trapezeartist Posted May 18, 2020 Report Share Posted May 18, 2020 I would like to try the clutch mod shown on this video https://advrider.com/f/threads/how-to-correct-beta-clutch-drag.1375397/ in order to reduce clutch drag. I'm hoping for a little advice from someone who has already done it. What is the mechanic feeling for when he pokes the screwdriver down the middle and works the lever? Free play before the pressure plate moves? Is there anywhere convenient where I can get the shims? I've tried eBay but it seems the standard 16mm ID shim is 22mm OD but the above thread indicates 16x25. Has anyone done it with 16x22 shims? Quote Link to comment Share on other sites More sharing options...
WillM Posted May 18, 2020 Report Share Posted May 18, 2020 I fitted two .25mm shims to my Rev3 last week. The OD of the shim is not too crucial as there is plenty of space for it, the 16mm ID is the more important bit. I had to make my own using a sheet of .25mm shim steel I had in stock. Along with the clutch plate modifications I found on here, the clutch on the old thing is now as good as it gets. Will 1 Quote Link to comment Share on other sites More sharing options...
dan williams Posted May 19, 2020 Report Share Posted May 19, 2020 10 hours ago, trapezeartist said: What is the mechanic feeling for when he pokes the screwdriver down the middle and works the lever? Free play before the pressure plate moves? Exactly Quote Link to comment Share on other sites More sharing options...
stu109 Posted May 19, 2020 Report Share Posted May 19, 2020 Hi I have a couple of KTM shims which I think are the right size. If you PM me I will send you them. Stuart Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted May 19, 2020 Author Report Share Posted May 19, 2020 2 hours ago, stu109 said: Hi I have a couple of KTM shims which I think are the right size. If you PM me I will send you them. Stuart Very kind. PM sent. Quote Link to comment Share on other sites More sharing options...
ssaulnier Posted May 20, 2020 Report Share Posted May 20, 2020 I used 3 of these 0.005" thick shims. Five of these shims was too much, 2 worked pretty good, but 3 seem to work best for my 1996 Beta Techno 250 in order to eliminate clutch drag. McMaster Carr part number 91437a555 will get you 5 of these shims. https://www.mcmaster.com/catalog/126/3456/ 18-8 Stainless Steel Shims for Shortening 16mm Diameter Screw Shoulders, 0.005" Thick Cheers, Steve Quote Link to comment Share on other sites More sharing options...
totty79 Posted May 23, 2020 Report Share Posted May 23, 2020 (edited) Sorry for the lazy question, I know I could just remove the cover and measure but is it definitely 16mm ID? It lost clearance through wear so I refited one of the thicker type friction plates until the shims arrived. I bought the shims from the dimensions in the parts book which says "Shim 15.25.1" but in 0.5 thickness, I also have .2 and .3 but the od is smaller on those sizes so I'm not keen on using them. Edited May 23, 2020 by totty79 Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted May 23, 2020 Author Report Share Posted May 23, 2020 7 hours ago, totty79 said: Sorry for the lazy question, I know I could just remove the cover and measure but is it definitely 16mm ID? It lost clearance through wear so I refited one of the thicker type friction plates until the shims arrived. I bought the shims from the dimensions in the parts book which says "Shim 15.25.1" but in 0.5 thickness, I also have .2 and .3 but the od is smaller on those sizes so I'm not keen on using them. I measured the spindle as slightly over 15mm. I think it was 15.15, so 16mm will do but be a bit sloppy. I’ve only been able to find shims at nominal 15 or 16 and I don’t know what tolerances there are on those figures. Quote Link to comment Share on other sites More sharing options...
totty79 Posted May 23, 2020 Report Share Posted May 23, 2020 Thanks. Sounds like I should be able to file them out if needed. Quote Link to comment Share on other sites More sharing options...
dan williams Posted May 30, 2020 Report Share Posted May 30, 2020 Ok so I got my McMaster McWashers. Gonna try this out. Quote Link to comment Share on other sites More sharing options...
totty79 Posted May 30, 2020 Report Share Posted May 30, 2020 I can confirm these fit https://www.ebay.co.uk/itm/Ricambi-Europa-Metric-Shim-Washers-15x27-5x0-5mm-BZPY-BS06304-05-10-pack/401638850844?hash=item5d838a811c:g:4GEAAOSwqnVb8bd1 I'm currently running one of the thicker clutch plates (3mm) with the rest standard (2.65), the 1mm washer, a 0.2 shim and a 0.5 giving a clearance of 0.3mm. It was noticeably better with a 0.1 clearance, but it closed up completely when checked after a few hours riding. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted May 31, 2020 Author Report Share Posted May 31, 2020 Thanks to the kindness of stu109, I acquired a couple of the KTM shims. I spent a while swapping between 1 shim (0.25mm) and 2 shims (0.50mm total) before settling on 2. Trying it on the drive there was still a bit of drag initially but I think that was just down to cold stick. I had a proper ride out for a couple of hours on Friday and everything worked fine. It wasn't a mega improvement; up changes are still clunky and I can't get neutral with the engine running. But I can now start the engine easily with the bike in gear and the clutch pulled in, and I can easily move the bike backwards with the clutch pulled in (both useful assets when I've just failed a section ?). I now need to check that I do still have a little bit of clearance and the thrust race isn't under any permanent load. (I think it's not because I couldn't generate any clutch slip in 5th gear even though I run with just 4 springs). Quote Link to comment Share on other sites More sharing options...
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