Wheels & Brakes

The wheels come off and it is clear when I compare the spacers and bushes inside the hubs and on the axle to the parts diagram that nothing is original. The spokes are removed using Fasst Company's spoke wrench. I cleaned the rims using my sandblaster prior to painting. The spokes were blasted too and blacked with Eastwood's metal blackening solution. I used Motorcycle Consumer News' technical library as my guide. This was the clearest and most detailed of the various wheel building articles out there. I used a Handy wheel balancing stand to true the wheel.

Tim Smith very generously gave me a pattern part for me to fabricate the spacers, some felt oil seals, and critically, a photo showing the order in which the spacers, washers, seal and bushes went on the axle. NOTE: In the photo I show the flat disk (#15 in the parts diag on Table 15) with the step facing the felt. It is not clear whether the step should face the felt or the bearing - logically, it should face the felt as the recess captures the felt but there are some bikes in which the step faces the bearing. The felt is compressed between the disk and the cavity in the threaded ring (#20). So, the external threaded ring (#20) presses against the felt seal (#19) which presses against the recessed side of the disk ($15) which on the opposite flat side pushes agains the bearing (#16). The 4 cornered internal threaded ring (#21) locks the whole assembly in place. Spacer tube (#22) is locked against the bearing race by the axle nut. By adjusting the tightness of the threaded rings, play can be taken up at the bearing. Too tight and it will ruin the bearing. The bearing itself is an SKF 6204zz radial ball bearing 20mm x 47mm x 14mm. The front hub had a speedo drive (see internal gear in the photo above) and so I got a speedo unit with pick-up from Stucchi. I fabricated a mount on the bars for the speedo. I also made the dust covers for the bearings but did not use them as I like the look of the slotted and drilled threaded ring nuts. I had to get a new axle from Stucchi as I did not trust the old one which seemed to have been welded at some point! The axle is inserted from the RH side with the axle nut on the LH side-a detail not clear in some of the drawings. I also made those dinky little covers for the inspection holes after Patrick sent me the dimensions - the little tang to lift the cover, the depression to keep it within the hole, and the spring behind is not obvious from the parts diagram. The screws to hold this cover plate is non-standard. Tim Smith provided these dimensions:











The rear wheel hub and axle was a mess but most parts were intact and just needed to be cleaned. I did have to get a new rear sprocket from Stucchi which I Locktited into the hub. There are 6 rubber bushes, 3 aluminum plates and 3 strips of leather that alternate in the hub. The rubber bushes were in good condition and were levered into position, along with new aluminum plates and leather strips.


For the brakes I found a savior in Industrial Brake and Supply in Cincinnati, Ohio. For $18 they not only sold me the brake lining material, but worried that I did not have the right diameter rivets, offered to rivet the linings onto the shoes if I shipped it to them. The brakes shoes, front and rear, came back with a nice looking liner on the shoes. A small smear of red wheel grease (though the purists might blanch at the thought of the grease melting and smearing the linings) and the brake shoes are done.

The manual gives the thickness of the brake shoe at 4mm for both front and rear brakes. If it is worn more than 3mm, it is time to replace.

The front brake spring on the shoes should stretch 96mm (+- 10%) with a load of 24kg, + 2kg - 1kg. (23kg to 26 kg). The rear spring should stretch 105 mm (+-10%) with a load of 17kg+-2kg. The front brake lever should have a 10-15mm play before the shoes contact the drum measured at the end of the lever and the rear brake pedal tip should have the same play.

The hub bearings were in good condition. The manual calls for screwing the threaded ring in or out to get a 0.01 mm side play. I am not sure where and how this play is measured - at the hub by rocking on the axle or at the circumference of the tire? When the hub rotates freely (tested when truing the wheel) and there is no play when the wheels are installed on the bike, it should be fine.

The tires come from Ceat India - the only place I could that makes Ceat tires. A dealer exports it to Boston and after filling up a thousand forms at Customs, I get two tires and tubes. Since I could not see any balance weights in any of the original factory photographs I did not balance the wheels. Wheels and tires are done.

