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Discussion Starter #1 (Edited)
Ever since I saw images of the HRC Grom online, I've been curious to know how some of the builders were able to utilize CBR250R clip-on handlebars on stock forks. See the following image to understand what I mean:

custom-honda-grom-hrc-msx-125-motorcycle-msx125sf-race-performance-parts-exhaust-accessories-min.jpg

Clearly the forks have extensions installed (40-60mm or so)... however given the way the factory caps attach to the internals, these images are a little confusing to me. These custom fork caps may just be machined internally to match the OEM cap (inner and outer threads with a jam nut). The next issue is that the extensions are cylindrical... how how are they torqued down? And how is the clip-on prevented from becoming a wrench and loosening the extensions?

Lastly, the other images of the bike show that it is running a standard rear shock and not an Ohlins part (or otherwise), which leads me to believe the front forks are being used as stock, as well.

custom-honda-grom-hrc-msx-125-motorcycle-msx125sf-race-performance-parts-exhaust-accessories-min.jpg
 

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All interesting questions.
The letters on the tank are Thai.
Thailand is a hotbed of creative innovative Grom products. :)
 

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Discussion Starter #3
The Singha sponsored track banner in the background was another good clue - haha.

I suppose the upper triple clamping bolt might be enough to lock the threads of the extension such that the clip-on cannot loosen it... but torquing them down would still be interesting. If they're solid and don't actually provide any lowering, they may just have a hole to stick a hex wrench through, like some Harley aftermarket extensions:

DEXATI20160529081956.png
 

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I lowered the rear swing arm and dropped the forks on my DRZ so I could install Vortex racing clip-ons.

IMG_1087.JPG

They work super, and I'd love to do the same on the Grom :)
 

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Hey, I just ordered a pair of front fork top extenders from Thailand for $38 shipped!
I'll be able to install clip-ons now without needing to drop the forks and rear swingarm. :)



Got them from bikerbitz.com.
 

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Discussion Starter #7
Where can I get those rearsets
Rakuten - from the Endurance store. I have a set. They look better in pictures than they do in real life - the tolerances are pretty loose and the hardware included is absolute garbage. I would suggest Sato racing as a similar, but better quality alternative.

Hey, I just ordered a pair of front fork top extenders from Thailand for $38 shipped!
I'll be able to install clip-ons now without needing to drop the forks and rear swingarm. :)



Got them from bikerbitz.com.
Let us know how those extensions work out for you... I expect they still lower the bike by ~2 inches in the front.
 

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Let us know how those extensions work out for you... I expect they still lower the bike by ~2 inches in the front.
I will. It's fun being the first lab rat to try out new stuff. :)
I'm just going to add them to the top as mounts for clip on bars and leave the fork in the stock position. The threads extend down into the fork tube past the upper triple tree clamps so they should keep the extenders snug.
 

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Discussion Starter #9
CBR250R clip-on bars are 37 mm bore, while the Grom is 41 mm up top. Boring the bars out is probably an option, but we're getting into serious machine work dollars now.
 

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Ever since I saw images of the HRC Grom online, I've been curious to know how some of the builders were able to utilize CBR250R clip-on handlebars on stock forks. See the following image to understand what I mean:

View attachment 81334

Clearly the forks have extensions installed (40-60mm or so)... however given the way the factory caps attach to the internals, these images are a little confusing to me. These custom fork caps may just be machined internally to match the OEM cap (inner and outer threads with a jam nut). The next issue is that the extensions are cylindrical... how how are they torqued down? And how is the clip-on prevented from becoming a wrench and loosening the extensions?

Lastly, the other images of the bike show that it is running a standard rear shock and not an Ohlins part (or otherwise), which leads me to believe the front forks are being used as stock, as well.

View attachment 81336
Where to buy that handle bar?
 

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Hey, I just ordered a pair of front fork top extenders from Thailand for $38 shipped!
I'll be able to install clip-ons now without needing to drop the forks and rear swingarm. :)



Got them from bikerbitz.com.
Be aware, that's a great way to get killed. On one side, your clip-on bar will act as a lever to unscrew that extended fork cap, and it will all happen in the blink of an eye. The one time we needed to run a similar set-up (the Gromukus), we machined an addition clamp to span between the two extensions on the forks, will the lone purpose of keeping them from spinning out.
 

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Discussion Starter #13
The upper triple should prevent the extensions from backing out if it's pinch bolts are torqued properly.
 

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The extensions won't be in the triple tree, unless you actually plan on raising the front of the bike 2". I'm not at all debating, just making sure you don't run into any surprises.
 

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You can see the added clamp here...
Would off the shelf fork braces work as an additional clamp for the top? I was looking for a solution to run a steering damper along with clip-on style bars such as the Race Barz.
 

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Discussion Starter #16
The extensions won't be in the triple tree, unless you actually plan on raising the front of the bike 2". I'm not at all debating, just making sure you don't run into any surprises.
This is correct, but the triple should clamp the area with the threads enough that you cannot loosen the extensions (without causing damage). This has been my experience, at least. Trying to loosen the stock fork caps without unbolting the upper triple has the same effect.
 

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This is correct, but the triple should clamp the area with the threads enough that you cannot loosen the extensions (without causing damage). This has been my experience, at least. Trying to loosen the stock fork caps without unbolting the upper triple has the same effect.
I know the top clamp can lock in the fork cap real tight, but with all the leverage being applied by the clip-on, it seems like there is still a chance of it coming loose.
 
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