SOHC.co.uk Forums > Project Board
CR750 replica build
CR21:
Quick 3D print of the breather box:
This will allow me to mock it up on the bike to check clearances with the seat etc
Cheers,
CR21
CR21:
In my view, there are a handful of important parts that really 'make' the CR replica true to the original bike:
- Fuel tank
- Exhaust system
- Fairing shape, style, fitment and screen
- And finally the rear hub:
The CR750 was produced as a works machine for Honda to demonstrate the advanced performance that the new model was about to bring to the market. The main campaign for doing so was at the Daytona in 1970, where Dick Mann ended up finishing first, other team members (and breakdowns) aside it was an impressive feat. A very iconic part of the Daytona winning bike, and the subsequent CR kit bikes was the twin leading shoe rear brake
This rear hub was cast in magnesium, but that did not make it light!
A company in Italy used to make a replica of the CR rear hubs, which looked very smart in the images I have seen online but were very expensive and are lo longer available. A CR 'guru' in the UK also made a batch around 10 years ago.
I was going to make a replica of the rear hub by scaling photographs and begging for measurements however this has never really excited me as it was replicating a replica and would only ever be a tribute rather than a detailed replica part.
Cut a long story short, after some serious looking I found an original part:
Another bit of this jigsaw started.
Also purchased the ignition for the bike so I can start to think about coil and CDI unit lugs:
Although this was expensive, it is nicely made and is rated pretty well.
Cheers,
CR21
CR21:
A little bit of progress today!
It took me a long time to re-set into CR mode after working on other projects for the last couple of years.
Got a few things done:
Started to re 'hang' the oil-tank:
Fiddly one to get right this and waiting for the correct style bottom brackets:
Fitted the right hand gear-change bushing, so that a right hand gear change assembly could be fitted if required:
Fitted up:
Welded in:
This bush accommodates the plain swivel bearing #5
Front hub
The original CR bikes had a magnesium front hub. This was a simple part with no ribbing
Ribs removed on the lathe
Going
Going
Gone!
As the offset is not quite central I will make up a 2mm spacer to sit behind the right side disc at some point.
Next frame jobs on the list:
- Front seat mountings
- Rear seat hoop and frame cross brace
- Steering damper mount
- Mirror image oil cooler mounts
Other jobs:
- Oil tank filler neck
- Skim the discs (or have them ground) down in thickness. As far as I am aware they were either 4.8 or 6mm thick
- Oil catch tank
Cheers!
CR21
Trigger:
Why did you take the cooling fins off the hub ? They are there is cool the hub :o
CR21:
--- Quote from: Trigger on October 21, 2019, 10:52:44 PM ---Why did you take the cooling fins off the hub ? They are there is cool the hub :o
--- End quote ---
Hi Trigger,
The CR's did not have this detail on the hub - this is why the ridges were removed.
Thanks,
CR21
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version