Painting

First, I need to find the right color. I take a part that has come painted in an olive, military green to my local DuPont dealer who scans it to get the composition of the colors.

I hate painting - you need to set aside vast blocks of time. Once you put on the primer, you cannot go away and finish the job over the next weekend. Juggling the schedules of The Wife, three kids and the drying time of DuPont is far beyond my skills.

So, I start by hanging the frame from a ceiling hook in a little alcove I have made at the end of the basement. I then clean it carefully with DuPont Final Klean 3901S and wipe down with a static control wipe. I put on my mask, turn my vent fans on and then spray a DuPont Fill'N Sand 131S acrylic primer-surfacer which is a fast drying, thick primer that fills in any pits on the surface mixed 1:1 with a DuPont V-3665S thinner. I have no idea if these are the optimum paints for such a project but these were recommended to me by the very helpful DuPont dealer. I wait for it to "flash dry" which takes about 10 minutes and then I repeat with another coat. After about 30 minutes, I sand it with 400 grit dry paper. I repeat this for all the parts.

Now, onto the fun color stuff. I use DuPont Chromabase for the base color coat. This is mixed with a DuPont Basemaker 7175S - Mid Temperature Activator-Reducer in a 1:1 mix ratio. Since the pot life is only 8 hours I am very careful to mix small quantities as this stuff is a pain to clean and quite expensive. I apply the first coat and it comes out nice and wet in a "original looking" olive green. I want 10 minutes for the first coat to flash dry and then apply the second. It is very tricky in my small booth to maneuver the frame so that I get to every nook and cranny while keeping the gun around 10 inches away to prevent paint puddling.

The problem here is that the clear coat has to go on within 24 hours and so I need to clean my paint gun after I finish a group of parts so that I can spray the clear coat. Once the frame is done I clean out everything and then after waiting around 30 minutes or so, start the clear coat. The instructions say that the base coat should not be sanded but there are some drips (!) and I sand them down. Let's see what happens...

I clean the frame with a tack cloth to remove any dust and start on the clear coat. I mix 4 parts of DuPont ChromaClear HC 7600S clear coat with 1 part of ChromaClear HC7603S Low Temp Activator-Reducer (the temperature in my booth is around 60deg, for 70deg they recommend 7605 Medium temperature activator). Spraying this is very tricky as the paint comes out very wet and if I linger over an area for more than 5 seconds, the paint builds up in ripples. I need to keep the gun moving. After one coat I wait 5 minutes for it to flash dry and then apply the second. Because of some ripples, I recoat it again after letting it dry an hour since the pot life is only 2 hours (at 70 deg).

After waiting 1.5 hours I sand it down with 1200 grit paper. If you are wet sanding the tank remember to dry out the inside with a hair dryer or the condensation from the water can lead to rust. This painful process is now repeated for all the parts including the wheel rims. What takes me 10 minutes to write on the blog actually takes over 15 days spread over many weekends.

Actually, prior to putting on the clear coat I added pin stripes to the mudguards and the leg shields. I just used tape as I was not confident in painting stripes neatly and did not want to ruin the paint. I did this before clearcoating because I wanted the tape to be covered by the clear coat. For the mudguards, I bought 1/8in. bright yellow and tomato red stripes made by Prostripe from my local auto supplier. They went on easily and even the bends around the edges of the mudguards and leg shields were not a problem. The picture of the front mudguard and the top bends around the leg shield show the tape.

