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Hi all again,
Can any one help me out with the pulley rad. or dia. for the spitdorf DU 5 type. Cheers Dale
Can any one help me out with the pulley rad. or dia. for the spitdorf DU 5 type. Cheers Dale
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http://www.splitdorfreg.com/blancard/splitgenart1.html
Dale:
This might help. Someone will probably have an exact measurement for you, but keep in mind that V-Pulleys have varying diameters, depending where the belt rides. So some variation in the turning ratio can end up happening. Also, vehicles of that era (cars/bikes) often used segmented leather pulley belts and depending on the width of the belt, (They come in all kinds of sizes) that can change the ratio.
If you can't get an original measurement, calculating the ratio is not hard. Figure out the 'needs' of your bike and then use a dynamo tester (any electric motor repair shop will have one) to figure out the RPM's needed to supply that output. Figure out the output shaft speed and you will be able to easily figure out the pulley diameter.
Finally, if it's a three-brush system, your dynamo may be adjustable by rotating the brushes at the back. In that case, you can compensate for pulley diameter once you have it on your bike.
One thing to consider is that back when the bike was new, there was a lot less 'night' riding/driving than there is today. Many of the vehicles of that era have dynamos that won't necessarily keep up with the full lighting system. On bikes, it probably will. On cars, running all the lights (heads/sides/tails) would put a drain on the battery, even if the car were running. Bikes use so much electricity in relationship to the size of the dynamo, unless it's loaded with spotlights, etc. likely that is never an issue. But something to keep in mind.
Most of the above is from working with vintage car electrical systems, not bikes, though not much is different in practice. So use as a guideline, not necessarily directly applicable to your machine. But just some of the things that we deal with all the time on early systems.
If your avatar is your bike, Dale... wow. Just wow.
Cheers,
Sirhr -
Hi Sirhr,
Thanks so much for the reply,
No the avartar is not my bike but will attach a couple at end.
I am looking at the spare parts list and the dia. seems to be a lot the same as the driver pulley which i have on the bike, but alas I am missing most of the electrical generation side of components. My late Grand father loaned them to someone many years ago.....And gone forever...
The main reason for the blog is , before I go to the expence of a pulley I just thought I would ask the Q's and see if some help came back. I appreciate the words, and being a qualified mechanic I understand the workings , but admit I am a little rusty being 57 and some time since my schooling.
Your help is much appreciated.Bike hasn't run for 35 years Dale
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