Thumper Club Forum
Technical => Project Progress => Topic started by: timbo on January 25, 2015, 01:33:21 PM
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Hi all. I'm sure loads of you have come across the problem of bent side stands with some sort of bodged repair on the side stirrup. And likewise with centre stands, which also have never seen any grease, and hence the centre tube is seized solid in the stands top tube. Even better, people remove them by simply cutting one of the mounting rings off the frame!
Now I'm no engineer or mechanic even, but here's what I did.
Bent size stands; throw in wood burner till cherry red, place in vice, hit with big hammer. Dead easy, now no longer banana shaped. I quenched them immediately in a bucket of water, tho I'm not sure if that's the right thing to do.
Missing or bodged stirrup on side stand; bend heavy rod to right shape in vice with hammer etc, weld on.
Centre stand lug missing off frame; welded a big heavy washer of the same dimensions onto frame. Jobs a goodun.
Seized tube in centre stand; new hacksaw blade up middle of tube, fit to hacksaw, then saw lengthways making two or three cuts right thru inner tube. The drift out the pieces with big hammer.
To make a new inner tube, I just found a piece of scrap tube, cut to length, drilled each end. So it now slides in from either side, with an R-clip at each end.
Side stirrup missing or bodged on centre stand; get a piece of solid bar, cut to length, throw in wood burner till cherry red. Place in vice and beat with big hammer, (I tried doing this with hollow tube first, with crap results, it just kinked when I tried to bend it, so I gave up). Weld to side stand, and make up a foot to weld on. Also weld on a couple of strenghtener pieces.
So, I know none of this is rocket science, but I just thought I'd share it as I was pleased with the results.
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http://moodle.sbc.ac.uk/sharedContent/repository/to_be_packaged/Engineering,Technology%20and%20Manufacturing/Manufacturing/Heat%20Treatment%20Processes%20-%20Steel/SC4_RESOURCE_SCREEN_4/SC4_RESOURCE_SCREEN_4.html
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One thing I'd add.
My XBR had a sagging mainstand - it wouldn't pull right up to the frame when 'up' - I had an MOT 'advisory' on it. I tried a new spring but that made no difference. This is how I fixed it.
Take off the main stand spring - watch your fingers!!
The top of the spring fits in a hole in a curved metal plate which sits over the top of the main stand spindle and has a hole at the other end which hooks onto the back of the spindle .
Drill a 4mm hole roughly 5-10mm further up the plate than the original spring hole. Put it all back together and hook the main stand spring through the new hole and back onto the mainstand lug.
Hey presto! no sagging.
(http://www.millemoto.de/gx/images/product_images/popup_images/ho012-xbr500_7897.jpg)
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Thanks for the tips and advice. I take it that means I should have let the stand cool naturally? :-\
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..............I take it that means I should have let the stand cool naturally? :-\
Not necessarily. Truth is I don't have sufficient knowledge in this area. I put the link up to show that all may not be as it seems (is it ever?). I suspect the side stand will be forged and relatively low carbon content. But just what it is, who knows! Also depends on what temperature you heated it to (cherry red suggests above critical) and how quickly you quenched it. I was taught this kind of thing during my technicians apprenticeship back in 1976, but my line of work never really demanded any real further knowledge in this particular area. I know enough to know you need to be careful!
Here's another link on the subject:
http://www.roymech.co.uk/Useful_Tables/Matter/Hardening.html
Do these side stands actually bend or just wear at the pivot point (in the pivot hole and on the pivot surface)?
Do your heat treated stands seems hard on the surface? Harder than an untreated example?
Even if you have changed the grain structure, normalising might help.
Good luck. Keep us informed.
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The centre stand on my old 250RS had also suffered the seizing on the pivot tube problem so my answer was to manufacture two plates which I had welded locally to the existing stand 'ears'. I then 'found'(you could go to say B & Q and actually purchase a length of steel rod) an old motorbike axle that would pass through the seized pivot tube, drilled the plates to suit the old axle and then with washers and a couple of decent sized split pins the job was a good 'un.
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Again, thanks.
The side stands definitely do bend , as the one in the middle of the pic was a good one I used as a ref. The other two were as bent as bent things.
But yes, the pivot point also wears, so the probs can be attributed to both probs.
For the latter, an option is to cut a piece of tube, and drift into the eye of the frame pivot.
Another option could be to add weld onto the stand bolt and grind to fit worn eye.
Another way I used satisfactrally to take up play, is to slide in a thin washer.
You can probably tell by now that I don't own a lathe or the knowledge to use one :'( I'm afraid its grinders and bodging here.
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............. I'm afraid its grinders and bodging here.
A well known firm of solicitors..... ;D
If the side stands bend that easily, maybe they don't so much contain carbon as putty! It's not as if it's a heavy bike like.
LOL.
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Evening all, interesting thread chaps. I took my centre stand off complete when building the cafe racer and still have it tucked away in the workshop should anyone req it. FOC just pay the postage. Cheers Michael
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Hi Michael, can you pm me your address if you still have the centre stand. I want it for a GB250 and it is the same, almost. I will then post you some dosh. Cheers Tim :)
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Morning timbo, I sent, no I,ll rephrase that I "think" I sent you a PM not sure if you received it?? I,m not brilliant with techno oligy. Anyway I,ve found the XBR centre stand , C bracket jobbie and spring so if you PM your address I,ll post it on to you. Best regards Michael
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I am absolutely hopeless with IT technology, so don't worry about it. Unfortunately I didn't receive your pm. Could you maybe email me your address to alison.machin@tiscali.co.uk
Again, thanks for your very generous offer Michael, and I will get a tenner to you to cover post and package asp :)
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Hi Michael. If this suits better, can you text me your address to 07950 179966, cheers.
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Hi again Michael, sent you a pm with my address, hopefully you received it.
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Good evening Tim , yes just picked up your message, leave it with me and I,ll get the stand etc posted off to you shortly. Regards Michael
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Hi timbo, I have finally got the XBR stand posted off to you, that,s the good bit, the not so good bit is the postage unfortunately came to £15. I.ve put my address on the parcel so just pop a cheque in the post once it lands at your place. Hope it comes in handy for you. Regards Michael
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You're a gentleman Michael, cheque will be on its way to you asp. As for postage, that's the one of the joys of living in this far flung outpost of the empire, in fact many ads on eBay now say, 'Will not post to Northern Ireland.' :'(
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No problem, glad to be able to help out. Cheers Michael