Another Benelli Egg bike

[cliffrod]

Great score- I think you’ll like that four shoe grimeca, Jim.   The bike is looking great!

[huub]

I got this in the mail from the UK yesterday, a Grimeca double sided single leading shoe front brake, I spent an afternoon stripping off a horrible silver paint job smothered in soft clear urethane. Then sanding, still plenty of wet sanding and finishing plus getting the shoes relined.



I think this will be a great upgrade

the 4LS grimeca might be a bit too much for the little benelli ,
the horrible paint is stock , i've got a new one somewhere in the shed , it came painted.
they are heavy , but apparently efficient.
I bought mine as a upgrade for the V7sport , but ended up fitting disks instead .

[Canuck750]

The brake is a double sided single leading shoe. It was stock on the Benelli 250 twin two stroke with drum brakes (and the corresponding Moto Guzzi bade engineered model) the brake also came on the Ducati Mark 3.
I managed to finally get all the original paint off and the pieces sanded and initial polishing done.
I agree that a double sided Twin leading shoe drum brake would be overkill.

The swept area of the brake shoes is about identical between the stock single leading shoe front brake and this double sided single leading shoe brake but I suppose that both sides are single leading there may be some brake improvements.
Honestly I wanted it because the backing plate vents are functional and it looks cool. 😊

[Canuck750]

Some progress on fitting a mechanical tach. I had a spare Benelli tach from my Benelli 650S restoration, the white face replica Veglia from India is as expected junk, the drive fitting thread is wrong, the glass came cracked, etc…
I bought an aluminum tach mount and Veglia 90 degree drive from Italy. The cable that came with the left side cover fits perfectly.







I now have to machine the left side cover from a 5 speed motor to fit this 4 speed engine. Not too much to shave off.



I owe Huzo credit for this Tim drilling idea, I bought another 18” front rim to fit to the double sided a Grimeca front brake hub. I made a 1/8” steel plate, formed to the diameter of the rim. Two steel bungs turned on the lathe with 10mm through hole. A removable sleeve that is 10mm outside diameter and 7.5 mm inside. A second sleeve that is 7.5 mm outside and 3.5mm inside. I used a piece of 3.5mm wire to form a spoke guide tool.











I drill a 7.5 mm through hole for the nipple then remove the guide sleeve and drill the dimple 10mm just enough to seat the spoke. The rim is set into the jug on the plywood sheet and the hub is dropped over a 15mm shaft welded to a steel plate. The curved steel plate with the the two bungs welded in are for the inner and outer spokes, each have a slightly different angle.

[cliffrod]

Thanks, Jim & Huzo.  Great to see that jig in action. 

I had wanted to build something like that over the years.  Some rims like 4402 borranis found on HD Sprints, are similarly drilled just a little different than proper Borranis or Akronts for a Ducati Single.  So the spokes flex just a little, like your earlier pics show.  Never had a failure but such things bug me, too.  I can see one of those jigs happening in my future.

[Canuck750]

Thanks, Jim & Huzo.  Great to see that jig in action. 

I had wanted to build something like that over the years.  Some rims like 4402 borranis found on HD Sprints, are similarly drilled just a little different than proper Borranis or Akronts for a Ducati Single.  So the spokes flex just a little, like your earlier pics show.  Never had a failure but such things bug me, too.  I can see one of those jigs happening in my future.

The jig worked well, somethings I didn’t explain very well.
First I made the steel curved plate, lots of heat and bending it across an old 18” steel rim. I ran a piece of 3.5mm steel rod, 90 degree bend at one end that drops into the holes in the hub. The other end of the 3.5 mm dummy spoke passes through the rim, then I put the curved steel plate against the protruding end of the dummy spoke and marked the contact point, then I drilled a large hole through the plate. Next I placed the first hollow dowel with the 3.5mm ID over the dummy spoke and passed this through the big steel bung with the 10mm hole, from the other (outer side) I inserted the hollow dowel with a 10mm OD through the hollow bung and grabbing the dummy spoke and smaller hollow sleeve. I aligned all of these three pieces and dummy spoke I. The hole through the plate and when the dummy spoke was running entered through the rim I welded the bung to the plate, repeat for spokes running in opposite direction.
Then I once again passed the dummy spoke throttle rim with the small 7.5mm OD sleeve, push the curved plate up against the dummy spoke and from the outside push the hollow pin with the 7.5mm ID through, once the dummy spoke is centered I clamped the curved plate to the rim and a second clamp holding g the curved plate to the plywood base. Then remove the spoke and small sleeve and drill through the rim with a 7.5mm bit. The. Pull out the larger hollow sleeve and with a 10mm bit and just touch the dimple to make a seat for the nipple big end.

