Wednesday, April 11, 2012

update for this spring

Not a whole lot to report. I have made a few changes to my bicycles which I will report here.

The road bike got that new rear wheel with the 9 speed drum and brand new 32 hole Mavic Monthlery rim. I also exchanged that lead-heavy Shimano bottom set for a much better Miche, both lighter and nearly perfect fit which is not that easy with the old-fashioned 68mm bottom bracket. Also found a pair of Miche 702 pedals with Ti axles and CF fittings.

The "stable" with the Wastyn, Lea, Pinarello single speed and Koga Myata ready to go.

Much more important tho, I finally got around to having my favorite motorcycle chainwheel maker, Leonard Sieg, make a 42t replica TA chainwheel for the original Stronglight D-49 cranks. These have not been made for a long time now and it is nearly impossible to find anything smaller than 52t, new or used.

Now the bike is as close to original as I can get it. Both rims are replacements, both 36 hole Mavics of the same type, but the hubs are the ones I used in 1962, Likewise the 165mm D-49 cranks, axle and cups, Unica Nitor saddle, Ambrosio bars and stem and Campa headset. I used the matching Unica Nitor seat post which I still have and which is probably much more valuable (rare!) than the Campa now installed but I wanted that Campa back then and could neither afford nor get it. Obviously the Miche 302 pedals are a misfit but I do ride this bike most. The original Campa track pedals are alive and still going strong on the green Lea mixte with short touring clips.

fixed of course

Campa, Nervex, Ambrosio

The Nitor was a revolution ca 1960, the first plastic saddle, available both as road and track saddle like this one. I have used and use other more modern saddles like the Specialized on the Lea but this one remains my favorite for riding comfort.

When I was active, I had two sets of wheels as well as both 165 and 170mm cranks, using the longer for sprints and the shorter for time trials, one wheel set basically for road and training and one with silks on the track.

Since I keep mentioning the Lea mixte and discussed it in some detail in the last entry, here are few pictures of that bike, custom built 1974 by Eric Prooft, owner of "The Cycles Lea" in Bruges.

Sunday, October 9, 2011

"and now for something entirely different"

In my last positings I neglected - forgot - to mention that I sold both remaining veterans, the 1954 BSA A7 unrestored and licensed and the 1955 Mondial , also licensed and running - quite well as I was able to log up a couple of hundred Kms before parting with it this year. It has gone to a (hopefully) better home.

That does not mean that I have lost interest in two-wheelers. Not in the least.
I have renewed my very old interest in bicycles and bike riding, though to be truthful, that was never actually completely dormant.
But as one gets older, it becomes increasingly evident, that one is responsible for one's own well-being. Now at 67 I decided that some more time spent actively with the bike was worthwhile. This means of course, unless one has unlimited free time, that other things like motorcycle riding or restoring one's own material have to be curtailed.

My courtyard looks like a bike store. Five racing bike of various flavors hang from their wheels at the front corner, behind that with the basket on the bars, our everyday but nevertheless custom-built "Lea" mixte of 1974. Farther back in the other shot another Lea mixte, this one from 1986 with derailleur and not all Campagnolo. Not seen, a Marin hard-tail mountain bike and a Specialized racing BMX from the early day of real BMX racing. This one lives as a collector's item on the upstairs wall; the little kids are not allowed to use it.

