Adding a tacho to a 1959 Dommi 99

The Dominators with a tach drive had a special timing cover that drove a 1:1 ratio tach drive gearbox from the end of the camshaft which drove a 2:1 Chronometric 8000rpm tachometer.

You will also need the special camshaft sprocket nut that has an extension that drives the gearbox, and of course a cable. The early Dominators with optional rev counters on them used a bracket that was held under one of the caps for the front forks.

Good luck with your hunt.....

Easiest to get the correct timing cover but the existing one can have a boss built up with weld and the appropriate holes drilled. As impoverished students, we built up a boss with araldite with some aluminium filings mixed in. it worked.

Previously wrote:

Hi, Can anybody tell me the procedure for installing a chronometric tacho to a 1959 model 99, I was nearly finished collecting the parts for the bike and my son decides that he would now like a British bike and has claimed the Dommi. The only problem is that he would like it to be a cafe racer!! so I am now starting to look for all of those type of parts.

Back to the point, what type of Chronometric tacho and gearbox should I be looking for as in ratios and where and how do you attach to the bike.

Looking forward to your replies.

Regards Andy

Hello Andy It Can Be very expensive to by the original equipment if you can find it that is, But you could alway get the electronic rev counter from Mick Hemmings For £150 ish and a lot cheaper too the original parts cost of just the rev counter Rc1300/00 2:1 ratio will knock you back around£350 and for the hole lot will cost well over £500 so its now up too you which way you go . for the original rev counter or the electronic rev counter . your AJD

Of course you can't fit an electronic rev counter if you have magneto ignition.

Scitsu tachos work with magneto ignition. (Sometimes need some fiddling - resistor or capacitor adjustment)

Cheers

Alan

Keep checking Ebay USA, one usually shows up there for sale every few weeks for around $100-$150 US, a lot neater and easier than welding a lump on the side of the standard cover. The correct one for your bike would hold the tach drive so that the cable points at about a 45 degree angle forwards and upwards. The covers that hold the drive so the cable exits vertically showed up on post 1962 bikes.

Previously wrote:

Hi, Thanks for the replies, I want to go down the original path and use a chronometric tacho, I have already found the tacho I just have to pay for it, I am still looking for the drive. I am guessing that the timing cover might be the hardest item to locate, worst case is I have to weld up a boss and machine.

If anybody has an original timing cover that holds the gearbox drive I would be very interested in purchasing or I have Norton parts for swapping if that's what you prefer.

Cheers Andy

What parts do you have for swopping?????

I think that the item on eBay @ £180-ish is the same as the one in the NOCshop @ £92.50. Similar to the original but not the same. Original Smiths 1:1 drives in good nick are like hen's teeth. Please, please somebody contradict me!

Also beware of getting the correct rotation, but I don't know which is correct. Buying from the club must be safe though.

I think they are being made by Speedograph Richfield - checkout their website

Andy,

I have two of the timing covers you are looking for. I am not interested in selling but would consider a swop if it was something I need.

I think you should be able to leave me a private message, so PM me with what you have.

Tony