Über den Einsatz von SunTour Perfect, Pro Compe und New Winner Schraubkranzfreiläufen: Unterschied zwischen den Versionen

Bis auf die 16-Zähne-Ritzel mit zwei breiten und integrierten Spacern, sind alle Ritzel mit vier Keilverzahnungen untereinander austauschbar, jedoch haben "Perfect" Ritzel etwas tiefere und abgerundete Einkerbungen, die man etwas zurechtfeilen kann, damit sie auf den Freilaufkörper eines "Pro Compe" oder "New Winner" Freilaufs passen. Die meisten 44 mm Schraubritzel sind ebenfalls untereinander austauschbar. Die 14-Zähne-Ritzel wurden mit zwei unterschiedlich breiten integrierten Spacern ausgeliefert, wie es auch in der Tabelle aufgezeigt wird. Das äußerste 14-Zühne-Ritzel mit 5,5 mm Ritzelabstand kann man außer bei "New Winner" sechs- und siebenfach auch auf einem Freilaufkörper für [[Ultra Spacing]] einsetzen, weil es dort zum äußersten Ritzel reduzieren würde.

 

The outer one or two New Winner sprockets use a threading different from other SunTour sprockets, and so sprocket availability may determine whether you will want to use a New Winner body. Only the New Winner's two innermost positions take splined sprockets, making a good sprocket progression with large sprockets hard to assemble -- but we have a workaround, keep reading.

 

The image below shows 5 kinds of special New Winner outer sprockets and gives their threading diameters. The E sprocket is attached to the X sprocket to make a 6-speed, and directly to the body to make a 5-speed.

 

The letter codes for the New Winner provide a nice mnemonic:

*    7-speed: U, L, T, R, R, A, A ; U, L, P, R, R, A, A ;

*    6-speed narrow: S, T, T, R, A, A ; S, P, T, R, A, A

*    6-speed wide: E, X, T, R, A, A

*    5-speed: E, T, R, A, A ; E, N, R, V, A ; E, N, R, A, A

Let's look at the photo of sprockets and spacers of the common 5-speed Perfect freewheel again. Because of the different spacings and numbers of sprockets, Perfect and Pro Compe freewheel bodies were made in several splined, threaded and total widths. Spacers of different widths established the different sprocket spacings.

The spacer behind the outer, 15-tooth sprocket is beveled to avoid interfering with the chain.

The two leftmost spacers, between the splined sprockets, are 3.5mm thick and the sprockets are 2mm thick, for a combined spacing of 5.5mm. The outer spacers are only 1.9mm thick because the outer, threaded sprockets are thickened near the center hole for the threads. 14-tooth threaded sprockets and 16-tooth splined sprockets have integral full-width spacers. Splined sprockets with 17 or more teeth are flat and use separate spacers, as shown. Ultra spacing uses thinner spacers. The table below identifies the different spacers.

5.5mm

spacing 52mm 57mm 3.5mm Steel, split ring

5mm spacing 52mm 57mm 2.7mm Steel, split ring, or plastic, with 4 splines

transition New Winner 52mm 56mm or

58mm 0.9mm Used in Ultra New Winner where the second splined sprocket does not overhang the end of the splines.

transition/

threaded All 44mm 54mm 1.9mm For 5.5mm sprocket spacing. Beveled spacer must be used behind a 15T sprocket

transition/

threaded All 44mm 52mm 1.1mm For 5.0mm sprocket spacing. Beveled spacer must be used behind a 15T sprocket

The next photo shows a Perfect body with three splined sprockets and two spacers in place. The red arrow points to one of the splines. The rightmost splined sprocket overhangs the larger-diameter section of the freewheel body, as shown, so that the spacer behind the next, threaded sprocket can secure the splined sprockets.

Perfect and Pro-Compe bodies designed for the narrower Ultra (5mm) spacing have a splined section to accommodate three or four sprockets and their narrower spacers. With some Ultra-spaced freewheels, paper-thin shims are needed in addition to the regular spacers so that the rightmost splined sprocket overhangs the splines and the threaded sprockets secure the splined ones.

With Ultra (5.0mm) spacing, the second-largest sprocket does not overhang the splines of the New Winner body, and so a special 0.9mm thick spacer allows the threaded sprockets to secure the splined ones, as shown in next photo. To engage this narrow spacer, the leftmost threaded sprocket has to have a wide flange.

When building up a SunTour freewheel, it is helpful to have an ample collection of spacers salvaged from disassembled freewheels. Sutherland's Handbook for Bicycle Mechanics, 6th Edition -- still available as a CD-ROM -- includes a complete listing of the different sprockets and spacers.

===Schrarubritzel mit mehr als 21 Zähnen===

The New Winner body takes only two splined sprockets, and threaded sprockets were sold only in sizes up to 21 teeth, requiring a big jump in size between sprockets if the splined sprockets are large. An aftermarket adapter to allow a splined sprocket in the third position was available once -- no longer -- but there is a workaround. The 15-tooth threaded sprocket's flange fits neatly into the opening in a splined sprocket with flat-top splines, and can be tack-welded onto the inside face of the larger sprocket (the side where the teeth are shorter), also serving as a spacer. The welds must not extend higher than the face of the smaller sprocket. Grind the welds down if necessary.

Splined sprocket modified into a threaded sprocket.

outside face of sprocket | inside face of sprocket

Freewheel and cassette bodies are designed so the rear derailer will clear the spokes with the smallest possible sprockets. With larger sprockets, the slant of the spokes allows an additional sprocket closer to the wheel. A dished sprocket, or one bolted onto the innermost splined sprocket, can be added without increasing wheel dishing or dropout spacing.

 

A dished sprocket will move the other sprockets 2 mm farther to the right, and can allow a body which was designed for 5.5 mm sprocket spacing to accommodate an additional sprocket in 5 mm (Ultra) spacing. Dishing a sprocket requires the use of a machinist's tool -- an arbor press -- and a forming template of 1/8" or 3 mm sheet metal with a round hole in the middle. The part of the sprocket which is to be bent should first be heated red hot to soften it and allowed to cool slowly, otherwise the hardened steel may crack. Avoid overheating the teeth.

 

On my Cannondale bicycle with 126 mm dropout spacing, I have a 7-speed Ultra-spaced freewheel with the largest sprocket dished, on a Pro-Compe 6-speed body. Because the sprocket is dished, the wheel dishing is more moderate than it would normally be, and so the wheel is stronger.

Thanks to Yellow Jersey bicycles for review of this article, and an article wth more information about these freewheels.

* [http://www.yellowjersey.org/stfw.html Mehr Informationen zu SunTour Schraubkranzfreiläufen bei Yellow Jersey (englsich)]

Dieser Artikel basiert auf dem Artikel [https://www.sheldonbrown.com/suntour-freewheel.html Using SunTour Perfect, Pro Compe and New Winner Freewheels] von der Website  [http://sheldonbrown.com Sheldon Browns]. Originalautor des Artikels ist [[John Allen]].