Primary drive Belt pulley

IBA...GATOR · Sep 10, 2015

looking for help with finding a primary drive pulley for a belt drive..... 32tooth 8mm HTD

After building the motor with what I thought was a Commando crank.....might not be now.....
It very well could be a Atlas crank ..... the motor is in the chassis now, so at this point it is what it is...
Maybe by the picture that I posted might help determined what is going on

I purchased a commando belt drive set up earlier this year & just getting back town to finish this project.....
after installing the pulleys I set the rotor in place...another minor setback...

I knew when purchased the 3 bikes( 65 matchless,71 commando & 75 MK3) 7 years ago,
that there would be discrepancies between the models

I'm so close to finally to hear it come to life , that it's just another part of the puzzle

It's not how you weather the storm,but rather how you dance in the rain..... Tripower

lcrken · Sep 10, 2015

Could you be more specific about what the problem is? I can't tell from the picture, so maybe I'm missing something obvious. Is the pulley hitting the primary cover, or is there some other problem?

Ken

marinatlas · Sep 10, 2015

Hi , as far as I could see , you are only just missing the rotor nut and that should be fine ..........but , may be I do not see very well!!!

Matchless · Sep 10, 2015

Not entirely certain what the problem is here. The crank looks like it is a Commando crank. The only difference on the drive end of an Atlas is the key way for the alternator rotor is milled in a different (angular) position. If this crank is from an Atlas you will just have to remark the timing line in the correct position. Apart from that all you appear to require is the sleeve nut & large Belleville washer to hold the pulley & rotor on.

Martyn.

IBA...GATOR · Sep 10, 2015

the problem is with the commando pulley.....this is as far as the rotor sits.....when I built this bike it was done out of parts... this build could possibly have a atlas crank..... I do not know as yet, if there is a difference in the output length between the Atlas & Commando crank ...
my thinking is that there is a difference

In that case I need 32 tooth 8mm HTD belt drive pulley for a atlas crank

baz · Sep 10, 2015

theres no difference on the crank not sure what the problem is,you do need to do something with those screws holding the inner chaincase on they need to be bolts and tab washers cheers baz

Dances with Shrapnel · Sep 10, 2015

From the picture, things look in order with regards to the crankshaft end and rotor. The rotor is held into place with a threaded sleeve with a hex top hat that shoulders against the steel portion of the rotor.

If there is running clearance between the belt sheave and crankcase you are good. You may not have the sheave fully seated so before final assembly, make sure the key for the drive sheave is in place and not cocked.

zotz · Sep 10, 2015

I'm not an expert but are there not differences in the balance factors between a Commando crank and an Atlas crank if you swap them?

Matchless · Sep 10, 2015

Yes, there are but that isn't the suggested problem. Early Atlas cranks were balanced at around 65%, later this was changed to 85%.

IBA...GATOR · Sep 10, 2015

zotz said:
I'm not an expert but are there not differences in the balance factors between a Commando crank and an Atlas crank if you swap them?

That was my question I posted awhile ago, because I went vertical... My thinking is that the 15 degree (or what degree it may be) to vertical would change the balance but to have a peace of mind,I sent the crank, pistons & rods out to Comnoz to balance... My only concern vibration fatigue over a long ride... in my application it is bolded ridged

IBA...GATOR · Sep 10, 2015

Dances with Shrapnel said:
From the picture, things look in order with regards to the crankshaft end and rotor. The rotor is held into place with a threaded sleeve with a hex top hat that shoulders against the steel portion of the rotor.

If there is running clearance between the belt sheave and crankcase you are good. You may not have the sheave fully seated so before final assembly, make sure the key for the drive sheave is in place and not cocked.

Honestly this is my first Norton build... after talking to Comnoz he let me know that I am missing the threaded sleeve & spacers (which you mention) Thanks

by putting the pulley & rotor on the shaft & looking at the alignment of the keyways & the space between the shoulder & rotor, It just didn't make no since to me...

If anybody has a picture of the sleeve assemble would help me, for I have never seen this breakdown in any manual

IBA...GATOR · Sep 10, 2015

baz said:
theres no difference on the crank not sure what the problem is,you do need to do something with those screws holding the inner chaincase on they need to be bolts and tab washers cheers baz

actually the harden screw bolts are going to stay... I'm just going to cut a notch in with the dremel & put the locking tabs in place... the cover had to be redrilled to fit this motor in a vertical position..... good attention to detail though

comnoz · Sep 10, 2015

tripower said:
Dances with Shrapnel said:

From the picture, things look in order with regards to the crankshaft end and rotor. The rotor is held into place with a threaded sleeve with a hex top hat that shoulders against the steel portion of the rotor.

If there is running clearance between the belt sheave and crankcase you are good. You may not have the sheave fully seated so before final assembly, make sure the key for the drive sheave is in place and not cocked.

Click to expand...

Honestly this is my first Norton build... after talking to Comnoz he let me know that I am missing the threaded sleeve & spacers (which you mention) Thanks

by putting the pulley & rotor on the shaft & looking at the alignment of the keyways & the space between the shoulder & rotor, It just didn't make no since to me...

If anybody has a picture of the sleeve assemble would help me, for I have never seen this breakdown in any manual

Here is what your missing. If a good used nut is OK I will send these out tomorrow. Jim

IBA...GATOR · Sep 10, 2015

Jim I appreciate that.... I've looked thru all the boxes of bolts, spacers & misc parts just nothing that looks like that.... Also is there a spacer that goes on the back side of the rotor to the shoulder of the crank ...I'm just not sure how the key will stay in place without something in between... this set up is defiantly a British thing ..... I'll give you a shout out tomorrow.....

Thanks again..... Tom

comnoz · Sep 10, 2015

tripower said:
Jim I appreciate that.... I've looked thru all the boxes of bolts, spacers & misc parts just nothing that looks like that.... Also is there a spacer that goes on the back side of the rotor to the shoulder of the crank ...I'm just not sure how the key will stay in place without something in between... this set up is defiantly a British thing ..... I'll give you a shout out tomorrow.....

Thanks again..... Tom

The rotor should seat against the sprocket. If the center of the sprockets is relieved then there needs to be a spacer that sets in the recess.

The rotor should not go all the way to the shoulder on the crank. It needs seat against the sprocket to hold it in place.

The rotor key is a half moon key so once it is installed in the crank and the rotor is installed over it, then it can not come out. Jim

Primary drive Belt pulley

IBA...GATOR

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comnoz

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