The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: 1KCBC on 14.02. 2007 06:00

Title: Dynamo belt
Post by: 1KCBC on 14.02. 2007 06:00
Hi everybody,How do you think about dynamo belt?
Title: Re: Dynamo belt
Post by: fido on 14.02. 2007 08:19
I've heard good reports about it and am planning to do this mod. at some stage  *yeah*
Title: Re: Dynamo belt
Post by: LJ. on 14.02. 2007 09:30

I tell you one thing.... It looks a darn sight cleaner in there! and for this reason alone I had considered getting one maybe later. Doe's this conversion actually push out more voltage? for example doe's it make the dynamo spin faster?
Title: Re: Dynamo belt
Post by: bsa-bill on 14.02. 2007 19:17
SRM make a good one that uses a toothed belt, the belt is reinforced with steel,
It runs about 10% faster than the chain and if you have installed  the wrong idler pinion bush will run when totally immersed in oil.
I've no connection with SRM other than a satisfied customer.
Downside is it's twice the price of other belts systems available, there is one on Ebay at present, I also have one spare.
a worthwhile modification whichever one you choose.

All the best - Bill
Title: Re: Dynamo belt
Post by: Beezageezauk on 14.02. 2007 19:27
Hi Guys,
The Dynamo Belt Drive conversion shown in the picture is the same one that I have had fitted on my A10 for the past 6 years.  Basically it is fit and forget.
This particular model is made by a friend of mine and is the exact size as the original sprockets and chain.  This means that the dynamo drive has the same gearing and does not run any faster than standard.  
These conversions obviously have many advantages over the original chain whereby the set-up is quieter (no chipping away of the cases with the chain) and cleaner in use (no packing with grease).  However, there is one disadvantage.  The small pulley will not fit through the opening in the cases when it is fitted to the dynamo.  This is simply because it needs to be much thicker in order to carry the belt.  The original small sprocket is only about 3mm wide where it goes through the cases.  Therefore the dynamo needs to be fitted on the bike before the small pulley is fitted to the dynamo.  Also, the small pulley needs to be taken off the dynamo before the dynamo can be removed from the bike.  I will recommend a Dynamo Belt Drive conversion to anybody who intends using their A7 or A10.
Beezageezauk.
Title: Re: Dynamo belt
Post by: a101960 on 03.09. 2007 20:31
The dynamo belt drive is a good mod, especially if you are going to go 12v. One word of warning! One of the kits from a major supplier can fail due to the way in which it is fitted. The problem that I encountered with this particular piece of kit was that the dynamo pulley would not pass through the crank case opening, if it was pre-fitted to the dynamo shaft, because it was to big to do so, now this means that it is almost impossible to tighten it up. What then happened in my case, was that the pulley worked loose and fretted on the dynamo shaft. This rendered the pulley U/S. I have since bought the Hawker Electrical version and it is designed so that the pulley can be fitted to the dynamo and tightened up before the dynamo is fitted to the bike. If you are considering fitting one of these kits, here is something worth knowing. If you are unlucky enough to find that oil is getting past the idler pinion, and finding its way into the dynamo drive cavity, then Hawker Electrical can fit a seal that will resolve this problem for good. You would need to send your inner timing cover to Shaun for the job to be done, but if you suffer from this problem it can be fixed.