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heavydabber

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Posts posted by heavydabber
 
 
  1. Exactly, shyted. Honda use F1 and MotoGP to advertise engineering excellence in cars and road bikes to millions of potential consumers around the world. Billboards of Tony Bou would sell what? Trials is so small that most people have never heard of him (outside Spain anyway, lol) And how many million Repsol reps do they sell anyway?

    Honda only got involved with Montesa in the 80s to give them access to the lucrative Spanish moped market which was protected in favour of the Spanish manufacturers. Otherwise Mont would have probably gone the way of Bult and Ossa :-(

  2. Light weight does not have to mean unreliable. I don't want an unreliable bike, I want a lightweight one that is reliable & performs well. As you say, the technology to achieve this is readily available.

    FIM introduced an increased minimum weight limit a couple of years back, it was not popular with many. Dadof2's suggestion to further increase this minimum weight does not get my support.

    But would the application of this technology be affordable? Manufacturers have to build bikes for the "masses" (even though those "masses" in the trials world are already few and probably dwindling in number) for it to be anything like economic.

    If you start building 50kg bikes with unobtanium (to make them strong/reliable enough as your request) how much will they cost? And how many could afford to buy them? It would put the sport even further out of reach for many. If one person has technology then everybody else needs it in order to compete with that person. And if they can't afford it, they'll go and do something else.

    At the risk of being flamed on here, I'd suggest that we need more affordable, lower-tech bikes, that might lead to easier sections and make the sport more attractive to many. Most people would hardly notice a couple of pounds of weight extra but the stronger and cheaper materials (eg steel over alloy and carbon) would make bikes more reliable and affordable. Twinshocks are now mostly 30+ years old, they were built of low-tech materials. How many modern bikes will be around in 30 years time?

    Look at Formula 1 as an extreme example. The organisers impose rule changes every year to try and limit the advantages of technology or the top teams would run away even more than they do. This keeps the sport within the reaches of the smaller, less financed teams (even though their costs are still stratospheric). It also keeps the designers on their toes as they try to find ways around the rule changes, be they smaller tyres or limits on fuel consumption.

    Trials and its technology has been allowed to run away with the result that it's so specialised, and thus so difficult at times that fewer and fewer bods are interested in taking it up. which is bad news for the sport and the manufacturers who sell the bikes and the kit.

  3. I had a new Rev3 after Shercos/Gassers and to be honest, I didn't think that on uphill stuff in particular, the back wheel followed the ground as well as on a linkage bike, it was like the shock just didn't react as fast no matter what I set the spring or adjustment at.

    The fact that Beta went back to a linkage on the Evo speaks volumes in my opinion, even after 8 years of development the Rev3 couldn't match a linkage set-up

    • Like 1
  4. Hi I've been offered a fantic 241 and was wondering if I could convert it to a twin shock using a 240 swing arm and if I can is there anything else I would need from a 240 to covert it.

    Cheers

    Definitely not in the Twinshock spirit......... :guinness:

  5. In your opinion.

    I have a different opinion. I'd gladly pay more money to have a lighter bike. Legislating against progress is plain daft.

    Even if in the name of weight saving it is unreliable or inherently weakly constructed? There's a significant difference between progress and a blind alley. Look at road-racing two strokes from a few years ago. Tuned to the point of unreliability and eye-watering maintenance costs, new pistons at 500 miles, cranks at 1000 miles for instance. It wasn't sustainable, let alone affordable or environmental.

    We can make bikes as light as you want with the technology that's available nowadays. The only limit is how many people can afford it. And most trials chaps don't have pockets all that deep....?

  6. Some early Shercos had the impeller shaft machined from too soft a material and the seal wore grooves, causing leakage as lineaway says. A new, harder shaft was supplied under some warranty applications (I know, I had one, but it was a long time ago, 2001/2 model, I think).

    The kit was new seals, bearings and a shaft and it was priced at @ £25, I think, would depend on the age of your bike

  7. That's a spot on analysis D of 2, especially with regard to the way trials bikes have developed. Have they/the sport just become too specialised? Are the bikes now just too expensive for something that only comes out of the shed once a week or fortnight and can't realistically be used for anything else?

    If 100 people learn to ride a motorbike, either round a field or with an instructor, how many of them will actually take up trials? 10? 5? Less? Has the sport become so specialised and expensive in terms of skill and machinery that it's no longer attractive to the mainstream to participate?

    We're talking £5k-£6k for a new bike and £300+ for a good set of riding gear. And that £5k-£6k bike is essentially manufactured as a disposable item to be changed every year for the newest model, the manufacturers would have us believe (with the depreciation hit). That is not a small amount of money for a couple of hours a week entertainment/competition, plus membership and entry fees, insurance, road tax etc etc. Certainly not in the current economy.

  8. I wonder if the FIM's increase in the minimum weight limit for WTC bikes wasn't intended to pass down into making production bikes a bit more robust?

    When it gets to the stage that Joe Punter's £6k bike is so light that it's snapping in two, that's not doing anything for either the manufacturers or the sport in general.

