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travasesino
01-23-2010, 3:07 PM
anyone running an open primary on a unit triumph?

pics?

KT
01-23-2010, 6:42 PM
I'd like to but damn the belt drives for the primary are expensive ....Who knows maybe down the road ..If you look in Tyler's 110 thread he is running a open primary

TRUMPNUT
01-23-2010, 7:16 PM
I'm running one on my pre unit . They can be tricky to set up on a unit . The crankcase breathes into the primary on the later units so you would have to figure out how to keep it from dumping oil every where .

Have you thought about just trimming the primary cover around the clutch ?

travasesino
01-23-2010, 9:39 PM
I'd like to but damn the belt drives for the primary are expensive ....Who knows maybe down the road ..If you look in Tyler's 110 thread he is running a open primary

yeah, it looks killer, but i am looking for unit motors, thanx though.

travasesino
01-23-2010, 9:40 PM
Have you thought about just trimming the primary cover around the clutch ?



you mean like this?

<img src="http://i34.photobucket.com/albums/d146/jasoncraze/projects/IMG_1599.jpg">

Torch
01-24-2010, 12:01 AM
anyone running an open primary on a unit triumph?

pics?

here is one we did.<a href="http://s457.photobucket.com/albums/qq294/A1dunn/crane%20truck/?action=view&current=primarycover.jpg" target="_blank"><img src="http://i457.photobucket.com/albums/qq294/A1dunn/crane%20truck/primarycover.jpg" border="0" alt="primary cover"></a>

wllgmr
01-24-2010, 10:47 AM
I just got my belt drive in the mail yesterday, so my cover looks like this today!

http://i569.photobucket.com/albums/ss138/wllgmr/primarycover1.jpg
http://i569.photobucket.com/albums/ss138/wllgmr/primarycover.jpg

Its the first one ive cut.

Jethro
01-24-2010, 10:52 AM
Man Torch, that is a sweet looking set up. Are you using the belt drive for Units from MAP?

TRUMPNUT
01-24-2010, 11:23 AM
I don't think its a MAP . It looks like the one that uses a GS500 clutch right ?

TRUMPNUT
01-24-2010, 11:26 AM
You know if you are doing it on the cheap you can just get the engine sproket and clutch basket for a pre unit and just run a 428 o-ring chain and drill a oil hole for lubing the clatch basket bearing .

sickboi55
01-24-2010, 12:23 PM
You know if you are doing it on the cheap you can just get the engine sproket and clutch basket for a pre unit and just run a 428 o-ring chain and drill a oil hole for lubing the clatch basket bearing .
on a pre unit with the o ring chain, how would you lube the clutch bearings?

travasesino
01-24-2010, 1:17 PM
I just got my belt drive in the mail yesterday, so my cover looks like this today!

http://i569.photobucket.com/albums/ss138/wllgmr/primarycover1.jpg
http://i569.photobucket.com/albums/ss138/wllgmr/primarycover.jpg

Its the first one ive cut.



looks good, man. =)

TRUMPNUT
01-24-2010, 1:26 PM
on a pre unit with the o ring chain, how would you lube the clutch bearings?You drill a 1/8 hole thru the preaure plate then the clutch hub all the way to the bearing so you can spay in lube when you lube the chain . I have ran then for mainy years like that even though the 428 chain is a hair smaller then the stock one .

Torch
01-24-2010, 4:42 PM
Man Torch, that is a sweet looking set up. Are you using the belt drive for Units from MAP?

That belt drive in the Bob Newby Racing unit. it is a bit more money that the others but is worth every penny.

fightclub
01-26-2010, 12:13 PM
Torch, you guys build some really tight Trumps, nothing beats your pre unit open belt drive though! Stupid new b ?. On my bike 69 Trump the engine and primary case share oil i believe? How do you run a belt primary and stop oil from pissing out of the cases? Do Newbery units come with something to plug these holes or am i way off base with what Im saying or thinking ?

Torch
01-26-2010, 11:03 PM
Torch, you guys build some really tight Trumps, nothing beats your pre unit open belt drive though! Stupid new b ?. On my bike 69 Trump the engine and primary case share oil i believe? How do you run a belt primary and stop oil from pissing out of the cases? Do Newbery units come with something to plug these holes or am i way off base with what Im saying or thinking ?
the early units up to 1970 have a sealed crank case and 1/4 time breather, they are easy, no real modifications are necessary.
if your bike is a really late 69 or has been converted to a 70 and later shared primary what you need to do is put the drive side crank shaft seal in behind the primary gear and plug the 3 little holes in the cases at about the "5 o'clock" position, and then we take the timing pin plug, drill it and tap it for a vent hose fitting.
It is a little work but not as much as a pre-unit is.
The Newby kit is only the pulleys, belts and the really trick clutch basket.

