Posts
581
Joined
2/10/2014
Location
GB
Edited Date/Time
4/8/2014 1:15am
I though some of guys might like to see this.
Most people think Honda's first attempt at an MX bike was the 1972 RC125M.
It wasnt. It was actually back in 1958. The RC70F. They never made it to production, they made, maybe 6? Maybe 10 or 12 maximum!! They made enough to show it off at the Tokyo motor show along with the sales "blurb". I've got photos at work that show at least 3 different versions, with different pipe layouts, plus one with lights.
It used a 250 twin cylinder engine,directly taken from the C71 road bike. Still with its 4sp rotary gearbox!!
One did make it to Canada, The colour photo is of this bike. It's the only one in any of the photos with the little chrome rear fender support. The red badges are also unique. It's also the only colour photo found so far!
At least one made it to the US. Here's Preston Petty racing one.
One was also sent over to Sweden for Bill Nilson to test. He proclaimed it to be absolute sh*t!! Honda went home and didn't look at another mx bike till the 70's!!
Non were believed to be left in existance, until the one sent to Sweden turned up in Spain!!
This is it on the day it turned up our shop for restoration, Direct from Spain, via the Netherlands.
The seat had been recovered, the footrest and brake pedal were "home made", the original coil had been replaced with a Bosch item from a car, it had lost its front number plate and gained a CB72 rear light assy...
But once on the bench, it became very obvious that other than the bits mentioned, it was completely original, it even still had its original, (completely worn) Nitto tyres and it's original chain and sprockets!!
Looking at it, its obvious why it was declared crap by Bill Nilson, It's got around 15BHP and weighs the same as Triumph twin! The Rotary gearbox must have been loads of fun too!!
Most people think Honda's first attempt at an MX bike was the 1972 RC125M.
It wasnt. It was actually back in 1958. The RC70F. They never made it to production, they made, maybe 6? Maybe 10 or 12 maximum!! They made enough to show it off at the Tokyo motor show along with the sales "blurb". I've got photos at work that show at least 3 different versions, with different pipe layouts, plus one with lights.
It used a 250 twin cylinder engine,directly taken from the C71 road bike. Still with its 4sp rotary gearbox!!
One did make it to Canada, The colour photo is of this bike. It's the only one in any of the photos with the little chrome rear fender support. The red badges are also unique. It's also the only colour photo found so far!
At least one made it to the US. Here's Preston Petty racing one.
One was also sent over to Sweden for Bill Nilson to test. He proclaimed it to be absolute sh*t!! Honda went home and didn't look at another mx bike till the 70's!!
Non were believed to be left in existance, until the one sent to Sweden turned up in Spain!!
This is it on the day it turned up our shop for restoration, Direct from Spain, via the Netherlands.
The seat had been recovered, the footrest and brake pedal were "home made", the original coil had been replaced with a Bosch item from a car, it had lost its front number plate and gained a CB72 rear light assy...
But once on the bench, it became very obvious that other than the bits mentioned, it was completely original, it even still had its original, (completely worn) Nitto tyres and it's original chain and sprockets!!
Looking at it, its obvious why it was declared crap by Bill Nilson, It's got around 15BHP and weighs the same as Triumph twin! The Rotary gearbox must have been loads of fun too!!
Thats putty! The stuff they put glass into window frames with!!
Once inside the motor it was obvious that it hadn't done a lot of work, backed up by the bike still having its original tyres. That Tab washer has only ever been tabbed over once!
The clutch is on the crank on early Honda's. Chain driven primary drive.
This bike is the great granddaddy of all our CR's.
Please keep us updated.
The Shop
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$189.95 - $239.95
Stevie
I do love an old dirtbike.
Thanks for sharing, keep the updates flowing please.
I don't know if it is true or not, but Honda were said to have had prototype 4 stroke MX'ers before they went with the 2 stroke Elsinores, that unfortunately never went into production. Basically same frames and suspension but with 4 stroke engines. I know Rex Staten rode a factory 4 stroke from Honda in about 75 but I mean before that.
More competitive XR's along the lines of the XR75, if you will. Not like the trail versions that came out years later.
Great find and history there, StevieD; thanks for sharing!
But a once over in the wash tank revealed that it was actually, under neither the gunge, pretty good!
The original reims were pretty shot.
There was quite a lot of frame damage.
I managed to strip the shocks down, (all 4 of them!) I was quite impressed at how easy it was to get them apart and the condition of them. Once they were all cleaned there wasn't any major damage or corrosion.
Phil Cox at Plastic Renovations said he could do something with it. The man was true to his word!! He managed to restore it!!! Sadly I cant find the photos of his incredible work.
We had a computor crash and lost a big chunk of the photo record for this build. So I'm going to have to jump to last photos of it.
