Internal Bar Heaters for 1 1/8 Handlebars

I have tried a number of bar heaters, heated grips and heated gloves but ceramic internal bar heaters have proven to be my favourite. They are very easy to install, allow me to run my preferred grips, do not increase the outside diameter of the grip, are quick and easy to use and have two heat settings with the highest setting being hot enough to ride in extremely cold, snowy conditions. I use the Polly Heater brand and while the company does not wholesale to motorbike companies, they are available on eBay by searching for "Polly Heater".

While building up a DRZ400 adventure bike and fitting it with 1 1/8" Renthal Fat Bars I hit a problem when going to install another set of Polly Heaters, the problem was they wouldn’t fit. The reason being is that 1 1/8" bars have an internal diameter of 14 mm opposed to the 7/8" bars having an internal diameter of 17 mm. Trying to find a ceramic bar heater to fit the smaller internal diameter of 14mm came to a dead end, after hours of searching the web and phoning multiple bike shops, I found no solution.

For a while I resorted to using Oxford Heated Grips. While these are a good product, they increase the OD of the grips and I don't like that. I had the idea to strip down the ceramic bar heaters to see if they could be modified to fit and the result couldn’t have been any better.

By stripping the metal casing from the Polly Heaters it leaves you with the bare ceramic heater that is a perfect fit inside 1 1/8" bars. By removing the metal case you are left with the ceramic heater. This is a delicate piece of ceramic however if you are careful while preparing them for the install, they slip inside the bars with an almost perfect fit and regain protection by being housed inside the bar itself.

Below is a photo step by step of the process I used to take a set of Polly Heaters, strip the casings and install them into a set of Renthal 1 1/8" Fat Bars.

Photo 1 of Internal Bar Heaters for 1 1/8 Handlebars
This is one of the standard "Polly Heater" internal bar heaters wrapped in the metal casing.
Photo 2 of Internal Bar Heaters for 1 1/8 Handlebars
The first step is to use a bench grinder to remove the collar that holds the outer metal casing.
Photo 3 of Internal Bar Heaters for 1 1/8 Handlebars
Carefully grind just the collar, trying not to bite into the ceramic heater itself.
Photo 4 of Internal Bar Heaters for 1 1/8 Handlebars
This is the result after the collar has been ground off and the ceramic heater is now sitting relatively loosely in the casing.
Photo 5 of Internal Bar Heaters for 1 1/8 Handlebars
Flip the heater over to carefully push out the ceramic element heater.
Photo 6 of Internal Bar Heaters for 1 1/8 Handlebars
In this photo I am using a large punch to push the ceramic heater element out.
Photo 7 of Internal Bar Heaters for 1 1/8 Handlebars
This is the ceramic heater element after removal. Two things to notice: firstly it has some casting imperfections which need to be cleaned up to fit inside the handlebar, secondly it is a split casting held together with small wires. Care should be taken with handling so you don't damage the wires.
Photo 8 of Internal Bar Heaters for 1 1/8 Handlebars
Carefully sanding off the casting imperfections with a belt sander. Once the imperfections are sanded off, the ceramic heater will easily slide into the bars without resistance.
Photo 9 of Internal Bar Heaters for 1 1/8 Handlebars
Inserting the ceramic heater element into the handlebars. Although the fit is remarkably good (which will aid in great heat transfer from the ceramic element to the bar) I also added a few drops of high temperature RTV to ensure the ceramic heaters stay in place directly under the grips and also so there is no vibration that could potentially crack/shatter the ceramic heater.
Photo 10 of Internal Bar Heaters for 1 1/8 Handlebars
Before the RTV sets, I use my hand guards to push ceramic bar heaters into the bars the correct depth. The final trick is to wire them up so both the low and high circuit are live. This will draw approximately 55 watts but it is essential to generate enough heat to combat the heat absorbing properties of the alloy bars.
Author of this article: RMOTO