750SSie conversion.

Mr Gazza · 19-09-2022, 07:36 PM

You may remember me picking up a tidy bog standard 750SSie a couple of years ago?
I've been thinking about a 750SS project for a very long time, I spent many hours studying pictures and slipping to sleep thinking about how my ideas could be done and if it would be possible. Buying the SS was a commitment, as I had reached a stage when I was convinced it would all work, and that an ie model was the way forward.
Obviously, I have done a lot more pondering and measuring since getting an actual bike and I'm still sure that it will all fall into place as I intend, Well we'll see.

Today Dacs came over and helped me weigh the bike dry and with the fuel tank full with me sitting in the riding position. This is for future reference when setting up the new suspension, and also to see if I shave any weight off during the build.
We also weighed my Monster for comparison, with about 3/4 of a tank full, then with me sitting in the riding position.

I'll be aiming at something more like the Monster's weight distribution as the riding position will be more upright and it will be naked.
My first Ducati was a 1992 750SS. I loved it but had a few moments when the rear end slipped out, I also found it quite uncomfortable at times, especially at sub 30mph speeds.
Above all that the power was great and the handling was superb. A fine motorcycle.
I traded up to a 1998 M900 and loved that even more.

Mr Gazza · 19-09-2022, 07:54 PM

With the bike weighed for reference, I can now start taking bits off and adding others.
The first thing I did was remove the original suicide stand and fitted one from a 620ie, this is identical to my M900Sie and doesn't flick up, but has a switch to cut out the ignition when down. I will wire this in when the time comes but as yet I don't know which cable to cut to splice it in. Unfortunately, my wiring diagram for the 900 does not show the stand switch! I will have to check the cable colours on the 900. Unless of course anyone can help out with a wiring diagram showing the stand switch?

Keeping the weighing going with my fancy new scales, I compared the new and old stands complete with brackets. Original; 0.4kg. 620ie; 0.08kg.. Ouch, not a good start and I'll be fitting a centre stand too!

I measured the free length of the forks from beneath the bottom yoke to the axle centre, so I can get the new forks in that exact position to retain the SS geometry and set the sags from there.
The rear is teasing me at the moment. I don't know how to measure the rear axle's relative position to the frame. This would be done fully extended and unloaded, so I can set sags from that position, but I don't know what to measure to as the seat rails will be coming off and there will be no reference, maybe I will have to make a fixture of some sort on the frame to measure from? Any ideas greatly received.

Luddite · 19-09-2022, 08:32 PM

Looking forward to following this one, Mr G!

Is this of any use? Side stand switch is no. 24

Mr Gazza · 19-09-2022, 09:17 PM

That's spot-on Vince. Thank you.
It made me wonder why I couldn't find the swich on my factory manual diagram, so I had another look and discovered that they have cut the diagram virtually in half and the part of the loom with the sss is on another page along with its own legend.
It appears to match the one you have posted up, but it's not in colour, nor in one piece as mentioned. The sss is number 16 on mine.
It's going to take a good hard study to see which cables I have to intercept on the SS harness to plug the switch into.
My trump card is a spare M900ie harness kindly given to me by Bitza..

Mr Gazza · 20-09-2022, 04:50 PM

It just came to me!
When I fit the centre stand, I can rest the front tyre on the ground and see what size wooden shim fits under rear tyre, or vice versa if it settles on the rear.
That should fix the position of the rear axle when the shock is removed.

Jez900ie · 20-09-2022, 05:02 PM

Quote:

Originally Posted by Mr Gazza

I compared the new and old stands complete with brackets. Original; 0.4kg. 620ie; 0.08kg.. Ouch, not a good start and I'll be fitting a centre stand too!

My math says 0.08kgs (620ie) is 3.2kgs less than 0.4kgs (the original), though I was surprised to know that 620ie had side stands made from carbon fibre?

I'll be following your thread with interest to see what you create. Have fun!

Mr Gazza · 20-09-2022, 05:05 PM

Sadly. that was a typo and the 620ie (and M900ie) stand is 0.8kg and made of forged steel.
So double the weight.
I'd have another look at your original maths. If it was 0.08kg it would be 0.32kg lighter I think?
Thanks for paying attention though..

Jez900ie · 20-09-2022, 05:11 PM

Quote:

Originally Posted by Mr Gazza

Sadly. that was a typo and the 620ie (and M900ie) stand is 0.8kg and made of forged steel.
So double the weight.
I'd have another look at your original maths. If it was 0.08kg it would be 0.32kg lighter I think?
Thanks for paying attention though..

Brilliant!

