Most of the time there straight slip on or bolt on, no need for any welding not cheap for a quality one! http://www.ebay.co.uk/itm/Yamaha-WR125X ... 1446493027 You need to seriously think it over, is this bike restricted? Will the new can break the restriction laws if so licence and insurance could be on the line! Moving on, are you going to be keeping the bike or is it just a stepping stone to bigger things? If the latter, l would save the money for the next bike. Another thing worth pointing out is that your going to be seriously blinging up your bike, those 125 are very high risk for theft anyway if l'm correct? This modification needs to be disclosed to your insurance company or you could seriously loose out. Hope this is of help