Belt Rim

[Rob]

Hi,

I am about to start to remove the old belt rim off my TS for painting and a clean up. The screws that fix the rim to the spokes (via the tab) are completely rusted and will need replacing. They apprear to be 3/16 x 24 tpi BSW.

To take it off I will have to drill out all the screws so I will not recover any. I was wondering if this thread is original.

Also the current screws appear to be punched after they are in place to help stop them coming loose. Is this the correct method? Any advise would be welcome.

Rob

[Chris]

Hi Rob The screws clamping the belt rim to the spokes were originally 3/16 Whit. with round heads and these are still available but quite difficult to find. Usually the tabs into which they screw are also rusted and just not worth cleaning up and painting even if the threads are not damaged by drilling out the old screws. I think a better solution is to make new tabs out of steel strip then drill and tap them 2BA. This way you get more threads although not so deep in the thin tabs. 2BA screws are readily available and no one will know the difference if you paint them. It would take an expert and very fussy person to notice even if you nickel plate the screws and only paint the tabs. Incidentally I have never seen the screws peened over to prevent loosening and I have never had them come loose. Chris.

[Ian]

I guess if you are worried about them coming loose Loctite would be a good option.

[Marcus]

Hi Everyone,

For my 1925 TS I have got 2 brand new wheel rims and a new belt rim. I have drilled the belt rim for the 20 short spokes that locate it to the wheel rim and I have made new clamp plates to secure it to the wheel spokes, however I am not sure how many of the clamps are correct. I have seen photos with the every 2nd set of spokes so 10 plates and some with them only every 4th set of spokes so only 5. Can anyone tell me how many there should be, I am inclined to every 2nd set of spokes so 10 plates

Many Thanks
Marcus

[Hutch]

Marcus,

I had a quick look at the 3 belt rims I have and two have 7 plates and one has 6. Non consistent number of short spokes between the plates!. On the two with 7 plates, they have 3 short spokes between all of the plates except for one segment which has two short spokes. The one with 6 plates has 3 short spokes between all the plates except for two segments which have 4 short spokes. All 3 belt rims are slightly different designs and I don't know which ones (if any) would be original, or a later replacement (genuine Douglas part or repro - no idea). All have patina that indicates they were used in period and not recent repro's. One is still on a wheel which appears to be an original (this is the belt rim with 6 plates) and has not been dismantled recently.

(the two rims with seven plates have the number of short spokes between the plates as 3,3,3,2,3,3,3 (i.e. 20 short spokes) and on the other rim with 6 plates, the sequence of the number of short spokes between the plates is 3,3,3,4,3,4 (i.e. 20 short spokes). )

The plate always seems to be close to one of the short spokes.

Can take some pictures if that helps. I will have a look through some period pictures when I get a chance and see if I can spot what was the norm back then.


Cheers

Hutch

[Hutch]

Marcus,

Interesting, I have found a couple of period pictures in which 2 3/4hp Douglas belt rims don't appear to have the plates fitted to the belt rim and rely on the 20 short spokes to do the job. In the 1916 Instruction / Part book there is a rear wheel shown without the plates on the belt rim.........So maybe originally no plates? Maybe "Colonial" , 4HP or later 2 3/4hp models had them for extra robustness (belts and braces)? Don't know and more research to do!

Cheers

Hutch

[Jonathan Hewitt]

Morning all, I have two rims here both believed original Douglas and they are both,  3,2,3,3,3,3,3.
   Try ebay No   115741166051 for whit screws. the seller has more than 1 length.
   Regards
Jonathan

[graeme]

On the original 1914 belt rims I have, there are so many holes drilled in them that it is hard to work out how many plates were fitted originally! I suspect they were probably fitted by owners when they found the belt rims moved without them fitted

[Marcus]

Thanks Everyone for the replies.

After Hutch's advice I looked at the parts manual and there are no clamp plates shown, however as the 20 spokes are straight and the belt rim is subject to torque from the engine and also the brake it seems sensible to me to have a reasonable number of clamp plates in place to help secure it to the wheel. I have made plenty of them and have a box of 3/16 BSW machine screws so will probably go with 10.

Cheers

Marcus

[cardan]

Hi Marcus,

For what it's worth I have built wheels for veterans with either short spokes, or clamping plates, or clips that attach to the spokes (Triumph style). I've not had a problem with any of these systems. Because the belt rim is large there is not a lot of torque to be transmitted. Short spokes and clamping plates seems a bit "belt and braces". The only problem with short spokes is making them: my thread rolling machines make it tricky to roll threads on spokes only and inch or two long.

Leon

[Edit: Should add that the screws for the clamping plates are almost universally 5/32W. 3/16 screws always look a bit chunky to me, but I have been called a wheel wanker...]

[Hutch]

Hi All,

I had a look in the later 2 3/4HP parts lists and part 1408D is listed from 1922 to 1927 as "Belt Rim Plate and Screw" I missed it in my previous quick search. I had a look in the 1919 2 3/4 HP Spares List Errata from 1919 and it is not listed and the highest part number in the Wheel Group is 1404D. So possibly the plates were introduced (or at least listed) by Douglas sometime between the end of WW1 and 1922 - possibly from improvements that were developed during ww1? Not sure.

I still looking for a period post 1919 picture of a belt rim with the plates fitted but have not had much spare time unfortunately. I've been pondering the reason for the unsymmetrical positioning of the plates? Maybe some reason, (like balancing the wheel?), that has been lost in the midst of time? - I have no idea but it has me intrigued!

Marcus - I think 10 will be plenty! If I get a chance I will measure the thread of the presumed original screws I have.

Cheers

Hutch

[Hutch]

Screws I have are 3/16 24TPI as discussed above. I see where Leon is coming from re screw size but the heads of these screws are fairly small compared to the thread size i.e. less than 5/16" across the round head, so maybe don't look too oversized?

-Hutch