pschrauber

The OT stated the frame number begins with 191, so its a model 191 made between 09/1976 to 02/1977, (1451 bikes where made of this model). Changes to the previous model where principally in the crankshaft. These bikes where in standard outfit fitted with alloy fenders. The later 199 build from 05/1977 to 09/1978 where red and had plastic fenders, these had too black fork bottles and colored engine instead of polished alloy for the previous 191. The 199 got a new tank first made of fibreglas later in plastic, (where the design of decals to the early fibreglas tank was the same as for the 191), a new seat design, new airbox, new sidepanels and chain cover. The foot lever for the brake changed their position too. There where some national differences between the exported models, (the bikes that where delivered to other nations where fitted with different components), back then - in the mid to late 70's - Sherpas delivered to the UK where still fitted with the metal gas tank and also with a chain cover to the front sprocket too, to name some specials for the UK bikes.

Good hint, the book "Historia de la SherpaT" from Francois Stauffacher has some good color picture from nearly any Sherpa made by Bultaco, ISBN: 84-607-3101-4. The red color that matches very good is Ford Sunburst red XSC1493A. Google pic's "Bultaco Sherpa 191" or "Bultaco Sherpa 190" and you find some pictures oo, btw. the 190191 had alloy fenders when the came out of the factory.

It is btw easy to determine if you have high tensile bolts or not. They should have a tensile strengh of at least 800N/mm

This bike was restored bei Helmut Hacker in Germany, he had a few ... Puch's as I know, He donated the bike to the Austrian trials museum. If you have any questions belonging technique ... you will find him at German Trials Forum www.trialforum.net, username: helmi-1.

Still have my TY 125 which was my first "bigger" trialsbike, the only big issue I had where the forks, it took me only some weeks and after a "teenager + bike" flip I managed to bend the stanchions. Back then when all spare parts where available not the biggest problem to get a new pair, beside being very costly for me as a teenager in the beginning 80's. As I have luckily got better in riding, I still feel unconfortabele with the fork as the standard one feel somehow "flexy" too. To cure the softish steering feel a switch to a bigger stanchion diameter was very desired from my side. So I searched, found and bought a good working and priceworthy used fork and clamps from a TY 250 mono through E-Bay, (via international search), for my TY 125. Very recommended from my side! So forks and clamps from the TY 250 twinshock or mono model do show up, - not too often -, but they do, you just need some patience.

I was first a little bit suspicious about the disc brake, (had the Honda CB 750 FOUR in mind as one of the first bikes that was delivered with a disc brake in 1969 as standard production bike), anyway as some posted that this Cheetah had them earlier and I'am not familiar with this brand I would say yes as it is part of the history of the bike itself. The bike might be be ahead in technical standards in comparison to others from the same era but when this was already 45 years ago so too you can't exclude it in my opinion as it has the right to operate in non-compliance under a variance or continuation permit, (hope this is the right expression in German it's Bestandsschutz). It would be something different if the bike is fitted with a technical improvement that was already illegal for use back then. As a comparison for this we had a two wheel driven SWM, that was used in the beginning eighties in national trials. This bike was foreclosed from national trials competition after some events. A very unique construction that was reliable too but had so many advantages back then compared to other bikes that this type of additional drive was not allowed.

There were different fork clamps made some had a recess for the allen srcew, some not, the fork clamps for the last Sherpas had threads inside the fork clamps and a recess so there where no possibility for swapping the bolt direction. As hewson stated you can switch to zinc plated or stainless steel type bolts these are not so apperent like black ones.

When it is contemporary than is OK, the grandfathering agreement here allows the exceptional of the principle, as we have a lot of self build bikes from the 60's and 70', like the Becker Montesa from 1979 f.e.: which was with mono suspension and the frame including the gas tank much ahead of the time.

The "rebuild" was done with some efford but not finished I would say. Quoted from the seller: "The disk brakes are original, ... "(original from which period, bike, ... ??? I will only believe this by proof, never heard from a trials machine from 1967 with disk brakes??? but if someone know, show and tell there is no problem to educate me ), If the front brake is not contemporary the bike would not be legal at most events in Germany. The exhaust looks strange and unfinshed too, the tank appears to be very large, it looks unbalanced in first view, the pic's aren't the best and the rest of the bike is hided in the shadow, (may be better so). A good project bike for further building up for sure.

