A few weeks ago, my friend Gerry (aka Mr. Gizmow) sent me this little jewel of a dual front sprocket assembly (13/15) with all the fixings.
I have been running a dual rear sprocket setup for about the last 3,000 miles with various size combinations including 47/50, 47/55 and most recently 55/65. A dual rear sprocket setup just barely fits between the sprocket mounting flange and the swingarm. Gerry's bombproof sprocket assembly has the sister sprocket (13 teeth) mounted inboard from the stock mounting position. Here it is mounted with the chain on the inner sprocket.
This got me wondering if a third rear sprocket could be mounted on the inboard side of the sprocket mounting flange. In order to do this, a split sprocket would be required. I remembered that one of Gerry's project had involved a sprocket that he had split in half and I believe he bolted back together. A call to Sprocket Specialists determined that they would be happy to split a 66 tooth rear sprocket for me and they asked me if I wanted a link lock. They explained that with a link lock, they drill holes on either side of the kerf and use a couple of master links to help keep the sprocket halves from flexing. So I said sure, give me the link locks.
Here are the rear 47/55/66 sprockets mounted .
It is tight, but there is clearance, even with my ATV rear tire. And the alignment is actually pretty good except for that rubber chain guard thingy that goes around the front of the swingarm. If this proves to be a problem, I may try to mount this guard further inboard, or possibly add a second one inboard of the stock one.
Do I really need a TW with 30 different speeds (or 36 if I used this setup on my TW226 6-speed)?
Of course not, but I just wanted to see if it was possible to do .
(Gerry, thanks again for giving me the opportunity to test out this prototype - it looks like a winner to me!)
I have been running a dual rear sprocket setup for about the last 3,000 miles with various size combinations including 47/50, 47/55 and most recently 55/65. A dual rear sprocket setup just barely fits between the sprocket mounting flange and the swingarm. Gerry's bombproof sprocket assembly has the sister sprocket (13 teeth) mounted inboard from the stock mounting position. Here it is mounted with the chain on the inner sprocket.
This got me wondering if a third rear sprocket could be mounted on the inboard side of the sprocket mounting flange. In order to do this, a split sprocket would be required. I remembered that one of Gerry's project had involved a sprocket that he had split in half and I believe he bolted back together. A call to Sprocket Specialists determined that they would be happy to split a 66 tooth rear sprocket for me and they asked me if I wanted a link lock. They explained that with a link lock, they drill holes on either side of the kerf and use a couple of master links to help keep the sprocket halves from flexing. So I said sure, give me the link locks.
Here are the rear 47/55/66 sprockets mounted .
It is tight, but there is clearance, even with my ATV rear tire. And the alignment is actually pretty good except for that rubber chain guard thingy that goes around the front of the swingarm. If this proves to be a problem, I may try to mount this guard further inboard, or possibly add a second one inboard of the stock one.
Do I really need a TW with 30 different speeds (or 36 if I used this setup on my TW226 6-speed)?
Of course not, but I just wanted to see if it was possible to do .
(Gerry, thanks again for giving me the opportunity to test out this prototype - it looks like a winner to me!)