For what it's worth... I went with the Haywood unit on both my bikes. I was a little uncomfortable with the idea of running a dry clutch). There was some machining of the primary case needed (maybe not necessary on your bike).
The result is dramatic... well worth the money. Compared with belt drive version, the stock performance of the bike would best be described as "sluggish"!
After I had it on my '78, it was a no-brainer to do the job on the '79. It is pricey but what you get is a totally different motorcycle.
I put electronic ignition on both also and that is the icing on the cake.
on my standard clutch i put grease on the rollers(some say it's bad because grease goes in the clutch afterwards...and they may be right!!!)
on thre map cycle kit there is a double ball bearing which seems closed and lubed!
i'm still looking for the advice of somebody who experimented the map cycle primary trans
I would like the testimony of someone who has any dry primary with about 20,000 miles on it.
A sealed bearing will work... sure...for awhile... but let's think about how much heat is in there... and think about the seal material (some kind of plastic, no doubt)... and think about how, eventually, given all that heat & rotating motion, the seal starts to leak... and how the lube evaporates and how the bearing fails.
I went with a wet system (Haywood) and I like knowing that those bearings are fully lubed at all times and that occasional oil change keeps up the quality of the lubrication.
I know lot's of competition machines are set up dry... but for the long run... is it really the best way to go?
Roy is right and i think,Dave ,that ,in fact in top gear the bearing don't heat very much as it don't rotate very much(remember that the axes of the hub and of the clutch are fixed ..so....what turns is is the gearbox main bearing)
tell me if iam wrong please
Dagad, your comment surprised me. My stock Triumph clutch worked quite well & I had no complaints about dragging or slipping. I did my belt conversions for performance reasons and I was under the impression that most folks were similarily motivated.
The Haywood belt drive with 16 plate clutch is smooth as silk... no slipping or dragging and a very easy pull. It's definitely a good deal better than stock but the performance boost is what is thrilling. You are exchanging a 4 lb chain for a 4 oz belt... not to mention the much lighter crank pulley & alloy clutch basket. The machine's responsiveness changes dramatically. If I compare before & after belt drive on the same bike (and I've put it on both my 140s)... I can only describe the pre-belt drive version as "sluggish".
Peintremondain... seems right about high gear... but who rides around only in high gear? Further, if there wasn't a significant amount of friction to be dealt with, would the stock clutch, as designed, be riding on 20 uncaged needle rollers?
This thread started as a query about the MAP dry belt drive and whether or not it was worthwhile. My 2 cents worth was an attempt to get some input about the longevity of dry systems in general. I had considered one when I decided to convert my '78.
...and so, my question still stands: opinions aside...does anyone actually have lots of trouble-free miles on a dry setup?
It would appear that some are unaware of a few of the qualities a motorcycle multi-plate friction clutch shoved on the end of the gearbox main shaft should possess. For example it should....
1 NOT slip when fully engaged, even when hot.
2 free off INSTANTLY WITHOUT DRAG whenever required, even when hot.
3 be EASILY operated by the user
4 possess the LIGHTEST ROTATING WEIGHT reasonably possible
On 4 alone you cannot call the lump fitted to late Triumph Twins clutches. Vastly overweight gearbox knackering flywheels YES but clutches never.
As for 2 my olde Triumph manuals state that before starting the motors one should use the kick starter a few times to free off the clutch or as a Motor Cycle Sport road test put it..'As with the last Triumph tested it was possible to start the motor with the clutch lever back to the bar' . The FACT that over the decades Triumph owners became so used to the ritual of freeing off the clutch first that they considered and still consider it 'normal' does not mean it is not a serious clutch problem that NO car owner would ever put up with!!
The guys at the factory soon learnt to park their bikes leaning against the factory walls with the clutch lever pressed back to the bar and to give the kick start lever a good kick to free off the plates before walking away.....according to a Triumph Service Manager I know......
As for 3 another Motor Cycle Sport road test reported for a 650 Unit bike.'It was as easy to change gear without using the clutch as with which was just as well as clutch action was heavy'. So what did Triumph do to increase clutch torque capacity for the 750 motor?? They increased the clamp load by 30% that increased the grunt required to operate the clutch lever by 30%........ It might be OK for those who ride a few hundred miles without changing gear but just try riding one through London. Funny how people have made hydraulic systems for the clutch.......
As for the Synchroflex AT10 belt......This belt was designed to be run DRY. it was NOT designed to be run with oil and as of a few years ago when I questioned the German manufacturer of the belt who referred my many questions back to their UK agents NO testing with oil had been carried out to determine the power losses that may occur in pumping the oil out from between the belt and pulleys. Now Mr Hayward one stated that he recommended his dry belt users to keep them well greased etc but any form of lubrication will reduce efficiency and worse increase the risk of the belt jumping teeth or 'ratcheting as its known.
As for lubrication of the rollers the recommended lubricant for the AMC clutch rollers is and I quote from the manuals 'a smear of anticentifuge grease'. AMC clutches are DRY clutches and suffer from slip and drag with oil on the friction interfaces...IF the owner applies enough of the available engine torque to them. Of course AMC clutches had a singlex chain running directly over the centre line of the rollers so that at no time did the pull of the chain try to pull the basket around off of them but with the triplex chain they had to shove thrust faces in to stop this occuring otherwise trying to slowly engage the clutch to get away from a stop becomes most interesting..Norton tried such a lump on the development Commando.....later used on the Commando that finished second to a works Honda at Spa ..finishing the 24 hour race at over 100 mphbut they had someone help push the bike away from the pits....and I bet the lump was a LOT lighter than the Commando vastlyoverweight unbalanced gearbox breaking flywheels!!
What wreree the wordsused to describe the QPD 4 friction plate diaphragm spring clutch fited to that Triumph Twin tested in The Classic Motorcycle not long ago??? wasnt it two words...A REVELATION .........Now that Triumph had a real clutch fitted.
How a clutch renowned for drag problems can be improved by fitting more friction interfaces into it thus reducing the gap per interface with the clutch freed off is beyond my powers of understanding. As far as I am aware such was simply a cheap bodge to increase clutch torque capacity to try to cure the slip problem suffered by every T140 owner I know. Well it was easier than having to strip out the clutch to wash the plates in petrol to remove the oil causing the slip.....a ritual; well known to MANY British bike owners over trhe years.
I assume that MAP supply different springs with their dry running belt systems?? Well if you use std 750 ones your dry MAP clutch will have enough torque capacity in it to take the max engine torque output of two motors without suffering from slip so the springs could thus be changed to lighter ones to reduce clutch torque capacity back to the required level for one motor and make clutch lever action a lot lighter....But somehow I suspect MAP as with many other system makers don't know how to calculate clutch torque capacity or the required clutch torque capacity. The ONLY one I know of being Bob Oswald of QPD in the USA who was making proper belt systems for triumphs before the other system makers had even heard of toothed belts. His T140 having been fitted with primary and secondary belts since 1978 ish........ :hammer:
I'm not going to argue ANY of your points, but I will say that a properly installed 'clutch' on a Triumph, with the appropriate amount of CHAIN (not CLUTCH) lubricant in the primary case, has always worked well for me.
iknow your point of view but assuming that my clutch is correctly fitted and having the good amount of oil it still drags and slips...sometimes
i can live with it but if i could do without ...it wouldn't be so bad
thank for your advice
i red your book:good!
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