totalshell Posted March 7, 2012 Report Share Posted March 7, 2012 (edited) dont think there has been a better looking monoshock beta these bikes look great , some work gone into magnisium this and titanium that to get the weight down. I think though that old Sammy Miller could shave a fair bit more off by simply doing what he did to his Ariel/ Bultacos. a lot of parts seem ripe for machining. the brake levers on modern bikes are numb and clumsy compared to the stuff Hope turn out for thier brakes, the brake discs seem fairly soild and thick for the work they do and some thinner lazer cut stuff would shed weight. The gear lever is still a solid bit of bent metal with a std. bit on the end.. no drilling or machining at all. my biggest potential weight loss is look at all the cap end bolts that are used swap them out for button caps that have been waisted for none structual componenets and how much might you shave off. all those great looking orange silicone pipes held on with spring steel strips when car manufacturers use twisted wire.. great looking bikes no doubt great riding as well but how much more weight could be lost if you could take it to the max. without overstressing anything. Edited March 7, 2012 by totalshell Quote Link to comment Share on other sites More sharing options...
Andy Posted March 7, 2012 Report Share Posted March 7, 2012 For those that never venture out of the forums, details here Quote Link to comment Share on other sites More sharing options...
gasgas249uk Posted March 7, 2012 Report Share Posted March 7, 2012 Beautiful bikes. They have all reached the minimum weight as per FIM rules , so they arent allowed to go lighter. Club riders could , i suppose. Quote Link to comment Share on other sites More sharing options...
dgshannon Posted March 7, 2012 Report Share Posted March 7, 2012 Always amazed at folks struggling to save grams of weight, here and there, and what they will pay to do it. Meanwhile, a lot more weight could be saved, for free, by simply pushing back away from the table, a little sooner. 2 Quote Link to comment Share on other sites More sharing options...
ham2 Posted March 7, 2012 Report Share Posted March 7, 2012 Beta magnesium crankcases..do they have a sell by date on them? Quote Link to comment Share on other sites More sharing options...
dadof2 Posted March 7, 2012 Report Share Posted March 7, 2012 In the last few weeks I have welded the following Beta parts - front brake lever, rear brake lever, sump plate and crank case. Over the years I have welded crancases on Yams, Hondas & Gassers. Had these been Magnesium I would not have been able to. A quick look on Beta website shows crancases to be about £300 (Yams & gassers are a lot more) and I guess the new Beta magnesium case will be.a lot more than £300 also. Is this realy progress when you pay a lot more to shave off a few % of a Kg and render the part un repairable. I watched the WTC indoor trial from Spain on saturday night and more or less only the top 3 could make a decent attempt at the sections. What is the point of this expensive weight shedding excercise when only the top few in the world can make use of it and its just an added cost for the rest. The sooner the FIM bans magnesium and ups the minimum weight limit the better. Bou & Co would be just as spectacular with an extra 5 or 10 Kg and as a prevous poster says the rest of us should keep further from the table. Over the years I've seen quite a few riders spend a fortune to lighten their bike, and judging by their girth and riding ability they have spent even more at the pub! Cheers Quote Link to comment Share on other sites More sharing options...
paul w Posted March 7, 2012 Report Share Posted March 7, 2012 (edited) Beta magnesium crankcases..do they have a sell by date on them? yes, last week, but they come with a "factory" drip tray In the last few weeks I have welded the following Beta parts - front brake lever, rear brake lever, sump plate and crank case Crikey, that sounds like a bad accident, skin a knee as well? Edited March 7, 2012 by paul w Quote Link to comment Share on other sites More sharing options...
totalshell Posted March 8, 2012 Author Report Share Posted March 8, 2012 my point is you dont need to spend on magnesium or titanium to save weight a bit of metal removal is all thats req. having said that when i was racing mountain bikes i always said a pee before the start was the best engineering you could do.. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted March 12, 2012 Report Share Posted March 12, 2012 Hi there Paul - not all off same bike / accident. Brake lever was off near new EVO - just dropped it on its side and the span adjusting screw dug in. Rear brake was off about a 2 year old bike - just caught it on a rock going up a stream bed. The sump guard on Rev 3 was removed to weld a small fatigue crack that was starting at the corner of one of the slots at the front. When guard was removed crank case damage became visible - the rubber cushion under the flywheel housing had been punched up through the right hand side crank case. Fortunately it could be welded by just taking engine out of bike and not having to strip it. Had the crank cases been magnesium I would think the bill would be about £600. Cheers Quote Link to comment Share on other sites More sharing options...
