[Press Release] 9point8 – We are pleased to announce our Slack-R, the only headset angle adapter for bicycle frames using the IS Standard. Utilizing our patent-pending modular system, customers can change their head tube angle (HTA) to slacken or steepen their geometry.
The Slack-R kit is installed in the Head Tube of an IS frame, and re-uses the IS bearings.
The available delta in Head tube angle is 1.2deg to 1.8deg, dependant on the specific geometry of the bike. How does this work?
CASE STUDY: Santa Cruz 2016-2019 Tallboy 3, size Large
Using the 2016-2019 Santa Cruz Tallboy 3 in size Large as an example. This is a great candidate for a Slack-R – it uses an IS headset and despite the 68° head tube angle we see a lot of riders wanting to make it slacker, similar to the 2016-2019 Tallboy! Two Slack-R kits are available for the Tallboy 3 (100mm head tube length), the “Bravo” kit 1.4 degree head tube angle delta and the “Echo” kit 1.8 degree head tube angle delta. The delta indicates the change in angle of the steer tube in your frame, but because of the combination effect of the increase in stack height from the bearing cups and the lowering of the front end due to the slacker head tube able, this doesn’t tell you exactly what the end result is.
Using the Bravo kit the resulting geometry on the Tallboy is shown in Figure 1: Santa Cruz Tallboy 3 Slack-R Transformation. Despite only a 1.4° delta, the overall change is actually 1.7°! Generally speaking, we expect a slightly slacker head tube angle than the listed delta. Remember, changing the head tube angle and adding cups to your headset will make other changes to your geometry:
- Small change in bottom bracket height
- Slight increase in stack
- Slight decrease in reach
- Noticeable increase in wheelbase
The Slack-R is available now at 9point8.ca or through your local bike shop. MSRP $99USD with free shipping in North America.
