I'd dearly like to know where these chain rings came from:This is the bit that I'm having trouble with! ... I think I need a technical drawing that describes the 6 holes on the Tongxin hub ...
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btw .. in Germany they still have harware stores! ...... I don't suppose anyone knows where I can get brackets shown in photo? - 2 metal brackets and a half clamp.Ok .. got what I need now ... I think! ....
Here are the measurements:
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So... My plan is to screw 2 chain rings using the exisiting holes. One with 18 teeth to connect to the front crank and one with 24 teeth to connect to the 15 teeth connected to my Rohloff ...
if anyone can spot any holes in my plan (sorry!) ... then please shout!
Sorry Jerry. I thought that the shaft was an extra component made as part of the using the hub for a chain/crank drive project that I've been trying to get to grips with all day! ... There is nothing wrong with my hub. Its not broken. Its still on my CX700 being used! ...Alan,
I am a little confused by the first picture are you saying you need another one of the screw on shaft shown ? Is it broken ? can't you use the exisitng part as a template ?
Was thinking to change the screws to longer more substantial ones. So that they do what they're doing now i.e securing the internal clutch plate and accommodate the extra chain rings I'm going to add ... is that not a good plan?Those holes are in the case cover and secure it to the internal clutch plate. The screws are not that long or substantial and I am not sure they will be sufficient to take the load of those rings ? Again don't you have the original to take the measurements off ?
Ok. So I guess its not ideal! .... So, Jerry, How would YOU do this? Is it better to drill new holes in the plate which is what one of the germans did? ... or something else? ...Ah another look and just to say that the hole spacing/fixings on the main shaft does not match the hole spacing on the cover plate. ...
It may work but as you can see above those screws on the cover plate attach and secure to that internal clutch ring not the fixing at the base of the shaft.
Cool! ... I'm going to have a go then. My Street Machine has spent too long in the shed and after a year of cycling its time for a change. The Tongxin has been excellent in my CX700 and is being promoted!Looking at the German Pedelec pics of the sprockets it appears they attach them to the outer case using the same screw/bolt holes as you say, but obviously as you say you would need longer screws. I guess you would also have to put a spacer between the sprockets to stop the two chains fowling each other. No need/or advisable to drill additional holes. I can't comment on the robustness of it all, though the outer plate also threads onto the casing. When you undo all those screws the internals spin freely and you have to line up the holes on the outside with the ones on the inside to insert the screws again.
I can't see why it would not work and I guess if the German Pedelec guys have done it then it must work of sorts. Some of those guys over there do some really neat stuff.
Regards
Jerry
or .. a hub cap! ... one of these with a hole in it connected to the spoke holes with screws ...Been thinking about the spoke holes in the hub. The germans machined them off for space reasons. I don't need to do that as I got loads of space. So.,... what about using the spoke holes to mount an adapter plate which I can use to connect my sprockets? .... Has anyone invented a "spoke hole adapter plate"? ... I lke the sound of it ...
Ok.. Trying to get hold of a product from First Principles that uses the spoke holes to attach an adapter plate that could be used for a disk brake ... (stay with me ..)Thinking about the adapter plate idea. Anyone taken a internal gear hub apart? I could really do with a ribbed cassette spindle onto which I can slip my 2 sprockets. ...