Cassette cogs in Shimano IGH & spacers
Re: Cassette cogs in Shimano IGH & spacers
Why are splines rounded for IGH cogs and rectangular for cassette cogs?
Re: Cassette cogs in Shimano IGH & spacers
Revisiting this topic.
Found a guy with CNC setup. He is willing to try but has no idea how to specify the splines in IGH cogs. I don't either.
Can the shape of the splines in IGH cogs be characterized or specified in geometric terms? Perhaps an equation?
Found a guy with CNC setup. He is willing to try but has no idea how to specify the splines in IGH cogs. I don't either.
Can the shape of the splines in IGH cogs be characterized or specified in geometric terms? Perhaps an equation?
Re: Cassette cogs in Shimano IGH & spacers
I would hazard a guess that the splines are 1/2 round so should be straightforward to write a CNC program. If not quite exact then dressing with a file should produce a good fit.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840
Re: Cassette cogs in Shimano IGH & spacers
It does look like a segment of a circle. Not sure how close to a 1/2 round.
Does anyone have tools with sufficient accuracy to measure this spline? Here are the parameters of interest.
Curious. What would you use to measure something like this & how?
Last edited by crg on 10 Jan 2023, 4:43pm, edited 1 time in total.
Re: Cassette cogs in Shimano IGH & spacers
Please could someone add a photo.
Thanks
Jonathan
Thanks
Jonathan
Re: Cassette cogs in Shimano IGH & spacers
I assume for IHG splines you mean the 3 splines for the cog. These have long been standard on Sturmey Archer and other hub gears, so using the existing standard would make sense. Shimano IHGs have been around for longer than we probably think (1950s/60s?), so they would have gone with the current (SA) design. Now Shimano are big enough to creat any standard they see fit (as we all know.....!)
Cassette splines were designed from scratch (no pre existing equivalent design existed), so they could start with a blank sheet.
Cassette splines were designed from scratch (no pre existing equivalent design existed), so they could start with a blank sheet.
Re: Cassette cogs in Shimano IGH & spacers
This sort of thing? That's a CS-S500.
Jonathan
Jonathan
Re: Cassette cogs in Shimano IGH & spacers
Try the back end of a set of drill bits over the spline until you get one that's close, Probably a common imperial size if it goes back to SA.
Then measure from the the top of the spline to the bore at the opposite side with some Vernier callipers. Then measure the bore diameter or the splined shaft it is going to fit on. That will allow you to draw it out full scale then sit the sprocket on top of it and see if its close. Even better if you've got CAD soft wear and a printer.
I don't think they are a particularly precision fit.
Then measure from the the top of the spline to the bore at the opposite side with some Vernier callipers. Then measure the bore diameter or the splined shaft it is going to fit on. That will allow you to draw it out full scale then sit the sprocket on top of it and see if its close. Even better if you've got CAD soft wear and a printer.
I don't think they are a particularly precision fit.
Cheers
J Bro
J Bro