The 191 is a 1978/9 model, not '77. Red tank, mudguards, sidepanels, silver frame, black engine, forks, hubs, polished brake plates and yokes.
They were nearing the end so almost everything was being painted now, not polished alloy = cheaper? I'm sure they had red mudguards from new, alloy were on the previous models '76 and '77.
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.
I know what you mean most Classic rules prohibit disc brakes too but it is as was available to be bought by me you or anybody else in the late 60's so is it right not to allow it in ?
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.
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.
hi all ive just ordered some magical fork springs theres magical oil allso on order its 7.3w will this oil be ok?
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.
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).
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 read this post with a lot of interest, I feel very lucky that here in Quebec we do not have any of those rules problem. At any of our competion ( I should say meeting ) only around 15 riders compete and you should see the bikes that are registered, the rules are twin shocks, drum brakes air cooled motor, and oh yes many laugh from most of the riders that are just there for fun, I sure wish that if '' competition '' get's in the way of our meeting they will change rules and make two class one for the riders that have to win something at all cost and one for the other that ride what ever they like and want to have a good time. You see for me trial riding is a sport and not a job, I have to be competitive at work. This year I hope to ride a modified TY frame with a well prepared 250cc motor just for fun, if the organiser decide that I should not compete for points I hope they will let me ride on the course they prepared at the competition they organised on the land they sometime rent all of that as the saying goes '' for fraction of the cost '' . I took some time last year to help ( a bit ) the organiser of one meeting and I can assure you that riding IS the fun part NOT organising. My hat off to any organiser specialy to the one that have to make new rules.
Guy
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.
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).
Video Of Highly Modified 199a
in Bultaco
Posted
Sorry I forgot to post the link, here it is: http://www.secciormotos.es/bultaco