Les Cycles Lea was founded in 1893 in Bruges and was disolved only recently because there was no one left to run the business.
I discovered Eric Prooft , the owner of LEA, during my first visit to the Festival van Flaanderen in 1974. This music festival with playing competition for harpsichord and later fortepiano with exhibition wis carried out every three years. !974, my wife and I were only tourists and, having discovered this fantastic 19th.c. store with real-life master bike maker, I had the first Lea made for my wife. Eric made the frame for these in batches to standard size and geometry as a typical bruggsche fiets, that is a Bruges bicycle. traditionally these differ from say an Antwerpsche fiets. This is due to the very different topography of the two cities and the street surfaces: Bruges mostly cobble stones, Antwerp mostly brick. As long as bike were made in smaller shops by artisans, such differences were catered to. The differences are both visible and obvious for the rider. French mites are different again. Unfortunately most all of this has died out with the artidan makers and the influx of cheap (in every respect) mountain bikes. Anyway, with the idea of getting a bike, we went to the historic shop just a few yards down the street from the gothic town hall and requested such. Between Eric's rudimentary English and my rudimentary French managed to convince him that we really wanted one of his bikes. From then the stock pile on the counter grew. What color, please; the frames were hanging high under the ceiling in metallic red, green or blue. He could do other colors but we would have to wait either until the new batch was finished or he would have to strip one a repaint it. He had his own enamel baking oven at the back, this, too, historic. We chose green. Good, the frame and a fork to match were laid on the counter. How should the wheels be? How much may they cost? What do you recommend? Fine; the hubs, rims and spokes were also laid on the table. Cranks and chainwheel? Fenders? Brakes? Saddle? I really highly recommend this one; it is very dear but will last for decades. OK (and it, a real leather woman's saddle, is still in everyday use!). Bars and Stem? etc etc. at the end a large stock pile covering the counter, all tallied up in pencil one the shop slip. Fine. 'Now you come back at the end of the week and I will have it ready to be adjusted and ridden.' So we came back on Friday and new bike home. It was not cheap. It has Campagnolo Record high flange hubs spoked with Mavic rims for tubulars, Campagnolo pedals, Stronglight D49 cotterless dural cranks and TA chainwheel, Mafac Racer center-pull brakes. A bike like that cannot be cheap. It is still going strong, so at the bottom line it was dirt cheap and it is still much lighter than other everyday bikes and lighter than a lot of would be racers. It has no shift at all; in Bruges you don't need one.

1977 and 1978 we bought each a 24" and 22" Lea mixte for the two daughters. These have been passed on in the meantime.

1982 while passing through Bruges from England - the ferries were still running from Zeebrugge and Ostende to Dover - I dropped in on Eric and had him take measure for a new road racing frame built to his best specifications for the flemish one day classics. The following year, I would be back to the Festival with my harpsichords and we would then finish the bike. All Reynolds 531 double-butted tubing with Campagnolo dropouts, this one got real baked-on enamel. Eric was only to glad for this since he did not like the metallic lacquers at all and only did them because they sold better. Wheels were again Campi high flange Record with Mavic GP4, 28 spokes in front, 36 at the rear with a then revolutionary 6 speed freewheel. Campi cranks and chainwheels, Campi derailleurs, Modolo Speedy brakes ( a small but high quality Italian company), Campi seat post, TTT bars and neck, Campi pedals. Some things have been changed since then. There is now a TA triple chainwheel crank set, a newer more modern Specialized saddle, Miche 302 click pedals and a Dura-Ace rearwheel with 7 speed freewheel. While this is a modern hub-integrated freewheel, unlike the screw-ons used on those historic Campi hubs, cogs for it are no longer available; Shimano changed the spline. Too bad, since the hub is really every bit as good as the Campis. I am making a new rear wheel with Miche B-Box hub with Campi splined drum laced into a brand-new(!) 32 spoke Mavic Monthlery rim which I chanced onto.
I finally found a rather rare Campi rear derailleur (Ebay France like that TA crank set) with long cage arm to manage wide ratio setups so the new wheel will have a 9 speed cluster.

Behind my two bikes in the second photo, there are two bikes with very small frames for the grandchildren. A Bianchi with aluminum frame, carbon fiber fork, and relatively modern Schimano 501 group. It is also the only bike with clincher tires. I bought this one used. Next to that and barely visible, an 80ies Pinarello "Treviso" road frame I built up as fixie so they are forced to learn an even, round cadence.
In the first photo, a japanese Koga Myata I bought for my wife many years ago, but which she does not ride, preferring the younger of the two Leas with derailleur. Altho a bit small, I will put fenders, lights, and Mafac brakes on it this week for myself to use in the winter.

Saving the best for last, This is the bike I ride most.
Made to measure for me in 1962 by Oscar Wastyn Sr. in Chicago, this is one of those professional 6 days bikes referred to on their homepage. Typical of the time, all Reynolds 531, with Nervex Pro lugs, and Campi dropout ends on the fork. I restored it a few years ago to nearly original condition, adding the single brake for everyday use but have since removed it again. Since I started training again, my condition has imporved to the point that I no longer think I need it. The Miche 502 clip pedals are of course not original; I used Campis, but the rest is still as it was, including the then high-tech Unica Nitor Mod.50 saddle: Campi Record high flange hubs, Gran Sport seat post, and pedals (originally), Mavic rims. Stronglicht bottom bracket and 49 cranks (Two sets with 165 and 170mm) and TA chainwheels, Ambrosio stem and track bars.
At the moment I am using campi Super Record road cranks with a 42t ring because I am unable to get new TA chainwheels. I will have a couple made this winter and put the Stronglight cranks back on.

