Sachs Torpedo Pentasport H5111
Some notes and photos of the Pentasport and P5 series of 5-speed hubs made by Sachs and later SRAM.
The series of hubs - also known as Sachs Torpedo Pentasport model H5xxx and SRAM P5 - were produced in different versions from year 1987 and well into the 2000s. The early models used dual pull-chains for gear shifting, later models concentric push-rods with a clickbox. Even though there are significant differences in the gear shifting mechanics, many components are compatible and interchangeable between the models.
The first version H5111 of the hub shell have the flanges machined from the same piece of steel as the rest of the hub shell and have a nice corrosion-resistant chrome plating:
Later revisions of the hub (in this case a model H5103 without a coaster brake) switched to a "tube" hub shell construction with pressed-on stamped sheet metal flanges to reduce machining time and material use (less metal is wasted when the flanges are not formed/turned from a larger-diameter metal stock):
The Pentasport model number nomenclature is:
- H5111: Dual pull-chain shifting, one-piece hub shell, coaster brake (the OG Penta)
- H5100: Dual pull-chain shifting, one-piece hub shell, no coaster brake
- H5113: Dual pull-chain shifting, hub shell with pressed flanges, coaster brake
- H5103: Dual pull-chain shifting, hub shell with pressed flanges, no coaster brake
- H5120: Dual pull-chain shifting, aluminium hub shell, drum brake
- H5213: Push-rod shifting, hub shell with pressed flanges, coaster brake
- H5203: Push-rod shifting, hub shell with pressed flanges, no coaster brake
- H5220: Push-rod shifting, aluminium hub shell, drum brake
See also the exploded-view diagram of the Pentasport model H5111 (pull-chains). For pushrod models, refer to the P5 diagram links in the last paragraph of this page.
A model H5213 with push-rod gear shifting. The hub shell is identical to the earlier H5113/H5103:
The SRAM P5 version of the hub. The chrome surface plating was replaced by a satin finish galvanization and the outer profile of the hub shell was simplified a bit:
In an - in my opinion unnecessary - effort to widen the gear ratio range of the hub from 224% to 251%, the tooth count for one of the sun gears, one step of the planet gears and the ring gear was changed in the SRAM P5. This makes the individual parts incompatible as replacement spare parts for older hubs, but if the whole "set" of related components are switched over, it will work (but with slightly higher jumps between some of the gears than you are used to).
(Note: The "Cargo" variant of the SRAM P5 retained the classic 224% gearing, identified by a yellow spring retainer screw in the left side of the axle instead of the red on the "normal" P5.)
The correct timing of the stepped planet gears is very important to get right during the assembly of the hub. Here is an example of an incorrectly timed planet gear:
There is a special unobtanium assembly tool to hold the planet gears in alignment while the planet cage is installed on the sun gears, but you can assemble the hub without it by carefully checking the position of the timing dots. The tool just makes the task easier and faster:
A rebuilt/refurbished internal unit from a late-revision hub, compatible with all Sachs Pentasport and SRAM P5 steel hub shells, an easy way to repair a 5-speed hub/wheel that is already laced with spokes:
The driver dust cap size for the Pentasport and P5 hubs is 64.5mm (outer diameter).
Be aware that the Pentasport (and P5 hubs until 2005) brake cylinder is visually similar to the Torpedo H3111/T3 type but not compatible due to a small difference in width:
Note: During production year 2005 the brake system changed to using three "loose" brake segments that is significantly different from the earlier two-piece brake cylinder held together with a spring clip:
The mechanical design change of the brake system also introduced a corresponding new shape of the top of the planet cage, brake cone, fiction spring and left axle cone and brake arm assembly (also shared with the contemporary SRAM S7 hub).
For more information about those changes and the cross-model compatibility with the S7, please review the P5 exploded-view diagram (and the version from before sep 2005) and the corresponding P5 spare part list (and the version from before sep 2005).
Page last updated 2024-07-29 07:45. Some rights reserved (CC by 3.0)