Try changing your model units to mm in the Document Properties, then export to Sketchup.
Also check the Import options in Sketchup to see if you can specify inch units for import instead of mm.
I'm working in MM as i'm based in the UK and I suspect that the sycode software is based on an imperial basis.
I have asked them if they can do this but they are on India time so I wont find out til the morning.
So I can either scale down my solidworks part by 25.4 times and then Export or as you suggested scale it down in Sketchup.
However, there doesn't seem to be an option to convert the downscale on import as uits greyed out so we have to manually scale down by 0.0393700787. Which while not ideal is a certain fix.
The only downside to this is that the part file size in terms of the exported from Solidworks file is very large and hangs the machine up when converting to Sketchup format. Combine that with the fact that the file size remains the same in Sketchup post scaling, which is prohibative when our competitors have much smaller file sizes than us for download.
Any further help would be appreciated.
Did you try changing your model units to inches and then exporting?