crashandburn Posted November 12, 2007 Report Share Posted November 12, 2007 i have heard that txt50 boys can be converted to manual clutch.any info on this procedure would be greatly appreciated Quote Link to comment Share on other sites More sharing options...
numbnuts Posted November 13, 2007 Report Share Posted November 13, 2007 (edited) i have heard that txt50 boys can be converted to manual clutch.any info on this procedure would be greatly appreciated I copied this information off a link ages ago, can't find it now, but it said: "I have ordered a couple of parts from Gas Gas to convert my sons GG50 to a full manual clutch. MIT 50032064 2mm Steel Clutch Disc MIT 50032052 1.5mm Steel Clutch Disc" don't know much more than that though!! Sure the guys at Gas Gas Uk will be able to help? Edited November 13, 2007 by numbnuts Quote Link to comment Share on other sites More sharing options...
crashandburn Posted November 21, 2007 Author Report Share Posted November 21, 2007 I copied this information off a link ages ago, can't find it now, but it said:"I have ordered a couple of parts from Gas Gas to convert my sons GG50 to a full manual clutch. MIT 50032064 2mm Steel Clutch Disc MIT 50032052 1.5mm Steel Clutch Disc" don't know much more than that though!! Sure the guys at Gas Gas Uk will be able to help? i tried them but to no avail. someone told me joe deacons father who is an engineer converted his txt 50 to fully manual and spoke about removing springs. the problem is i have no way of getting in touch with him Quote Link to comment Share on other sites More sharing options...
peterb Posted November 24, 2007 Report Share Posted November 24, 2007 Hi there, I have not tried this conversion but this imay be worth considering. The clutch, in auto mode, works with increasing rpm by flinging out the 8 x 8mm ball bearings on the back plate to allow or force the clutch plates to move together to each other. The plates are held apart by either the 2 small return springs, or the larger central spring - not sure as I haven't pulled one apart. Looking at the parts drawing, you would either need to remove the two smaller springs or, the larger central spring to allow the plates to be compressed together without the motor going. Hope this makes sense. Incidentally, the 2mm thick plain plate can be fitted in lieu of one 1.5mm plate to the trials TXT50 motor to allow the clutch to take up at lower rpm. (Thanks to Jim Snell for that one) Bye, PeterB. Quote Link to comment Share on other sites More sharing options...
crashandburn Posted November 25, 2007 Author Report Share Posted November 25, 2007 Hi there,I have not tried this conversion but this imay be worth considering. The clutch, in auto mode, works with increasing rpm by flinging out the 8 x 8mm ball bearings on the back plate to allow or force the clutch plates to move together to each other. The plates are held apart by either the 2 small return springs, or the larger central spring - not sure as I haven't pulled one apart. Looking at the parts drawing, you would either need to remove the two smaller springs or, the larger central spring to allow the plates to be compressed together without the motor going. Hope this makes sense. Incidentally, the 2mm thick plain plate can be fitted in lieu of one 1.5mm plate to the trials TXT50 motor to allow the clutch to take up at lower rpm. (Thanks to Jim Snell for that one) Bye, PeterB. cheers for the info peter i will be trying it out in the near future but in the meantime anymore info wont go a miss Quote Link to comment Share on other sites More sharing options...
mashman Posted December 5, 2007 Report Share Posted December 5, 2007 Having completely refurbished the auto clutch on my lads TXT Boy, heres some background info (from memory): The current setup uses 4 springs to keep the clutch pack apart and look just like a conventional wet multi plate clutch pack in a road bike - however working in reverse. On a conventional wet multi plate clutch pack the springs are used to exert pressure on the clutch pack and provide drive, in the auto TXT Boy it does the opposite. The clutch pack is compressed by 8 x 5/15" ball bearings that fly out due centrifugal force in machined recesses. The recesses are machined at an angle that forces the balls to ride against the rear of the clutch cage and thus compress the pack. The clutch lever operates on a central boss that engages with a cross pin that straddles a large washer which in turn has the 4 springs mentioned previously behind and ultimately the rear of the clutch cage. By depressing the clutch it affectively keeps the clutch cage and hence pack from being compressed by the action of the ball bearings. In order to convert to manual operation, I would envisage the following: 1) Remove the ball bearings 2) Remove the existing 4 springs 3) Design a system that allows mounting of the 4 springs in such a way that they work in reverse - eg, compress the clutch pack. NOTE - the existing clutch mechanism should theoretically work without modification as a means of dis-engaging the clutch I'm sure could be done and indeed sounds like other have succeeded, although it's a shame that no-one has published any details on the design. Basically it boils down to Step 3 as the only issue as far as I can see. I have been thinking about this mod on my lads bike and will go away and give some serious consideration. Will report back if I get any where. Regards - Martin. Quote Link to comment Share on other sites More sharing options...
