750 roadster re build

Well the case bolts will now be 7/16 and 3/8, just need to drill and ream the holes. Im tempted to tap one side of the cradle as well so the case nuts are more of a lock nut, nothing lost if that doesnt work. Since I have welded up the cradle holes it might be a bit of a mission getting everything square again, Im kind of thinking that the best way will be to set it all up on the mill table (engine cases, cradle, gearbox and swingarm) and see how it goes from there. Im also going to have a go at fixing the crack in timing cover with some of those aluminium brazing/soldering rods.

On another note Im trying to decide on colours so I have been playing with some spray cans and spare tank, I think the wee Suzuki might end up with the spare roadster tank on it....

Why not weld up the crack in the cover. Easy enough. If you're getting a new one I'd be interestred in yours. I have a chrome one now, and am de-chroming my bike.

bwolfie said:

Why not weld up the crack in the cover. Easy enough. If you're getting a new one I'd be interestred in yours. I have a chrome one now, and am de-chroming my bike.

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Its close to welding, well it looks the same when its done and if it doesnt work Ill grind it all out and weld it properly

Im slowly making some headway, Ive got a couple of reamers and a tap on the way to clean up the case bolt holes and cradle holes so most of my progress has been on cleaning up frame bits, I actually wish I had of taken a photo of the back wheel before I started cleaning it, I had to scrape gunk off it before I could even try scrubbing it....

The front brake is back together and the mesh screens painted, it is vented now though as I didnt realise that the blanking plates were alloy and dropped one in the tube I was using to clean the steel bits... it disappeared. The oil tank is cleaned and painted, it took a lot of shaking with a handfull of old nuts, bolts and petrol to get the crap off the inside of it. Then the nuts really didnt want to come back out again either. There were some broken welds on the battery tray so I welded that up again, I actually fully welded it to make it easier to paint, it is damn near impossible to get all the oil from between the lap joints on it. I also rounded off all of the sharp corners on it, I dont particuarly like bits that can take off chunks of skin.






Starting out on the back brake now. Does anyone know how much movement is allowable for the riveted pin? I realise that the bolted plate will hold it reasonable well but this one seems rather loose.



A bit more playing around with spray cans to have a look at colour schemes (they need sanding back and repainting anyway)

The mesh screen on my '69 front brake was brass with some kind of plating, so I just cleaned it up with some acid, polished it and put it back on looking brass. Yes the blanking plates are Aluminum, mine polished up fine, but are in the storage bin.

Dave
69S

After seeing all of the out of alignment posts on here recently and since Im in the process of fixing my cradle I set up the swingarm on the mill bed to see how square it was (or wasnt). I clamped down the spindle on a couple of V blocks and one end was about 5mm higher than the other (I actually measured the height of the axel slot). It was pretty easy to straighten, I put a packer under the low side and wound down the high side with a third clamp. They are not the most rigid fabrications around, you could probably twist one by pulling on the top of the wheel when it is fitted to the bike.

Cheesy said:

A bit more playing around with spray cans to have a look at colour schemes (they need sanding back and repainting anyway)

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Lot easier to Photoshop than paint and sand. :mrgreen:

swooshdave said:

Cheesy said:

A bit more playing around with spray cans to have a look at colour schemes (they need sanding back and repainting anyway)

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Lot easier to Photoshop than paint and sand. :mrgreen:

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For some... I never got the hang of photoshop, this is kind of like sneaking the desert before dinner :lol:

Cheesy said:

Well the case bolts will now be 7/16 and 3/8, just need to drill and ream the holes. Im tempted to tap one side of the cradle as well so the case nuts are more of a lock nut, nothing lost if that doesnt work. Since I have welded up the cradle holes it might be a bit of a mission getting everything square again, Im kind of thinking that the best way will be to set it all up on the mill table (engine cases, cradle, gearbox and swingarm) and see how it goes from there.

Click to expand...

Since you're ordering off the menu now, I strongly suggest you go with some aircraft AN bolts for your engine mounting. You can specify their AN size and diameter for a perfect fit to your new reamed holes, and get a proper length "grip" that has no threaded portion until it protrudes outside of your engine cradle. Threads are lethal on bolt holes.

I won't do a build without using them.

Holmeslice said:

Cheesy said:

Well the case bolts will now be 7/16 and 3/8, just need to drill and ream the holes. Im tempted to tap one side of the cradle as well so the case nuts are more of a lock nut, nothing lost if that doesnt work. Since I have welded up the cradle holes it might be a bit of a mission getting everything square again, Im kind of thinking that the best way will be to set it all up on the mill table (engine cases, cradle, gearbox and swingarm) and see how it goes from there.