[Canuck750]

I got the tachometer sorted, the engine side cover needed the front back section milled down 7mm to fit this 4 speed motor.



The tach drive unit needed a slotted fitting on the end of the flywheel nut, I don’t have all the bits Benelli used so I just milled up a slotted and threaded insert that screwed into the tall flywheel nut.





The cable fits nicely and I am pretty happy with the way the tachometer position and mount turned out.

[SIR REAL ED]

Looks fantastic!!!!

Nice work!!!

[Dave Swanson]

Its getting serious now! 

[Canuck750]

I have made some progress with the Benelli 250, the upholstery shop finished the seat cover, an experienced craftsman with over 40 years experience who is also a motorcyclist and does a lot of work for vintage enthusiasts. The seat pan was powder coated and the foam was saved with just a top layer of new foam, the grab strap is not installed yet, he copied the heat stamped pattern of the original cover and I am quite pleased with the look





I had repaired the stainless steel side bands by knocking flat the dents with a tiny brass punch, sanding the stainless smooth and polishing then fitting new stainless bolts and nuts





The front brake is together, new aluminum rim, Buchanan's stainless spokes, the hub and brake plates took a lot of hours to sand out the pits and scratches and polish them up, the four brake shoes were relined and the shoes arced on the brake plates in my lathe.
As per the original Benelli design for securing the stays to the fork legs, the plates just slip over the cast lugs on the fork lower leg and the fender bracket acts as a stop to keep the stays in position, this is how Benelli designed the dual front brake on the Tornado 650S and the 250C - 2 stroke twin that used the dual sided drum brake.The thinking must have been that the greater mass of the cast lugs were stronger than loading the 6 mm diameter threaded studs that hold the front fender. Every photo I could find on-line where this dual sided front brake is fitted to an egg motor Benelli or Motobi uses this mounting design.

I drew the brake plate stays in AutoCAd and had the pieces water jet cut from 3/16" stainless steel









I need to make up a pair of custom length front brake cables and I am going to machine a front brake lever dual cable perch to match the design used on the V7 Sport. The parts I got from Italy are pretty flimsy in my opinion and do not fit the cable adjuster in the lever perch nor does the cable holder really fit the lever. easy enough to make new pieces out of stainless steel to match the much better Moto Guzzi design.



I am waiting on a machine shop to repair the damage done to the cylinder head by the previous shop I had used. I had provided new custom made valve guides to be installed and the seats cut to the new valves provided. The shop failed to measure the outside diameter of the new guides and just drove them into the head, cracking the aluminum and setting the guides crooked. The shop told me I should have told them the guides may be over sized and either the head needed boring or the guides turned down to suit. I though a machinist should have actually measured the guides before just pressing them in!

After six weeks of trying to get the first shop to repair the head I just gave up and took the head to a new shop that will remove the guides, weld and bore the head and make new guides.

Very disappointing but sometimes I have to just move on and get the job finished.

[Dave Swanson]

The first "machine" shop isn't qualified to work on lawn mower engines. 

Sometimes you just wont be able to get satisfaction.  Good on you for moving on. 

[cliffrod]

The progress looks great, Jim.

[Canuck750]

The progress looks great, Jim.

Thanks Clint!



I finished fabricating the dual brake cable lever parts, copied the Guzzi V7 Sport setup, the parts need zinc plating to finish it off. I used a 2.8 slitting saw blade to cut the cable paths in the dowels, I don't know what the steel composition is of the pieces I turned, but after two cuts with coolant the darn blade is dull.  I just need to cut the cable ends and solder on brass ferrules

[Canuck750]

I made up two cable ferrule ends today, I had a length of scrap 10mm diameter brass, turned down to 6.4mm, drilled a 2.7mm through hole, parted off at 7mm, opened up one end of the ferrule to 4mm.



I am not too comfortable soldering cables, it seem the cable needs a lot of heat while the brass gets hot super quick, lots of flux and then solder



I think its a good solder joint?



The 6.4mm ferrule just slides into the 6.5mm opening in the post



and the two cables are finished



now if I could just get the damn head back from the second machine shop I could finish this bike and get to tuning it and final sorting