New from components manufacturer, Wolf Tooth, are these Lower Headset Extender Cups which will allow you to change the head angle of your mountain bike even if you couldn't before. Do you think a slacker more stable bike sounds tempting? It may be but read on, as it's not all just about head angle....
Wolf Tooth has designed a new option for riders who wish to slacken the head angle of their bike offering a geometry update to get a more aggressive setup. The Wolf Tooth headset extender cups are designed to lengthen the axle to crown height by 10mm. Wolf Tooth says this is to allows you to adjust the geometry of your bike frame by increasing the effective fork length by 10mm. The new headset cups allow you to do things like use a rigid fork on a suspension-corrected frame or use a fork with a shorter axle-to-crown height rather than what the frame was designed to use. They can also be used to increase the bottom bracket height and slacken the head tube angle in a different way to those we have seen before from Cane Creek or Works Components angle sets.
There is an option for frames with external bearing cups and an option for zero stack frames where the internal bearing cups are pressed into the frame. The alteration of 10mm by the headset cups will probably give you a 0.5 degree decrease of the head angle of your bike.
Pros and Cons
That's where things start to get messy, adjusting the fork length in this manner not only slackens the head angle but it also will lift the bottom bracket slightly. A slacker head angle might also mean you feel a difference in the steering of your bike as getting a slacker head angle whilst not changing the offset of your fork will give more 'trail', which might lead to slower steering at slow speeds, yet it might feel more stable at higher speeds. You might notice, you might not and what's more, it might bother you or it might not! One person's perceived feeling of the alterations over another's can be very different. Other ways you could also slacken your bikes head angle is by the aforementioned angle sets or by inserting a different air cartridge, taking say a 150mm fork to say a 160mm fork.
Same goes to a higher bottom bracket are all subjective to tastes too, it'll probably make your bike feel more lively and easier to change direction but it might make it less stable in the rough stuff. It'll all depend on the geometry figure you start from with regards to bottom bracket and the head angle combined with how you like your bike to handle.
There is a third thing that comes into play too - stack height, this will affect your seated position but also your position when you stand on the saddle and ride downhill. Although handlebar rise isn't part of stack height, in order to keep a similar feeling when riding with the Wolf Tooth headset cups inserted you might need to fit a lower rise bar.
There’s a fourth variable too – effective seat angle, it’ll get slacker as you slacken the head angle with this headset cup, not a huge amount but slacker all the same and in terms of climbing ability it’ll probably impact negatively.
Wolf Tooth also notes that it could help maintain your current geometry if you are changing forks. Putting a rigid fork onto a suspension corrected frame might need some extra axle-to-crown, as may changing from various road, cross, gravel, or bikepacking forks. We reckon this is the most beneficial application, using this to simply slacken the head angle on a mountain bike leads to more geometry adjustments than you you might at first realise. You might use it if you wanted to keep a similar stack reduce travel in the fork but you’ll need to make sure you have plenty of room in the steerer tube to make this adjustment, in this scenario, head angle would stay the same too.
The extended lower cups are machined from 6061 alloy in the USA and weight 62-68g. They are sold on their own (you need to buy an accompanying upper headset cup if you need a complete headset setup) and include Enduro stainless steel sealed bearings.
Available now, they come in two versions – EC to fit 1.5″ lower headsets with external cups that press into a 49mm ID or ZS to fit 1.5″ lower headsets with internal Zero Stack cups that press entirely into a 56mm ID headtube, both cost $54.95.
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