For the tank I got a little more ambitious and decided that I would hand paint the stripes. I bought a collection of paint striping brushes but it was a complete disaster. I then discovered The Striper by Finesse Pinstriping Inc. It is basically a stencil tape in various widths that you stick to the tank and then you paint with a artist's brush inside the tape. It is very flexible and can even do tapers. Paint striping for the masses! You can even order some of the more common colors but any paint or brush can be used. While purists quibble with the use of tape, The Striper allows for authentic pin striping. A coat of clear coat on top of the stripes on the tank finishes the whole job. The last task is adding the Moto Guzzi logo transfers that I bought from Paul Montgomery of Moto Guzzino. I clean the tank sides with soapy water to remove any oil, wash it down with water and making sure the two eagles are both pointing forward, slowly slide them onto the wet surface and position them correctly. Remove the backing and with a soft paper towel press them into the tank making sure there are no wrinkles. Done!

One last "cheat": Since many parts got nicked in the assembly process I needed to touch up the bike after assembly was done. I was too lazy to buy a new batch of paint, mix and spray it. Instead, I shipped a color sample (a metal plate I had spray painted while painting the frame) to Custom Finishes, Inc. at 5021 Highway 14 South, Brighton, TN 38011 (phone:901-476-5846,901-476-5848) and they mixed three spray cans of the olive-green paint for a total cost including shipping of around $100. I then just sprayed the nicks and polished them up. Quick and easy!

For the record the official colors are as follows as translated by Patrick Hayes from the specs shown in the first blog entry.

Super Alce (Army version) 1946-1951

Overall color: Khaki-Olive (Military green)
Fuel tank: with chromed sections, Eagle with Moto Guzzi and pinstripes in gold, black, and red.
Fenders: Eagle with Moto Guzzi and pinstripes in gold and black.
Leg Shiels: with pinstripes in gold and black.
Toolboxes: with pinstripes in gold and black.
Exhaust pipe and muffler: chromed
Rims: chromed

Super Alce 1952-1956

Overall color: Khaki-Olive (Military green)
Fuel tank: Khaki-Olive, Eagle with Moto Guzzi in gold with no pinstripes.
Fenders: Eagle with Moto Guzzi in red and pinstripes in gold and black.
Toolboxes: with pinstripes in gold and black.
Exhaust pipe and muffler: black
Rims: painted in khaki-olive
In 1955, the double muffler gave way to a more conventional single muffler.

There is a third version for the Traffic Police -"Il Carabinieri"
I do not have the official factory specs. However, I have a copy of an article from the May 2005 issue of Moto Ciclismo d'Epoca by Vittorio Crippa with color photos of a Carabinieri version. It seems to be like the army version except that the pin striping is gold and red without any black. While the color for the army verison in Mario Colombo's book is specified as dark olive-green, the color for the Carabinieri verions is light olive-green, a color that incidentally was common on a number of Lambrettas of that period. Any help here is appreciated.

The Frame - Part II

I am not done with the rear mudguard. Tim Smith points out there is an internal brace for the rear mudguard that is riveted on the inside near the swing arm. So, I cut out a metal brace and teach myself how to rivet - get a gun from the local Ace Hardware, drill the rivet holes of the right diameter and then press the gun. It comes out fine! I had to be extra careful since this was pointed out after I had painted the mudguard. But, nothing got scratched.

The Frame - Part I

I inspect the frame and there does not seem to be any damage. Lots of parts are missing though: front and rear footrests, rear handlebars, side stand, rear seat with its springs, the mounts for the rear seat, the leg shields, and the tool boxes. The front and rear mudguards are not standard SA. Looking closely at the rear I find a metal valence has been tack welded onto the original rear mudguard. I remove this and, viola! the original SA shape emerges. Calls and emails are sent to Stucchi for the rest and a month later a large box shows up filled with Italian art.

Front Suspension

I remove the handlebars and the steering head nut and check the steering head ball races. They actually look OK with no grooves or pits. But several of the upper and lower ball bearings are missing.

I know there is a problem with the front girder suspension since there do not seem to be any damper adjustment knobs, there are some circular disks made of something that vaguely looks like asbestos and no sign of the tiny springs I see in the parts manual. Emails to Elisabetta at Stucchi do the needful and a month later interesting cardboard boxes filled with treasures show up.