crashandburn Posted December 12, 2007 Author Report Share Posted December 12, 2007 Having completely refurbished the auto clutch on my lads TXT Boy, heres some background info (from memory):The current setup uses 4 springs to keep the clutch pack apart and look just like a conventional wet multi plate clutch pack in a road bike - however working in reverse. On a conventional wet multi plate clutch pack the springs are used to exert pressure on the clutch pack and provide drive, in the auto TXT Boy it does the opposite. The clutch pack is compressed by 8 x 5/15" ball bearings that fly out due centrifugal force in machined recesses. The recesses are machined at an angle that forces the balls to ride against the rear of the clutch cage and thus compress the pack. The clutch lever operates on a central boss that engages with a cross pin that straddles a large washer which in turn has the 4 springs mentioned previously behind and ultimately the rear of the clutch cage. By depressing the clutch it affectively keeps the clutch cage and hence pack from being compressed by the action of the ball bearings. In order to convert to manual operation, I would envisage the following: 1) Remove the ball bearings 2) Remove the existing 4 springs 3) Design a system that allows mounting of the 4 springs in such a way that they work in reverse - eg, compress the clutch pack. NOTE - the existing clutch mechanism should theoretically work without modification as a means of dis-engaging the clutch I'm sure could be done and indeed sounds like other have succeeded, although it's a shame that no-one has published any details on the design. Basically it boils down to Step 3 as the only issue as far as I can see. I have been thinking about this mod on my lads bike and will go away and give some serious consideration. Will report back if I get any where. Regards - Martin. Quote Link to comment Share on other sites More sharing options...
crashandburn Posted December 12, 2007 Author Report Share Posted December 12, 2007 this is some of the best info i have had to date,it's nice to have an idea on how it all works in there. I will probably be having a tinker with it over the xmass so in the meantime any extra info will be tip top. cheers Quote Link to comment Share on other sites More sharing options...
spinner Posted December 13, 2007 Report Share Posted December 13, 2007 You had better figure out how to add some flywheel weight to the motor if you are going to convert it to manual operation only. A manual conversion was completed by some California guys a few years ago but the bike stalled all the time. The best modification that we did to ours was to replace one of the thinner clutch plates with a thicker one. If I remember correctly there are 2 1.5 clutch plates and 1 2.0. By replacing one of the thinner plates with a thicker one it took all the slack out of the clutch and made it engage at a lower rpm. Hope this helps Quote Link to comment Share on other sites More sharing options...
garethr Posted October 18, 2008 Report Share Posted October 18, 2008 The best modification that we did to ours was to replace one of the thinner clutch plates with a thicker one. If I remember correctly there are 2 1.5 clutch plates and 1 2.0. By replacing one of the thinner plates with a thicker one it took all the slack out of the clutch and made it engage at a lower rpm. Hope this helps So instead of 2 x 1.5mm plates and 1 x 2mm plate, you have 2 x 2mm plates and 1 x 1.5mm? Would 3 x 2mm plates work or is this too much?! Was the diference with this mod quite noticable?? Are there any negatives to this mod? The little gasser seems to need quite a lot of revs before it bites, and then it takes off! I'm looking to increase the rear sprocket to 60T and hopefully change the clutch plates as mentioned here. Are there any special tools required? Cheers! Quote Link to comment Share on other sites More sharing options...
spinner Posted October 21, 2008 Report Share Posted October 21, 2008 No negatives that I remember, clutch just engaged a lot quicker. Only special tool was needed was a to mill down a socket to get the clutch nut loose. I can't remember the size for sure but it was a 13,14,or 15mm Quote Link to comment Share on other sites More sharing options...
garethr Posted October 22, 2008 Report Share Posted October 22, 2008 Thanks Spinner... I've taken the kickstart & casing off, but cant see how to get at the clutch plates! Sorry for being thick, but I havent done anything like this before. How do I swap over one of the clutch plates for the new one please?? Quote Link to comment Share on other sites More sharing options...
garethr Posted October 22, 2008 Report Share Posted October 22, 2008 STOP THE CLOCK! I've just managed to add the thicker (2mm) clutch plate in place of one of the thinner (1.5mm) plates. Thanks to a few pointers and an exploded diagram of the clutch assembly from Kev & Luke at GasGas technical. Wasnt too tricky really in the end. The bike is much improved and the clutch engages earlier and smother. It's biting a bit and the bike wants to creep forward when it's on tickover which isnt a big problem. I'll try and slow down tickover to see if I can get the balance right. I've also added a Talon 60T rear sprocket and the bike really has been transformed. These mods are musts! Quote Link to comment Share on other sites More sharing options...
serpexc Posted December 12, 2010 Report Share Posted December 12, 2010 (edited) Does this mod make the clutch full manual, or just help it engage sooner? Just picked up a used TXT50 for my sons to ride in the back yard. Edited December 12, 2010 by Serpexc Quote Link to comment Share on other sites More sharing options...
feetupfun Posted December 19, 2010 Report Share Posted December 19, 2010 I have just tried another way to make the TXT Boy clutch engage at lower RPM and it works well. Someone in an earlier thread noticed that the parts list for the motor in the trials GG50 lists two clutch springs while the racing GG50 motor lists four springs and they postulated that some GG50 Boys had been fitted with motors with four spring clutches. I have not heard yet of anyone else taking two springs out but it is terrible riding weather here and a long weekend for me so I carefully pulled my son's bike's clutch cover off and had a look. Yes it had four springs and taking two springs out looked simple enough and the design is such that the change in the loading pattern on the pressure plate does not cause any problems so out they came. Amazing, it hooks up nicely a bit above idle now, it does not creep or drag, the manual clutch still works fine and there are no problems putting it in and out of gear with the motor running. Our GG 50 Boy was part of the first shipment of 2011 models to Australia. Quote Link to comment Share on other sites More sharing options...
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