The Superstar Components Stretchset lets you adjust the reach of your bike by 5mm or 6mm (depending on your current headset size/type and whether or not your fork has a tapered steerer tube) in either direction.
I aimed to add 5mm to the reach of a Scott Ransom, and installation was pretty easy, although it’s worth taking time to ensure the engraved alignment markings are exactly where they need to be.
Once fitted, I had no issues with anything coming loose, and the quality finish and solid sealing have kept water and grime out of the bearings throughout testing – impressive, considering the reasonable price.
On bikes previously fitted with an internal headset (like mine), the external lower cup increases the stack height and therefore slackens the head and seat angles, as well as lifting the bottom bracket and extending the wheelbase.
If you manage to maintain the same bar height (by removing 15mm of spacers from below your stem, to counter the increase due to the lower cup) then, with the changes to the angle of the frame, the actual increase in reach is more like 3mm, which is pretty hard to notice.
That said, with the other alterations taken into account, the bike feels very stable in steep, rough terrain. It’s a shame about the slacker seat angle though.