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Re: My 4G Restoration Blog
Posted: Fri Sep 13, 2019 10:00 am
by paul.wirdnam
nevhunter wrote:I'm NOT an expert but I think they are used outside the nuts to protect them from the "end of auxiliary spring" fittings marking the nuts as I think they will foul the hexagons without them. The 3 W/NG's I've been involved with are that way and look right. One had a complete set of forks NOS done that way. I'll try to check with the manuals I have 3 of different periods but I expect they would all be the same. I'll get back to you but not tomorrow. You can swap them over easily anytime if they are incorrect. Nev
Thanks Nev. I had thought about them being on the outside of the nut, but then they would rattle and Waller, who is usually right, has them on the inside. I notice that my '46 VH, which has the same girder forks, is missing these washers
BTW: I've just checked....the hex nuts do not foul the end of the auxiliary springs.
Re: My 4G Restoration Blog
Posted: Fri Sep 13, 2019 4:42 pm
by chris.shearwood
paul.wirdnam wrote:
So it looks like I have the correct original washers for '39 type girder forks with auxiliary springs but I haven't found any other photos on the internet of bikes with these washers. As expected, these 1/8" washers are also listed in the W/NG Parts Book, but can I find a photo of a W/NG with them....no!
I cannot work out what they are for. Are they there just to cover up excess thread on the spindle? In my case, I have (old and new) half depth nuts, and without this thick washer, quite a number of threads are visible on the spindle, which means the auxiliary spring mounting could slide across and damage the threads. But with the washer, the mounting would only rub against the face of the nut. Many W/NG I've looked at have full depth nuts and there would not be room for this 1/8" thick washers.
Hello Paul,
I`m far from being an expert so I can`t tell you much about the purpose of those washers other than to say that everything seems to go together well when the washers are on the insides of the nuts as per Waller.
Re: My 4G Restoration Blog
Posted: Fri Sep 13, 2019 5:23 pm
by paul.wirdnam
Many thanks Chris. Other than mine, yours is the first bike I've seen with these washers

Re: My 4G Restoration Blog
Posted: Sat Sep 14, 2019 3:27 am
by nevhunter
Done a big check up, Neither of the two 39 forks still here have the washers fitted. I've looked up the W/NG maintenance manual Book No.101/A1,3B and they are where you have fitted them. I cannot see what purpose they serve, though The nut is quite thin and a wider nut would seem to be a better idea BUT there you are. Waller is right as usual. and the New Old stock set are the same . I just made a phone call to the lucky owner to confirm.. Nev
Re: My 4G Restoration Blog
Posted: Thu Sep 19, 2019 9:28 pm
by paul.wirdnam
Lots of progress over the last week. My new built wheels seem in-line with the frame etc, so I must have got the off-set correct. Plunger rear end and fork all done and mudguards in:
Number plates done. Handlebars on. And bottom half of engine and gear box in the frame:
P.S. Make sure you put the breather pipe and union on the engine before putting the gearbox and/or engine into the frame

. Otherwise, you'll have to make up a special spanner to get to that union hex head...
Barrel on with no broken piston rings:
Having read about John Davies recent problem on his 4G with oil spewing out of the magneto sprocket crankcase aperture, I carried out the same modification I did on my SF31 Sloper in 2012. Having measured up, I use exactly the same seal: a Viton 20 x 26 x 4 garter seal. Back in 2012, I initially used a bog standard Nitrile seal but, due to the heat, it became hard and brittle quite quickly and started leaking, so I switch to the more expensive Viton seal which can withstand much higher temperatures. BTW: you'll not find this Viton 20 x 26 x 4 seal on any website but they are available to special order.
Using a reamer, I opened up the aperture to 26mm; this provides a tight push fit for the seal but I'll also use some Loctite 480 to bond the seal to the case. On the sprocket, I turned down the worn out scroll, and then sleeved the boss with some phosphor bronze I had lying around. The sleeve is 638 locited on, turned down to 20mm and serves two purposes. 1) the boss on the sprocket was not deep enough for the 4mm seal, so the sleeve extends the boss all the way back to the face of the magneto and 2) it provides a nice polished surface for the seal to run on:

Re: My 4G Restoration Blog
Posted: Thu Sep 19, 2019 10:11 pm
by JohnnyBeckett
HI Paul it a nice bike you are doing a lovey job it will look very nice wen done i like your tyres what make are they and wear did you get them from
Re: My 4G Restoration Blog
Posted: Fri Sep 20, 2019 9:17 am
by paul.wirdnam
JohnnyBeckett wrote:HI Paul it a nice bike you are doing a lovey job it will look very nice wen done i like your tyres what make are they and wear did you get them from
They're MITAS tyres. Available from most tyre companies although I got mine from
https://www.vintagetyres.com/
Re: My 4G Restoration Blog
Posted: Fri Sep 20, 2019 9:21 am
by john.davies
Hi Paul, nice job. I still have not sorted my oil leak out yet, put he bike to the back of the shed and have been playing with my others. I was wondering where you got the seals from as I need to get on with it. Cheers, John
Re: My 4G Restoration Blog
Posted: Fri Sep 20, 2019 1:57 pm
by paul.wirdnam
john.davies wrote:Hi Paul, nice job. I still have not sorted my oil leak out yet, put he bike to the back of the shed and have been playing with my others. I was wondering where you got the seals from as I need to get on with it. Cheers, John
Hi John, I know bearingboys (
http://www.bearingboys.co.uk) can get them because I phoned them up to check 20 x 26 x 4 in Viton hadn't become obsolete since 2012. They made some enquiries and said they could get them, but minimium quantity was 5 and as I already had 1 left over from my 2012 Sloper work, I used that rather than order 5 more.
Re: My 4G Restoration Blog
Posted: Fri Sep 20, 2019 7:25 pm
by JohnnyBeckett
HI Paul Thank you for geting back to about the tyres i will look them up and see if i can get sum for my bikes