This thread has been very quiet for a while... But I have been doing a huge amount of research, and have become somewhat CR obsessed!
Picking back up on the tank strap:
I have managed to source the correct rubber part to fit in between the steel bands, and have ordered some stainless steel rod to allow me to make my own replica tank strap.
Frame modificationsThis research is what I have been whittling away at ready for a Christmas frame altering session. This is the list so far:
- De-lug all road mounts.
- Fit machined and fabricated rear sets. I have produced a CAD model and drawings for the rear sets, which like the image below have a 12mm thick boss, which houses the footpeg and mounts for the brake pedal and exhaust. This part is welded in-between two folded sections to create a triangular bracket. These 'inserts' will either be waterjet cut or I will machine them. Luckily I have managed to get hold of a sketch with measurements from a kit bike to be able to accurately place the rearsets onto the frame.
On these rearsets I am going to mount a set of replica aluminium pegs with the all important cured rubber over moulded grip. These are replicas cast from the original parts, with a bronze bushing pressed into them. They will be held into place by a custom 'replica bolt' which I will turn up.
Replica footpeg clamping bolt CAD:
Onto these rear sets mount the rear exhaust hangers, the brake pedal again a cast item with a rubber over moulded grip. The footpeg mounts through a bush, and depending on the gear set-up is on the left or the right side. The rear brake is cable operated with a large and very complex cable, a cable stop will be placed onto both rearsets to allow for both left and right gear changes.
Replica Brake cable 'stop':
The left gearchange is simple, as it uses a conventional style pedal in reverse from the output shaft. However the 'special' gear change option was to have a changeover shaft for British racers, this comprises of a linkage assembly, bearing holders and another frame modification to house an olive bush. This is a modification that I would like to fit at a later date so this is another frame modification.
The fuel tank mountings are fairly simple, it mounts at the front with the original HONDA rubber mounts, and at the rear it is held in with the replica strap. The frame is modified with an added 'Arc' which braces the frame for the tank strap, and provides a mounting point for the front of the seat. Again I have managed to acquire a drawing for this part
The rear of the frame is cut off, and the seat support loop is lowered. I may also add a rear frame loop as well if I feel that the seat requires supporting.
Other frame mods include an additional steering damper (a simple flanged plate that fits ontop of the lower yoke around the left fork tube and is secured by sharing the pinch fork pinch bolt) the other end of the damper fits to the frame rail underneath the tank with a clamp, a detail that is still to be resolved.
FairingThe fairing is mounted in three places, at the headstock with the conventional 'pinched tube' onto a bracket, either side of the engine mounts to support the rear of the fairing, and on the frame rails by the headers to support the lower front part of the fairing (I believe this was a modification rather than being original however I don't want the fairing flapping.
I have managed to get a set of accurate rear fairing brackets that bolt onto the rear engine mounting plates, which again are really nicely made parts and are supposedly very accurate, similar to the ones below but detailed in a different way:
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The front 'main' fairing bracket that I have purchased is a 'tribute' part that is relatively close to the original, however I may make my own/try to source a more original one further down the line.
The fairing has been a real head-scratcher, as many replica fairings just do not look right in my eyes, this could be down to decal placement, or even the fitting of the fairing itself, I am really unsure. This led to contacting many people that have built replicas including some self-confessed classic racing Honda 'Anoraks' in order to trace down a good replica fairing.
I eventually traced down a fairing from a supplier in London and the story says that he purchased the moulds from a guy who made the mould from a 'Genuine CR Daytona fairing' so it should be pretty spot on. I am happy with the shape, and it seems to be the best that I can find. Listening to various recommendations from different people who have built accurate replicas seems to be the way forward with this build, there is a wealth of knowledge of these bikes that simply did not exist during the TA125 build and it is a real help.
After looking at many available seats on the market I was not really happy with any of them, the Meadspeed unit seems to be reasonable quality but the shape is wrong. The only seat that I did like was the Airtech seat but with shipping and a swab base it becomes a ludicrous amount! Luckily I have managed to track down a guy who has a seat mould, supposedly taken again from an original Honda racing part. The aim is to borrow the mould and create a seat for my bike potentially from Carbon
which would be great!
WheelsThe front wheel aside from having the double disk conversion is pretty straight forward. The hub will be turned down to remove the central cast ribs to resemble the original magnesium CR part.
The rear hub is a point of discussion of these CR bikes. Originally the CR had a twin leading shoe, cable operated brake cast in magnesium, a real work of art and a focal point of the bike. Sadly these hubs were only ever made in very small batches, and any replicas are also made in small runs and are massively expensive from £3500 upwards
For me this is a step too far financially, and I will be finding an alternative way of achieving a similar look. There is a company in America who are making a replica back plate to fit the standard K series CB750 hub, however this is still in development and again is not cheap. I think I will try to work out a way of mounting a cable boss to the existing brakeplate unless a replica part becomes financially viable.
ExhaustsI think that a good chunk of the CR appeal comes from the exhausts, not only the sound but the look of the original 'Swept' pipes. After researching this topic it appears that there is only one supplier who makes these exhausts properly, hydroformed with a welded seam, complete megas with a reverse cone and smoothly bent header pipes they really are a work of art! Made by Simon Tappin, these will be going on my bike!
Clip on handlebars The original CR clip on handlebars were hinged around the yoke and clamped into place by a pinch bolt, this was for ease of disassembly without the need to remove the top yoke. As far as I know nobody makes a replica clip on, and as I want clip ons as close to the original I am going to have to make them myself! "Why" You may say when standard clip ons that will do the same job are less than £100? Well it's the details that will hopefully make this bike, and it is a good challenge for me to get stuck into!
The original CR clip ons were a two-piece clamp, cast in Titanium and then had a tube attached to the casting to form the handlebar. I doubt I wil be using titanium, however I will aim to make the parts as light as possible either in a racing steel or aluminium. In order for the master cylinder to clear the clamp on the right unit the clip on needs to be angled and kinked to prevent a clash. I have drawn the parts up using a CAD program to be able to create the design, look at tolerances and of course check the clearance angles with the master cylinder.
RHS CLIP:
LHS CLIP:
All in all the preparation seems to be going well for the frame modifications at Christmas
Full steam ahead!
I have referred to people without naming them in this post quite a lot, and this is because most of them are not part of forums or even online at all. I have been overwhelmed with the help and enthusiasm from suppliers and people who are in the Honda scene, thanks to you guys if you are reading this!
Cheers,
CR21