As I said, this is the bike I ride most. If you have not ridden a fixed gear, preferably a real track bike, you don't know what a bike really is. After that you are spoiled. Even the best pro road bike is a clumsy makeshift by comparison.

While I have no need or desire for a modern road bike, I do test ride everything I can get my hands on, regardless of whether I could afford it or not. No aluminum bike has ever impressed me and few are that much lighter than my Lea and only very few carbon fiber bikes. Even the ones that did impress me I would not trade for my Lea. It weighs all of 9kgs with the vintage parts. With modern material like radial spoked carbon fiber rims and a carbon fiber group it could easily be reduced to about 7. With the Reynolds 531 steel frame.

What I really do want, however, is a track tandem like this:

I procrastinated and so missed this one that was for sale in France. There will be another chance. Or have one made.
Bob Jackson Cycles would make one, silver brazed with Reynolds 631 tubing, for 1600£.

Saturday, October 8, 2011

more news

This year I decided I did not need (who does?!) two so similar rides as my Skorpion XP and my Yamaha SZR. I decided to sell the Yamaha. Not so easy as I found out. Or rather easy enuf, if the price is next to nothing. This was not an option, however.

My SZR is the second oldest one recorded in the owners list in Germany, Nº.132; the first 100 units were not exported out of Italy at all. International sales began with 101.
Since getting it, I have little by little tried to refine it and remove as much weight as possible without resorting to a hacksaw and angle grinder. One of the first moves was to replace the impossibly clumsy clipons with Gilles GP Lights like I was using on all my MZs. A Brembo adjustable blake lever was fit.
New solid pegs as replacements for the utterly impossible fold-up junk were made up using third party so-called racing pegs (so-called because such pegs are not legal in actual racing) and adapters I turned from stainless. The lower one for the right side, turned down for the brake lever. The left side without, since I use a reversed shift lever, first gear up.
Prisms for a ra ing paddock stand were fit using pop rivet-nuts.
A new CNC milled chain wheel with 43t was gotten from Sieg and installed with DID 520ERT2 chain.
Bridgestone BT090 in 120/70 and 140/70 were fit.

By and by, nearly all bolts and nuts were replaced by either aluminum or titanium from Poggipolini. Both brake lines were replaced with steel braided lines from ABM, again with aluminum banjo bolts.
The front rotor was replaced with a Brembo Racing cast iron unit, together with Carbone Lorraine C55 sintered racing pads. Of course, the rotor is bolted on with Ti bolts, the caliper bolted on and also bolted together with Ti bolts as is the rear unit as well. Thankfully, the Yamaha (made in Italy by Belgarda SPA) has Brembo calipers to begin with.
The passenger pegs and their brackets were removed, the bike registered as a single seater. Those things are actually 14mm solid steel and really heavy. I found a CNC milled quick release fuel cap by TWM that fit the OEM (from Acerbis) tank out of the box. I hate those locked gas caps, especially when the ignition key has to be used. I guess this is a leftover from the racing days; race bikes don't usually have ignition keys.

With some convincing, I was able to get Glaeser to make and offer a bubble wind screen for the SZR.

After more coaxing and convincing, I was able to get a Termignoni cup exhaust, never mounted,much less used, from Heinz Weber who had bought it with the idea in mind of reworking it for his very special 14" Skorpion side car bike. Something he thankfully never got around to. When the SZR was introduced, a cup challenge was also started in Italy for which Termignoni made these exhausts which are very well made and light. Now that they are no longer made, they are very scarce and coveted.

With that mounted, I got a high-end can from SR-Racing, made for the XT660R. The can is big but it is also very quiet even though it does not have a DB eater inside. Well thought out and executed as one is to expect from SR.

