Oilite or Lead-bronze bushes on Girdraulic, timing and RFM?

Martyn Goodwin

Martyn Goodwin

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Non-VOC Member
The nylon bushes were already installed when I purchased the bike. Apparently they were installed by Matthews around 2001 but the bike was never used after that, till I got it in 2011 - by then the forks were seized solid. I tried penatrating oil but it seemed to just make things worse. I full rebuilr the forks using bronze bushes from Covenrty and now have forks that - to me - seem to be near perfect.
 
Trinorvin

Trinorvin

Forum User
VOC Member
Hi, thanks to all for your advices,
tomorrow I will heat the case and remove the timing train spindles; one of the camshaft, two of camfollowers (front one of them is loose) and one of small idler. Bronze or cast iron for big idler, I do not know for the moment, any advice?
Concerning bushes, I will tend to choose bronze bushes for the front forks and timing train with fitting of grease nipples in the centre of the links (As described in last MPH page 4 and 5, thanks Bill). I would prefer to leave "plastic" to modern bikes and can see that this material sustain controversy!
And more adequate would seem to fit Oilite bushes on seat stays and link between UFM and RFM.
I will try to debrief as the work (and problems) go ahead!
Have a nice week end.
Trinorvin
 
V

vince998

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VOC Member
clevtrev said:
9 times out of 10, the spindles will drop out before you have finished heating !
I use aluminium bronze for rotating bushes. Loaded nylon with high tensile stainless for the girdraulics and eccentrics.
Click to expand...

I used the Nylon bushes in my Girdrailics once. They didn´t take to kindly to the shock loads caused by doing a somersault out of a ditch though!!!. Bloody things were all oval afterwards
 
V

vince998

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VOC Member
Trinorvin said:
Hi, thanks to all for your advices,
tomorrow I will heat the case and remove the timing train spindles; one of the camshaft, two of camfollowers (front one of them is loose) and one of small idler. Bronze or cast iron for big idler, I do not know for the moment, any advice?
Concerning bushes, I will tend to choose bronze bushes for the front forks and timing train with fitting of grease nipples in the centre of the links (As described in last MPH page 4 and 5, thanks Bill). I would prefer to leave "plastic" to modern bikes and can see that this material sustain controversy!
And more adequate would seem to fit Oilite bushes on seat stays and link between UFM and RFM.
I will try to debrief as the work (and problems) go ahead!
Have a nice week end.
Trinorvin
Click to expand...

Oilite bushes work very well within a copious oil environment (and do posses certain "run-dry" safety values), but i wouldn´t use them in an exposed area such as seat stay bushes or suspension links. (Unless you can fit the old type drip oilers sinmilar to those i have on my old Grayson lathe :), that would look pretty cool!!
 
Howard

Howard

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VOC Member
vince998 said:
Oilite bushes work very well within a copious oil environment (and do posses certain "run-dry" safety values), but i wouldn´t use them in an exposed area such as seat stay bushes or suspension links. (Unless you can fit the old type drip oilers sinmilar to those i have on my old Grayson lathe :), that would look pretty cool!!
Click to expand...

Real Oilite bushes are impregnated with grease, and intended to run dry. Stand a new one on a piece of kitchen towel, and watch the lubricant come out (slowly). If you store them, always put them in a sealed plastic bag, or they can dry out before you use them.

H
 
Howard

Howard

Well Known and Active Forum User
VOC Member
vince998 said:
How long does the oil last Howard?
Click to expand...

Good question Vince. Answers vary from "How long's a piece of string" to "It lasts the life of the bush". The lube is only used when the bush is working (heat or pressure) I've used Oilites working 8,750 hours/year, that's 250,000 miles at 30 mph. :)

Oilites are a cheap effective way of providing a maintenance free bearing, for low impact loads. I've used them in lots of designs, and sold more than I can remember with no problems. Fit and forget, until they wear, then repace them for a couple of pounds. You can relubricate them, but that's not what they're intended for. If you're fitting NOS Oilites, soak them in oil overnight first.

I personally wouldn't use oilites in Girdraulics, shock loads can cause them to break or crumble. "Proper" bronze bushes with grease grooves would be better, but the right grade of nylon or one of the Nylatron bearing materials is probably the best option now.

These are just my opinions, based on 40+ years designing (amongst other things) low tech sewage and water treatment machines that run 24/7/52, but I'm sure someone will tell me I'm talking through my hat.

http://www.nskamericas.com/cps/rde/xbcr/na_en/CNSK_Oilite.pdf

H
 
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