Mr Gazza · 01-10-2022, 06:27 PM

Tomorrow I might be able to get stuck in and take some of the red bodywork off.
Then the game will be to see if the new different shaped tank will fit anywhere, if at all!

Having a spare few minutes this afternoon, I had a bit of a ponder and got to thinking about fitting (and making) finned valve covers. This has been discussed in theory on here in another thread. (I'm sure Pantah ones would go straight on?)
The temperature sensor in the horizontal inlet cover kind of messes this up a bit and I wondered if it would make a massive difference if I fitted it to the vertical inlet instead.
Surely it can't be all that different a temperature up there?
It probably wouldn't matter if the vertical covers were not finned as I don't think they will be seen.

Also to be considered with this, is my plan to do away with the oil cooler, so things could well be a bit warmer than normal anyway.
Come to think about it, I would also need a cooler-bracket-less cover with a sensor hole. Do those exist?

slob · 01-10-2022, 11:02 PM

i have no practical experience of this, so don’t know of it’s even possible but the sensor in the valve cover is the one used by the ecu, so you’d almost certainly need to adjust the ecu to correct for the rear head running hotter than the front one

slob · 02-10-2022, 08:17 AM

620 valve covers have no cooler bracket but it would be easy enough to cut the ears off one

Mr Gazza · 02-10-2022, 09:27 AM

Ah yes, 620 cover. Thanks for that Rob.
The temperature issue is probably going to be a question for BSD or the likes, although I would think that the horizontal is probably a more even temperature, probably? Who knows without putting a sensor in both places and comparing? Could be an overthinking rabbit hole!

slob · 02-10-2022, 12:52 PM

simple question for BSD (or Avanti, CJS etc.) is the temp input editable

Mr Gazza · 02-10-2022, 09:56 PM

I can't wait to get to the stage when the question is relevant.

It seems to be taking a while before I even get to what I would call a starting point, however there has been some progress.

Emzedder has very kindly lent me a tank to see if it will fit the SS frame. It is sadly rather badly damaged with holes, crazing and blisters, but with care I can make a clone which can be tried on the frame.

First stage is to add an extended flange around the periphery by hot gluing balsawood all round. The bobbins at the back are blanked with plasticine, as is the filler flange. The balsa is masked with aluminium tape as supplied for joining foil backed insulation.

I called in to a tyre fitters and begged some old valves which they had cut out. I stuck these on the tank with hot glue.
Note the lovely set of dumbbells gifted to me by Ally-m900. brilliant for forming radii in plasticine. A couple of lovely metal spatulas there too which are great for sculping.. Thanks Ally.

The valves were bonded in when I laid up over the tank. Some bits of wood were bonded over the mould for feet.
You can see how the air releases the mould when injected into the valves with a tyre inflator. The whiter areas are just from the first little puff.

When the mould is released, I cleaned off all the plasticine and broke off all the balsa flanges from the tank and pushed it back into the mould. I then scratched the mould with a scriber all around the edge of the tank to get a reference to trim the final moulding.
I added a disc of Formica to form a flat land where the filler neck will be fitted and faired it into the lines of the mould. The troughs left by the plasticene fairings for the bobbins were refilled with plasticine and smoothed flat-ish. Other dodgy looking areas were "papered over" with aluminium tape.

I double gelled the mould as a thicker gel coat is going to be desirable with all the finishing that the moulding is going to need with all the reproduced damage and the cutting and shutting to get the thing to fit.
Once laid up and cured it popped out of the mould with the greatest of ease with a puff into each valve. Very satisfying..

Mr Gazza · 03-10-2022, 05:51 PM

Well, yesterday I removed the tank from the SS and had a go at seeing if the new shape was going to fit. Obviously not in its present form!

After a great deal of pondering, I bit the bullet and hacked the moulding in half. Well, I cut a side off to be more accurate, so as to preserve the flute in the top and the filler recess.

It looks almost credible with a bit of fairing removed and more trimming to let the moulding down on the frame. But many problems have manifested.

There is so little clearance between the frame and fork legs on full lock, that the tank cannot be within the arc of the legs, so with the front parts outside of the forks, it makes the front very wide indeed and not anything like the nice slim original! I don't like any of the contemporary "retro" styled Ducati tanks because of this and really wanted to do better, but the frame is the master here!
At the rear the tank extends too far back and will overlap the side panel that I intent to fit. I intended that to cover the upright frame tube behind the rear pot, but the tank is much further back than that. I think this will also put the knee cut-outs too far back to sit in the right place as well. I am loath to cut the moulding vertically in front of the knee cut-outs, to shorten it in that way as it will detract from the nice long silhouette that I desire.
It's got to fit and look right in order to make the whole project worthwhile. If this doesn't work, I will knock it on the head and restore the SS to original or better and sell it on, so at this stage I can afford to mess up quite a bit of fibreglass.
Hopefully I will get a few minutes tonight, to hack and ponder some more, but it's not looking good at the moment!

