Sióg is the word for Fairy, or some say Síóg. Sidhe is the word for the mounds that are supposed to contain them or just a general adjective for anything Fae/ethereal. So something like:
Tine na Sióg
You could also say:
Tine Shidhe
The slight difference being the first means literally "Fire of the Faeries" where as the latter is more like "Fae fire". If going for the latter I'd prefer:
Lasair Sidhe
meaning "Fae Flame" since it fits a bike more.
Although as a point of interest the word "Fairy" isn't the best translation for them since it conveys they are some sort of small humanoid race parallel to humanity. Usually however Irish storytellers were fairly clear that a Sióg was simply an ancient dead person normally confined to a mound but with some limited power to walk around outside the mound on certain days* and often at night. In this sense they are fairly close to English elves if you read actual English folklore before the French "fairy" idea came in.
*But not Halloween funnily enough.
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The dialect I use is Munster Irish, particularly Cork Irish, so words or phrases I use might not be correct for other areas.
Ar sgáth a chéile a mhairid na daoine, lag agus láidir, uasal is íseal