I install the steering pivot tube with the 19 ball bearings on top and 20 on the bottom held with red grease. The play between the pivot and the bearing should not exceed 0.10mm. Basically, if you can rock the fork tubes in the steering head, replace the bearings.

After much trial and error I figure out how to mount the two sides of the girder, pull them up tight, keep the little springs and their bushes in the holes on the damper mounts, and finally, muscle in the big central spring and the two small springs.

Now to check alignment. First, I pass a rod through the front wheel axle and measure up-down twist relative to a flat plate that is flat with the two under-engine side plates on which it rests. OK! Then to measure twist relative to the L and R side of the frame. This is tricky and I am not sure I get it correct! The problem is making sure the fork is facing dead straight ahead. Of course, I have not checked whether the steering head is straight - I cannot find a rod that is long enough and straight and the right dia as the steering column. But, after eyeballing the fork as best as I can to make sure it is pointing straight ahead, I measure from each side of the girder to the front frame mounting lugs that are welded onto the spring box. Slightly off, but good enough since I have no way of preventing twist in any of the links of the front fork if I try to straighten it. Leave well enough alone!

The distance between the two inner faces at the top mount of the girder fork needs to be 140mm (70mm on each side of a center line) and between the inner faces at the bottom through which the front wheel spindle goes through needs to be 160mm (80mm on each side of a center line). There are three holes in the fork through which rods (19 and 30 in Table 12) and the front axle pass through - they obviously have to be parallel with each other. While 19 and 30 are in the same plane, the front wheel axle is offset from these two by 28mm.

I now rock the whole assembly to and fro - the bronze bushes seem OK as there does not seem to be any play in them. Wonder of wonders! (If the dia of the 6 bushes is 0.10mm greater than the pivots for any of the suspension arms they need to be replaced). I would have to press in new bushes and then ream them.

The following are the specs for the springs and the dampers:

The inside and outside faces of the 2 damper pads need to be smooth without any scoring or pitting.
The inside thrust faces of the 6 bronze bushes should be flat without any pitting, scoring or side to side play.
All the pivots need to be smooth, the threads clean. There are grease nipples that need to be checked and red wheel grease injected.
The main central compression spring has an unloaded length of 236+-2mm. A 100kg weight should compress the length from 236mm to 198 mm. If the weight needed to compress is less than 80kg, replace the spring.
The two side tension springs have an unloaded length of 133+-1mm. A weight of 25+-1kg suspended from each spring should lengthen them 136+-3mm. If the weight needed to stretch them to this length is less than 22kg, replace the springs.

A Note on Assembly:
The dampers are assembled as follows:

The cork disk (#41) is slid over the protruding boss on the lower link (#13). Next, the spring mount plate (#42) goes cheek to cheek with the cork disk. Now, mount the girder leg (#11). Slide the three metal pressure pins (#55 with dia of 8mm and length of 15mm) into the three corresponding holes in the girder leg. The steel disk (#56) goes next. There are now 8 small steel spring (#57) that get squeezed between the inner disk (#56) and the outer perforated disk (#58) - see the photo above. These are tricky to install - use a lot of thick grease - and the side plates need to be compressed to hold them. The central fork pin nut (#60) is threaded onto the central pin (#39) and the wing nut (#59) screwed onto the central fork pin nut (#60). The dampers are tightened with the wing nut till there is no side play and only smooth up and down movement. The main spring is assembled first under the steering column and only at the end, using a rod, did I lever up the leading links on #13 to install the two smaller side springs (#48) which slide over the carrier pin for the springs (#37) and tightened with the nut for the side spring pins and carrier bolt (#38). The upper link (#29) is joined to the steering head gear (#26) and the clevis fork on the side spring (#50) slides into the front arms on each side of the link (#29) and tightened with bolt #52. The rod (#30) goes through the steering gear head (#26) and the two rear arms of the upper link (#29), rod #40 goes through the central tube on the upper link (#29).

