ken_hosking

I aim having difficulty with the wiring of a lanyard kill switch for a 74 Sherpa T 250. The bike has previously had a multipurpose switch but this has disintegrated. I have eliminated the leads to the lights leaving three leads. I still have a spark with any combination of these leads. Any advice would be much appreciated.

There are more riders in the Beta Factory team than just Bincaz and Grattarola. I believe that the photograph is that of Carlo Alberto Rabino, who is not a Factory rider as I mistakenly suggested. However, Beta lists Lorenzo Gandola, Sondre Haga and Aniol Gelabert as Factory team riders in Trial 2. The photograph was taken during an arena style trial and that might explain the reason for having a larger fluid reservoir.

In the attached photograph of a Beta, being ridden by a works rider, there is an interesting object in the intake area. Could it be a fuel injection system?

Yes, that is indeed the probable explanation. I had overlooked the fact that the hub and pressure plates can move independently from the basket, albeit by only a small amount. Thanks for that insight, bikerpet.

My view is that when the clutch is engaged the clutch plates can't readily move in the basket as the whole assembly is locked up. My best guess remains that the noise is caused by backlash in the primary drive gears, or the gearbox, caused by the pulses coming from the engine, as you noted. I should perhaps have started this post as an all-bikes post, rather than a Beta post, as they all do it, as technowaldo rightly pointed out.

My purpose in raising this matter was not that I am at all worried about the noise, but rather that I would like to understand the mechanism giving rise to the noise. Who knows what insights might be forthcoming from the discussion?

Thanks for the feedback Dan: I felt certain that you would have a theory relating to the noise. However, I continue to be of the view that it is gear backlash that is causing the noise. The primary drive and gearbox gears are straight cut rather than being helical in all trials bikes (to the best of my knowledge) and gear chatter is to be expected when the gear train is not loaded. Just to add another variable to the mix, some trials bikes make more of a whining noise than others. Presumably this is a machining tolerance issue in the components of the drive train.

I am interested in opinions regarding the so-called clutch rattle that occurs when the engine is running, but which lessens when the clutch lever is pulled in. My view is that the noise does not come from the clutch at all, despite the commonly used name, because the noise is at its loudest when the clutch is engaged and the clutch plates are locked together. I suspect that the noise comes either from chatter in the primary drive gears or chatter in the gearbox; probably the latter as the gears in the gearbox should be stationary when the clutch lever is pulled in. It’s not just a Beta issue, as all the various brands that I have ridden have made the same noise.

Colour scheme seems to be imitating that of the Vertigo

If the noise diminishes when you pull in the clutch lever, it is indeed something that all trials bikes do to a greater or lesser extent. Whilst the noise is often referred to as clutch noise, I believe that it is caused by backlash in the primary gear train, because when the clutch lever is let out, the clutch is locked up and is unlikely to be making any noise itself. I suggest that, if the primary gear train used helical rather than straight cut gears, the noise would be much less intense.

I installed new main bearings in a 2011 Evo 290, reassembled the bottom end of the engine and, before proceeding further, checked that gear selection was working. With the engine in the frame and the chain on, I was able to spin the gears and check gear engagement. However, I could only select first, neutral, second and third before the selector drum appears to jam. I pulled the engine down again and checked the assembly instructions in the workshop manual, but on reassembly experienced the same problem. On my 2016 Evo I can select all the gears when the engine is not running merely by moving the bike back and forwards to enable the selectors to move. Anybody have any ideas as to what I might have done wrongly in reassembling the gearbox on the 2011 bike?

Hi Booty, the bruvs went to the WTC round in Corsica in 2014 and pre-purchased tickets via a web site that the organisers had set up. A search of the web might be worthwhile. The same system operated for the two WTC rounds at Maldon in 2012 and 2014. We also visited the Beta factory in Italy and I am certain that a tour could be arranged there if you promised to sell the old 4RT and to move up to a superb Italian trials bike! Regards Ken

1.5%, ie 15 ml/litre equates to a fuel to oil ratio of 67%. In company with other Beta riders in our local group, I use an 80:1 mix, that is, 1.25%, in my 300 Factory. The bike seems to run more cleanly on this ratio than on the recommended 1.5%. Using a 98 octane fuel for this model seems to be mandatory unless you enjoy hearing detonation from the engine. Riders of Gas Gas and Sherco bikes often mix their oil and fuel at 1.0% (100:1) with no apparent detrimental effects. I suspect that the Beta recommendation of 1.5% is highly conservative for off-road trials use, but for extended on-road usage it might be prudent to increase the oil/fuel ratio to the manufacturer's recommendations.

Not sure if the video about which you are complaining is the FIM official summary or something else as we don't have Motors TV down under. However, I have long been a critic of the FIM summary videos that waste half of the film time on 'atmosphere', cut the individual scenes right in the middle of manoeuvres, are massively overproduced and which have truly horrible music that drowns out the sounds of the event.

