Stronglight are best known for their cranksets. They pioneered aluminium cranks in the 1930s, developing the square tapered bottom bracket axle which is still the most common standard eighty years later. I run a Stronglight Impact Compact chainset on my Look KG223, it’s a very capable and good value for money, and won’t look out of place on older bikes.
In addition to chainsets and bottom brackets, Stronglight are also known for their headsets, which is where this oddity fits in. This came to me on a Motobecane randonneur I’ve been working on. This bike has a French threaded headset, but someone had seen fit to install this English threaded riser all the same!
Replacing the headset top cap, the riser extends the effective height of the steerer by around 6cm. The limiting factor to vintage bike fit is often handlebar height. Quill stems are usually limited to 10cm rise or less. This riser can be used to set the handlebars a little higher. It’s no magic bullet – care should be taken that the stem expander is not putting pressure on the threaded section of the steerer. Stem failure is scary and no risks should be taken in this area of the bike. Due to this consideration, it generally allows 3-4 cm rise maximum, but that can make a lot of difference.
I’ve been using it on my steel Look for about a month and the higher hand position is really working for me. I have fewer aches and pains in my hands and back while riding, and can use the drops much more comfortably. Compared to other options for raising the bars, it looks pretty elegant!