Well Known and Active Website User
Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Hon. Editor and Webmaster by calling 07977 001 025 or please CLICK HERE.
You are unrecognised, and therefore, only have VERY restricted access to the many features of this website.
If you have previously registered to use this forum, you should log in now. CLICK HERE.If you have never registered to use this website before, please CLICK HERE.
I think I have woke up on another Planet !,I put new + 0.020" Omega 8:1 pistons in my Rapide last year. They weighed 450.38 grammes each complete with pin, circlips and rings. I had it bored with 2½ thou clearance. It ran fine after a short running-in period and I've two or three thousand miles since including a bit of "spirited" riding.
I put together an Excel spreadsheet to calculate what the balance figures would be. I can't upload it to the forum as the extension is not allowed. The link below is to a Google Drive account. If it works it may display the sheet and you may be able to download it and open it in MS Excel. If you have a Gmail account you should be able to open it online using Open With Google Sheets. If anyone has been able to access this could they confirm it? If you can use Excel please tell me if my formulas are wrong. I have left some sample figure in place to play with.
U r talking abt radius, or 1"dia, or r u talking abt Firefly tuning?Ok so i have checked out this new crank assembly i have here, very similar to David's one with some minor differences but my pistons are much heavier on account of the pistons being 92 mm. Both little ends of rods equal 367 grams, pistons are 446 grams each. David found he needed 113 grams opposite the big end to bring the crank to a neutral balance and I needed 117 grams, so very similar. Only difference now is I'm thinking this crank should be balanced to 60% as it is going into a new featherbed frame. I will need a hung weight of around 388 grams to achieve this.......So I'm going to need plenty of machining at the big end of the flywheels to make this happen. I inquired about the cost of a length of Mallory metal, about $250 AUD for a piece 1/2" diameter and 200 mm long.......... Where's that damned hacksaw Bill..............