The next step was to modify the cooling system. the the thermostat housing, filler, and some hoses were gotten off eBay from a YF600.
A T-junction, and hose clamps from a local supplier and a length of garden hose as well.
Unlike the SZR, grown-up Yamahas had a car-like two-circuit cooling system with a true thermostat which is shut when cold, routing the coolant back to the engine without going through the radiator. The "new" thermostat was placed in the center, the feed hose from the water pump to the engine cut apart and spliced with that T-junction so that the coolant from the thermostat, when closed, returns directly thru that garden hose to the water pump. You can see that both the return line from the cylinder head and the garden hose are both at the bottom of the housing below the thermostat valve. Only when it is hot enough, is the coolant allowed out the top of the housing to the radiator. The thermo-feeler for the thermometer is also in this housing so the reading is that of the coolant as it returns from the cylinder head. The modification is easily done, the parts cheap and it is well worth it. The engine now reaches 80ºC. with a few minutes and holds that constant. The original setup almost never exceed 60º except on hot summer days at traffic lights. 60º is too cold. Of course it is easy to block off part of the radiator and many do this to increase the operating temperature.

I left the engine untampered with - or rather I did only those things that required removing the side covers: I fit my lightened flywheel/freewheel assembly and of course I fit that solid balancer gear before something bad happened. The engine itself has never been opened as far as I know. there is no tuning save the lightened flywheel assembly and the exhaust.

I fit a SilentHektik Motocoil with BERU PowerCable as I am wont to do with all my stuff. I normally use a BERU 12-5DU plug, a very standard plug, no precious metals no nothing. Just good.

I usually modify the plug to a semi surface discharge type, a trick I learned from Tony at Silenthektik.

Of course, I also installed the (for me) requisite Ignitech Sparker TCIP4 set to a maximum spark advance of 29º and the limiter set to 9500RPM. Since finding out about Ignitech three years ago or so, I have sold at least 100 of these boxes all over the world. they are definitely worth it.
The big advantage is being able to set the curve so that one is rid of the chain lash etc. The engine runs smoother, in particular at the bottom end, but I revv this one regularly to 8500 in the lower gears and run it at a constant 7000-7500 in 5th on the Autobahn for 100 km at a time. Despite the stock engine, this bike, reduced from nearly 190kg to 167, is fast for what it is. It takes some nerve and more than a little tuning to be able get away from me. On the back roads, I seldom get out of 3rd, rarely into 4th, never into 5th. keeping the revvs between 6500 and 8500.

After loosing a nut on the rear axle despite using a torque wrench, I decided to revert to the old-fashioned style using a cotter key to secure the slotted nut, the pin itself secured with a length of braided stainless.

This is the state of the bike I wanted to sell. It must be obvious that I cannot sell this for going el cheapo rate. I offered for less with the original exhaust as well. In neither case was there any interest, at least no one inquired although I know that SZRs a constantly sought after.

I resigned myself to retiring the MZ to the attic for the time being. THe MZ is not for sale; it is a one-off bike.

Thus reconciled, I decided it was time to go for Gilles rearsets on this one, too. As mentioned above, the left side had been fixed with a makeshift. this would not do for the Gilles, so I made new part to be welded to the frame and took the bike up to my friend's metal fabricating company. Rolf is an artist with the TIG welder. Nevertheless, he had requested I wait until he had gotten his new AC/DC welder. Since most of his work is done with stainless, he normally needs only an AC welder, of which he has several. His large "Linde" AC/DC unit did not work to his satisfaction with DC, however, and he had ordered an array of new welders to the shop to try out. Then he called me up. We lifted the bike up with the crane onto the welding table (as we had with the other bike for the new exhaust), unhooked the battery, etc, and Rolf welded the new part on so that only someone really in the know can detect it. I lucked out in finding the exact same color in a spray can and the repair was finished, like new - better than new.

Gilles supplied me with 15mm sheet 6061 and I made up the two very different mounting brackets myself, the old-fashioned way, marking out by hand with scribe and square and centerpunch, drilling the holes and tapping. Only then did I cut out the outline at the bandsaw and finish with various files. then the two plates were milled to thickness from behind, there being a 3mm difference between top and bottom mounting points and Gilles' standard thickness being 10mm at the bolting pattern. Done, the brackets went to Gilles to be anodized. the standard parts were picked from the stock list as necessary and - voilá - my AS31GT4SU rearsets were finished. I am satisfied and Gilles is, too, that they look like they had been factory made. In drawing up, I had tried to keep to the Gilles style. As nice as they are, there will be no AS31GT4SU offered by Gilles. The two very different brackets are much too expensive for such a limited market.

I can supply the drawing and the parts if someone wants to make the brackets on his own. One person, admittedly a real SZR "nut", is doing just that at the moment.