    A year or so ago there was an interview with Scorpa boss Marc Tessier where he predicted the coming downfall of a couple of un-named manufacturers. Enduro etc bikes were subsidising loss making trials bikes, which were sold too cheap and in insufficient numbers (and I don't know how you square that circle). He might well have been right though.

  9. As per Newton's 3rd law, every action has an equal and opposite reaction and with Jotagas' design the reaction is straight though the main beam of the frame whereas other makes are vertical and need an outrigger that needs to be quite substantial to react the forces without flexing.

    Yup, I'd go with this, the stresses are directed straight up the main frame side-member which is obviously already there, so why not use it for a shock mount?. From an engineering point of view, advantages over a centrally mounted shock are:

    No need for the weight and complexity of a braced central cross-member to mount the top of the shock to

    Much improved access to shock and linkage maintenance

    Allows for a bigger airbox and more direct airflow into carb

    From a selling point of view it's novel and different

    Disadvantages

    Vulnerability to damage

    Doesn't contribute to centralisation of mass/weight

    I don't personally think that the design of the actual linkage is a million miles different from the old Yam TY/TYZ arrangement, the short link just runs direct to the bottom shock mount, obviously dimensions will have been worked on and optimised since those days and shock technology and development has moved on light years which is where the massive improvements will be, but principally it works in much the same way. But it's thinking "outside the box" and has moved things on!

  10. Personally, I think that this increase in the minimum weight limit is more geared to reducing (or cutting out altogether) the use of expensive, exotic materials.Ultimately the aim, I think, is to keep prices down. Face it, let Honda loose with their cheque book and you could have a trials bike that weighed as little as a mountain bike, but at what cost? How much is a 4RT Repsol even now compared to the opposition?

    I remember the Japanese works GP motocrossers of the late 70's and early eighties. Price and the available materials of the time were no object.The fact that each bike was trashed by the end of the GP was seen as a price worth paying for development and success. But it wasn't sustainable, Who'd buy a production MXer that needed a total rebuild after each meeting, it's expensive enough as it is?

    So they increase minimum weight limits and manufacturers have to use plain old steel instead of titanium and carbon fibre. They did it in the late eighties and early nineties in 500 GP road racing. Suzuki and Schwantz had a considerable weight and manouverability advantage before. But Suzuki weren't stupid, they used being obliged to add weight to the bike cleverly, bracing the frame to make it stiffer and stronger. Which made it more crash damage resistant and therefore a bit more sustainable. So the rules achieved their aim.

    Look at the number of current manufacturers in the game - Gasser, Ossa, Sherco, Beta, Jotagas, Scorpa, Montesa/Honda, Tarres off to start something new, Dougie Lampkin involved with Vertigo. How many of those will be left by the end of next year (or get off the ground at all) with prices and therefore sales the way they are?

    It goes back a bit, but remember the days when the UK Montesa, Bultaco and Ossa importers all sold 1000 bikes a year each. How many do the UK importers even sell between them now? And would there still be a market, say, for a modern mono trials bike with an air-cooled head and barrel? Food for thought.....?

  11. I've used a Sherco or Beta Rev3 tensioner spring from the tensioner to the bar on the swing-arm in the past to assist the radial spring, the radial spring also acts as the brake pedal return spring but they're a bit pathetic, Is the end of the bar cross-drilled to take a split-pin? If so, fit the spring, next, a 6mm washer then secure it all with a split-pin, job done!

  12. It's about making real active changes to save our beloved World trials sport from the long and painful death it's currently facing.

    The technological changes are wonderful and a benefit to us all, but there's no doubt in my mind that they are helping to ruin the World sport.

    I don't like these changes but I can totally understand it. Something needs to be done and thank fully Michaud has had the balls to do something.

    I won't need a new bike now :)

    Think I'd go with the above. Trials has moved so far away from the mainstream and become SO specialised both in (very expensive) machinery and skills that there are fewer and fewer people to become interested in it and take it up? Which means fewer bike sales (if there can be fewer in the current climate) and ultimately the death of the sport if you pursue the theory all the way to the end. Lots of biker people will watch the indoor and outdoor world championships and wonder at the skills involved in it - but how many will actually be inspired by it to try it, buy a bike and take it up in the sort of numbers that the manufacturers need to make it break even?

    Personal thought? I think we need a control tyre like so many other branches of motorsport....

    • Like 1
  13. That's a good question and I think the answer's yes, they were around 14" (I think). Certainly the whole bike is "jacked up" compared to a MAR. I've got a Trials and MX News from 1980 with a test of the TR77 and they're enthusing about the nearly 14" of ground clearance - and then describing how the UK contracted riders of the time (Tony Calvert etc) were cutting and shutting the steering head angles to try and get them to steer......I think they were being touted as Ossa's second coming.....

    As Woody says, shock angles moved down and up between the MAR, Mk3 and TR77, a good way to tell is to compare the top shock mounts relative to the side panel mounting tabs; the Mk3 has them adjacent to the lower tabs; on the TR77 they've moved back up to the upper tabs.

    There's a very useful American website called "Ossa Engineering" with promo pics and quantities by engine and frame number of everything Ossa ever built, TR77 numbers were about 600 in total, I think.