19-09-2022, 07:36 PM	#1
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	750SSie conversion. You may remember me picking up a tidy bog standard 750SSie a couple of years ago? I've been thinking about a 750SS project for a very long time, I spent many hours studying pictures and slipping to sleep thinking about how my ideas could be done and if it would be possible. Buying the SS was a commitment, as I had reached a stage when I was convinced it would all work, and that an ie model was the way forward. Obviously, I have done a lot more pondering and measuring since getting an actual bike and I'm still sure that it will all fall into place as I intend, Well we'll see. Today Dacs came over and helped me weigh the bike dry and with the fuel tank full with me sitting in the riding position. This is for future reference when setting up the new suspension, and also to see if I shave any weight off during the build. We also weighed my Monster for comparison, with about 3/4 of a tank full, then with me sitting in the riding position. I'll be aiming at something more like the Monster's weight distribution as the riding position will be more upright and it will be naked. My first Ducati was a 1992 750SS. I loved it but had a few moments when the rear end slipped out, I also found it quite uncomfortable at times, especially at sub 30mph speeds. Above all that the power was great and the handling was superb. A fine motorcycle. I traded up to a 1998 M900 and loved that even more. __________________

19-09-2022, 07:54 PM	#2
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	With the bike weighed for reference, I can now start taking bits off and adding others. The first thing I did was remove the original suicide stand and fitted one from a 620ie, this is identical to my M900Sie and doesn't flick up, but has a switch to cut out the ignition when down. I will wire this in when the time comes but as yet I don't know which cable to cut to splice it in. Unfortunately, my wiring diagram for the 900 does not show the stand switch! I will have to check the cable colours on the 900. Unless of course anyone can help out with a wiring diagram showing the stand switch? Keeping the weighing going with my fancy new scales, I compared the new and old stands complete with brackets. Original; 0.4kg. 620ie; 0.08kg.. Ouch, not a good start and I'll be fitting a centre stand too! I measured the free length of the forks from beneath the bottom yoke to the axle centre, so I can get the new forks in that exact position to retain the SS geometry and set the sags from there. The rear is teasing me at the moment. I don't know how to measure the rear axle's relative position to the frame. This would be done fully extended and unloaded, so I can set sags from that position, but I don't know what to measure to as the seat rails will be coming off and there will be no reference, maybe I will have to make a fixture of some sort on the frame to measure from? Any ideas greatly received. __________________

19-09-2022, 09:17 PM	#4
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	That's spot-on Vince. Thank you. It made me wonder why I couldn't find the swich on my factory manual diagram, so I had another look and discovered that they have cut the diagram virtually in half and the part of the loom with the sss is on another page along with its own legend. It appears to match the one you have posted up, but it's not in colour, nor in one piece as mentioned. The sss is number 16 on mine. It's going to take a good hard study to see which cables I have to intercept on the SS harness to plug the switch into. My trump card is a spare M900ie harness kindly given to me by Bitza.. __________________

20-09-2022, 04:50 PM	#5
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	It just came to me! When I fit the centre stand, I can rest the front tyre on the ground and see what size wooden shim fits under rear tyre, or vice versa if it settles on the rear. That should fix the position of the rear axle when the shock is removed. __________________

20-09-2022, 05:05 PM	#7
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	Sadly. that was a typo and the 620ie (and M900ie) stand is 0.8kg and made of forged steel. So double the weight. I'd have another look at your original maths. If it was 0.08kg it would be 0.32kg lighter I think? Thanks for paying attention though.. __________________ Last edited by Mr Gazza; 20-09-2022 at 05:09 PM..