The bottom lugs on the steering head pivot (#17) go in between the two clamped arms of the lower leading link (#13) and pivot on the long pin (#19). The long pin (#39) goes through the central tube of the lower link (#13) and is locked in by the two nuts (#60) on either end. The center spring carrier plate (#43) sits on two bosses on either side of the girder arms at the bottom of the upper triangle in the girder leg and is held by two bolts (#44). At the upper end, the spring upper carrier disk or cap (#46) sits inside the spring and bears against the steering head gear (#26). Phew! A few SA enthusiasts have reportedly grown an extra hand to assemble the front forks.

One final note on the cork disks that are used as dampers: If worn and the original cork is not available Jerry Kimberlin suggests using clutch lining - see McMaster-Carr #60895K71.

Someone on the Guzzi Singles Google Group was selling a Super Alce head light and a speedometer mounting bracket. Not having an original of either I bought both. Fitting the speedo mount was an interesting exercise. I thought it would be a simple job to unscrew the steering head retaining nut (#66), put the mount over the stem, and tighten the nut back. Wrong! One moment of carelessness and the whole front end almost dropped out of the steering head! I tried all I could to push the front end back into the head but it just would not go in enough for the nut to engage the threads. I had to let the whole front end drop out of the bike.

With the front end off the bike, I realized that I had damaged the threads on the steering stem nut. The only way to fix it was to remove the steering stem and recut the threads. Which meant stripping the entire front end. AAAAAAAGH!

So!

Below you see the steering stem with the nut and a circular metal ring that is part of the steering damper. Looking at that ring made me realize that I did not know how the steering damper actually worked. More on that later. But first, I had to fix the threads.



I wanted to see if I could cut the new threads with my Patriot CNC machine. I mounted it in a 4 jaw chuck on my lathe and indexed it.







Here is the stem mounted in the 4 jaw chuck and on a live center at the tail stock.

However, looking closely at the threads made me realize that I would need to recut them completely, which meant, I had to take metal off, which I did not like. So, I welded up the threads, remounted it, and then set my CNC thread cutting program to cut new threads.

Look Ma, no hands!

After cutting the 27mm x 1.5mm external threads (the original threads, as far as I could make out, are 29 x 1.0mm), I bought a nut from the hardware store and cut 27mm x 1.5mm internal threads. If you do not have access to a lathe, Chinese taps and dies are available on eBay for $25 each. I actually got a tap and die to see how good my thread cutting was, as it was the first time I cut a thread this large on a critical component. Glad to say it was fine!

Now, onto the steering damper. After much pondering, I figured out how the damper works.

When the steering damper knob (#70) is tightened, the central rod (#61) that screws into it and is inside the steering stem, pulls up a metal tang (#63) that slides into a slot on the tube (#62) attached to the bottom of the rod. This tang, which is inside the steering stem (#17), also slides through vertical slots cut in the steering stem itself. A metal ring (#64) slides over the outside of the steering stem and sits on top of the ends of the tang that protrude from the vertical slots of the stem. Sitting on top of this ring is a Celeron ring (#65) that also slides on the outside of the steering stem. When the metal tang is pulled up by twisting the damper knob, it pulls up the metal ring (#64), which in turn pulls up the Celeron ring (#65). Celeron, which is also called Garolite (http://www.ebay.com/itm/like/121335290890?lpid=82&chn=ps), is a tough phenolic that acts as friction damper when compressed by the rising ring into the inside of the steering head. It deforms into a wider circumference and starts to rub up against the inside of the steering head. If it is still there on a bike, it might be very brittle and start to delayer. I wrapped mine in Gorilla tape and reinserted it into the steering head. The position in the photo is approximately where it will sit when inside the steering head.

Here are some photos of the front end being assembled.

The bike did not have any of the leg shields, footrests (front or rear), tool boxes, rear carrier or the correct seats. Stucchi provides! Now I dismantle the front and rear suspension and the frame for painting.