Darmah Rear Sprocket

If you need technical information or help with your BOSCH ignition squarecase Ducati 900SS - Darmah engine - post your FAQs, comments & questions here.
David Frith
Cucciolo - the Lil Pup
Posts: 11
Joined: Sun Apr 22, 2007 7:36 pm
Location: Belmont, NSW, Austalia

Darmah Rear Sprocket

Post by David Frith »

Hi, I have just replaced the chain and rear spocket on my 79 Darmah.
I found I needed to make a spacer to mount the spocket out from the sprocket mount, as to give enough clearance for the chain.
Is this normal to have to do this, so that the chian doesn't interfear with the sprocket mount?

Dave
Dave F

User avatar
BevHevSteve
SITE OWNER
SITE OWNER
Posts: 2191
Joined: Wed Mar 10, 2004 8:53 pm
Location: Lafayette, California
Contact:

Post by BevHevSteve »

no that is not normal. You must be using a very small sprocket on the back..... 34 teeth or close? Normal is 38 or 39 which is fine as-is with no space problems.
Image
Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
Ducati/Euro Spares -> https://Store.BevelHeaven.com
Facebook > http://facebook.com/Bevel.Heaven
Twitter > http://www.Twitter.com/BevelHeaven

David Frith
Cucciolo - the Lil Pup
Posts: 11
Joined: Sun Apr 22, 2007 7:36 pm
Location: Belmont, NSW, Austalia

Post by David Frith »

The rear sprocket I fitted was a 36 with a 16 front.
The new chain I used was a 530 "x" ring chain which seemed larger than the one I removed.
Once I spaced the spocket I needed to adjust the wheel space to make sure front and rear sprockets were aligned.
Do you see any problems in doing this?

Cheers from down under.
Dave F

wdietz186
Cagiva Alazzura
Posts: 703
Joined: Sun Sep 10, 2006 5:40 pm

Post by wdietz186 »

Dave, The o-ring chains are wider than the original 530 chain fitted. If you have width clearance issues you could make spacers to fit behind the sprockets. The front sprocket can be spaced about 6mm by turning the sprocket around [ I think! its been a while since i had mine apart.] The rear can be spaced with a piece of aluminum machined to fit between the sprocket and the carrier. Be sure to fit longer bolts too. I did it to my 900ss to use a wider tire.

sevicke
Mariana
Posts: 41
Joined: Fri Mar 20, 2009 11:56 am
Location: christchurch new zealand

Post by sevicke »

too highly geared its more like a combi (vw beetle) than a harley dosnt go thump thump more brmmmmm and likes to rev set it free

mizike77
860 GT / GTS
Posts: 272
Joined: Sun Jul 06, 2008 9:37 am

Post by mizike77 »

wdietz186 wrote:Dave, The o-ring chains are wider than the original 530 chain fitted. If you have width clearance issues you could make spacers to fit behind the sprockets. The front sprocket can be spaced about 6mm by turning the sprocket around [ I think! its been a while since i had mine apart.] The rear can be spaced with a piece of aluminum machined to fit between the sprocket and the carrier. Be sure to fit longer bolts too. I did it to my 900ss to use a wider tire.
HHmmm....My front spocket is mounted so that it is offset further from the engine. Should I turn it over? It thought the stock set up was to put it on so that it is off set away from the engine.

User avatar
lomax
Mariana
Posts: 44
Joined: Fri Jan 16, 2009 4:36 am
Location: Limburg, Germany
Contact:

Post by lomax »

I purchased a sprocket with 36 teeth shortly, but did not mount it yet. It is made of aluminum (found that a little strange, since today sprockets are made of (surface hardened) steel).

The sprocket is the same as it is (originally ?) mounted on my '80 SD.

I want to change the chain too. The (mounted) chain size is exactly the same as it is for my '99 Suzuki GSX 1200 - a 530 size O-ring chain.

I wonder what you guys need to change - I hope to fit the new patrs with out any changes.....


Cheers

Joe
You are in doubt ?......ask a Kraut ;-)
Cheers from Germany
(Ducati 900 SD, Suzuki GSX-R 1000 K6, Suzuki GSX 1200 Inazuma)

User avatar
lomax
Mariana
Posts: 44
Joined: Fri Jan 16, 2009 4:36 am
Location: Limburg, Germany
Contact:

Post by lomax »

Reassembled the chain and rear sprocket today - now I know what you are talking about - see the pictures

http://www.funpic.de/fotoalbum/foto,264660.htm

Is it necessary to place distance pieces behind the sprockets or could I also use another chain size (e.g. 525 type) ? Looks like I should replace the plastic glider as well.
I found a small o-ring (inner dia. about 4 mm) behind the clutch rod housing. Where did this o-ring come from ? Is it placed around the clutch pushrod or did it come from somewhere else ?

