Hawkshead T stem - how to fit ?

[aSTerix]

Has anyone fitted the Hawkeshead T stems, if so can you advise how to fit correctly. specifically:

1) Does the top hat shaped rubber go on tire side ?
2) Which was does the dome washer face ie dome towards wheel or away ?
3) Does the smaller diameter part of the top hat rubber go through the rim ?

I can see several ways of fitting this stem and can't find any instructions on Hawkshead website

thx Steve

 

[woodybelle]

Here is a photo of mine installed, I hope this helps. I couldn't find instructions either.

 

[aSTerix]

Here is a photo of mine installed, I hope this helps. I couldn't find instructions either.

Interesting, the rubber gasket is on the outside. Can I double check, your T stems only have one rubber gasket (the one shown in photo ) ?

Did you deform the dome washer on inside when nut was tightened ? Can you recall what torque was used for the first nut / Many thx

PS I have sent email to Hawkshead support asking for instructions and a diagram, I will post here if I get anything

 

[woodybelle]

I had my tire shop install the stems so I can't answer the questions about another seal or the washer, sorry.

 

[Andrew Shadow]

1) Does the top hat shaped rubber go on tire side ?

The rubber seal installs on the outside of the rim, the side exposed to ambient air, with the flat part against the T-valve.

2) Which was does the dome washer face ie dome towards wheel or away ?

The washer installs on the inside of the wheel, the side not exposed to ambient air, against the rim. It is a conical washer. Orientate it so that it is installed so that it creates a cone with the outside diameter of the washer against the rim and the inside diameter, where the through hole is, is domed away from the rim and against the nut. Tightening the nut collapses the cone so that the hole in the washer is forced towards the rim. This compresses the washer between the nut and the rim causing a constant tension fit similar to what a lock washer does.

3) Does the smaller diameter part of the top hat rubber go through the rim ?

Yes.

As installed configuration;



I would also suggest that the rubber seal be lubricated before installation, preferably with something such as an O-ring lubricant or similar. This reduces the friction between the seal and the rim during installation. This allows the seal to penetrate further in to the rim creating a better seal. It also helps to prevent the seal from getting damaged trying to overcome the force of static friction while the nut is being tightened. This allows the seal to bottom as much as possible initially during installation. As the rubber seal compresses over time, this will help to maintain the constant tension applied by the collapsed conical washer as there will be less initial compression for it to absorb. This will help to prevent the possibility of the assembly coming loose over time.

 

[aSTerix]

I had a chat with Hawkeshead tech support, They confirmed that the rubber gasket (thats what they call it) is fitted on outside of the rim. I then clarified what "outside" mean't: the side of the rim that does NOT have the tire touching it .

They do not have a torque setting for the first nut.

I asked what their patent number was but they didn't have it (I was going to look at the patent document) so I suspect it isn't actually patented

So for anyone reading this thread in the future, Andrew Shadow's post above gives the best instructions and guidance