Moulton TSR rear pivot

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Mick F
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Re: Moulton TSR rear pivot

Postby Mick F » 21 Jun 2020, 10:17am

I suppose you're right about that, but it'll be many many times down the line before that is realistic .............. fingers crossed.

However, these are the third set in now for me. Bike brand new in March 2016 and has done less than 8,000miles.
That's two pairs of bushes worn, so that's one set per 4,000miles.

Considering that my Mercian has done 50,000miles since 1986 when I bought it ............. had it been a Moulton TSR, it would have consumed more than a dozen pairs. :shock:
Mick F. Cornwall

rfryer
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Re: Moulton TSR rear pivot

Postby rfryer » 21 Jun 2020, 10:36am

I replaced my bushings a couple of years ago with the factory ones, and didn't think to examine the housing in any detail.

But, I'm now wondering, what's to stop one from fitting longer bushings, so as to increase the bearing surface and hence reduce wear? Are longer bushings available, and if so, are there any obstructions (other than the grease nipple) that would prevent them from being inserted? Or would longer bushings prevent lubrication from getting where it's needed?

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Mick F
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Re: Moulton TSR rear pivot

Postby Mick F » 21 Jun 2020, 1:23pm

One thing to check next time, is to put the new bushes on the new spindle and feel the play and the freedom and how they slide back and forth.
Then, after fitting the bushes, you will find that the spindle goes in firmly and with zero play.
This will be because bronze bushes are softer and squishier than the rigid steel frame tube and therefore compress.

It has been suggested, and it's true I'm sure, that fitting new bushes and fitting a new - but slightly over-sized spindle - then parallel reaming to accurately suit the new spindle would be the best most Rolls Royce way of doing it.

............ but you'd need a non-standard spindle custom-made first.
Mick F. Cornwall

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Mick F
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Re: Moulton TSR rear pivot

Postby Mick F » 21 Jun 2020, 1:33pm

One thing I didn't say, was that this morning I fitted the new modified Simply Bearings bushes ............ at a few quid each ........... but fitted the old original spindle and the old original securing bolt and washers. Nowt wrong with the bolt and washers, and the spindle is hardly worn at all.

I still have the brand new spindle and bolt and washers, so all that's needed for a refurb, is modified Simply Bearings bushes.
https://simplybearings.co.uk/shop/p1205 ... _info.html

I bought a pack of two for £6.04 including VAT and free delivery.
Mick F. Cornwall

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Mick F
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Re: Moulton TSR rear pivot

Postby Mick F » 17 Jul 2020, 7:31am

Had a chat with my mate yesterday afternoon and asked him if his dad would be happy to modify more of these bushes. He said he'd be delighted.

So, I'm going to buy eight new bushes (four pairs) and they will see me ok for years and years.
One pair seems to last 4,000miles, so that'll be 16,000miles worth.
Mick F. Cornwall

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fausto99
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Re: Moulton TSR rear pivot

Postby fausto99 » 17 Jul 2020, 8:53am

A bit late to the party I know, sorry. You've fitted grease nipples to this pivot, but have you thought about actually drilling through the pivot housing tube and oilite bush and then fitting those little oil reservoir things with a flip lid, so that you can have a drip feed of oil to the bush? They used to be common on steam engines and lathes.

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simonineaston
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Re: Moulton TSR rear pivot

Postby simonineaston » 17 Jul 2020, 8:57am

whoa - steady, Fausto! - that could upset Mick's entire strategy... :wink:
byyeee,
SiE

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Mick F
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Re: Moulton TSR rear pivot

Postby Mick F » 17 Jul 2020, 9:11am

Knowing what I know now about these pivots, it matters not what you do to lube the bushes as the pivot hardly moves.
Any grease will be too thin in the place where they wear.
I've proved it by removing them and rotating then 45degs and all play went. The only wear in one area and not all round.

Putting an oiler in wouldn't help at all as the thing doesn't rotate, just jiggles over a tiny arc.
Grease often with a grease gun is all that's needed ............ but they'll only last 4,000miles.

Terrible design, but cheap enough to replace so long as you don't buy a whole kit from Moulton. Mine is still on the original spindle and the original securing bolt as there's nothing wrong with either of them.

