Problem fitting slim throttle to standard bicycle handle bar

Remus

100 W
Joined
Jan 16, 2010
Messages
114
Hi all,

My current ebike has a throttle fitted to the right side of the bicycle handle bars.

Here's an example of my current throttle.
current.jpg

The large housing on the inside of the throttle interfer with the shimano trigger shifter's currently fitted.

Here's a pic of how I've got the throttle, brake and gear controls layed out

20230610_214922.jpg

This layout forces me to twist my hand at an awkward angle to operat the brakes, and reaching the gears are a pain the butt.

I've been putting up with this for a LONG time as I didn't ride much. BUT I've been working as a food currier for Uber Eats and Door Dash for a few months, and now that I'm riding a LOT the un natural layout of these controls is causing some RSI.

So I purchased a slim style throttle which I only just found out about, here's a few pics of examples.

t-htwist_slim.jpg
This is similar to the one sold by Grin Technologies Ltd, here's their product
Right Half Twist Throttle (50cm Cable)

I want to make it clear I did not buy mine from Grin Tech, I purchased from ebay China seller. They are similar in appearance, and operation.
Here's a very important requirement that Grin Tech makes clear at the top AND bottom of their page for this item. The ebay seller did not make this warning.

Note, this throttle secures to the ID (inside diameter) of the tubing, not the outside. For bicycles with aluminum handlebars that have too much wall thickness, the interior expansion bolt will not fit in. The handlebar tube ID must be at least 17mm

When I could not get my throttle to install, I contacted the seller, who said i would have to wait a while so they could contact the manufacturer for more info. Seems the Seller had no clue how to install the item or its requirements.

It wasn't until after I could not get help from seller, that I had a closer look at the Grin Tech page and noted the internal diameter of the handlebar had to be at least 17mm, mine is 14mm. And the external diameter of my handle bar is a standard 22.5mm

None of the bike stores in my area even sell handle bars (Really). So I've contacted an online seller explaining my requirments, and am waiting for them to get back to me. Does anyone have a lead on a handle bar with an OD of 22.5mm and an ID of 17mm ?

Thanks.
 

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You can ream the end of your handlebar to 11/16" using a reamer or (carefully) a drill. You can replace your bar with a fancier lightweight aluminum bar with thinner wall, or you can replace it with a cheaper steel bar that also has a thinner wall.
 
You can ream the end of your handlebar to 11/16" using a reamer or (carefully) a drill. You can replace your bar with a fancier lightweight aluminum bar with thinner wall, or you can replace it with a cheaper steel bar that also has a thinner wall.
Thanks for the input Chalo, my problem is finding a handlebar that states its ID... I can't see that information on any of the online bicycle parts sellers...
 
Thanks for the input Chalo, my problem is finding a handlebar that states its ID... I can't see that information on any of the online bicycle parts sellers...
Any steel bar will have a large enough bore. A nice lightweight aluminum bar that boasts its weight will also be thin enough. Bog standard OEM aluminum bars tend to be chubby at the grip end.
 
A course round file (rat-tail) would hog out enough material without much effort, without altering the OD. If don't have the file and can't borrow one, the money would be better spent on a new bar.
 
Have you considered a trigger type speed controller
33fe78035c327bbc9445a694c83fa096.jpg



there are a number of design options and one may suit your handlebar configuration better?
 
Have you considered a trigger type speed controller
33fe78035c327bbc9445a694c83fa096.jpg
That's exactly what I'm running currently. I thought I was a confirmed half-twist throttle preferential type but tried out this narrow type trigger throttle and now quite prefer it. As mentioned above, very easy to fit it so it doesn't interfere with the other controls.

The other feature that minimizes the RSI for me is liberal use of cruise control where applicable.
 
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