How I made a muscle bike suicide shifter, top tube mount

[Indyjps]

How-To Making a musclebike shifter out of spare parts, used in Slow Roll MBBO#5
http://www.ratrodbikes.com/forum/index.php?threads/mbbo-5-class-2-slow-roll.100071/
Finished result.

Cut a piece of bar off an old set, grind a fishmouth for a good fit to the top tube, weld it on. I've seen in another thread where this can be slotted and hose clamped onto the top tube.

 

[Indyjps]

I modified a grip shift, actually did a SRAM and shimano style. so my pics will show 2 different shifters.
If you've ever had 1 of these apart for service, there's an inner sleeve that goes over the bar, and an outer sleeve that twists with the grip.
You need to cut down the inner sleeve leaving enough for good support. I cut mine even with the welded on bar end on the top tube. eye ball it, see where you want to cut.

 

[Indyjps]

Now you have a mounted shifter, with the outer sleeve hanging over 1-2 inches. you want to make a rod pass thru that part of the shifter for your lever. Center up the shifter travel, mark center.
The ID of the outer sleeve is approx 25mm, 1 inch.

I used a 1/4 connecting nut to insert into the sleeve, which caused me a few issue, these come standard as 7/8" long. I welded a nut to it to make up the length and ground a slight radius on it for a light press fit into the outer sleeve.
Doing this again, I could have tapped something, passed the rod all the way thru and nutted it or I'm sure someone will come up with a more elegant solution. If you step up to 5/16 or 3/8 the connecting nuts are longer.

You need to drill thru the outer sleeve to line up the threaded insert. measure carefully.

Even though it's a light press fit, I didn't want it moving around when I unscrewed the shifter, so I gobbed some construction adhesive in there.
Looking back, I could have been cleaner in this step.

Bottom with set screw

Top with hole for shifter rod

 

[Indyjps]

I used a piece of golf club shaft tapped 1/4 with all thread for the shifter rod. any piece of stainless, aluminum etc can be used here. Keep it light or it will jiggle around while riding and cause misshifts. The ball is just an equipment knob from ace hardware, again tapped and all thread into the golf club shaft.
Shaft had anodizing sanded off and polished.

 

[Indyjps]

This shows the cover. it's a piece of ceiling fan, so it will be hit and miss to find something that will fit over the shifter.
Clearanced, centered, screwed into the top tube.

Clearanced around the shifter, had to notch it for the shifter set screw.

Installed, this is actually with the SRAM shifter.

Here's the shimano style installed to show cable routing.

 

[Indyjps]

Hope this helps someone out. I stole ideas from multiple other threads, wish I could give credit, but I don't remember where. If you have improvements feel free to post up or IM.


Here's a connecting nut for reference, anywhere that sells all thread will have them. I keep a few sizes around, they're very useful of you're fabbing stuff up.

 

[Duchess]

Similar to what I did on Retro Rocket, except I used shaft collars on the outer shift sleeve and passed a 3/8" tube through it completely (I used a tube so I could run wires up to a switch for the lights), and drilled and tapped an M5 set screw to hold it in place.

Without the support of the handlebar grip that usually holds the shifter part in place, I found mine trying to come apart, so I rigged up this thing to keep it together. The shift tube passes through the hole in that modified thumb bolt, which is secured to the bracket that bolts to the handlebar. Behind the thumb bolt is a bearing to hold it secure and centered in the open end of the handlebar and facilitate rotation of the shifter.

 

[Indyjps]

Similar to what I did on Retro Rocket, except I used shaft collars on the outer shift sleeve

Awesome, liking the collar.

Normally the grip compresses the outer sleeve to the shifter, there's a notch on the outer sleeve that fits into the body of the shifter to hold it together. I noticed this notch hold was stronger on the shimano than on the SRAM style.
The cover I have limits side to side movement of the outer sleeve, I'll definately keep an eye on it.

Agree that with out a cover or limiting device of some type to hold the outer sleeve towards the shifter, you may have it wanting to pop apart.

 

[Duchess]

Yeah, I thought it was going to be fine and never actually came apart, but it did open up a hair on the one quick shakedown I did, so I decided to stop it before it did. My hidden wire idea had to be changed, too because I had it come out of the shift tube inside the collars so that it could pass inside the handlebar into the rocket body, but the clearance I could make between the outside of the bearing and a notch I cut in the handlebar didn't have me feeling confident it wouldn't strip the insulation of the wires, short out, catch fire, and do a Vanguard TV3 impersonation. Now the wires come out the bottom of the tube into an extension spring that goes into the rocket body, acting like a housing that I think looks nicer than shrink tube.