There should be filled up with 180 cc or 0.18 liter oil for each "forkleg"

As you have ordered the oil already I would give it a try. The best way to find out the right damping for the forks is by practise, as it depends a lot of your personal riding style too. If you will find out that the damping is too soft you then might go up. Standard fork oil has SAE 10 for the Betor legs, a little bit "thicker" and therefore will lead to a slightly stiffer damping. I personal like the softer fork more as for me this set up helps me more while lifting up the front wheel. The "lighter" oil will also make the fork more sensetive which keeps the bike more steady too in my personal experience.

Works fine, it depends on your weight too, for my weight, (around 70 - 72kg), with full gear I'am very pleased with this oil. With more weight you might need a stiffer damped fork and an oil with is less thin like SAE 10. As "thinner" the oil as smoother the damping effect of the fork will be, as "thicker" as stiffer. The standard oils begin with SAE 5 and goes up to SAE 15, so 7,3 is just in the middle. A good compromise.

As Naichuff posted the brake plate on the right side sits straight to the right lower fork leg. Any tolerances will be balanced out by the bush on the left side. Be sure that the bush on the left side of the bike runs free and is not fastend by the bolts on the left lower fork tube. I had an little issue with the bush while mounting the front wheel due to a little metal chip that worked like a choke and so jammed necessary movement.

As my post #19 is a ultra short story, You find a little longer one here: Webermichel (comes from KTM's homecountry as riding a big bore two stroke KTM by myself). To the Maico, does the bike share some spec's/technic with the Bundeswehr Maicos back then?

Mmmh .... no They used their own engine parts, actually the biggest bottom and crank they could find which would be from a 400 or 440 cc engine and combined this with the cylinder from the 250cc. In the mid 70's KTM thaught as many factorys back then trials bike will sell easy in the next couple of years, and first ratings of the importers and dealers gave 4-digit numbers they could probably sell. So they started the project. Just when all the prototype job was over and Walter Luft and Krahnstöver had made their job in developing the bike the predicted numbers where only three digits just under thousend. KTM then abdonade any further production plans abruptly, (they just had annouced the bike to pubilc) but withdraw the bike from the big German bikeshow IFMA. Here the bike: To the Maico bike: (more important!): Very nice bike and thank's for the pic's with Hans Cramer!

The mentioned weight loss is a good idea and will have a lot of effect. Here a comparison what you will loose in weight between the big flywheel weight of the 350 to the 250cc model: I personal would only change the right crank weight and try with this, it will change the habit of the engine already a lot. When exchanging the rotor too the engine will get really "snappy". The use of the smaller flywheel weight was done very often, some former Bultaco riders in Germany even tried to turn them down which is not easy as the flywheel weight is completly hardened. (Anyway I have been told that a weight reduction on the rotor side too will make the bike/engine less useable for trials, I persoanl haven't tried out this). If you really can't get away from the need of reeds, here some NOS ones from the US E-Bay, (as mentioned there where a lot of Pursangs sold in the US, a complete set up): Bultaco reeds

There is a factory that is specialist in hard chroming mechanical parts, they do also stanchions for motorcycles, they will charge you around half of the costs you mentioned in your first post, (with aligning the stanchions if necessary (up to 1/500!) too). Here the address and pic's of their work: Wissing Hartchrome I have sended them two pairs of stanchions in the past already and they did a perfect job.

I have heard that there where a few Sherpas around, as I remember right, (definitely not sure here), had Paxau once fitted one to an engine? Fitting reeds to the Bultaco engine would be not allowed in general in Germany or at the Inter Nordic Cup, (Scandinavia). Probably if you build a completly replica bike. If you really want to go with reeds I would try to get the Pursang reed intake and maybe also a cylinder (if possible to loan?) just for blueprinting and determine how the reds should fit best. The Pursangs had a reed intake, maybe you can find a reed intake in the US:

