sawtooth Posted October 13, 2009 Author Report Share Posted October 13, 2009 Having just measured a matching male and female morse taper on a CMM, and finding one being 2.858 degrees included and one 2.888 degrees, i'd happily call that the same angle. A note on the taper: The tapers of the crank hub and flywheel hub are different. They are machined at a slightly different angle from each other (it's known as a ".001" interference fit" or a "Morse Taper") so they stick together, and why you need a puller to get them unstuck. When you lap the parts together, the interference fit is gone (the taper angles are now the same), so the parts are not as secure. As such, I'd add a little more torque valve (if torque setting is given in a range, say 38-42 Ft Lbs, use the higher number at least) and check the torque after a couple of heat cycles (riding sessions) as it will probably back off a little (which happens to new bikes if the flywheel fastener is not checked after a few rides). Sometimes, a little red Loctite ("non-serviceable" Jon Quote Link to comment Share on other sites More sharing options...
jse Posted October 13, 2009 Report Share Posted October 13, 2009 Having just measured a matching male and female morse taper on a CMM, and finding one being 2.858 degrees included and one 2.888 degrees, i'd happily call that the same angle. O.K., you win. Jon Quote Link to comment Share on other sites More sharing options...
copemech Posted October 14, 2009 Report Share Posted October 14, 2009 (edited) One can argue this all day in degrees or inches of measure, but it is actually the slight difference combined with the slight plasticity of the metal that creates the greatest bond under pressure. If I were to lap fit a set, I would then put in a slight differential , using some method, if not for anything else to insure the contact will indeed break on demand! It should do so, or be permanatly in place! I have no idea what the torque spec is on the Beta, on the Sherco it is 72 ft/lb the Beta should be similar, but ? Edited October 14, 2009 by copemech Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 14, 2009 Author Report Share Posted October 14, 2009 (edited) The idea was not to cause argument, it was to find a definative answer so i don't bugger the bike again. Engineers blue showed that the mating parts were the same angle (on my bike at least) so have lapped the two parts and torqued the nut up to 140NM. The bike now starts and runs fine, thanks for everyones input Edited October 14, 2009 by SawTooth Quote Link to comment Share on other sites More sharing options...
laser1 Posted October 14, 2009 Report Share Posted October 14, 2009 Maybe thats why the torque setting is so high..??? Thats up there. Quote Link to comment Share on other sites More sharing options...
jse Posted October 14, 2009 Report Share Posted October 14, 2009 The idea was not to cause argument, it was to find a definative answer so i don't bugger the bike again.Engineers blue showed that the mating parts were the same angle (on my bike at least) so have lapped the two parts and torqued the nut up to 140NM. The bike now starts and runs fine, thanks for everyones input I apologize for the flip comment, it was uncalled for and certainly not indicative of what I intended to express. E-mail is a quite "cold" way to communicate and lacks the tone, volume, cadence and inflection of the human voice, as well as lack of facial expression, and a comment meant to be funny came across as crappy. Copey will vouch that I'm much, much more goofy than I am grouchy. At 140 Nm (about 103+ Ft lbs) and lapped, it should hold well. If it slips again, look at where the crank stub protrudes through the flywheel hub. The end step of the stub is often very close to the washer surface inside the hub and when lapped together, the stub will fit slightly farther down in the hub, sometimes far enough so that the step then contacts the washer. All the torque is then on the washer/stub end area (the stub has bottomed out against the washer) and not on drawing the stub in against the flywheel hub. Jon Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 14, 2009 Author Report Share Posted October 14, 2009 No need to apologize at all, i know how the internet can be. Thats some useful info on the washer, will keep an eye on mine and check the torque after riding. Quote Link to comment Share on other sites More sharing options...
dan williams Posted October 15, 2009 Report Share Posted October 15, 2009 Heh heh, You know how much I appreciate your technical prowess Jon but man you really "went to town" on this one. I'm sorry but I can't help but sit here chuckling at frustoconical shape, interpenetrating parts and cointegration. A good engineer can get your head spinning with technical jargon but a great engineer can make it sound dirty at the same time. Quote Link to comment Share on other sites More sharing options...
nzralphy Posted October 15, 2009 Report Share Posted October 15, 2009 Beta Rev4T workshop manual has the flywheel nut torqued at 120Nm. I'd say the 2T should be the same. Quote Link to comment Share on other sites More sharing options...
jse Posted October 15, 2009 Report Share Posted October 15, 2009 Heh heh, You know how much I appreciate your technical prowess Jon but man you really "went to town" on this one. I'm sorry but I can't help but sit here chuckling at frustoconical shape, interpenetrating parts and cointegration. A good engineer can get your head spinning with technical jargon but a great engineer can make it sound dirty at the same time. Dan, Obviously, not my personal wording (hence the quotation marks, I try not to be as obtuse) but you know what? I re-read that explanation and I did experience an intense desire to nibble my OWN ear...... Jon Quote Link to comment Share on other sites More sharing options...
copemech Posted October 16, 2009 Report Share Posted October 16, 2009 Dan,Obviously, not my personal wording (hence the quotation marks, I try not to be as obtuse) but you know what? I re-read that explanation and I did experience an intense desire to nibble my OWN ear...... Jon "In some cases the cointegration results in material transfer across the zone of contact, i.e., cold welds." And if you get that just right you will never, ever, have to worry about it coming loose again! Beat to your own delight! Deal with the remains! It's all good! Quote Link to comment Share on other sites More sharing options...
dan williams Posted October 16, 2009 Report Share Posted October 16, 2009 Beat it to fit. Paint it to match. Quote Link to comment Share on other sites More sharing options...
zippy Posted October 17, 2009 Report Share Posted October 17, 2009 Dan Williams Posted Today, 05:01 PM Beat it to fit. Paint it to match. Be sure you give it a really good 50/50 paint job. "looks great at 50 feet away, while traveling 50 MPH" Quote Link to comment Share on other sites More sharing options...
yeoblade Posted November 24, 2009 Report Share Posted November 24, 2009 I seem to have the stator problem. Revs to about 2 - 3 K then cuts out until rpm drops back again. Do the two philips headed screws on flywheel need to be removed first before using puller?(the ones where in a previously posted photo , are used to fix the holding tool in place). And is the nut normal left hand thread. 2002 rev3 Also has anyone known of this problem coming and going at all? thanks Julian. Quote Link to comment Share on other sites More sharing options...
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