Sachs Torpedo Pentasport 5

[Robdet]

Hello,

I would like to build a bike, with Sachs Torpedo Pentasport 5 speed internal gear hub with break. What are your opinins? Will it wit work? Won't it be a
problem, that hub has got internal break?

Thank you for your help,

Robert

 

[Sidewinder Jerry]

Personally I'd stay away from internal hub brakes as a primary and/or only way of stopping. You most certainly want a double mechanism braking system. Meaning both a front and rear brake, preferably disk but at least rim. Use the coaster as an emergency brake only. As for an internal geared hub, I recommend either a 3 or a 5 speed. Here I'm going to assume you're wanting to build a shifter using a shift kit.

Post pictures of the engine and the bike you want to use. Other useful information will be total weight (rider, build), engine performance & dimension specs, terrain (hill grade and frequency).

Last of all do you have access to a welder? I personally prefer steel frames because they are easy to weld on.

 

[Sidewinder Jerry]

The ratios for your hub are:

1) 2/3
2) 7/9
3) 1
4) 1 2/7
5) 1 1/2

 

[Robdet]

Thank you for your help.

I would like to weld two holders to the rear folk, to be able to mount hydraulic V break, Magura HS 33 evo 2. ( https://www.magura.com/en/components/bike/rim-brakes/productdetailpage/?p=2597 ). That will be the main
rear break, but besides this there is the inside break as well. At the frond I would like to mount disc brake. I would like to use Herkules frame for the project.

I have a Martinelli engine, ( https://allegro.pl/oferta/silnik-spalinowy-do-roweru-komplet-80-cc-jakosc-8985654186 ), 3,50 kw 6000 rpm. Total weight of the bike will be arround 15 kg. I was
thinking to mount with the rubber mounting, on the rear wheel, as it is here: http://fullcycles.org/the-motorized-bicycles-how-to-get-one/ What do you think, will it work like this? I would like to use the bike lowland without mountains, bigger hills

 

[Sidewinder Jerry]

What is the total total weight being moved (your weight and the bike's weight)?

Do you live where there's lots of hills?

Would you like to run your 2 stroke engine drive system through the 5 speed Sachs hub? Then you'll have 5 gears the engine can use; instead of a single drive ratio on the left side. If you do want to build a shifter; you'll need a Sick Bike Parts 2 stroke shift kit.

**2 Stroke HD Shifter Kit

Motorized bicycle, motor bike, electric bike, ebike, pedal assist

sickbikeparts.com

 

[Robdet]

Total weight will be cca 90 kg. There aren't lots of hills. I would like to use the gears just when I'm pedaling. I would like to do just single drive ratio on the left side with the torpedo pentasport hub. What do you think, will it work like this?

 

[Sidewinder Jerry]

You'll then need to read up on how to do left side drives when a coaster brake or drum brake is used. Yes it can be made to work.

 

[Robdet]

Thanks, I'll look for it precisely.