Replacement chain Idler

The Prototype idler . . . . Taught me a lot.
I changed some critical design features and it did not perform well.

I moved the idler away from frame and this put too much leverage on the bracket and bent it.
The cassette cog is not ideal because it has teeth designed to help change gears, so there are 2 teeth offset and others have chamfer on one side. So I took to it with grinder to reduce the effect but it is not ideal for this application.
I made a version 2.0 with larger bearing but I couldn't get the centre accurate so it isn't running True. I want to look for another cog any way so this is a temp version to keep me on the cycle ways.

I'm hoping to find a used 14 tooth freewheel sprocket to see if that is more useable. I know I can buy a new cog from an industrial supplier but they cost a bit. Will see how I go.

 

Playing around with what I have on hand........
Smallest I could find in my parts was this 16 tooth Back Pedal brake cog.



Its a very good quality cog. High quality steel and this being off a childs cycle - it has Very Little wear.
Probably would have been better if it was more worn, as I expect this to add to the noise for a bedding in period.
Didnt really want to go larger - 16 tooth, as it will get very close to the top bracket - but really want to try this style of cog.

 

They are built strongly, the only way I could see to get it off was to grind it....


Here's one I prepared earlier

 

Couldnt find any Space race Super Nylon for the side plates, so I want to try that Nasty Noisy aluminium side plates. See how that goes, while I keep looking for the Super Grade nylon.


Am working on the alloy hub, this is a little more complex because it has to be a 2 part unit. Nearly half done - just having some difficulty with end boring the hole for the bearing [ this Electrician doesnt know everything about Lathe work but I will get it done ].

 

hate it when daily jobs get in the way of a good Trike Repair.....
Had to rush the idler to finish it so I could ride home.
Turned out better than I expected with that time penalty.

Side view after the ride home.


The brass screws were quickly snipped off - not my preferred method.
Re-used the old guard - wanted to make a new one.

- It was not overly Noisy as I expected it to be. In some gears it was very quiet, in gears with more offset there was only a little noise.
I suspect that the better Tooth shape made it better. The side plates dont seem to touch the chain when that cog controls the chain properly.

 

Impressed that the cog was such good quality, Drilling it was nearly impossible, it bluntened the drill. Discovered that there was a very thick Case Hardening.
I had to grind into the cog metal in order to drill it.
The tooth design is smooth and deep - so Glad I tried this part.


bit dark - hope you can see something in this pic.
Note: there is space on the shaft for the Idler to move across as required.

 

notice how close to the bracket above the side plates are, I had to grind them down to miss.


The side plates dont touch the chain - I hope that this doesnt mean that the chain will jump off more easily....... I dont think this will be a problem because the tooth is quite deep and the guard is close

 

Looking at these pictures, here at home I realized that I assembled it incorrectly.
The metal bracket that holds the power chain Tube is meant to follow the idler as it slides across ....... but I placed it on the other side of the Guard bracket, so it cant move across. Means I have to get all greasy again tomorrow.
I intend to degrease the chain tomorrow and soon I will be using rock and roll Gold Lube. just waiting till next pay.

 

It probably weighed more, but I made an idler out of a single-speed cog, threaded on a Bottom Bracket cup. It worked fine, but it was replaced by a Hostelshoppe idler, and then I lost it when I swapped houses.

 

I like the idea of that simple construction John. Think that would be Strong and easily maintained. Did you have side plates on it ? , how did you attach them.?

 

Looks like the design, at least worked, and always a good thing to save $$$$$$.....

 

Ive done 400 miles on it now, am really liking this Idler.
It runs quiet and its strong and sturdy.
Still not happy with the route of the return chain in the tube. It makes the chain twist slightly to the side because goes around the right side of the chain retaining guide. Thinking of running it underneath to straighten up the line but worried of course about Ground clearance.
Will look into that later. Ive got 400 km to ride in 14 days to reach my next target.

 

...............and Good Luck on 400 km x 14 days.....