rm 250 rg3 triple clamps

Yep

Why?

Looks ?
Turning slower?
Sharper?

Call rg3, any doubts.

That's a massive offset change tho on your 2004 rm 125.

2004 rm 125 had a 24.5 mm offset
In 2005 they shortened it to 22.5mm

People have put 2005 clamps on 2004 bikes for this reason. Bike corners better and front feels more planted.

Making your bike have 20 mm offset is really going to skew geometry. Prob make it great for supercross. High speed rough tracks will prob lead to more head shake. Just guessing cause I've never run 20 mm offset clamps on a 2004 rm 125.

I ran stock 2005 rm250 clamps on my 2004 125 to get the better offset. Front end traction improved.

When I sold the 250, I put the aftermarket 2005 clamps on my 2004 125 no worries.

The 20mm will be fine on the 125, I've got them my my rmz450 and it's not too twitchy, plus, even if it were, you can dial it out with fork height and sag

Yeah 22.5 is the offset going by that part number.