The continental nordic spike 700c winter spiked tyre are studded tyres that are officially approved for road use theyre available with 120 and 240 studs of hardened steel making it possible to get out and about even in bad weather the 120 stud version is best for riders requiring rubber contact in a straight line as the studs are only positioned in the shoulder tread areas if clear tarmac also forms part of your winter journeys with a mix of snow then this option may be best the 240 studs