Manufacturing Jockey Wheels

From: Clint Everett ceverett@san.rr.com
Date: Sun, 24 Sep 2000
When cutting the groove in a chain management jockey wheel, taper the sides of the groove.
If a chain rides against the side of a vertically cut groove, the chain links can easily catch the upper lip of the groove and jump out.
http://www.ihpva.org/com/PracticalInnovations/chain_mgmnt.htm
Placing the axle through the skate wheel and then press the wheel against a metal cutting blade in a saw bench. A small piece of rectangular rod the same size as the width of the groove you're making can be clamped onto the saw bench and the wheel pressed down on the rod to moderate the speed of the wheel. see picture 1 & diagram.

Mount the skate wheel on a bolt with washers each side so that the wheel can't spin on the bolt. Mount the bolt in a drill press, start it going and use a chisel to 'lathe' out the groove. See Making a chain management idler wheel

Using a bench grinder, mount the skate wheel (without bearings) in place of the grinder disk. This then makes a temporary 'lathe' to grind the grooves.

'Woody'

From: Andrew Hooks
Date: Thu, 7 Dec 2000
Subject: [trikes] Real simple idler wheels
List-Id: Recumbent Human-Powered Trikes <trikes.ihpva.org>

Something you might be interested in... To get the chain under the cross memember but keep it up off the handlebars is a very fine balance on the trike I am building. To get around this problem I needed a very small idler for the return chain. For this I have just used a skate board bearing ($2.50) and glued an o-ring ($0.50) to it. Because the return line is slightly offset from where it wants to go it is held on against the larger idler of the drive chain.
FYI, I initially tried a teflon block guide similar to the windcheetah but found it too noisey. The above solution is completely noiseless.

Making them quieter

From: Mitch Kirschner
Date: Fri, 9 Jun 2000
Subject: [hpv] RANS chain idler "silencer"
List-Id: Human Powered Vehicles Mailing List <hpv.ihpva.org>

The idlers on my '99 Stratus recently became noisier. Or maybe I'm more sensitive to the noise than I used to be. Even the slightest accelerating force on the drivetrain, regardless of the gear, resulted in a nerve-jangling grating noise.
I wasn't ready to experiment with chain tubes yet, so I cut up an old inner tube (folded over once, i.e. a double layer of rubber) to the exact circumference and width of the idler wheels. Then I taped it good and tight around the groove in the idler wheel with a piece of black electric tape. The electric tape strip is about 1" longer than the circumference of the idler wheels.
So far, after almost 150 miles, the solution has been wonderful. The electric tape looks like it's the natural surface of the idler wheel, and it shows no signs of wearing out any time soon. The best part is that the idler noise is now so subtle (if it exists at all) that it's drowned out by a combination of wind noise and the pleasing purring of the rear derailleur.
Anyone else tried this particular solution? Have I possibly added significant friction to the drivetrain? I'm mainly curious. Unless I've lost 3% efficiency or more, I probably wouldn't be motivated to venture into the chain tube realm, at least not right away.
Date: Fri, 9 Jun 2000
From: Jim McNamara
Subject: Re: [hpv] RANS chain idler "silencer"
List-Id: Human Powered Vehicles Mailing List <hpv.ihpva.org>

I particularly like Lightning Cycle Dynamics approach to solving this problem. They cut a groove down the center of their delrin pulleys and then slipped a neoprene o-ring in the groove. The chain links are cushioned by the neoprene which results in noise reduction. This solution proved to be simple, inexpensive, and effective.
Date: Mon, 16 Apr 2001
From: J W Schermerhorn <skemi@capital.net>
You start with an 'O'-ring which is slightly smaller than the hub diameter of the pulley wheel. The hub is the bottom of the groove which you cut out of the skate wheel. The O-ring should be about twice the thickness of the gap between a chain's sideplates and it's rollers, when looking at it from the end of a link. Don't confuse this with the width of the rollers, which corresponds to the thickness of the chainrings and cassette sprockets. I don't recall exactly what this dimension ((sideplate dia. minus roller dia.) divided by two) is on our chains but I use a ring which is 3/32" thick. Cut a groove around the middle thickness of the pulley hub where the center of the chain runs. The groove depth should be half the thickness (half 3/32") of the 'O'-ring. It will retain the O-ring in the center of the pulley hub. The idea is that the 'O'-ring will ride on the center of the chain's rollers, which reduces the contact pressure of the chain's sideplates on the pulley hub. You've probably noticed that your pulley's hub has two rows of dimples worn into it by the chains's sideplates. The O-ring reduces this wear considerably, especially if you change the ring before it wears down to the surface of the pulley hub.

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Wednesday, 18 July 2001