Sachs 505 - Lots 'o' friction

Mike (MA) /

Hello,

I recently bought a 1980 Sachs Hercules Prima w/ the 505 1D engine/transmission. It ran when I bought it, but I can't quantify it much more than that. I opened up the transmission to clean it out, and cleaned the piston/bore/head while I was at it. After putting it back together, I noticed that the amount of friction required to pedal it (even without the rear wheel connected and without the piston/flywheel engaged) seemed really excessive. It could have been like this when I bought it.. I don't know. But I've compared the amount of friction to my Puch, and it's like an order of magnitude more than the Puch. I've since reopened the transmission to see of any bearings were misseated, but found nothing that looked amiss. Are there any usual suspects that might be introducing the friction?

THanks,

Mike

Re: Sachs 505 - Lots 'o' friction

If it's a friction you feel for 1/3 to 2/3 of the pedal circles,it may be a bent pedal shaft,or misaligned or bent engine case.If it's a constant friction,it's probably a bearing that's seizing or somebody didn't get a thrust washer back in where it's supposed to be.Just guessing!

Re: Sachs 505 - Lots 'o' friction

Reeperette /

Does it have a decompression lever ? If so, yer supposed to hold that down while manually pedalling, so far as I understand.

Pedalling with the decompression lever not pulled would feel like that...

Dunno much about Sachs tho, whether they have one or not.

-R

Re: Sachs 505 - Lots 'o' friction

The old Sachs parts bike I have does have one Ree.But he said the flywheel was disengaged,so there wouldn't be any need of compression release,would there?I don't know my Sachs' either.But I think they're pretty well-built engines.

Re: Sachs 505 - Lots 'o' friction

Mike (MA) /

Thanks for the input Reeperette & Don. But yup, Don's right.. the piston/clutch/flywheel were not engaged, so the decompression plug wouldn't help me here. Don, I like your guess about a frozen bearing. There's also some lateral play in the axels & gears that I don't like... I just got a 505 engine/trans parts breakdown, so I can check to see if bushings/spaces/washers are missing and causing the lateral play. And while I'm in there, I'll check each bearing for a stubborn one.

Thanks,

Mike

Re: Sachs 505 - Lots 'o' friction

Ron Brown /

Ree,

The decompressor is only used for starting the engine and is only needed on peds with a centrifugal starting clutch. Without a decompressor, when you begin peddaling, the clutch begins to engage, the engine drag prevents the rpms from increasing to where the clutch can fully engage and you just wind up generating heat (and sweat), while slipping the clutch. The decompressor allows the engine to turn easily enough for the clutch to reach full engagement speed, then you release the decompressor and away you go.

As an example, my Motobecanes and my Batavus have almost identical engines, with no transmission and a simple external belt drive from the engine crank to the pedal crank. The only real difference is that the Motobecanes use a centrifugal starting clutch with a decompressor and the Batavus uses a manual (no slip) starting clutch and no decompressor.

Ron

Re: Sachs 505 - Lots 'o' friction

Sounds like you've got `er covered,Mike! Here's to your success and pure `pedding enjoyment!

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