TroopThrowback
01-30-2010, 11:45 AM
It is a little work but not as much as a pre-unit is.


What's the difficulty with pre-unit open primaries?

turtle
01-30-2010, 4:43 PM
great job I like the flow and the lines

Torch
01-30-2010, 9:50 PM
What's the difficulty with pre-unit open primaries?

most pre-units don't have any provision for a crank shaft seal.

wllgmr
03-19-2010, 7:38 PM
bump. anymore?

TRUMPNUT
03-20-2010, 8:04 AM
most pre-units don't have any provision for a crank shaft seal.

Pre 56 unless it is a 6t then it was 50

Torch
03-21-2010, 8:35 AM
on a pre unit with the o ring chain, how would you lube the clutch bearings?
Here is what we have learned about belt drives.....It is the clutch bearing that is always the problem, and on belt drives the belt tension puts a constant strain on the clutch bearing, if it is an open bearing like the stock one then it won't get any lubrication and they won't last very long, most of the cheaper belt drives have a sealed clutch bearing that is roughly the same diameter as the stock bearing, and because of the stress of the belt tension they fail rather quickly and you will see the whole basket flex every time you pull the clutch in and this flex interferes with the proper function of the clutch plates.
The only belt system we have used without any disappointments is the "Bob Newby Racing" unit, and it is because the sealed bearing on the BNR unit is almost the same diameter as the clutch basket, the bad news is they cost about $700.
Another thing to consider is the belt it self. On some belt drive systems the use their own belts so you can only buy replacements from the manufacture. the BNR units use a Goodyear belt so you can get one anywhere and you can get a belt for Units or or a another belt for pre-unit swing arm bikes or the longer one for pre-unit rigid models and Goodyear belts come in 10 m/m increments so you can even use them as we have on custom frame pre-unit bikes.

Here is a pic of my son's bike with the old QPD unit on it, we have since changed it to the Bob Newby unit.<a href="http://s457.photobucket.com/albums/qq294/A1dunn/?action=view&current=Andysbike.jpg" target="_blank"><img src="http://i457.photobucket.com/albums/qq294/A1dunn/Andysbike.jpg" border="0" alt="Photobucket"></a>
http://www.ClassicCyclesInc.com

wllgmr
03-22-2010, 3:07 PM
QPD

http://i569.photobucket.com/albums/ss138/wllgmr/1-10.jpg

Torch
03-25-2010, 8:34 AM
NEWBY
<a href="http://s457.photobucket.com/albums/qq294/A1dunn/bike%20shots/?action=view&current=newby.jpg" target="_blank"><img src="http://i457.photobucket.com/albums/qq294/A1dunn/bike%20shots/newby.jpg" border="0" alt="Photobucket"></a>

GreaserMike
03-25-2010, 8:39 AM
NEWBY
http://www.chopcult.com/gallery/albums/album-36/lg/BS3.jpg

I run Bob Newby belt drives in several of my bikes and I wouldn't run anything else.

You get what you pay for.

GreaserMike
03-25-2010, 8:44 AM
NEWBY
<a href="http://s457.photobucket.com/albums/qq294/A1dunn/bike%20shots/?action=view&current=newby.jpg" target="_blank"><img src="http://i457.photobucket.com/albums/qq294/A1dunn/bike%20shots/newby.jpg" border="0" alt="Photobucket"></a>

Bob Newby clutch and a Classic Cycles motor mount.....Now THATS NSFW!!!

Coco
03-25-2010, 10:08 AM
QPD

http://i569.photobucket.com/albums/ss138/wllgmr/1-10.jpg

That QPD looks as if they are using a Norton type clutch.

BRad82
03-25-2010, 5:20 PM
On my 68 650 I'm running an open Primary and it leaks a little oil. Not to sure wher it is coming from. Can anybody help me?

Torch
03-25-2010, 10:00 PM
On my 68 650 I'm running an open Primary and it leaks a little oil. Not to sure wher it is coming from. Can anybody help me?
More than likely is a leaking crankshaft seal.