  14. Woody's absolutely spot on with his verdict on the TR77, I've got one myself, and Ossa seemed to think that the holy grail of trials was to increase ground clearance as much as possible and the best way to do it was whack longer shocks and forks on the standard geometry - which gives the centre of gravity of a giraffe. One way to bring it back to MAR geometry (but not for the purists) is fit shorter shocks (13.2"?) and shorten the front fork damper rods by an inch at the bottom, but this requires engineering. From memory if you try to drop the forks too far up through the TR77-type yokes (different to MAR), they foul on the handlebar?

    A lot of TR77's also ran Motoplat points type ignition rather than the usual Motoplat electronic. Allegedly due to supply difficulties during the throes of the Spanish industry, but the points are the same as Bultaco/Montesa and are available though genuine originals are better than the pattern stuff if you can get them

  15. Does anyone know what happened to Howard Jackman who rode a 240 Armstrong in the 1984 SSDT? He may have been a works rider.

    Does anyone know what happened to Howard Jackman who rode a 240 Armstrong in the 1984 SSDT? He may have been a works rider.

    He was Jim Sandiford's 200 Montesa rider, being regularly placed in the top 10 in the British Champs in the early 80's then he switched to the Armstrong for 1984, riding the 250 alongside Steve Saunders on the 310/320 I think. He was a tidy rider in his day too.

  16. Hi Amo, re your correct colour of green enquiry, I restored my TR77 using SEAT Kent Verde green, it's not a million miles away from the original shade but is slightly darker than the shade of green on Gonelli plastic mudguards, hope this helps!

  17. Hi guys,

    I have a recently bought a Fantic 240 which is coming as a few boxes of parts. I have a few questions which I hope all the Fantic nuts here can help my with.

    1. Does anyone know the rim offset for the front and rear wheels? The bike is coming with rims/hubs disassembled.
    2. Can anyone recommend a period carb, and settings? I cannot run an OKO as it will be ineligible for our national Twinshock class. Has anyone tried a Mikuni VM26? If so, do you have setup specs?
    3. If I can get hold of a 200 top clamp, does it bolt straight on? Any mods required?

    Thanks in advance guys,

    Cheers,

    Ben

    I know its a bit of a distance from you but I've always found the UK's Dellorto importers to be brill at info and parts supply (seem to have everything!), even to the specs/jetting/setup of carbs originally supplied on bikes, they're called Eurocarb in Tilehurst, Reading, www.dellorto.uk , they're usually cheaper than buying the carb parts through the bike's dealer too! Think 240 carb was a 26mm Dellorto PHBL (I stand to be corrected!) hope this helps

  18. Up to now, I've got away with using a Beta (orange, as in tool company) filter strap wrench to hold flywheels in place but in attempting to remove my flywheel from my Transalp on the weekend (not been off for 22 years), I broke it. I eventually achieved the desired result of removing the flywheel bolt with the use of a 1p coin.

    However, I've seen proper, heavy duty, metal band flywheel strap wrenches (i remember my old REV3 flywheel being jammed on with one), however can't find them for sale in the UK ? Anyone ?

    Sealey have just started advertising a universal motorcycle flywheel holder in the flyers they put around workshops, looks similar to the genuine Honda one for small mxers, think it was about

  19. Sunday the day of rest? Well had to break the 250 Gripper down a bit more. Front end today.

    1st slight challenge was there was the end of a 5mm allen key broken off in one the the yoke pinch bolts. Took the other screw out and just hacksawed through the screw in the slot. Head then just dropped out.

    Thought I'd have to drill the rest of the screw out so once the yoke was off I set it up in the milling machine but as soon as the drill touched the back of the screw it wound it out.

    Headstock bearing outers came out of the frame fairly easily. and used my usual method to remove the bottom inner from the stem by heating the bottom yoke a bit and just pressing the stem out.

    Forks will need re chroming and one is slightly bent. Also one seems to have a problem as the leg can be pulled way way out of the slider! I expect a circlip has popped at the bottom of the leg or even missing. They can wait a bit.

    Any recommendations for decent fork refinishers? I now have a reasonable batch to get done!

    Wayne....

    Wayne, for fork rechroming try Dynasurf in Cheshire. Their main line of work is resurfacing piston rams on JCB's/Cats etc but they seem to do stanchions as a bit of a sideline, I had some Marzocchis done a couple of years back and it was about

  20. No, I`ve never needed to this with bikes before so never gave it a thought, how is it done and whats in the expansion chamber.

    Be careful with the front pipe as the expansion chamber is lined with a layer of sound-absorbent material (read fibreglass wool) behind a metal mesh skin that keeps it all in place, check the u-bend at the front of the pipe to make sure its not coked up also same thing with the outlet to the silencer.......but did it run like this before you rebuilt the engine?!! Chain tensioner spring might be a bit weak or the bush and/or tensioner arm itself worn or even seized up, most things available from Bill Pye at Frankfield Fantic, hope this helps

  21. There was an absolutely MINT Explorer on Ebay a couple of weeks back, in Scotland somewhere (SSDT country from memory), red with silver frame, it didn't sell, asking price was set at

 
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