gasgas249uk Posted March 12, 2012 Report Share Posted March 12, 2012 In the last few weeks I have welded the following Beta parts - front brake lever, rear brake lever, sump plate and crank case. Over the years I have welded crancases on Yams, Hondas & Gassers. Had these been Magnesium I would not have been able to. A quick look on Beta website shows crancases to be about £300 (Yams & gassers are a lot more) and I guess the new Beta magnesium case will be.a lot more than £300 also. Is this realy progress when you pay a lot more to shave off a few % of a Kg and render the part un repairable. I watched the WTC indoor trial from Spain on saturday night and more or less only the top 3 could make a decent attempt at the sections. What is the point of this expensive weight shedding excercise when only the top few in the world can make use of it and its just an added cost for the rest. The sooner the FIM bans magnesium and ups the minimum weight limit the better. Bou & Co would be just as spectacular with an extra 5 or 10 Kg and as a prevous poster says the rest of us should keep further from the table. Over the years I've seen quite a few riders spend a fortune to lighten their bike, and judging by their girth and riding ability they have spent even more at the pub! Cheers I hear what you say , but ive had magnesium engine cases and wheel hubs welded successfully by a number of welders at minimal cost.Each 3 foot 95% mag rod cost only a tenner , then some time . About 40-70 quid for a good amount of work and saved me hundreds . So the components dont have to be replaced , they can be repaired cheaply. I dont agree with that fact that only a few riders can make the most of the weight saving. Riding gets easier for everyone with a lighter bike. If this had been the view all along wed all be still on modified bultos from the 70's. We wouldnt be attempting half of the sections today at club rounds if we were all on Bultos . If we didnt want progress we wouldnt have Beta evos , Shercos ,new Ossa's or Gas Gas pros at all. The lighter the bike , the easier it is for clubmen to move it around, mid section, bounce, and pull over rocks. The factories will never risk huge quality issues and getting huge recalls and warranty claims so they wont make anything to thin or to light. My point is that the minimum weight rule should be reduced to 60KG and let progress continue.The quality wont be affected as factories cant risk it. The price cant rise as the consumers wont buy it. The consumer is safe. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted March 12, 2012 Report Share Posted March 12, 2012 gasgas249uk. On the weight limit I guess we will just have to disagree. Having said that I think it would only make a few kgs at the most to make bikes really tough. Its not just the thickness of sump guards and cases that could do with an extra mm or two, I bet there are hundreds of riders each year strip out M8 x 1.25 pitch threads into aluminium. Moving to M9 or M10 by 1.5 pitch would go a long way to curing this. On the subject of welding magnesium I maybe chose my words badly. Instead of saying I can't weld it, I should have said I am reluctant to weld it for a number of reasons. The American Welding Society states "welding [of magnesium castings] that may contain oil in pores should not be welded" and "the welding of some alloys in the as cast conduition is not recommended because of the greater risk of cracking". Some cast magnesium requires several hundred degrees C preheat and up to several hours at 450 degrees C post weld heat treatment. Cast magnesioum alloys have very high shrinkage contraction on solidification, this leads to high stress levels in the welds which can cause sudden complete component failure at an unknown time in the future. With an aluminium crancase you can get away without pre or post weld heating, usually avoiding the need for an engine strip. With magnesium alloys the need for pre and post weld heat means a full strip is probably essential, especially when the need to try to get oil out of pores is taken into accound as well. Some casting alloys also contain other alloying elements to increase fluidity during casting to enable them to flow into thin sections of the mould, these additions make them effectively unweldable. Cheers Quote Link to comment Share on other sites More sharing options...
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