I have followed the discussion also very interested. I believe, not sure here, the very easygoing rules you have left so much room for interpretation depending the bikes that this new class of modified twinshock bikes just appeard. Once the evolution is present there is no way back. This was probably encouraged through the fact that monoshock bikes modified to twinshock bikes where allowed. Then I believe with your higher numbers of riders the competition between the clubs and riders is harder as in my country f. e.. As you have more riders in the hole a second "modded twinshock class" should not be a problem? There is in my personal view one point that has to be solved, a new segregation concept has to be developed between the modified and the standard twinshocks (and between the modified twinshocks to the EVO class too). When this is done you might be out of trouble again. I understand and esteem every rider that want to keep his bike as original as possible as a contemporary technical machine which includes that he want's to ride sections that will fit to the bike. I have too deep respect for some of the rebuilds that where shown here so far, (I personal would not go as long in every aspect expecially when it is an invention which haven't shown up when the bikes where in regular use), and understand the demand of these builders/riders to take part in a competition. Anyway my personal opinion is along with our rules we have, just as an example here recorded: Twinshocks from 1966 and newer: The bike should be prepared in accordance with the age. Components, with the twin-shock motorcycles are not common and were not possible, should not be used. The design of frames, front forks, engine, transmission, exhaust systems and wheel hubs must meet the twinshock standards of the trial motorcycles from 1966 (and newer). The motorcycle must have two spring legs. In each case a shock on the left and right rear wheel, which is supported on the frame and the rear swingarm. Disc brakes and cooling water are prohibited, as reconstructed monoshock motorcycles. Further prohibited are: hydraulically actuated clutches, reed valve two-strokes in, carbon-aluminum and titanium parts for the rear swingarm, frame, frames, axles and tires without tubes. Exception: handlebars, levers and attachments or parts have been found earlier for the construction or series of twin-shock motorcycles were series of twin-shock motorcycles were used. (Grandfathering). Due to the grandfathering rule the TY with reeds is allowed, likewise twinshock bikes that have an aluminium swing arm as standard are allowed. The grandfathering rule is also the "loophole" for any prototype bike that was ridden back then and open also in my personal view a chance for anyone who likes to screw around and to modify his bike as long as this was a clearly contemporary and commen modification, (it should belong to the creator/rider of the modified bike to clearly prove this by evidence whenever in need). Maybe this helps and enriches the possibilities where to go in the future, to choose the single flowers that suits you best out of the bouqeut of different possibilities is certainly your job.

Found it here it is: And a third pic:

There should be a recess for the metal fastener in the chain guard plastic, the metal fastener should fit in there spot on. I have seen replica plastic chain guards that doesn't have this recess.

The older Bultacos had a bracketmounted to the swing rm, even some for the electric, from there where a pull switch mounted that was attached to the wire or rod through a small fastener, as you can see here, (sadly without the switch): The resistor was placed to the brake light and rear light wiring, (look up position nr. 8): The original resistor was very archaic build and wil not work if heavy corroded, (mostly the case): The horn and speedo is here also shown. Instead of the archaic resistor there was an electronical unit also available that do the same job, (was fittet to the Metralla bikes f.e.), made by Facomsa: For both types you have to call up vendors if they still have them, in need PM. The original switch or a contemporary replacement for the handlebar, ... I should have a pic .... ? (Have to through the photo stack).

The standard seal slightly greased and the cover shoud fit thight. You can check your cide case by placing is on a glas plate if the the side case is only slighly wrapped you can mount a big sheet of grindpaper for metal with duct tape on the side on the glas surface. Then you might grind the side case edges with water and rotary movement to align them again, (this works only if there are one some tenth of mm to align). Might sometimes be a problem too, (I had this issue), check the drain screw for the clutch oil, mine must have got a hit from the stones and was slightly bend so the head of the srew did not seal the drain hole proper.

To the fork clamps pinch bolts: The fork clamps for the 199b allow just one mounting direction as the threads are inside the clamps. My older Sherpa 175cc had allen screws the screw head towards driving direction. I personal don't like the upper mount of the speedo above the upper fork clamp so much, in my personal view, (taste), the speedo really sits enthroned there. (this is my personal view) So I will go beside the left side of the right engine mount. For both posibilities you need a bracket where you can attach the speedo, its just a Z-angled piece of metal with to holes (one for the steering steam and another for the speedo) or a L-shaped metal sheet again with two holes one for the engine mount, the other for th speedo. If you don't get the parts then you have to make your own. Best in my experience is to fabricate a model out of plastic sheet or cardbord first to get the right dimensions. (so did I for the lower mount). Then cut and drill and bend the plate to the spec's or let it be done by a local locksmith. (You need a shorter speedo cable too for mounting the speedo to the left side of the front engine mount.) speedo drive to the front wheel: I don't believe there is enough space to fit a mechanical speedo drive, the one for the rear will not fit to the front axle and has the wrong ratio for a 21" wheel too.

Yep expecially the Bultaco bikes, sometimes they show up in French Flea-Bay or the French good coin bazar for silly high prices, must be very collectable? I Can't remember the price exactly but it was over 100