K6:
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.
AshimotoK0:
--- Quote from: K2-K6 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.
--- End quote ---
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.
K2-K6:
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
AndyD:
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
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