baldilocks Posted October 10, 2006 Report Share Posted October 10, 2006 Anybody know why some people change the master cylinder and hose on the Pro. I've seen quite a few with the bigger master cylinder on with a larger diameter hose and i'm wondering if this would change the clutch action ? cheers Quote Link to comment Share on other sites More sharing options...
jaysee Posted October 11, 2006 Report Share Posted October 11, 2006 No change at all to the clutch action, you still pull it towards the handlebar to engage. Do you use the clutch? Quote Link to comment Share on other sites More sharing options...
endo kid Posted October 11, 2006 Report Share Posted October 11, 2006 No change at all to the clutch action, you still pull it towards the handlebar to engage. Do you use the clutch? do you use the clutch most clutch levers pull towards the handlebar to disengauge the clutch Quote Link to comment Share on other sites More sharing options...
rhaines Posted October 11, 2006 Report Share Posted October 11, 2006 No change at all to the clutch action, you still pull it towards the handlebar to engage. Do you use the clutch? Can't imagine you get many cleans with that clutch!!! The larger master cylinder does make a difference. It makes the clutch have a slightly smoother action and makes it slightly lighter to use. I am not sure how this works because the actual cylinder assembley is the same so I think it is the pivot points on the levers that are slightly different to give that effect. Quote Link to comment Share on other sites More sharing options...
dan Posted October 11, 2006 Report Share Posted October 11, 2006 The larger master cylinder does make a difference. It makes the clutch have a slightly smoother action and makes it slightly lighter to use. I am not sure how this works because the actual cylinder assembley is the same so I think it is the pivot points on the levers that are slightly different to give that effect. Surely the larger reservoir and hose means more power at the slave for less pressure at the lever? Actually, shouldn't that be larger reservoir and smaller hose... so there's more fluid to push but it's sent at a higher pressure. I'm not quite as clear as I'd like to be on the effects of different changes to hydraulic systems. Quote Link to comment Share on other sites More sharing options...
grib Posted October 11, 2006 Report Share Posted October 11, 2006 The size of the reservoir and the hose make no difference, it is the diameter of the master cylinder that make a difference. A bigger diameter master cylinder will require more lever force (for the same lever pivot point), as an example if the master & slave cylinders were the same diameter you would only have to pull the clutch lever a millimetre or two to disengage the clutch but you'd need hands like Geoff Capes to do it. Quote Link to comment Share on other sites More sharing options...
gasgas Posted October 12, 2006 Report Share Posted October 12, 2006 it is the diameter of the master cylinder that make a difference. So, what we look for, to lighten the pull, is a smaller diameter master cylinder, but with more stroke, to get the neccesary displacement at the slave cylinder!? Which master cylinder will that be(part nbr)? Some people telling about a Montesa master cylinder? Quote Link to comment Share on other sites More sharing options...
grib Posted October 12, 2006 Report Share Posted October 12, 2006 (edited) Yes, the ratio of master cylinder cross sectional area to slave cylinder cross sectional area gives you the actual mechanical advantage Edited October 12, 2006 by Grib Quote Link to comment Share on other sites More sharing options...
seandellear Posted October 12, 2006 Report Share Posted October 12, 2006 (edited) After studying this post and my phsics books, to lighten the clutch there needs to be a smaller master cylinder but then this means you need more stroke to move the slave the same distance as before, so I guess its all about getting a balance. Edit:This is my 100th post I am now an advanced member! YAY!!! Edited October 12, 2006 by seandellear Quote Link to comment Share on other sites More sharing options...
bigdamo Posted October 13, 2006 Report Share Posted October 13, 2006 After studying this post and my phsics books, to lighten the clutch there needs to be a smaller master cylinder but then this means you need more stroke to move the slave the same distance as before, so I guess its all about getting a balance.Edit:This is my 100th post I am now an advanced member! YAY!!! so whats the answer Quote Link to comment Share on other sites More sharing options...
ikb Posted October 13, 2006 Report Share Posted October 13, 2006 A smaller master cylinder will make the clutch lighter but you will need to pull the lever further for the cluch to disengage. And to complicate matters I think the 02 side casing had a diferent size slave cylinder!! The answer is to leave as standard and make sure the cluch pack is the correct thickness as when it gets worn the bevel spring sits at a steeper angle making the clutch harder to operate. GasGas UK sell steel plates of diferent thicknesses to sort it out. Quote Link to comment Share on other sites More sharing options...
grib Posted October 13, 2006 Report Share Posted October 13, 2006 I agree, my 03 250 pro has a standard master cylinder, correct clutch pack thickness and ATF in the gearbox, the clutch action is fine. Quote Link to comment Share on other sites More sharing options...
zman92020 Posted October 17, 2006 Report Share Posted October 17, 2006 Now you're got me thinking . . Given the clutch, clutch springs and the slave cylinder remain the same . . . no matter how you figure it, it will always take the equal amount of force [ pressure x fluid volume] to move the clutch plates a given distance.. so what will make the clutch lever easier to pull is only greater leverage, but this equals longer movement . . . If you increase the master cylinder bore, then youre pushing a larger volume of fluid but its harder to pull . . . everything just works of the other so it seems to me there is no magic way to achieve easy lever movement with a shorter lever stroke . . Quote Link to comment Share on other sites More sharing options...
grib Posted October 18, 2006 Report Share Posted October 18, 2006 Shorter lever stroke will always equal more force to pull the lever no matter how it is achieved. I would have thought that a longer lever stroke would give a more progressive clutch, but then I suppose you may run in to problems with the clutch not disengaging fully. Quote Link to comment Share on other sites More sharing options...
no1 Posted October 18, 2006 Report Share Posted October 18, 2006 Adjust your clutch plates to 9.8mm fit a 06 125 raga clutch casing and bingo light clutch Quote Link to comment Share on other sites More sharing options...
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