Seems like nobody likes to install new springs on the Shinn brakes. It can be done (sometimes) with a screwdriver using the pry and pop method. But after one frustrating day spent struggling with my springs (4 of them, 2 on each side), I decided to take the time to may a spring stretcher tool.
I used a gas welder, a hack saw and a die grinder to make the tool. It's constructed of scrap steel tube. Photo 1.
The stationary part of the tool is 2inches of 1/2" tube with a 1/4-20 nut welded to one end. Also on the nut end of the tube a 3/4 inch by 1/2 inch piece of steel flat is welded on with a slot hack sawed in it to fit the loop end of the spring (the "fork"). (Photo 2) A 1/4-20 bolt is screwed into the nut on the end of the stationary tube and provides the force to stretch the spring.
The movable part of the tool is a 2 inch length of 3/8" tube that fits nicely inside the 1/2" stationary tube. One end of the tube is welded closed so the bolt can push it. And the other end has a 1/2 by 3/8 flat welded on with a "spur" that can grip the hook end of the spring. (Photo 3) The movable part also has a 1/8" peg that rides inside a 1/8" slot in the stationary part. The slot/peg is to keep the movable part of the tool from rotating when the tool is under tension. (See "IF I make another" below)
The spring tool is easy to use. Install the spring loop end onto the brake, Push the fork end of the tool down over the loop to lock the tool in place, Engage the spur in the hook end of the spring and, Crank the bolt actuator until the tool expands the spring as much as you need. Great for an old geezer like me because everthing happens in slow motion and I can even expand a spring and pause, go get a coffee or something, then come back later and finish the job. Wonderful!
IF I make another tool. If I made another tool I would eliminate the peg/slot setup and just have the 1/2 by 3/4 flat ride in the slot. In other words, make the stationary tube a little longer with a longer slot and no peg. I'd also put a big handle on the bolt, that little wing nut thing really hurts the fingers!
No comments:
Post a Comment