E-bike: Deore RapidFire Throttle Dilemma

(Linked from Conversion to eBike)

Table of Contents


The Deore RapidFire interferes with the throttle. I could not accept what is shown at 5:00 on https://www.youtube.com/watch?v=4b1dk7J_3v0.

In my case it concerns Shimano shifters of type SL-M590, but other models suffer from the same problem.

You see the problem? Changing speeds moving your hand to the left. Unacceptable. RapidFire has two handles, I opened the housing, removed the first handle and tried to bend it. Don’t! It broke in two and it took me a lot of energy to weld it again without burning the handle box. And that box… It looks like a wrist watch on the inside. Again, don’t follow my path. If you’re curious, look at the next two pictures.

… A wrist watch!
Broken… Very small area to weld, toilet paper made wet and add heat, surprised it is a strong (and ugly) Weld.

The alternative…

The RapidFire Hack

So I grinded and grinded the right SL-M590 until I was able to switch gears. But the button is ruined afterwards and needs restoration. This is serious small scale work. See pictures how I solved that.

On the back side all interfering material is removed. On the front side a shaped aluminium plate is added. Made on an anvil with a hammer, great exercise! In between MS Polymer filler.

Another look. More MSP added per day.

Shrink tube does the rest. I use 3:1 tube with glue on the inside. Poly-olefin feels nice and there are no sharp edges. SOLVED!

The only drawback – if you don’t count the hours – is that the power switch is on top with the key in driving direction – not very logical, indeed very odd, but…Who cares!

Problem solved. Have fun!!

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