19-09-2022, 08:32 PM	#3
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Looking forward to following this one, Mr G! Is this of any use? Side stand switch is no. 24

01-10-2022, 06:27 PM	#9
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	Tomorrow I might be able to get stuck in and take some of the red bodywork off. Then the game will be to see if the new different shaped tank will fit anywhere, if at all! Having a spare few minutes this afternoon, I had a bit of a ponder and got to thinking about fitting (and making) finned valve covers. This has been discussed in theory on here in another thread. (I'm sure Pantah ones would go straight on?) The temperature sensor in the horizontal inlet cover kind of messes this up a bit and I wondered if it would make a massive difference if I fitted it to the vertical inlet instead. Surely it can't be all that different a temperature up there? It probably wouldn't matter if the vertical covers were not finned as I don't think they will be seen. Also to be considered with this, is my plan to do away with the oil cooler, so things could well be a bit warmer than normal anyway. Come to think about it, I would also need a cooler-bracket-less cover with a sensor hole. Do those exist? __________________

01-10-2022, 11:02 PM	#10
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,712	i have no practical experience of this, so don’t know of it’s even possible but the sensor in the valve cover is the one used by the ecu, so you’d almost certainly need to adjust the ecu to correct for the rear head running hotter than the front one

02-10-2022, 08:17 AM	#11
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,712	620 valve covers have no cooler bracket but it would be easy enough to cut the ears off one

02-10-2022, 09:27 AM	#12
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	Ah yes, 620 cover. Thanks for that Rob. The temperature issue is probably going to be a question for BSD or the likes, although I would think that the horizontal is probably a more even temperature, probably? Who knows without putting a sensor in both places and comparing? Could be an overthinking rabbit hole! __________________ Last edited by Mr Gazza; 02-10-2022 at 09:32 AM..

02-10-2022, 12:52 PM	#13
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,712	simple question for BSD (or Avanti, CJS etc.) is the temp input editable

02-10-2022, 09:56 PM	#14
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	I can't wait to get to the stage when the question is relevant. It seems to be taking a while before I even get to what I would call a starting point, however there has been some progress. Emzedder has very kindly lent me a tank to see if it will fit the SS frame. It is sadly rather badly damaged with holes, crazing and blisters, but with care I can make a clone which can be tried on the frame. First stage is to add an extended flange around the periphery by hot gluing balsawood all round. The bobbins at the back are blanked with plasticine, as is the filler flange. The balsa is masked with aluminium tape as supplied for joining foil backed insulation. I called in to a tyre fitters and begged some old valves which they had cut out. I stuck these on the tank with hot glue. Note the lovely set of dumbbells gifted to me by Ally-m900. brilliant for forming radii in plasticine. A couple of lovely metal spatulas there too which are great for sculping.. Thanks Ally. The valves were bonded in when I laid up over the tank. Some bits of wood were bonded over the mould for feet. You can see how the air releases the mould when injected into the valves with a tyre inflator. The whiter areas are just from the first little puff. When the mould is released, I cleaned off all the plasticine and broke off all the balsa flanges from the tank and pushed it back into the mould. I then scratched the mould with a scriber all around the edge of the tank to get a reference to trim the final moulding. I added a disc of Formica to form a flat land where the filler neck will be fitted and faired it into the lines of the mould. The troughs left by the plasticene fairings for the bobbins were refilled with plasticine and smoothed flat-ish. Other dodgy looking areas were "papered over" with aluminium tape. I double gelled the mould as a thicker gel coat is going to be desirable with all the finishing that the moulding is going to need with all the reproduced damage and the cutting and shutting to get the thing to fit. Once laid up and cured it popped out of the mould with the greatest of ease with a puff into each valve. Very satisfying.. __________________ Last edited by Mr Gazza; 02-10-2022 at 10:00 PM..

03-10-2022, 05:51 PM	#15
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	Well, yesterday I removed the tank from the SS and had a go at seeing if the new shape was going to fit. Obviously not in its present form! After a great deal of pondering, I bit the bullet and hacked the moulding in half. Well, I cut a side off to be more accurate, so as to preserve the flute in the top and the filler recess. It looks almost credible with a bit of fairing removed and more trimming to let the moulding down on the frame. But many problems have manifested. There is so little clearance between the frame and fork legs on full lock, that the tank cannot be within the arc of the legs, so with the front parts outside of the forks, it makes the front very wide indeed and not anything like the nice slim original! I don't like any of the contemporary "retro" styled Ducati tanks because of this and really wanted to do better, but the frame is the master here! At the rear the tank extends too far back and will overlap the side panel that I intent to fit. I intended that to cover the upright frame tube behind the rear pot, but the tank is much further back than that. I think this will also put the knee cut-outs too far back to sit in the right place as well. I am loath to cut the moulding vertically in front of the knee cut-outs, to shorten it in that way as it will detract from the nice long silhouette that I desire. It's got to fit and look right in order to make the whole project worthwhile. If this doesn't work, I will knock it on the head and restore the SS to original or better and sell it on, so at this stage I can afford to mess up quite a bit of fibreglass. Hopefully I will get a few minutes tonight, to hack and ponder some more, but it's not looking good at the moment! __________________