Belt drive (cooling) (2009)

Status
Not open for further replies.
Triton Thrasher said:
FastEddie- is your link actually saying that modern Japanese bikes have alternators that get too hot?


Is it written by an enthusiastic amateur?
Click to expand...

I’m only interested in the Brit Bike content. Japanese bikes have never given me any issues in this regard personally.

The advice within seems to work. Well it does for me at least.

I believe the author is quite clear in describing himself as an amateur enthusiast.

Not sure of the relevance of that though from your perspective, doesn’t it apply to all of us ?!

If you have different specific advice, please share.
 
I don't claim to be an "expert", but I don't believe there is a belt drive manufacturer that specifies their kit requires cooling.

I, too, am of the belief that opening the primary case up in any way, invites debris and accelerated wear.

(I could be wrong)
 
On the cooling front, Tony Hayward didn't recommend any venting for his syncroflex belts in a Triumph when I spoke to him.
I suspect a commando chaincase is a bit cooler given it's larger volume?
Also didn't Matt @ CNW say he saw some front pulley wear on hard anodised pulleys in vented cases in last week's belt thread? Apologies if I've misquoted but it was definitely someone who knew their stuff?
I'm fitting a recently purchased used RGM kit in a few weeks, no plans to vent but then I run a MOSFET reg /rec .
 
I’ve run Hayward system in a dry(ish) unvented Triumph casing for many years.

The £8 CBR600 regulator might have MOSFETs in it. Pretty sure it’s the shunt type. Of course the Alton alternator is mounted onto the outside of the crankcase, in the dynamo position.
 
wavey_davey said:
On the cooling front, Tony Hayward didn't recommend any venting for his syncroflex belts in a Triumph when I spoke to him.
I suspect a commando chaincase is a bit cooler given it's larger volume?
Also didn't Matt @ CNW say he saw some front pulley wear on hard anodised pulleys in vented cases in last week's belt thread? Apologies if I've misquoted but it was definitely someone who knew their stuff?
I'm fitting a recently purchased used RGM kit in a few weeks, no plans to vent but then I run a MOSFET reg /rec .
Click to expand...
If you mean this one. https://www.accessnorton.com/NortonCommando/new-old-belt-drive.32383/ I don't seem to recall seeing the post by Matt.
 
Just to play Devil's advocate here, how many that think no venting is necessary would vote against Tri Spark ignition because it sits next to that 'hot' engine?
But.... A personal view here from a prior RGM belt user, I think alignment and bearing condition are major factors (probably mentioned elsewhere), even when set up with the correct tension my chaincase would be the second hottest part of the bike after a run. Only when I reverted to chain to allow the starter to be refitted did I find inadequate shimming behind the clutch basket.
 
swooshdave said:
If you mean this one. https://www.accessnorton.com/NortonCommando/new-old-belt-drive.32383/ I don't seem to recall seeing the post by Matt.
Click to expand...
You're right, I had a quick look at that post after posting above and couldn't see anything. Problem is I have been reading up on the historical belt threads as prep for the intended RGM belt fitting, so could have seen it in pretty much any thread mentioning belts, lightweight clutch plates, second adjuster, etc etc , apologies. I DID see that Hobot had spoken to Mick Hemmings, Tony Hayward and Steve Maney and none of them recommended venting (according to Hobot).
 
wavey_davey said:
You're right, I had a quick look at that post after posting above and couldn't see anything. Problem is I have been reading up on the historical belt threads as prep for the intended RGM belt fitting, so could have seen it in pretty much any thread mentioning belts, lightweight clutch plates, second adjuster, etc etc , apologies. I DID see that Hobot had spoken to Mick Hemmings, Tony Hayward and Steve Maney and none of them recommended venting (according to Hobot).
Click to expand...
I'm guessing that the oil in the chain case doesn't offer as much cooling as we assume it does.
 
