Thumb Throttle to Twist

gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
Hi All

I have just built my first e-bike and it is amazing fun. I have one issue in that the gears are thumb change and the throttle is also a thumb control. In Cornwall where there are more hills than the rest of the world combined (!), it is frustrating to try to change gears to a better gear for climbing said hill whilst trying to power the bike. Is it possible to convert the thumb throttle to twist please? I have 6 wires going into the thumb controller, some of which are battery management. I would like to put these into a different battery management controller, possibly on-board computer. Any recommendations please?

And tomorrow I am starting to build a sidecar for the bike.

Thanks for the help.

Rich
 

mike killay

Esteemed Pedelecer
Feb 17, 2011
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I have just replaced my thumb gear changer which was on the right hand side with a SRAM grip shifter which I put on the left hand side.
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Surely, a pedal sensor would be a better solution. Full width throttles break easily when you go over a bump.
 

gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
what about a thumb throttle on the left side ?
I tried this but when you do that your thumb has to stretch over the battery indicator panel. Makes it harder to use.
Thanks for the reply though.
 

gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
I have just replaced my thumb gear changer which was on the right hand side with a SRAM grip shifter which I put on the left hand side.
In the event that I might look stupid.... can you explain a bit more please? What is an SRAM gear shifter please and does it get in the way of the front cog shifter please?
 

gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
Surely, a pedal sensor would be a better solution. Full width throttles break easily when you go over a bump.
I had a pedal sensor fitted but you can't control the amount of throttle.
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
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In the event that I might look stupid.... can you explain a bit more please? What is an SRAM gear shifter please and does it get in the way of the front cog shifter please?
SRAM shifters are often twist shifters. https://www.sram.com/en/sram/models/ts-mrx-a1 . Like other gear changers they are typically one on the right for back derailleur and one on the left for front. You can fit them the other way; not practicable to fit both on same side. Of course you only have one (rear) shifter for single chainring on the front, typically fitted on the right but could be on the left.
 
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flecc

Member
Oct 25, 2006
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Surely, a pedal sensor would be a better solution. Full width throttles break easily when you go over a bump.
I've always used half width throttles/gear changers which don't suffer that problem, so I've never broken one. They are also easier to hold stable on bumpy roads. Here's one pair of mine, throttle left and gear change right:



 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Another problem that affects nearly all installations of full and half-width throttles is that the large boss on the inboard end gets in the way of the shift levers and sometimes the brake leavers too. You'll be lucky to get one that works with your other stuff.
 
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flecc

Member
Oct 25, 2006
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Another problem that affects nearly all installations of full and half-width throttles is that the arge boss on the inboard end gets in the way of the shift levers and sometimes the brake leavers too. You'll be lcky to get one that works with your other stuff.
Never had a problem with brake levers or even bell, as shown below, but I agree that a twistgrip throttle is best paired with twistgrip gear shifting on a single chainwheel bike. Thumb shifters don't mix with twistgrips.

 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Never had a problem with brake levers or even bell, as shown below, but I agree that a twistgrip throttle is best paired with twistgrip gear shifting on a single chainwheel bike. Thumb shifters don't mix with twistgrips.

but you don't have lever shifters, nor hydraulic brakes!
 
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gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
SRAM shifters are often twist shifters. https://www.sram.com/en/sram/models/ts-mrx-a1 . Like other gear changers they are typically one on the right for back derailleur and one on the left for front. You can fit them the other way; not practicable to fit both on same side. Of course you only have one (rear) shifter for single chainring on the front, typically fitted on the right but could be on the left.
Thanks for that information and it is a very simple way of sorting the problem.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Got to admit I have Sram twists on the Swizzbee 3 x 9 and actually like the operation of them, brakes are both hydraulic no issues with these.
If you have Sram gears you need 1: 1 twist shifters, if you have Shimano gears then make sure you buy Sram 2:1 twist shifters.
 
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gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
Thanks for all the replies. The opinion seems to me to use gear shifters on the left and leave the thumb throttle in place. Is that because replacing a thumb throttle with twist throttle is difficult or illegal please?
 

flecc

Member
Oct 25, 2006
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Thanks for all the replies. The opinion seems to me to use gear shifters on the left and leave the thumb throttle in place. Is that because replacing a thumb throttle with twist throttle is difficult or illegal please?
Strictly speaking all throttles on pedelecs manufactured in the last couple of years are illegal, not that anyone takes any notice of that. Hence the pedelec name, power only regulated through the pedalling.

Changing from one to another isn't particularly difficult for anyone handy with bike maintenance.
.
 

mike killay

Esteemed Pedelecer
Feb 17, 2011
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Might be of interest but I have fitted a 6 speed twist changer on the left hand side of the handlebar. The numbers are upside down but I never notice.
I guess that the human brain can read numbers upside down without a problem.
 
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gucu

Finding my (electric) wheels
Oct 30, 2019
20
1
Thank you all for your answers. Time to fit a twist grip to the left hand side. Without your replies this might have gone badly wrong!