Click to expand...

Since you're ordering off the menu now, I strongly suggest you go with some aircraft AN bolts for your engine mounting. You can specify their AN size and diameter for a perfect fit to your new reamed holes, and get a proper length "grip" that has no threaded portion until it protrudes outside of your engine cradle. Threads are lethal on bolt holes.

I won't do a build without using them.

Click to expand...

Being from a metric country that doesnt take to kindly to cad plating I have not had much to do with AN bolts in fact Im not sure if they are really even available here, from what I have found on the net it apears that there is a close tolerance verson of each size?

I did as homeslice advices, got mine AN bolts from Aircraft Spruce and ran em almost like a racer and they still slip right in, when ya get em aligned just right.

I'd vote against threading the cradle d/t stress risers in threads and expansion thermal loads and vibration working on the peaks to weaken up again.

The Al repair stock is good stuff, just needs distorting level of local heat, but main down side it the color match. The little i did was darker patch. A good Al patch paint would be nice to blend in better. I'm picturing the jeweler like dressing to get the contours and seams just right again. Earthquake huh, is that better or worse luck than a head delivery left at garage door the wife backs out over?

hobot said:

I did as homeslice advices, got mine AN bolts from Aircraft Spruce and ran em almost like a racer and they still slip right in, when ya get em aligned just right.

I'd vote against threading the cradle d/t stress risers in threads and expansion thermal loads and vibration working on the peaks to weaken up again.

The Al repair stock is good stuff, just needs distorting level of local heat, but main down side it the color match. The little i did was darker patch. A good Al patch paint would be nice to blend in better. I'm picturing the jeweler like dressing to get the contours and seams just right again. Earthquake huh, is that better or worse luck than a head delivery left at garage door the wife backs out over?

Click to expand...

Hmm hard to know, did she do much damage to the head in the process? At least my timing cover isnt quite as critical as a head.

Well a little bit of progress in the right direction, more earthquakes slowed things down a bit again...

Shims/spacers made for the rocker spindles and ready to go together



Bosses welded to the swingarm spindle tube, still have to drill so size and tap (yes I will go out and buy a UNF tap instead of using a metric one...)



As the welds on the cradle were worse than crap I ground as much of them off as I could and re-welded them, the plates still had mill scale on them which had been welded through



And finally some leftover bits from work that I think I will try and use to make a decent centre stand pviot, it may end up working a lot like the swingarm pivot arrangement

Well the timing cover repair seems to have worked alright, I ground out the crack with a carbide burr in the dremel then preheated the cover in a small toaster oven (very handy, worth the $40 to not get in trouble for using the kitchen) then used one of those aluminium solder kits (ideal 720)











The colour difference between the solder and the cover is much more apparent in the photos than it is in real life.

The rabbit wanted in on some of the cleaning/polishing action.....

The aluminum solder stuff is great. But as they oxydize the differance will become even more evident.
It's not in a highly visable area so your fine.

Slow progress as of late, you get that with a baby though. I have managed to sell some other toys to fund a few more commando parts that I needed - gearbox bits, just need sleeve gear bushes and a lay-shaft bearing now, then I can pin/lock the bearings and put that back together.

Ive also got the cradle mount bosses on the crankcases welded up and machined flat again to fix the slogged out holes. On the motor side that just leaves reaming the case bolt holes and aligning/re-drilling the cradle holes. After that its just bolting the motor back up (some other new bits for that which almost look too good to put inside a motor).

Ive also been playing around with some body work, well a fastback style tailpiece....







This is an MDF plug, made by cutting longitudinal shapes out of 16mm MDF and gluing them together, about 18 pieces across the width. It was then sanded, filled and sanded again. If I was to do this again I would make the cut out profiles so they were on the out side of the shape I wanted and not have to use filler. The wood was a lot easier to sand than I thought.

The profiles for the plug were made from the CAD model I started doing here

vapour-ware-commando-t9236-30.html

Another thing that I didnt take pictures of was putting the rocker spindles back in, some of you may have better ways of doing this but this way worked for me. I found it almost impossible to heat up the head, stack the rocker and two spacers and get the spindle through the whole thing... while its too hot too touch, fun times.

for my improved method I assembled the spacers and rocker using the non sharp end of a 12.5mm drill bit to hold it all together, then put it in a toaster oven to heat it up. I could then carefully slide out the drill bit and replace it with the spindle. Once it cooled down a bit I did the same thing for the next rocker.

Get hold of Dave Sewall in Hornby he has your fastback tail and tank moulds save you doing them your self.

I love the CAD model.