Imperial German Pickelhaube Evolution 1842-1915
 
The Model 1891 Pickelhaube
The features introduced in 1887 proved to be completely unsatisfactory; the front visors were easily damaged without the leather trim and the loop and hook system used to hold on the leather chinstrap resulted in chinstraps being lost. An AKO of 08 January 1891 introduced a new model of Pickelhaube which attempted to address these shortcomings.
The brass front visor trim was reintroduced and a new and ingenious system of securing the chinstrap was introduced. The leather chinstrap was changed to a double buckle and the end of the strap was fitted with a brass loop with a cut "V". The chinstrap loop was designed to fit onto the corresponding post, keeping it secure but allowing easy removal. Unfortunately, this easy removal explains why so many surviving examples are missing the leather chinstraps today.

Generally, soldiers of the Garde Infantry retained their flat silver or brass chinscales in garrison and replaced them with the M91 leather chinstrap in the field.

M1891 Preußen Infanterie Regt Nr. 83
1891 also brought about a final reduction in the height of the helmet, giving it a more domed appearance that remained for the life of the Pickelhaube. The eagle Wappen was also reduced in size to 115mm and obtained a more refined shape. For the first time, the gap between the wings and the legs was now voided. Like it's predecessors, the M1891 utilized threaded bolts on the reverse to secure it to the helmet shell. The final modification was the introduction of a new 48mm Kokarde with a large center hole to fit the M91 chinstrap posts.
 
Click on the thumbnail picture for a larger picture and a full explanation.
Front Plate
Spike Base
Side & Liner
Rear Spine
Side Post
This period photo shows an issued M1891 Garde Pickelhaube worn by a veteran of the Franco-Preußen war. Note the flat chinscales secured by M91 posts.
 
References