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Post by m1mental on Jan 14, 2011 8:24:50 GMT
They look like DRT red strong springs to me I fit drt 8 spring conversion clutches to my M1 Rebuilds with 4 plate carbon newfren. with a bit of shimming and various steels and plates it may be possible to 5 plate it.
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Post by firej on Jan 14, 2011 16:52:32 GMT
looks like the cone shape helps reduce the drag. equals out the pressure ?
do you have some mesurements of your ring and spring types I might have a go at making one...
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Post by paddyfitz on Jan 14, 2011 18:36:43 GMT
I did run an XL2 12 spring setup for awhile. Shimmed the tree up as suggested. Couldn't get it to hang on & once it got hot, would drag. Tried falc plates (they did hold the longest), Malossi plates, Newfren plates, did a DRT outer plate w/ 5 plates, swapped out the basket & bottom plate, tried different spring configurations... same deal. Thusly, I ended up with the DRT 8 spring full meal deal. It held & didn't drag. Mind you - this is race track application, not riding around in the streets. The tracks we use are not by any stretch of the imagination like riding around in the street... It was a very expensive year for clutches on my part. I think Dayn's idea is great & his bike did reeeally well with that setup - no bones about it.
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dayn
100 Sport
Posts: 87
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Post by dayn on Jan 14, 2011 21:00:40 GMT
I gave it a pretty good think and it seemed to me that heat was the real killer. I believe that a proper wet clutch is intended to be cooled by the oil bath, however on a small frame there is really just a drip of oil on it that lubricates it but doesn't really cool it. Fine for 3 hp not so good on a track where you have 15+ hp and are thrashing it. I ordered a set of Falc plates to look at and was disappointed that they were still based on a steel plate. This is why I went with the Polini plates to throw the heat better. Logically when I think about it the thing you are trying to protect from heat is the friction material and so it makes sense to use aluminum on the thing the material is stuck to. Plus they are significantly cheaper. Ideally tho a dry friction material version would be available.
The next issue was the single spring of the old style clutches. All the stiff springs I tried would become coil bound before the clutch spider came in contact with the UFO limiting the amount the clutch can release. This is why I came up with my spring holder and designed it specifically to allow the clutch to fully release while applying greater more even pressure.
The cone is to give the springs as much support while allowing them to sit as far down in the UFO as possible. The springs are a Japanese spec die springs. I believe that DRT uses common die springs in his stuff which have a different coloring system but are limited in size availability. Anyway the red version of these springs is weaker than the green.
I have over 5 race weekends on this clutch and its still holding. Haven't noticed any clutch drag presumably due to the improved heat dissipation.
I made a few spare holders for the local boys but if anyone on here wants one PM me (I hope this is not against board rules)
Cheers
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Post by amazombi on Jan 14, 2011 21:10:34 GMT
I alway had the drag problem with the thinn steel plates. Steel is a shitty heat conductor, so my thinking was, that once the plates get hot after a sprint-style launch, they are not the same temperature all the way through but distort like a Pringle crisp. Hence the drag, the clutch doesn't release properly. Once on the move on the track it doesn't matter because you don't really use the clutch any more, at least I don't. Using the beafier top plate does help, I believe, because that too warps with the heat. The cork friction material typically used on Vespa plates is quite shit because it's a bit like a sponge. It gets compressed by the clutch springs, and you need a lot of actuation room for the clutch to release properly. The sinter stuff used in motorcycles (some of the new clutches use bike clutch plates) is much better in that respect. My solution in the end was to use a beafed up top plate and four original thickness surflex clutch plates with original thickness steel plates and 8 heavy springs in a CNC machined basket and spider.
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Post by Juan on Jan 14, 2011 21:11:47 GMT
Dayn, no board regulations here as we try to keep things as free as possible and help others so fire on.
I'd also look at the Surflex Alloy platers before going with the Polini items.
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Post by amazombi on Jan 14, 2011 21:41:51 GMT
PLC uses aluminium plates too. It shifts heat much better than steel, so there is less chance of it to warp. On top of that it's friction coefficient is significantly higher than that of steal (it's got more grip), that also helps to stop the plates from slipping. Some people are concerned with the rubbed off ally contaminating the oil and ruining bearings. I don't think that is an issue so, both Yamaha and Honda offer ally plates for racing even on two strokes which don't have an oil-filter.
The Hartz clutches use sinter type bike plates, which need very little room to actually separate properly. I think this makes them superior to the cork rubbish.
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Post by amazombi on Jan 14, 2011 21:43:23 GMT
Dayn, no board regulations here as we try to keep things as free as possible and help others so fire on. I'd also look at the Surflex Alloy platers before going with the Polini items. I wasn't aware Surflex made Alloy plates. Their stuff usually is very good, so that would certainly be well worth a look.