Basically, this is the last day I saw it. The owner decided he didn't want me to complete the build. There was very little left to do. Fabricate footrest, finish the fabrication of the brake pedal (it was 95% done) repair and test fit the exhausts, fabricate a front plate, then fit the cables, controls etc. (and find a correct type ignition coil so we could actually start her) The chrome platers had messed up the (unobtainable!!) tank panels but we were in the process of having new ones made.
All the cables, we made (using the originals as patterns), along with all the cable fittings. We had to make every single nut, bolt spacer, etc for it. Re-chroming things like that never works so we made it all, EXACTLY as per the original items.
We had new rims made to match the original shape and profile, we even got the DID logo stamped in them. Finding the correct style and size tyres was a massive ball ache!!
We had to have new handlebars made. Talon made us new sprockets EXACTLY as per the originals.
Our Paint shop managed to find a bit of un-faded paint under the tank to colour match. They did a beautiful job. They also matched the semi/satin-chrome finish on the engine side covers.
All the engine cases, head and barrel etc were fully vapour blasted (after the broken fins were repaired) so the cases were as fresh and as clean on the inside as the out. All new bearings and seals through out. I was looking forward to starting her up and doing a lap or 2 of the yard! Sadly, it never happened. But I feel pretty good about being able to work on this piece of Honda History.
Not many people will ever lay eyes on that bike, let alone be able to turn a wrench on it. Well done.
Pit Row
I remember my RC70F machine quite well but never thought I'd again see one looking like new.
The shocks were there primarily to hold the springs.. not much dampening.
However, It had a dry sump engine with good power (for its day).
Cool !!
Pres, how did it it ride? I would be fascinated to hear your thoughts! Was the rotary gearbox a bigger pain in the ass as I imagine it be? I couldn't imagine riding it off a curb let alone ripping the through the desert ot it!
Working on it was really cool for me, (I'm a complete Honda nut so working on there History was a great feeling) but I cant imagine any more unsuitable for off road racing!
Stevie
The suspension/shocks were about like a road bike. That ditch at Corriganville (aka Hopetown) is an example:
1st time I tried jumping into it the impact ejected me and the bike out separately. Next lap I just rolled thru it at the bottom and did a wheelie coming out -that was what the early picture showed. Rotary gearbox: During racing I always concentrated on exactly what gear I was in so the rotary gearbox was not much of a problem. However, road riding a rotary gearbox could a problem for me if I tried shifting to a higher gear only to 'miss the shift' by into neutral.. but, then the next punch was 'low gear'... that was a real shocker!
Actually, if one concentrated, it was kind of nice if, for example, you see a signal ahead that just turned red then just punch the gear lever once and you were in neutral. Then after coming to a stop just punch it down once and you were back in low gear ready to leave the signal! (sure beats having to backshift 5-6 times on a regular gearbox)
It seemed to be one of those ideas that looked 'good on paper', but in actual use it could become dangerous if it was misused!
Great thread.
Wow. What other bikes had that type of gearbox?
re the gear box. We're pretty sure it was one of the issues Bill Nilson had with the bike. The motor in it had never been apart, (or so we thought) There were no signs of it being worked on, everything was as it would be on a bike that had only done enough mileage to wear out a set of tyres. As we cleaned the gunge and muck off the engine internals there, in the bottom of the 'box was a gear tooth. The gear cluster was complete and in virtually perfect condition. Just some normal wear marks on the engagement dogs but no missing teeth on any of the gears. On closer inspection, 2 of the gears were "different". They were the correct, genuine Honda gears, but they seemed lighter in colour and just looked different. What we think happpened is that Bill Nilson fell foul of the rotary 'box and jammed it from top into first and broke it. A Honda technician then pulled the engine and replaced the gears in the fastest possible way.... by turning it upside down and pulling the bottom half of the crank case off, leaving everything else in the cases, hence why it looked untouched. He obviously missed the broken tooth lying in the bottom. This method wouldn't have been widely known at the time as Hondas were still very rare ( pretty much unknown in Europe), so it could only have been done by a Honda employee. The new gears could have been from a different batch explaining the difference in appearence.
Sorry, can you guys tell that I'm properly geeked out about this stuff? I absolutley LOVE the history of motorcycles, I like to think of them as old men (and ladies) with stories to tell, that should be heard and respected.
I'm going to try and find the other pictures, they must be on the computor somewhere!!
Stevie
I love the stories that can be pieced together from bike archaeology. Like a cool version of time team.
The bike looks so dated because it's a 50's bike, but with the obvious Japanese quality that has made them world beaters.
It's not visually a million miles from a newer Greeves chassis-wise with that leading long front end, and those bars, yet the motor design is a decade ahead of anything coming out of Britain in the 50's.
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