Semi-Internal Headsets 6061AL-T6
9.5 mm stack height for frames machined to take the cup inside
What It Is and Who It Is For
A semi-internal threadless headset in fully CNC machined 6061AL-T6, running two sealed cartridge bearings. It weighs 98 grams per set, measures 28.6 by 44 by 30 mm and adds only 9.5 mm of stack, made up of 7.5 mm upper and 2 mm lower.
Why Buyers Choose This Part
9.5 mm total stack
Less than a third of the stack of an external cup headset, which gives the frame designer control over front-end height.
Still fully serviceable
Two sealed cartridge bearings that press out and replace, rather than a bonded assembly that is scrapped when it wears.
12 grams lighter than the external set
98 grams against 110 grams, with a wider 44 mm cup that houses a larger bearing.
Problems It Solves
- An external headset on a frame designed for internal cups raises the bars too far
- Low stack headsets are often sold as sealed units that cannot be serviced
- Mixing headset standards across a model range complicates spare parts
Who It Is For
- Frame designers who have machined the head tube for an internal cup
- Brands building bikes where handlebar height is tightly specified
- Workshops replacing a semi-internal headset on a modern frame
Application Scenarios
- Frames with head tubes machined for semi-internal cups
- Low stack front-end builds
- Replacement on a frame where an external headset will not fit
Technical Features
- 44 mm cup diameter to suit an internal seat in the head tube
- 9.5 mm stack, split 7.5 mm upper and 2 mm lower
- 6061AL-T6 machined throughout
- Two sealed cartridge bearings
Published Specification
| Weight | 98 g per set |
|---|---|
| Material | 6061AL-T6, full CNC machined |
| Diameter | 28.6 mm x 44 mm x 30 mm |
| Stack height | 7.5 mm + 2 mm = 9.5 mm |
| Bearings | 2 sealed cartridge bearings |
| Colour | Anodised red, gold, titanium, blue or black |
Every figure in this table is transcribed from the VALORIDER catalogue specification for this product. Nothing has been estimated.
Product Views
Compared With the Alternatives
Against our VH-01 external headset this saves 23.5 mm of stack and 12 grams, but it only works if the frame has been machined for it. An external headset will fit a wider range of frames.
Customisation and Manufacturing
Machined parts are cut from solid bar on the CNC side of the Shiyan Town plant. Alloy, tolerance and anodised colour are all specified at drawing stage, and the mark is usually lasered rather than printed so it survives handling and solvent.
- Alloy and tolerance built to your drawing
- Laser marking or engraving on the anodised surface
- Anodised colour matched to an approved sample
- Polybag, card or colour box packing
Fitting and Living With It
Step 1
Check the head tube is reamed and faced for a semi-internal cup before fitting.
Step 2
Press both cups square and fully home.
Step 3
Budget only 9.5 mm of stack when calculating steerer length.
Step 4
Preload with the top cap, then torque the stem bolts to the stem manufacturer's figure.
Others in This Part of the Catalogue
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View specificationGuides That Cover This Product
Choosing a Bike Headset External or Semi-Internal
The frame decides, not the rider. A 33 mm stack against a 9.5 mm stack, and what happens if you specify the...
Read the guideSealed Cartridge Bearings and Why Pawl Count Matters
Two bearings, four bearings, six pawls. What those numbers on a hub or headset specification are actually...
Read the guideSemi-Internal Headsets 6061AL-T6 Questions
What is the difference between semi-internal and integrated?
Will this fit a frame designed for external cups?
What stack height should I allow?
Can the bearings be replaced separately?
Quote Semi-Internal Headsets 6061AL-T6
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