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dayn
100 Sport
Posts: 87
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Post by dayn on Jan 15, 2011 0:48:34 GMT
Interesting, I didn't know that Surflex did that either. Where did you see them?
The Hartz definitely looks like a nice solution and considering it's a basket and all it's good value too. My concern is having to offset the wheel and how that would change the bikes handeling....
I went with the thin steels in my clutch to allow it to spin freely and if you have a look at my picture I had to use the oil thrower to keep the top plate in the basket (which is a bit shallow) even then it was/is close. I think one of my next projects is going to be making a taller aluminum basket. This should hopefully give me more room for thicker steel plates and hopefully aluminum plain plates too, tho they would have to be pretty thick for the tabs to last.
I guess I have a crappy riding style where I constantly slip and work the clutch to stay in the power band around the tight tracks we race on. Even still I can't say I noticed any drag on the clutch, tho what you said Amazombi makes sense about the thin steel plates.
Cheers,
Dayn
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Post by ttscshaggy on Jan 15, 2011 1:14:57 GMT
i like the the look of that dayn i cant find the ally surflex plates anywhere , Juan did you dream it ?
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Post by amazombi on Jan 15, 2011 7:39:07 GMT
dayn: What tire are you using in the back? Dunlop TT92? If so you need to use an offset rim, or space out the rim anyway. My experience is that even though this is not ideal in theory you don't really notice it when you ride. If you really dislike the idea you could always weld up the clutch cover plate and machine it. If done properly it will still clear the rim/wheel and give you the extra space required inside. Rumour has it that SIP has a XL II clutch cover coming out which has been designed to accept these larger clutches without spacers.
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Post by Juan on Jan 15, 2011 8:14:23 GMT
i cant find the ally surflex plates anywhere , Juan did you dream it ? No, they came via Chiselspeed but I'm not sure if they're listed on-line anywhere. I'm just going out to work so I'll have a browse later this evening.
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Post by Juan on Jan 15, 2011 17:16:25 GMT
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Post by jonnysnatchsniffer on Jan 15, 2011 19:56:40 GMT
i got surflex ally plates in mine, came with stronger spring too, got them off adspeed no doubt via chiselspeed
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Post by Juan on Jan 19, 2011 18:38:59 GMT
I'm going to pin this thread.
I've been thinking about things here as logically as I can and what I've come up with is that Lauro really designed the clutch for sprinting without any other competition entering his thought chain. It makes sense to use steel in those circumstances given the price and the limited use in a 150m sprint meeting. With the violence of the launches if can fully understand his thoughts toward building a durable basket and he's probably not in the slightest bit intrested about circut racing elsewhere on the Globe but given the feedback on his accepted Genius an alloy version would be exquisite.
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Post by eean on Mar 3, 2011 20:35:22 GMT
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Post by lambrettasx on Mar 17, 2011 21:09:10 GMT
Despite we sell expensive solutions I personally prefer 4 carbon plates in engines with less than 25hp. Not because they are better or equal to the CNC clutches but they are much cheaper. I played a lot with 5-plate conversions and DRT top plate. but it never worked sufficiently. There is just not enough space unless you weld up the basket and so on. You also need to use thin intermediates that warp quickly, so you always have drag.
The Newfren 4-plate carbon ones work much smoother than cork ones but need heavy spring pressure to work. I suggest to use the following: 4-plate carbon plates, 1mm intermediates from Surflex e.g. (newfren comes with 0.8mm) and heavy uprated springs like Worb5 or ours and Cosa XXXL springs inside (also availabe at Worb5, me and SIP). It is still easy to pull if using an XL2/HP clutch cover.
If you got more than 25hp forget all that conversion stuff and go for a proper CNC made one like K&G, Hartz4 or 5 or similar. In the end it saves money as you don't need to swop clutch plates for the next 5000 miles. K&G and Hartz4 are tested up to 40hp when using all 10 heavy springs.
The engine Sticky was using in that Spanish 6h endurace had the above 4-plate Newfren composition. It had about 20-22hp.
The text may sound a little bit biased but I had so much pain on clutch killing small go karts tracks, so this is my unvarnished opinion.
edit: Cork plates need less pressure to deliver the same torque transfer. On the downside cork needs more space to compress and release and it burns up much faster when slipping or used excessively in drag and track races.
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Post by charliec on Mar 28, 2011 16:47:38 GMT
are any of these compatible for regular smallframe clutches or all XL2 only? . i looked through and got a bit cofused not my finest hour ;D
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Post by paddyfitz on Mar 28, 2011 17:53:44 GMT
The DRT & Newfren are based on the V range smaller inner basket.
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Post by charliec on Apr 1, 2011 16:09:36 GMT
is there a way to get a 5 plate cluth for a small frame whithout the springs? ( beacause with my shit budget i cant afford no top plate) - is there an alternitive? - or will 5 plates just be shit with a standard no spring setup?
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