Alloy Sprocket woes

[Ninemeister_imp]

Glad you have a resolution. I might suggest getting 2 blanks, as the setup time and cost of metal treatment would be little more.

What is odd is that you ordered a standard sprocket, but got one with 6 bolts rather than 5, which would not have fit any stock Honda.
Also odd is that the sprocket adaptor was made with a 112mm bore rather than the larger bore of the original drive flange, creating the need for a special sprocket.

It's the other way round. I ordered and got the standard 5 bolt, then found out my sprocket and hub is a custom 6 bolt.

The adapter is also a spacer, pushing the sprocket over by ~10mm and presumably into correct alignment. Given the wear on the teeth and none on the sides, I would say it's done a good job.

[Frulk_imp]

35K is high mileage for the running gear (chain and sprockets). I’m around 22K and considering replacing them as well.

[Ninemeister_imp]

This was the Renthal supplied.

To be fair to the supplier, I ordered a sprocket to fit a stock CB11 and this is what they sent. It's only when offering it up did I realise that the parts on my bike were not stock.

Hey, I'm not complaining, I love those Excel wheels and they are one of the reasons why I had to buy it as soon as I saw the advert.

At the moment it's looking likely that I will have to have a sprocket made which is no big deal aside from the 2 weeks more off the road waiting on the hard annodising.
I should also mention that I have sent the information on the sprocket to Takashi (Samurider) who has recently shipped me the additional White House parts for the K10 package. Parts arrived (great service!) but as yet have had no response on the chain wheel.

All of the listed bikes use 112 bore, but 5 bolts. So their error as they still sent the wrong parts for a stock CB1100, even if your wheel is non-standard. I noticed also that it has 36 spokes vs the CB1100s' 40, but not to worry as the Africa Twin uses 32 spokes. And the spokes are stainless, as they are stamped with "B", signifying Buchanan's Spokes, who are a very high grade wheel and spoke specialist in the US. They won't break.

It is likely an off-the shelf sprocket as they would not have made an adaptor for a non-standard sprocket. Can you look for any casting numbers/letters/markings on the inside of the flange and hub? Then I can see what brand hub it is. I looked through all the Hondas that would have wire spokes with a disc and cannot find any match.

Thanks for your input.
As I said, I can't blame the supplier because I ordered the standard part not knowing that I had a special item on the bike.

I've looked for casting & part numbers on the hub, there are none. Likewise on the spacer ring.

Anyway, the problem is now seemingly solved. Once I realised it was a special part that had to be machined, the supplier suggested they make one from a Renthal blank, then have it hard anodised. Since I don't want to live with the 4 week turnaround, they are sending me the blank so I can spend an afternoon on my lathe and milling machine to bore it out and drill to suit the drive hub (Helps when you're a mechanical engineer ).

I'm now waiting on quotes for hard anodising and PTFE coating...
So now I'm looking at that spacer ring and thinking what weight I could machine off it...

LOL, the fun never stops.

Draughted two options on the CAD tonight for the spacer ring modification to reduce weight. Both have the centre hole opened up significantly.

Straight sided one obviously a lot easier to machine, so have added holes to allow water to find its way out from the cavity it creates inside the drive hub.

Profiled version matches the shape of the hub (or will do when I've adjusted the CAD angles) so looks "right", still to add drain holes of some sort.