it looks like I had a digital misfire there and my replies to your helpful comments and questions didn't come through when I tried to post them on Saturday!! I’ll try on a PC rather that a tablet.
Ron I totally agree it looks very wrong; helter skelter springs 😊 that’s great and about as useful. I assume I did get the right saddle as used the correct part number on dragonfly and went that. I did look about on eBay at the time and there was nothing so had to shell out about £70 fror Dragon's but it looks Ok and a lot better than the absolute pile of the hideous green dual seat that it came with.
Your bike looks bloody marvellous, how do you get the engine casings like that? Are they coated or is it just a lot of elbow grease? It did raise another question. I see you have no plug cap. I have been trying off and on to pinpoint a rough running/misfire/poor idle issue to be electrics or carb. On electrics front I read that a resistive plug cap can be problematic for a magneto but probably best in another post.
Ian I’d like to take you up on your kind offer of drawings for the triangular plates and posts if I may. It looks like ill need to get these made, or at least the plates. Dragonfly seems to show something that resembles the posts. It looks like my middles size springs (100 mm long) might do the trick. You mention some front brackets, do you have a drawing of this or part number for these too?
Jan’s thread is extremely extensive indeed. My bike is a post war 1947 variety so may have had some kind universal type saddle? I’m not too fussed with authenticity as the bike is a bit of a mongrel in various areas anyway (rear wheel/chain/carb). I just want to get the correct bracketry this fit this saddle to frame.
I attach a few more pics showing mounting holes and frame holes.
Neil when you get your spring posts and springs set up to your required height. Set the saddle level with the springs upright and then make up two stout plates (Say 1" x 1/8") that you can bolt/weld to the nose of the frame which arrive at the front mounting.
Re my crank cases. When I built the engine some years ago, I grit blasted them with medium aluminum oxide grit and then gave them a rub over with fine wire wool to get a dull sheen. Ever since I just clean them now and then with a paint brush and white spirit. :+1: Ron
As my M20 had been a daily ride from 1949 through to 1984, The saddle nose mount was trashed and worn conical at each end
So I drilled ( not easy ) then reamed ( even harder ) the hole true ( well better than it was anyway )
Then I made up 2 steel top hat bushes by welding high tensile washers to some tube
These were trimmed in the middle so when inserted from each side & done up tight there was around 0.010" clearence in total between the bush &the frame lug.
If I do it again I will shoot for 1/2 that or go thicker & fit some friction washers not sure yet
The upshot of this ismy saddle can only move in a single plane arc up & down so it does not slew from side to side like a jelly on a plate.
This makes the bike feel a lot better when you ride as your backside is not going side to side
Bushes have a 0.001" running clearance inside the frame which seems to be enough to get grease through
When you set up the saddle height , have the bike sitting on its wheels, not the stand as I did initally .
Sit on the bike and keep on adjusing the pillars so that the saddle is level or tipped slightly up with you sitting on it
If you don't then the seat will slop backwards when you are riding so you will be sliding off all the time .
Even worse is the rear rail that the pillow springs anchor to will be consistantly digging into your rear end , definately not comfortable as I fund out .
Some where in this sites vast archive is instructions for alternative spring mounting using wire so the springs anchor to the top edge of the rail rather than the bottom.
Down side of doing this is there is nothing to hold the felt in place .
I went one further and cut a plate out of a 3 litre milk bottle to sit directly over the springs then wrapped the felt in heat shrink wrap ( used on pallets ) so the felt no longer gets soaking wet then rusts out the pillow springs .
"Even worse is the rear rail that the pillow springs anchor to will be consistantly digging into your rear end , definately not comfortable as I fund out ."
This is something I've been looking with my Czech seat Trevor. To my mind there should be some kind of padding under the cover. Like a compressed sheet of Coir about 1/2" (12.7mm) thick.
Whilst on the subject of seats, does any have the dimensions for the rear seat mountings. I guess the thread size is 5/16" Cycle. Is the hex size 0.600"? (15.24mm)
Then we have springs, what shape should they be?
BTW Neil,
We have in stock the same seat as you got from Drags,
My M33 has a single saddle, with which I had problems with the rear rail causing discomfort. I removed the cover and fitted a piece of pipe lagging over it and refitted the cover. It doesn't show but takes the pain away.
"Even worse is the rear rail that the pillow springs anchor to will be consistantly digging into your rear end , definately not comfortable as I fund out ."
This is something I've been looking with my Czech seat Trevor. To my mind there should be some kind of padding under the cover. Like a compressed sheet of Coir about 1/2" (12.7mm) thick.
Whilst on the subject of seats, does any have the dimensions for the rear seat mountings. I guess the thread size is 5/16" Cycle. Is the hex size 0.600"? (15.24mm)
Then we have springs, what shape should they be?
BTW Neil,
We have in stock the same seat as you got from Drags,
Hopefully some one with better computer skils than mine will be able to dig up the modification which from (unreliable ) memory was originally a period RAME modification along with the clutch nut modified to allow adjusting the squareness of the lift .
The original padding on mine was 1/4" thick felt which was just about cut into 5 strips by the springs
So I tried various tricks to put some thing solid between the springs& the packing
Loom tube worked fairly well but the milk bottle was by far the best as it is flexiable enough to contort every which way yet hard enough to allow the spring windings to slide over without pinching.
Next time I do it I will make it bigger & hit it with a hot air gun so it wraps around the springs and down the sides a bit better.
I should really get some HDPE sheeting but hey milk bottles are effectivly free and I have other things to spend my money on as you will find out shortly .
The pallet wrapping was the last mod and I am really happy with it as the cover will dry out quite quickly but the felt took days
And riding for 2 to 3 days with a wet bum is also not fun and I ride for fun not to proove I am superman .
"Even worse is the rear rail that the pillow springs anchor to will be consistantly digging into your rear end , definately not comfortable as I fund out ."
This is something I've been looking with my Czech seat Trevor. To my mind there should be some kind of padding under the cover. Like a compressed sheet of Coir about 1/2" (12.7mm) thick.
Coir will disintegrate very soon, leaving a lot of coconut dust on your rear mudguard. Originally they used a 3/8 thick sheet of horsehair felt. Difficult to find these days, but I've found a supplier who sells these sheets for a very reasonable price.
"Even worse is the rear rail that the pillow springs anchor to will be consistantly digging into your rear end , definately not comfortable as I fund out ."
This is something I've been looking with my Czech seat Trevor. To my mind there should be some kind of padding under the cover. Like a compressed sheet of Coir about 1/2" (12.7mm) thick.
Whilst on the subject of seats, does any have the dimensions for the rear seat mountings. I guess the thread size is 5/16" Cycle. Is the hex size 0.600"? (15.24mm)
Then we have springs, what shape should they be?
BTW Neil,
We have in stock the same seat as you got from Drags,
Do you sell just the seat cover without the frame? My bike already has a good saddle frame and springs, I just need a cover that fits a matchless universal saddle frame