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Z1B swingarm dimension at pivot.
Posted: Thu Jun 03, 2021 10:41 pm
Author: sharpeyie
Restoring a ’75 Z1. Swingarm had been fitted with roller bearings which were shot. Decided to replace with original style collars and add new grease caps.
Whilst waiting for grease caps to arrive from Z power, I fitted the swingarm temporarily, which was very snug to say the least. When grease caps arrived with o-rings they are each about 4mm + thick adding approx. 8mm or more to the overall width of the swing arm at the pivot. I am shuddering at the thought of the stress it is going to take to get this to fit into the frame and I am afraid I’ll do permanent damage to the it.
It can’t be right. Can anyone let me know what the key dimensions should be before I go ahead and have to take a bottle jack to splay the frame?
Ideally; width of the arm at the pivot before collars and; thickness of the grease caps (in case they're wrong.)
Any help would be appreciated.
Thanks a million.
Stewart.
Re: Z1B swingarm dimension at pivot.
Posted: Thu Jun 03, 2021 10:49 pm
Author: zed1015
The frame width should be is 235mm between the pivots and the fully assembled arm should be the same.
Re: Z1B swingarm dimension at pivot.
Posted: Fri Jun 04, 2021 6:22 am
Author: z2.john
As Zed1015 says, the fit (with caps) should be a slide into the frame. The caps with o-ring should only add about 1-2mm per side as they fit over the swing arm.
Do you have the correct swing arm? Are the new bushes seated fully (don't forget the spacer inside the swing arm between bushes)?
Set up is as below. (note that your end caps will probably look different to the ones in the pic as this is the early type end cap)
Re: Z1B swingarm dimension at pivot.
Posted: Fri Jun 04, 2021 10:10 am
Author: wilsonsjw11
If the swing arm has been powder coated make sure the ends where the bushes press in are clear of coating and are bare metal as that will add to the overall width.
I have been restoring an original UK registered 73 Z1 and someone had power coated the arm with the bushes intact.
How it ever passed an MOT is beyond me as the bushes and sleeves were as one with rust!!
Regards
Steve.
Re: Z1B swingarm dimension at pivot.
Posted: Sat Jun 05, 2021 12:18 am
Author: sharpeyie
Thanks to all for the replies.
Briefly in response to all items raised:-
a) The arm has been powder coated but the collars were cold-pressed in after the end were rubbed down (I’m glad to be able to report that ‘I saw that one coming.’)
b) 235mm is the magic number I was looking for. Thank you - that is the key bit of info that will inform my next move.
c) The end caps I think are much more than 1mm thick; nearer 3. The ‘O' rings that came with them are of the order of 3mm also so even compressed to f**k, collectively this is adding a shit load to the overall width. I think they are 'the wrong trousers Gromit!’
I’ll check in the morning and confirm.
Thanks all.
Stewart.
Re: Z1B swingarm dimension at pivot.
Posted: Sat Jun 05, 2021 5:42 am
Author: wilsonsjw11
Stewart,
The pattern items are a poor copy of the originals.
Try John Browse for originals or there are some on EBay but not cheap.
The arm is a tight fit at times.
Regards
Steve
Re: Z1B swingarm dimension at pivot.
Posted: Sat Jun 05, 2021 8:26 pm
Author: sharpeyie
Yeah so I checked again. The arm across the pivot INCLUDING the bushes are at 233mm. Add the expected 1mm each for caps and we have the magic 235. The problem is the caps I have. I couldn’t measure the thickness precisely but they are at least 3.5mm thick each in terms of what they add to the overall width of the arm. The O ring itself doesn’t compress down much less than 1.5mm either so you have essentially 9-10mm added to the over width of this arm.
WTF!
Pattern items a poor copy??? Yup you got that right - unusable. Ebay it is then - will try John Browse too (any suggestions as to where I find him?)
OK guys, again I am in your debt.
Thank you.
Rgds,
Stewart.
Re: Z1B swingarm dimension at pivot.
Posted: Sun Jun 06, 2021 5:42 am
Author: wilsonsjw11
John Browse:01978 355556.
At least the later Z1B item should be more available.
Regards
Steve
Re: Z1B swingarm dimension at pivot.
Posted: Sun Jun 06, 2021 8:40 am
Author: z2.john
if you get desperate you could try ebay number 164865407699
Re: Z1B swingarm dimension at pivot.
Posted: Sun Jun 06, 2021 10:34 am
Author: 000zeds
z2.john wrote:if you get desperate you could try ebay number 164865407699
https://www.ebay.co.uk/itm/164865407699 ... SwDF5dthHT