Dear OTK experts...front stub axles and rear axle

I know nothing about OTK chassis so I admit total and utter ignorance on the topic.

What’s the difference between the HST SA2-BSD and HST SA2-BSD 1B stub axle?

Also, where do I find 40mmx1060mm axles that are not for DD2?

I believe the 1B version has more Kingpin Inclination built into the stub.

Thanks! That helps! I

Just trying to visualize, does this mean the part that your hub sits on is welder higher or lower then stock? or is the part that attaches to your tie-rod is bent at a different angle, being higher or lower then stock?

Not to be that guy, but the kingpin inclination is the same regardless of spindles. KPI is just that. The angle the kingpin sets relative to vertical when viewed from the front of the kart. You can only adjust the KPI by spinning around the eccentrics, which in turns moves the kingpin angle around giving you caster/camber adjustments. The 1B spindles has the stub axle potion welded on a different angle giving you a different caster, camber, and scrub radius. 1B is usually used for kids to reduce the effort needed to turn the wheel. You can use them as an adult, but require aftermarket eccentrics to get the caster/camber back in the right window.

Thanks, that’s what I originally thought and I was having a hard time visualizing how a stub axle would change that. good insight !

I think they state it has an increase in kpi but its probably a translation issue.

Basically the angle between the bit the wheel mounts to and the bit you mount to the frame is different. See angle x in image below.

So if you change the stubs from standard without modifying anything else you will have different camber without changing the caster.


Agree, it would have bene more correct to say the stubs are built to allow for more KPI

With a fixed stub / KPI relationship as karts have, making a camber adjustment is really a by-product of changing the KPI.

Mechanically, KPI works the similarly to caster (but at a different rate - slower initally) in that the inside tyre is driven it into the track, but oppisingly for the outside wheel (drives it into the track, rather than lifting it).
Scrub radius is also reduced.