Speedfight !! shock fitted XD

Discussion in 'Scooter Projects' started by Speedy 172, Nov 27, 2007.

  1. bait

    bait Active Member

    Messages:
    1,667
    probs a stupid question minor but what dus the engine angle effect? can it cause any warping etc and i never plan on getting one but wouldnt jack up kits have the same effect?
     
  2. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    steeper the angle on any pivitiong pointcreates more force for the same movement.. so basicly the triangulation of your engine is off.. meaning the same bump will move the engine less, wiht ALOT more force (more likely to crack) other than that the engine angle really is irelevent, its more geometry if the "swing arm" as it were. look at the angle on any ROAD bike's swing arm (road meaning NOT crossers or supermoto's), specificly those desighned to go fast... wont see ANYTHING close to that angle when you triangulate it (regardless of the shape of the swing, the start and end point hight relation is VERRY important wiht handeling/strength of componants) jack up kits reduce the wheelbase aswell as raising the rear and shortening the effective botom length of the suspention triangulation. by increasing the rear length. this is also no good. think of it as a bar. your whel is one end, its bolted to the frame the other.. the shorter the bar the harder it is to move but the shorter the travel. its ALL about leverage and movement.
     
  3. bait

    bait Active Member

    Messages:
    1,667
    got ya :tup: cheers for that bruva
     
  4. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    just to add... playing wiht the rear will ALWAYS mess the front up... you need the same wheelbase/rake angle/pivot angle and hight of ANY vehicle running your engine (they vary, but have been calculated to work/not be unstable) match this

    getting the rear right will inevitably throw the rake angle out, meaning you have to space/shorten the forks or plain move the rear engine mount position up down left or right to gain the desired effect...

    im in no way a chassis/frabme builder... nor am i spouting i know it all... i know verry little on this subject. if your putting bike's together from amny diff moddles its worth noting rake angle whelbase blah blah. why do you think ALL aftermarket frames are fully ajustable (as in whel position, rake, suspention pivot point, mount position blah blah) all for use wiht certian forks. if all this seems erry complicated then stick to whats been done/easy.. incorrect geometry kills QUICKLY (tank slappers arnt a fluke, speed wobbles and sudden swerving are a few of the results of poor bike desighn, hence there tested throughly round tracks and modified on the fly) they ether spend months working out the perfect setup, or take somone elses frame and ride hight/.wheel position and just desighn the bike round that. even wheel size can throw this out teribly (big wheel at the back, small at the front, soon be dead)

    if your doing ANY conversion, even if its a long endgined zip please buy a chassis manual/frame building book... somthing to give yo an idea of wheel geometry as it REALLY didnt bother me till i was tank slapping at 90+ on the nsr runnning new forks/diff shock...
     
  5. bait

    bait Active Member

    Messages:
    1,667
    i dont plan on but would i be right in thinking changes to the rear shock that affect engine angle means that a change to the front needs to be made and vice versa to keep evythin kushty

    just done loads of lil sketches so i cud take it all in lol
     
  6. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    it basicly means fucking about wiht EVERYTHING untill its right...

    easiest way is how you SHOULD have built it... have the frame sat as it needs to be wiht no lump in (as in how you want the frame forks and vice versa siting) THEN mock up the engine mount position.. wheelbase is how far towards the centre of the frame the mount is, angle is determined by the hight/length of the engine and the 2 points, can prittymuch be perfect by trimming the mount position ansd shock length, but it aint gona be easy seing as how your bikes buitl an to do it properly you need to pritymuch strip it back down. like all these shitty kits, there made for 50 ejngines.. i wouldent trust it wiht that let alone an engine making 10 times the power of the desighn brief. BODGE.. sorry (all 125's wiht this kit are, can see it a mile off)

    have a good messure up, grab a stock speedy if you can, mark out the wheel positions on a floor/ angle on the forks and engine and the position and length of the shock.. move EVERYTHING else around to keep things as they should have been in the first place. (i know speedy's dont have forks, but the ride hight will give you a good idea, and the ludix will give you the correct angle. m,essure wiht a spirit level obv)
     
  7. Speedy 172

    Speedy 172 Active Member

    Messages:
    1,137
    right minor
    ive had my bike measured ride height wise
    and its just abit higher riding position wise
    ive got my viva stripped down and ive checked the forks on both they are near enough the same give or take a few mm
    so how can i drop the runner shock abit ?
    cos it will also raise my ice bracket :banana:
     
  8. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

    Messages:
    14,276
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    et2 monster
    well, if the ride hight is correct and the wheelbase is correct the only way is to move the engine mount downwards and towards the front of the bike.
    if its a little higher than it should be at the rear then you need to sort a shorter shock.. you can alternativly move the shock mount forward. i recon its all down to the conversion kit.. these sort of things are made, they work, but are hardly rigorously tested on tracks and the like as the manufactor's do... if the ride hight rake and level is correct tho the only real risk there is snapping the engine. the shock action is determined by an ajustable shock so can go prittymuhc anywhere at any angle. but obviously shorter action wiht a stiffer shock means alot of force, where as the same travel on the whel with long action on the shock means reduced force (why the ice has a long shock as the mount is far forward)
     
  9. Speedy 172

    Speedy 172 Active Member

    Messages:
    1,137
    it isnt the conversion kit minor
    its the gilera mount
    and a mount made on frame for the gilera shocker
    but needs to be anit lower on the shocker
    the wheelbase is bang on with my mates speedy 50 and my vivacity 70
     
  10. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    get some pics up of how its installed (or copy them from the beggining of this thread) interested to see what youve done to get the lump in as a 125 mount needs some serious welding for the silent block to work, unless youve just solid welded one section of it in place :confused:
     
  11. Speedy 172

    Speedy 172 Active Member

    Messages:
    1,137
    the peugeot mount was ground down
    the gilera mount was ground so it could centralise into the peugeot mount
    then they were welded ino place with a steel bracket welded on for support
    then the shock moved back
     
  12. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    14,276
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    et2 monster
    useless..... pics ;)
     
  13. Speedy 172

    Speedy 172 Active Member

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    1,137
    il get some later on :punk:
     

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