Greetings from Brisbane

[Gavin]

Hi Mate, once you have the correct front engine mounts for your frame, the best way i have been told (and used very sucessfully on my 3rd plunger frame) is to lay the engine on its side on  a well prepared (Padded) benchtop.
Then overlay the the frame on its side and bolt it up loosely. When done, simply lift the frame back upright, and you have managed to keep all the paint (powedercoating) on the frame !!!
Unless you manage to get the essentials back to front, but also living down under, I assume you can sort that !!!

[Greybeard]

As experience tells us, squeezing a fully loaded engine unit into a newly refinished frame is a nightmare, and it is far easier to build the motor into the frame. Crankcases and attached gearbox are quite manageable, the web above the camshaft makes a good lifting handle.

I agree.

[Superflash]

Oh goodie I did wonder why they seemed a bit sloppy...thanks for the info.

[Superflash]

Alrighty then. Have managed to get a pair of plunger mounts for 40 bucks each. Will consign the SA ones into the box of interesting but bloody useless parts... Just need to get the spacer thingy that goes in the middle. Still waiting for the piston set to arrive then I can send the cylinders off for the big rebore. Think I shall have to get a decent set of whitworth spanners before too much longer.

[muskrat]

Think I shall have to get a decent set of whitworth spanners before too much longer.

G'day SF.
Get two sets, both ring and ring/open end as well as sockets of good quality. At least 1/4 5/16 and 3/8. Throw in 2BA and ignition spanners. You'll be set for life.
Cheers

[Swarfcut]

While you flash the cash, a few cheap Cycle and Whitworth Thread taps and dies are worth having, to clean up rusted and gummed up threads. Carbon steel will be fine, 1/4, 5/16, 3/8 sizes cover most fixings.  Threads into alloy are Whitworth, Cycle thread on the common nuts and bolts.

Swarfy.

[Superflash]

Ok, stupid question time.... do these "cycle" threaded nuts and bolts go under any other name? The nice lady at the local nuts and bolts shop here could almost get her head around whitworth, but when I asked about cycle threads, she kinda when into a blank stare... . I'm guessing these are pretty much a Brit Bike exclusive thing yes? I suspect there is a definite difference back in old Blighty compared to the colonies here where everything in any auto shop you care to name is almost entirely metric. Cheers

[Joolstacho]

BSC, (British Standard Cycle thread). Also known as '26tpi' (though that pitch is not right for all the sizes).

[Greybeard]

Ok, stupid question time.... do these "cycle" threaded nuts and bolts go under any other name? The nice lady at the local nuts and bolts shop here could almost get her head around whitworth, but when I asked about cycle threads, she kinda when into a blank stare... . I'm guessing these are pretty much a Brit Bike exclusive thing yes? I suspect there is a definite difference back in old Blighty compared to the colonies here where everything in any auto shop you care to name is almost entirely metric. Cheers

Most everyday outlets, (Halfords, DIY stores etc.) here would have no idea about Whitworth or Cycle threads.
You have a local nut and bolt store!? I need to use the Internet to buy, well, most things actually.

[muskrat]

G'day SF.
As Jools said most cycle threads are 26tpi for all sizes (1/4, 5/16, 3/8 etc) but can come in other tpi's and be called CEI threads. Brass thread is also 26tpi but has a different thread angle (55 for brass, 60 for BSC/CEI/BSCY).
If you need a 5/16 or 3/8 nut or bolt in a hurry your local pushbike shop has axles (to male a stud or bolt) & nuts in bsc/cei.
https://www.motalia.com/Html/Charts/cycle_chart.html
For nuts bolts and taps & dies. https://www.classicfasteners.com.au/british-threads/
Cheers
ps: another trap are the head bolts in BSF.

[bsa-bill]

think I'm right in that 7/16 can be 26 or 20 tpi above that it 20 tpi

[Swarfcut]

Superflash... It all goes back to BSA'S origins, diversifying from gun manufacture to bicycles, hence CEI  (Cycle Engineers' Institute).  The fine threads were found to be better at resisting vibration, handy to stop thing falling off on unpaved roads.  This system was carried over as production got under way with motorcycles.  BSCy and CEI are different notations for the same thread system. Thanks to Napoleon we have the metric system, which by all accounts can also have its variants. Being a world wide standard, this is what your local parts store stocks.
  Specialist or internet suppliers are your best bet. eBay search should bring up plenty of choice.

 Have a look at the literature section of the forum. There is a handy listing of fastener part numbers and their threaded specs. Plus a list of suppliers for most things you will need.

 Bill...Cycle thread has a 60 degree thread form. 7/32" to 3/8" are 26TPI.  7/16" and above maintain the thread angle but are available as 26 or 20 TPI, up to 3/4".  That's the end of my chart.

 Smaller diameters also change the TPI.   1/8" is  40 TPI.    5/32 & 3/16" are both 32TPI, then we are off to 26 TPI at 7/32" and upwards until 7/16" and larger offers 20 and 26 TPI.

Swarfy.

[bsa-bill]

ill...Cycle thread has a 60 degree thread form. 7/32" to 3/8" are 26TPI.  7/16" and above maintain the thread angle but are available as 26 or 20 TPI

Thanks, Swarfy (76 and still learning or maybe 76 and being reminded) 

[Superflash]

Too true. At 58 it's a pleasure to be able to still live and learn.  Thank you all for all the words of wisdom. It's been a privilege. Tony

[trevinoz]

Bill,
Generally speaking cycle thread on most bikes is 20 tpi from 7/16" but Royal Enfield liked 26 tpi so much that they used it on almost every thread on their bikes, even over 1".