I was just curious if anyone ran shoulder bolts in place of the standard kingpin bolts on your front ends? Shoulder Bolts I know have a higher tensel strength the standard kingpin bolt....any thoughts?

Thank you
My experience with shoulder bolts body is strong but threaded end will snap easy. I have toyed with the idea of aircraft bolts. The threaded portion is same od of shoulder.


Premium User
I have used shoulder bolts as kingpin bolts on all Legend karts for the last 10 years and have never had a failure of the bolt in any way. MUCH better than standard bolts, fit the bearings and heims very nicely. A little hard to drill the safety wire hole through the threads but a good cobalt bit works for that.


Premium User
The down side to shouldered bolts or anything for that matter with a squared corner step down in size is the steps corner. It’s hard to get a proper radius in the corner to make them strong.
I’ve heard of a few breaking in some hard crashes but never heard of a problem with them shearing/ breaking under racing fatigue in go karts racing. I have heard that most bolt companies like Fastenal are using China as bolt suppliers now. I have heard from a friend that does bolt shear testing that there are only a few companies that sell USA made steel bolts and his testings found China grade 8’s are not as strong as the USA made
Many years ago, when I built karts, I used 2 brass shoulder bushing and then would ream out the ID to fit the OD of the bolts.
Nice to see you posting Al, always liked your help you offer in kart racing, certainly a pleasure knowing someone such as you in our sport so unselfishly helping anyone who asks for help in tuning. Hope your doing well.
Danny Stephen