And finally, I was fed up with undependable blinker relays and ones that might work at idle but not at speed. I got myself a "m-flash" digital relay from Motogadget and am rid if those problems.

update; news

Almost a year since I reported anything here; not a whole lot to report. Since my last writing, I have built a couple of engines, both 3YF and SRX.

Last fall, about this time, I did some mild tuning(101mm flat top WISECO, Megacycle 280/2 and Kibblewhites, porting; solid balancer gear, the usual) on a SZR which included modifying the airbox to accept a TM34-B65. Using a standard flexible idle adjuster similar to the one standard to the SZR, I routed the idle through the airbox and out through the left side where it can be reached by a long Phillips screwdriver. Normally, with both the SZR and the Skorpion the idle adjuster is inaccesible as long as the the seat and in the case of the SZR the tank are in place.
I made a one-off exhaust system for it. Using header for the XT660R gotten off eBay, The OEM XT 660 headers are 32mm ID instead of31,5 OD like the original SZR, thus nearly the same as the Termignoni headers that were once available (and which I use myself) I rebent those around the oiltank and made a Y-junction under the engine leding into a larger connecting bend to the Rombo can the owner already had. All joints are slipon.
I also modified the cooling system using YF600 parts (thermostat housing and filler) to be a true two-circuit temperature controlled system, unlike the original (and that of the Skorpion as well) in which the thermostat only reduces the cross-section slightly. Through the modification the engine reaches operating temperature quickly and remains at an almost constant 80º. The original system never reaches a good operating temperature at all except in summer city traffic. It is probably alright in Rome...
Otherwise, the torturing OEM clipons were replaced with PT which I had in my racing kit.
I also built up an engine for a heavily customized Skorpion using a bottom end from me. It has a SZR cluster with shorter 5th gear, solid balance gear, roller chain conversion, roller crank bearing on the right, much lightened balance shaft, lightened cfankshaft with Carillo. The cyclinder got a 101 flattop WISECO, the head was ported, a Megacycle 280/2 an Kibblewhites were already installed. A TM36-B70 is mounted with an oval K&N, there is no airbox. The owner had made up his 2-2 exhaust system utilizing two Akropovic cans.

The owner had also converted the frame to "oil-in-frame" - you can see the return oil line in the photo - and also made a very spartan seatframe. He had fit a tank from a Cagiva MITO to which he laminated a glass racing seat from the classic scene, the whole of this hinged at the front; you can just barely make out the black steel hinge bolted behind the head.

The seat frame carries the entire electric under that seat cowl on two levels. I made the entire wiring loom for this bike, utilizing a SilentHektik electronic fuse box , a 4,5Ah LiFePo battery, an Ignitech Charger rectifier, and an Ignitech Sparker ignition.

Fuse box and ignition are on the top level. The black capped connector hanging down across the blinker in the photo is for the battery charger so the nothing need be removed or opened to charge the battery.
Beneath that, the battery, with its separate connection posts. Everything is connected to the two posts, not directly to the battery which can be removed without disturbing anything else. Next the the posts is the starter solenoid with the shortest possible heavy plus cable from the post and leading straight to the starter. Likewise, the heavy minus lead to the starter is separate from the rest of the harness. Two further 2,5mm2 ground wires (blue) ground the seatframe and the the fork with switches and headlight. the separate fuse older is in that charging lead.

The key lock and ignition switch was mounted on a new, welded-on bracket on the frame on the right side. In front of that, you see the oil temperature pickup fitted to the frame. The ignition switch turns on +12v from the battery to the SilentHektik fuse box and nothing more. That box has 3 8A automatic fuses, the blinker relay and a relay as well. that relay switches +12v for both the ignition box and coil on when grounded by the kill switch. The fuses are for 1) the front end, 2) the tail end and 3) extraneous stuff like the horn. The blowers and thermoswitches have their own inline fuse completely separate from the ignition key. Basically, this entire setup is as I have it in my own Skorpion and ha on my blue bike as well, both with the SilentHektik fuse box. A Silenthektik Motocoil is used together with a BERU PowerCable R118-060.
Personally, I prefer the BERU Ultra spark plug as well. I use a 12-5DU.

This is the finished bike. I was not able to test ride this one so I could not weigh it at the farmer's coop.

over two years ago, I reported on the Gilles rearsets I put together for the Skorpion. Gilles agreed to offer these officially for the Skorpion as AS31GTMZ01. Several sets have been sold including two sets to England.