bpatton said:
How you take care of the cooling issue depends on which belt you're using. Neoprene belts have to be run dry and are probably more sensitive to heat so you need to vent them. The RGM (Hayward) urethane belt can be run wet or dry and probably isn't as sensitive to heat. Neither one of them need lubrication. The main source of the heat in the primary is the alternator but it's nothing compared to the heat that's getting sucked over from the engine directly to the case. Luckily, the surface area of the primary is huge and aluminum bleeds off heat like a champ so it's probably a wash. I like to run the primary closed to keep dirt and water out. I use ATF in the primary because I read somewhere that the ATF splashing around gets on the alternator and establishes a thermal connection for it to the case. Whether the alternator is warming the case or the case is warming the alternator is anybodies guess. BigStu comes to my mind whenever I think of Syncoflex belts. You can find out about belts by doing a search on this list on Syncroflex.
Click to expand...
Per Bob's suggestion, I've downloaded the Syncoflex belt catalog. According to the catalog, their Gen III belts are good to 100 C, so those would "hopefully" be able to tolerate a closed primary. Bob says their polyurethane belts can be run in oil. That would be nice [if factual in real life] for the Mk III, if you want to retain the stock electric start system. Has anyone here run a belt primary in an oil bath besides Bob? It appears he is no longer around this group. What brand/model belts are supplied with the various makes of Norton belt primary kits???
 
Unless you are going to have some sort of air scoop to force air into the chaincase, I can't see that a few holes would have any beneficial effect in lowering the temperature inside the primary chaincase. If you use something effective enough to lower the temperature it's also going to be effective at sucking in moisture and dirt/dust.
 
Ran a QPD ? belt system fully enclosed , no breathing , on my former 72. Perfect alignment , no issues, easy to install. Then busted up my ankle and sold it to move on to the MK111 model in my now later years.
 
chaztuna said:
Per Bob's suggestion, I've downloaded the Syncoflex belt catalog. According to the catalog, their Gen III belts are good to 100 C, so those would "hopefully" be able to tolerate a closed primary. Bob says their polyurethane belts can be run in oil. That would be nice [if factual in real life] for the Mk III, if you want to retain the stock electric start system. Has anyone here run a belt primary in an oil bath besides Bob? It appears he is no longer around this group. What brand/model belts are supplied with the various makes of Norton belt primary kits???
Click to expand...
As I understand it the poly belts can indeed be run in oil. The rubber belts not.

IMHO running in oil is less preferable as you don’t gain the advantage of a dry clutch.

There is also the theory that oil can stress the belt tension. The theory goes that oil will trap twixt belt and pulleys at speed, increasing their effective diameter, and thus tightening the belt. I’ve heard folks attribute belt failures to this phenomenon in the past, but have no personal experience of such.
 
Fast Eddie said:
As I understand it the poly belts can indeed be run in oil. The rubber belts not.

IMHO running in oil is less preferable as you don’t gain the advantage of a dry clutch.

There is also the theory that oil can stress the belt tension. The theory goes that oil will trap twixt belt and pulleys at speed, increasing their effective diameter, and thus tightening the belt. I’ve heard folks attribute belt failures to this phenomenon in the past, but have no personal experience of such.
Click to expand...
Nigel, The Barnett clutch plates work extremely well in ATF. Oil or ATF I think should also extend the life of the splines on the belt wheel and the clutch hub.

The theory of oil being trapped between the belt and pulleys definitely sounds plausible to me. It would be an interesting engineering exercise to determine how much more slack would be required. More frequent belt changes would probably be advisable.
 
Harley's have been running closed belts forever.
I ran a 96 CI, 90 hp, 106 ft lbs, enclosed belt drive for about 20k miles before I sold it.
Actually broke a secondary belt, having a little fun. Primary was fine.

Not that means anything here, just thought I'd jump in.
 
After taking a hard look at the previous thread and this one while considering belt drives for my bike one influence remains for me.
Any venting for heat or seeking cooler air for heat/friction also exposes the belts/drive gears/clutch to dust or dirt or sand or water and all the other strange stuff you sometimes find. Clean is good...dirt and grit are the enemy, there is a reason there are a variety of filters all over the engine and tranny.

The ATF I use in the drive/clutch has its purpose...lubricate to reduce heat from friction and minimally, disperse heat.
Creating an access for unwanted grit to invade the drive system, to me, runs counter to clean.
To each his own. I was thinking about converting to belt drive due to noise and spiking performance a bit. I'll stick with chains for now as the performance has been reliable. Once things start to wear I will give a sealed belt drive another look.
 
For what it's worth, I run a dry Newby belt in a vented and screened chain case.

The only "grit" I've come across inside the case is dust from the clutch plates and belt.

I vented the case because it was getting quite hot. It is noticeably less so now that it's vented, with no other changes. Vents are on the outer only, and face to the side.
 
I don't ride in nasty dirty environments, and the only grit that I see in my primary is some blue fuzz from the belt.
 
Status
Not open for further replies.
Back
Top