Cheers

Joe
You are in doubt ?......ask a Kraut ;-)
Cheers from Germany
(Ducati 900 SD, Suzuki GSX-R 1000 K6, Suzuki GSX 1200 Inazuma)

MartinMille BANNED
BANNED
Posts: 817
Joined: Fri Sep 21, 2007 8:15 pm

Post by MartinMille BANNED »

You could remove the sprocket carrier, and Lethe a 1.5mm step into it this should give you clearance, is the larger chain rubbing on the engine cases or is that just dirt and grease build up ?

User avatar
lomax
Mariana
Posts: 44
Joined: Fri Jan 16, 2009 4:36 am
Location: Limburg, Germany
Contact:

Post by lomax »

Hi Martin !

That was my idea, too (just learned a new english word = lethe) It is just grease - sorry for not cleaning the case :oops: But because of the 16 teeth front sprocket the chain comes really close to the housing.

Joe
You are in doubt ?......ask a Kraut ;-)
Cheers from Germany
(Ducati 900 SD, Suzuki GSX-R 1000 K6, Suzuki GSX 1200 Inazuma)

MartinMille BANNED
BANNED
Posts: 817
Joined: Fri Sep 21, 2007 8:15 pm

Post by MartinMille BANNED »

why dont you do a 15 on the front and put your mind ad ease knowing its not going to hit, I'm running a 15/36 on my SSD

User avatar
lomax
Mariana
Posts: 44
Joined: Fri Jan 16, 2009 4:36 am
Location: Limburg, Germany
Contact:

Post by lomax »

Your ideas are the best - that is exactly, what I intended to do now.

I found a 15 teeth sprocket in my garage and will mount it.

Is a 106 link chain o.k. for the 15/36 drive ? Or would I need to shorten it ?

Cheers

Joe
You are in doubt ?......ask a Kraut ;-)
Cheers from Germany
(Ducati 900 SD, Suzuki GSX-R 1000 K6, Suzuki GSX 1200 Inazuma)

MartinMille BANNED
BANNED
Posts: 817
Joined: Fri Sep 21, 2007 8:15 pm

Post by MartinMille BANNED »

dont know Joe , I would have go and count but for its worth I didnt take any links out just readjusted the chain

User avatar
lomax
Mariana
Posts: 44
Joined: Fri Jan 16, 2009 4:36 am
Location: Limburg, Germany
Contact:

Post by lomax »

Here are the pics of the ground parts (housing and shaft/bearing seat). The sprocket was turned to outside, so the grounded shaft seat results from an earlier set up.

http://www.funpic.de/fotoalbum/foto,265043.htm

I will definetely switch to an 15 sprocket and put a ring beneath the rear sprocket for alignment.
I had a 106er chain mounted and will get a new one of the same size tomorrow - it should work for the 15er sprocket too.

Cheers

Joe
You are in doubt ?......ask a Kraut ;-)
Cheers from Germany
(Ducati 900 SD, Suzuki GSX-R 1000 K6, Suzuki GSX 1200 Inazuma)

User avatar
BevHevSteve
SITE OWNER
SITE OWNER
Posts: 2191
Joined: Wed Mar 10, 2004 8:53 pm
Location: Lafayette, California
Contact:

Post by BevHevSteve »

I am sorry if this is insulting anyone here - but you guys are all way off base on this. Running a 16 tooth front sprocket and an oring chain on your DARMAH is absolutely posatively OK to do...........

I run 16/39 on all my BOSCH ign bevel drives. NO PROBLEM.

It is obvious to me just looking at these photos, that this bike was allowed to run with a very badly worn out and stretched out chain - just look at the badly worn teeth on the sprockets..... The teeth are all hooked like crazy.

C'mon guys...... machine spacers.... my goodness. Just get a new chain and some new sprockets and properly adjust that chain. Yes an ORING chain.

Case Closed.
Image
Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
Ducati/Euro Spares -> https://Store.BevelHeaven.com
Facebook > http://facebook.com/Bevel.Heaven
Twitter > http://www.Twitter.com/BevelHeaven

Post Reply

Return to “Squarecase BOSCH Ignition Engines > SD, SSD Darmah, late 900 SS & 900 GTS”