Just buy bushes from Simply Bearings and trim down the flange thickness. £6 a pair for 4,000miles of use.

The bushes are pre-oiled but are designed for rotation equipment, not for pivoting on a tiny arc.
Mick F. Cornwall

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Re: Moulton TSR rear pivot

Postby jb » 17 Jul 2020, 7:17pm

You'd probably be better off with hardened steel bushes for that job. But they would need to be kept well oiled to prevent rusting.

I suspect that the oilite bronze bushes aren't so much wearing but being spread slightly by the constant road chatter. Oil absorbent bronze is quite soft.

Anyway probably not worth it now you've got a stock of them.
Cheers
J Bro

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fausto99
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Re: Moulton TSR rear pivot

Postby fausto99 » 17 Jul 2020, 10:15pm

Mick F wrote:Knowing what I know now about these pivots, it matters not what you do to lube the bushes as the pivot hardly moves.
Any grease will be too thin in the place where they wear.
I've proved it by removing them and rotating then 45degs and all play went. The only wear in one area and not all round.

Putting an oiler in wouldn't help at all as the thing doesn't rotate, just jiggles over a tiny arc.
Grease often with a grease gun is all that's needed ............ but they'll only last 4,000miles.

I obviously don't ride my Mk1 anything like as much as you do your TSR. I replaced the nylon bushes with oilite ones way back in the 80s and have not touched them since. No signs of any wear or play yet. I will have to take it apart to investigate the rubber squeaking, so I'll have a closer look then. Having said all that, my lockdown project carbon tube converted Mk1 will have a grease nipple fitted to the tube centre while it's still in pieces.

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Re: Moulton TSR rear pivot

Postby cycle tramp » 18 Jul 2020, 12:34pm

fausto99 wrote:I obviously don't ride my Mk1 anything like as much as you do your TSR. I replaced the nylon bushes with oilite ones way back in the 80s and have not touched them since. No signs of any wear or play yet. I will have to take it apart to investigate the rubber squeaking, so I'll have a closer look then. Having said all that, my lockdown project carbon tube converted Mk1 will have a grease nipple fitted to the tube centre while it's still in pieces.


Smug face 8) see my previous comment dated 18th May 2020 [ i.e. page 19 ]
Last edited by Graham on 19 Jul 2020, 9:52am, edited 1 time in total.
Reason: ref to page 19

Brucey
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Re: Moulton TSR rear pivot

Postby Brucey » 18 Jul 2020, 12:49pm

in the far mists of time I had a couple of Mk1 moultons and I couldn't understand why I couldn't get the swingarm spindles out. Nor could anyone else. I recently found out that the very earliest Mk1 moultons were fitted with bronze bushes, not plastic ones, which explains why they can seize up so completely, if neglected.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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Mick F
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Re: Moulton TSR rear pivot

Postby Mick F » 23 Jul 2020, 2:29pm

Mick F wrote:Had a chat with my mate yesterday afternoon and asked him if his dad would be happy to modify more of these bushes. He said he'd be delighted.

So, I'm going to buy eight new bushes (four pairs) and they will see me ok for years and years.
One pair seems to last 4,000miles, so that'll be 16,000miles worth.
Bought them the other day, and delivered this afternoon.

You can order "by the each" - or packs of five or ten.
Five would be pointless as they're used in pairs of course, so I bought a pack of ten.

Including Vat (free delivery) the bill came to £16.45 ........ that's £3.29 a pair for the five pairs.
I'll get all ten modified, keep maybe three pairs

If someone would like a couple of pairs, I can post them off at the cost price (plus postage) .............. but it may be a couple of weeks or more before I can get them trimmed down.

If nobody wants them, I'll have enough to keep my TSR going until I'm way past cycling age! :lol:
Mick F. Cornwall

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simonineaston
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Re: Moulton TSR rear pivot

Postby simonineaston » 23 Jul 2020, 9:28pm

I've just bought a ten year old TSR frame for a new project (Alfine hub...) so I'd be daft not buy a couple of pairs off of you, Mick!
byyeee,
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rfryer
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Re: Moulton TSR rear pivot

Postby rfryer » 23 Jul 2020, 11:07pm

The bushes in that frame have been replaced, probably less than 1000 miles ago. :D