Apart from these two, I built up another two XTZ engines and an SRX engine as well as redoing a Ducati M900. Don't ask!!!!

Wednesday, December 29, 2010

Swapping clusters

Last year, I wrote about various clusters:

I did not go into what must be done to change the 3YF transmission into a 4SU unit.
3YF is the XTZ , the engine used in all MuZs, 4SU is the Belgarda SZR and the engine used in that bike which was assembled by Minarelli in Italy. Minarelli also builds the new 4-valve XT660 engine.
In that posting, you can see the different ratios and that the only difference between the 3YF and 4SU is 1st gear. Everything else is identical.
So, for those MZ riders desiring the better cluster (that the Skorpion should have had to begin with!) the easiest way to go is to obtain an SZR cluster thru eBay or similar source. They are not offered very often, however, and the price can be unrealistic as are the prices of many XTZ parts at eBay.
Lacking the complete cluster, one can order the mainshaft and loose 1st gear for the 4SU from any Yamaha dealer:
Mainshaft: 4SU1740100 list price 125.00€
1st. gear: 34K1721100 list price 40.00€

This is a 4SU cluster. The mainshaft is at the top, 1st gear at the right on it. This gear is milled directly onto the shaft. That is why the mainshaft must be exchanged. 2nd gear at the far left is pressed onto the mainshaft. This presents the main problem when rebuilding the 3YF cluster with the 4SU mainshaft. A suitable press is mandatory and one must make (or find) a piece of steel pipe into which the whole mainshaft will fit, allowing 5h gear -second from the left - to rest on the rim of the pipe. Thus set up, the shaft can be pressed thru the 2nd gear and fall free.
All the parts can are then assembled in the same oder onto the new mainshaft and the 2nd gear pressed back on. For this job, it is best to have a different piece of pipe into which only the shaft itself fits, allowing 1st gear to rest on the rim. Being observant of course, one will have measured the axial tolerance of 5th gear to turn freely as well as the exact amount the shaft stands proud of 2nd gear. Turning a small piece to fit exactly flush with the end over the shaft before disassembly will make assembly nearly fool-proof.
I have reassembled several Skorpion clusters with the 4SU mainshaft and it is not higher science but you do need, as I said, a suitable press and the mandrills to insure the the parts are moved straight. It is not necessary to heat the gear at all.
Bottom line:
As I have repeatedly written, it is a must-do for anyone riding a Skorpion hard. Apart from needing to the break the engine completely, the actual job takes only about 30 minutes, a couple of cheap and easy pieces of pipe, a lathe and the press.
The total cost for the parts (here in the EU) ±170€ plus the scraps of pipe. 200€, even 250€ are thus acceptable for a used cluster in good condition if one does not have the machineshop at hand.

If and when one does get into this, one could consider going for a shorter 5th gear; see chart below.
Slipstream offers (or at least offered the pair of gears for 270£. Here in Germany, Joachim Pethke has made pairs and such pairs do turn up in the ESA (european supermono assoc) scene.
I am using a used pair myself.
Obviously, the pressing is the same to change 5th.
At one time, OVER made racing clusters for the XTZ engine, used both by theirselves and marketed as Yamaha works clusters. These cost 2500DM in the 90ies. They now generally go for over 2000€.
Koehler here in Germany made clusters for MZ and these very occasionally turn up. I have installed one.
Slipstream offers (-ed?) a close ratio cluster as well, on my dated price list at 1500£.
Again, the ratios of the OVER and Koehler clusters as well as the shorter 5th gear are on that chart:

I do not recommend either of the race clusters for street use; I have extensive experience with the OVER myself.
For serious track outings, tho, they cannot be beaten if the motor has been freed up and the ignition suitable without rev limiter.
For street use and the rest of us (including me now) the longer 1st of the SZR together with a shorter final ratio opens up a whole new world of fast Skorpion riding - and big game chasing.

Oh, and one more thing, another important must do for anyone running the 3YF or 4SU hard:
One must replace the gear on the crankshaft for the balance shaft with either that of the new
XT660 part no. 5VK-E1536-00
or of the Raptor 700 pat no. 1S31153600
Both fit, Shown in the picture here:

is that for the Raptor. The XT660 gear is a 1:1 replacement; the thick steel washer behind the gear must remain in place.
The Raptor gear is as much thicker as the washer is thick, so the washer must be removed. The gear as far as size and module is identical. I prefer this solution.