BDL Belt Drives?

[CaptMike]

I'm going to put a belt on the '57 and have been looking at the BDL unit's that have 1.5" belts. After reading most everywhere I could I just don't see the differences between the 8mm and the 11mm (belt/systems). On the BDL site it shows both for a Closed Primary. I know I could call them but I feel that I'd get the most reliable info from you guys.

My other question on belts is what to do with the Crankcase Breather?

[Sir_Rat]

Capt Mike
Either 8 or 11 will work just fine for you. You gotta do something with the breather, I put a hose on the end of mine and routed it back out of the primary and put a tiny little air cleaner filter on it to keep the oil vapors from spraying the undersides of my bike. Some guys will route it back to the rear chain to act as a rear chain oiler. Are you going to run the BDL clutch pack or just their belt drive? Those aftermarket clutches are one of the best improvements you can make over stock and well worth the extra dineros...IMHO ...good luck!!

Aloha....Mike

[mr. z]

Both will work fine, 8 or 11 mm is the pitch of the belts. I believe BDL, Primo, etc. came up with the 11mm pitch idea to match the original ratio of the stock sprockets(engine & clutch drum) better then the previous 8 mm.

[mr. z]

Forgot to mention breather in my previous post.

Like Sir Rat said, you are gonna have to run a hose from the breather. Mine runs from the breather nipple thru a cooling vent in my inner primary cover to an un-obstructed location under the bike.

You MUST prevent any oil from getting on the belt, if oil gets on it, and soaks it, it will break down the rubber compound and snap, which is no fun far from home(ask me how I know).

Another thing you must be sure to do is alighn tha sprockets, which I believe we have here in the knowlage base on this site. If you don't the belt will prematurly fail.

Finnaly, you need to vent you primary cover in some way to keep the belt cool, the way I did it was to make some vent slats in my inner primary cover,(aftermarket cover, don't do this to an old original OEM cover) but here in Arizona from late spring, thru out summer I also run with the outer cover off.

Belt drives get a bad rap, but if you do these precautions, you'll have many, many miles out of them

[rmcrh]

8 mm is my belief. I have been stranded trying to find a replacement 11 mm and will never run one again.
RRHAWG will differ with the concern of oil on the belt. We, RRHAWG and myself, are very opinionated about belts and believe in the usage save 11mm. Do not close off the oiler.

[Robert Luland]

Just shoot yourself in the foot now and get it over with! The chain rules!

[Hubbard]

Hey Robert, Just curious how often do you have to adjust your chain? I ran a diamond and got horrible service from them. Seems like they didn't last very long either. And before you ask yes my oiler was oilin'

[james]

They forgot to mention the breather tube from the case to the inner primary has a 90 degree bend to it. You have to get rid of that 90 degree bend in order to install a hose to vent to where ever you want. I had a belt drive for a brief period and instead of cutting off the bend of a oem breather I bought a aftermarket breather to cut up and install a vent tube outside the inner primary. The 11mm primo belt drive I had was so tight and the trans adjusted full forward, I didn't like it. Not hoggin out the trans plate for further adjustment, I'm back to the chain now.
I have a Primo belt drive set up with less than 100 miles on it for sale.

Jim

[PanJud]

Love mine, have had the same 11mm Primo belt for about 7 years. I Sawed the end off the breather and slid a hose over it, bent it in a soft 180, and drilled a hole in the inner, ran it out through there, with about 4" extra. Did not consider a filter on it, OR providing air circulation for the belt, though. I live in a relatively cool area in the mountains. Glad that was mentioned, I'll look into it.

BIGGEST plus with the belt: NEVER have to adjust the thing...NEVER. (I DO inspect it with regularity) With the chain, had to put bike on lift ever 200-300 miles, slide the tranny back, then SLLIIIDDdeee the wheel back. (That was WITH the compensating sprocket) Belt acts as a big, long shock absorber, eliminating the tranny working itself loose, and kills half of ALL the non-exhaust noise on the bike. The original design, with the HUGE, unsupported space between the engine sprocket and the clutch hub was a total loser

[Robert Luland]

Ya know Hubbard, why is it that the guys on this forum got so many problems with their bikes. I can't really remember ever having to adjust the primary but a couple of times after stretch out. If it isn't belt drives, ignitions, batteries, led lights, modifying star hubs. For crying out loud leave the poor machine alone and ride it as it was intended. If ya got to screw with something, go out and buy a basket and be done with it. I will tell ya this. If I was riding from NJ to Davenport, I sure as hell wouldn't have a belt on that motorcycle. The biggest modification I ever did one of my bikes was put a mag on one of my 60s. I call it my get me home bike. Bob L

[PanJud]

Gonna go out on a limb here: "My bike is running perfectly" is not the subject of very many posts in a mechanical-related forum

[mr. z]

"just ride the machine as it was intended". Easier said then done.

With all due respects, ya have to understand these machines are 50-60 years old. In 50 or 60 years, most, if not many of them suffered for decades from ham-handed abuse from people that really did not know what in the hell they were doing. I cannot tell you the half-assed things I have seen, and have had to correct on bikes over the years. I also build and restore street rod cars and trucks from the 50's that have had many years of torture under the wrong hands as well.

I have belonged to this forum for only a little over a year, this is the place where guys post their issues and other guys help them out isn't it? That was my understanding.

And the advice Cotton brings to the table is invaluable, I luv reading his posts.

One last thing, I agree the chain rules-but only in aluminum enclosed primary, electric start bikes. Those are where a primary chain belongs. In tin-primary bikes it is my OPINION that a belt is better. Just my opinion.

Hope I don't ruffle any feathers, that is not my intent

[Larry]

A properly lubricated primary chain will go thousands of miles between adjustments.

[indianut]

One last thing, I agree the chain rules-but only in aluminum enclosed primary, electric start bikes. Those are where a primary chain belongs. In tin-primary bikes it is my OPINION that a belt is better. Just my opinion.

What he said! I have ridden MANY Cross Country Miles on my basically Stock Pan with an 8MM Belt drive. I keep a spare in the bags. My current belt probably has over 30,000 miles on it. It keeps the bike clean. It prevents me from having to adjust the Trans, rear wheel, clutch linkage, and shift linkage, (and if a Rigid frame, rear brake linkage) just to tighten a primary chain. That being said, a chain with a comp sprocket IS smoother than a belt any day. If I could ever decide a GOOD way to put an adjusting shoe on my Pan with the Tin Primary Cover I MIGHT go back to a chain!

[steinauge]

In my experience belt drives work fine until they dont.That is to say failures tend to be sudden and occur with little warning.If you have a primary chain failure you knew it was coming for quite a while.I run chain primaries in all my bikes these days with no problems of any kind.I sure do see a lot of people with belt drive trouble,especially the 3&4 inch versions.