Modifying and Installing the Seat Rail Frame Kit (SR400/500): From Cutting the Frame to Final Welding
A frame kit that involves cutting the rear frame of the SR400/500 and welding on new seat rails. We explain the cutting dimensions, beveling, tack welding, choosing a shock mount, and final welding.
- Frame modification: cutting at 28mm from the stock shock mount
- Fitting and tack-welding the seat rails, and using the two shock mount options
- Notes such as stock bolt-on parts no longer fitting after modification
The Seat Rail Frame Kit lets you rebuild the rear of the SR400/500, seat rails and all. It requires cutting and welding the stock frame and is intended for professional use.
Here we walk you through the frame cutting position, prep work, tack-welding the seat rails, welding the shock mounts, and final welding.
01 Before you start
This product requires welding to install.
02 Cutting the frame and prep work
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As shown in the diagram, cut the frame at a point 28mm from the stock shock mount.
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Cut the front side off at the base and smooth it out.
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On the rear side, clean up the cut face, strip the paint, and bevel the edge.
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Tack-weld the included pipe end caps in place.
03 Fitting and tack-welding the seat rails
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The seat rail ends are finished to match the frame, but because every bike is slightly different, some bikes may need additional fitting.
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Fit the seat rails to the frame.
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Tack-weld each joint.
When fitting the seat rails, the width at the rear may not match. In that case, adjustments such as spreading the frame are needed.
04 Installing the shock mounts
There are two shock mount options. Insert the included suspension mount bushing, set the offset to suit the shock you're fitting, then weld it in place. If the inner side is too long, it will need to be cut.
We recommend using the front one as the shock mount. The rear hole comes with a 14mm→10mm adapter collar, so you can use an M10 bolt there to mount a fender bracket or other parts.
You can also drill the hole to make a bolt-on shock mount. In that case, however, you will likely need to fabricate an offset collar or similar.
05 Final welding and finishing
Fully weld all joints and you're done.
Parts that fit the modified frame are generally one-off fabrication territory. Please note that stock bolt-on seats, fenders, and similar parts can no longer be used as-is.
This is a demanding product intended for professional use, so we strongly recommend having it installed by a skilled shop. Minor adjustments or workarounds may be needed due to individual differences between bikes. For any questions about the swap, please reach us through our contact form.
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*Installation is at your own risk. If you're unsure about doing the work yourself, we recommend consulting your local motorcycle shop.
*The content and photos reflect the time of writing. Please check each product page for current specifications, fitment and stock.