Cascao is correct. Removing material by stamping is a far easier and cheaper process than machining a recess, with tolerances that are suitable for anodising.

Any organisation that allows a basic grammatical error to appear in the very first line of the introduction to trials regulations (01.01 in the link provided by laser1 in post number 6) has little claim to professionalism. Maybe the time has come for the trials world to divorce itself from the FIM, leave motorcycle speed events with them (that appears to to be what FIM sees as the top priority in any case) and have a new world trials body that has a balanced representation from riders, manufacturers, organising clubs and, dare I say it, spectators/enthusiasts.

A great quotation and it seems, sadly, that Euripides was right about the FIM. The FIM seems to have overlooked the massive potential for urban trials and indoor trials. The proposed changes and especially non-stop, would be counterproductive to the success of those events. And where are the next generation of riders coming from, for indoor, urban or traditional trials? Many will come from cycle trials where non-stop would be nonsensical. The FIM's actions seem to be driven by desperation with no strategic thinking beyond making changes in the hope that something might work. Madness indeed.

I need to preface my comments by declaring that I am far from being a top level rider, having returned to trials in my sixties after a long absence from the sport. My bike is light and I find that to be very helpful at my level of ability. It is a 300, but it is less peaky that my earlier Evo 250 and, to my mind, it is easier to ride. The FIM promised a number of changes in the bid to stem the fall in sales of trials bikes and to increase the participation rate. However, they seem to have overlooked the fact that the real problem was the global recession: the unemployment rate in many countries where trials is popular might be an indicator of the root cause of the problem. In my view, by tinkering around the edges with non-stop (officially declared a success, but without any evidence being apparent), higher weight limits and engine capacity limits, the FIM are likely to inflict even more damage to the sport than the economic recession. Hopefully the national bodies around the world will ignore the latest idiocy from the FIM and run trials the way that the majority of riders and spectators seem to prefer.

Why, why, why do trials video producers seem to think that it is necessary to have loud head-banging music playing? What is wrong with just listening to the bike? Even FIM videos are massively over-produced and annoying.

Great visuals, but why the loud music? Personally I would rather hear the bikes and the crowd.

Whilst there is some logic in feetupfun's suggestion, I think that there is ample evidence that the name Beta was intended to be a name, despite its origin as a set of initials, from the beginning. I don't think that analogies with names like AJS, DKW or BMW are relevant in this case. It is probably time for a person from Beta, particularly one who speaks Italian and who knows the story intimately, to make a post.

I think that we need to recognise that Beta is an Italian company and that therefore Italian, not English, pronunciation rules should prevail. In Italian, 'e' is pronounced similarly to the English 'ay' whereas 'i' is pronounced more like the English 'e'. To me, that means the pronunciation should be Bay-ta. However, I would be interested to hear from a native Italian speaker on this subject, particularly since the name 'Beta' is an 'artificial word' formed from the initials of the two persons who ran the original company at the time when the name Beta was adopted. The name does not appear to have any relationship to the Greek word 'beta'.

A pair of S3 Hardrock wide footrests not only improves the appearance, but provide a very good platform that feels much better on the feet than the standard Beta footrests.

I am able to report some success after tinkering with the carburettor. It seems that the pilot mixture was too lean, not too rich, as after fitting a size 50 pilot jet, the response was much improved. I then tried a size 4 slide (OEM was 3.5) and lifted the needle to the top notch. The engine runs very sweetly now and detonation has all but disappeared. In relation to Dan William's last post, Motorcycling Australia does not permit the use of leaded fuel or fuel with greater than 100 octane rating in MA controlled events, so that changing the fuel is not an option for me. Since making these changes, and experiencing better engine responsiveness, I find that I seldom use first gear now.

Thanks for the feedback Dan. After riding for two days over the weekend my impressions of the lower gearing are that, even though I have reduced the final drive ratio by less that you have done, I seem to have a similar effect. I find that using second gear is easier than before, especially where a tight turn precedes a step or a climb, and third works well also. As for the mixture, re-fitting the stock pilot jet and dropping the needle one notch made the bike feel much more responsive. Unfortunately, the engine suffers from detonation when hot, but not under load, rather when the throttle is rolled off rapidly. At first I suspected that the noise was mechanical in origin, but an experienced mechanic who rode the bike felt certain that it was detonation. I changed the plug, making certain that the gap was correct, tweaked the pilot air bleed screw but to no avail. I remember that I had the problem prior to lowering the needle, but after fitting the smaller pilot jet. It has been suggested to me that the engine could have a carbon build up, but with only 30 or so hours since new I rather doubt that would be the case. I am using ethanol-free 98 octane fuel with a 1.5% oil/fuel ratio using Motorex oil. Any suggestions would be welcome.