Author Topic: The 1970 Daytona CR750s.  (Read 251555 times)

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Offline Tintop

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Re: The 1970 Daytona CR750s.
« Reply #875 on: February 18, 2020, 06:56:07 am »
You can also try Hagon - http://www.hagonshocksusa.com/   I used them on my sidecar and was pleased with quality.
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Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
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77 CB550 Cafe build
550/750 Filter Thread
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Offline CR750

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Re: The 1970 Daytona CR750s.
« Reply #876 on: February 28, 2020, 12:19:55 am »
Try YSS nap.
W r e n c h  ·  R i d e  ·  R e p e a t

Offline napoleonb

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Re: The 1970 Daytona CR750s.
« Reply #877 on: April 19, 2020, 07:01:38 am »
I went for these IKON's with so much choice in spring ratings, (spring and shock) heights etc. i chose this combination of parts.
They are the best trade off between form and function for my liking and have Progressive springs, adjustable dampening and 3 positions pre-load.
They also came with extra rubber bushings to fit my frame, still have to modify the rear fork to accept the eye on the bottom.
« Last Edit: April 19, 2020, 07:03:11 am by napoleonb »

Offline Phlex100

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Re: The 1970 Daytona CR750s.
« Reply #878 on: May 16, 2020, 02:29:16 am »
Keihin Tickler Vintage Racer carbs CR 31mm smoothbore Vintage race carbs

Possibly off an ULTRA rare Honda CR750 which is a over 200,000 motorbike in mint condition....these are the same carbs. May be jetted differently but that is an easy fix.

https://www.ebay.com.au/itm/293581749087


Offline Paul Barter

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Re: The 1970 Daytona CR750s.
« Reply #879 on: September 19, 2021, 04:25:58 pm »
I'm looking for a rear RHS brake cable for a Cr750, I messaged Daniel Mercier and got no reply.
If I can't find one I'm going to have to make one, Ive checked out Venhill and other cable companies pages but can't find
the parts required, so short of having to machine all the metal parts can anyone make a suggestion or know someone who might be able point me in the right direction?

Cheers
Paul

Offline Tintop

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Re: The 1970 Daytona CR750s.
« Reply #880 on: September 19, 2021, 04:49:39 pm »
Have you checked Motion Pro's custom cable page? 
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
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Offline Paul Barter

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Re: The 1970 Daytona CR750s.
« Reply #881 on: September 21, 2021, 12:31:41 am »
Yes been there too! cheers

Offline pekingduck

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Re: The 1970 Daytona CR750s.
« Reply #882 on: October 06, 2021, 10:17:05 am »
I thought I'd share a couple stories on CR750 parts from my days in the mid-late '70s as a parts man at some Honda dealers in L.A.  I happened upon a black exhaust pipe/muffler hanging on the rafters, way in the back one day.  I was curious, so I climbed up, and brought it down.  It was incredibly light - couldn't have been more than a pound or two - less than some burritos I've had. 

The "muffler" section was empty, and had the CB750's contour. My recollection was that it was made in 2 halves, with a welded seam, but can't be positive.  I looked at the tag, and it was something like 18400-300-970, and I knew from the 970 number it was a CR part.  I looked up the price - a couple hundred I believe. It was a lot at the time, and I had no use for it, so I hung it back up.

A while later, I came across another 970 part, a forged aluminum rear brake pedal.  I asked the parts manager about these 2 parts, and he said I could have the brake pedal. They'll never sell it, but the boss would notice if the pipe was missing.  I ended up giving it to a friend who was amassing a collection of other rare CR singles and twins, and he used it on one of his CR71 restorations. 

At another dealer, Bill Robertson & Sons, I came across a box of transmission parts in a dusty box on the top of a dusty shelf during a spring cleaning assignment. No one knew what it was or wanted it (no, not a CR750 trans), so I took it home to learn about transmissions.  It had 5 gears on each shaft, but they were poorly fitted, tight in some areas, so needed some sanding/filing to get things spinning. 

Turned out later it was a race kit 5-speed for the 250/305 Superhawk/Scrambler.  One of the sons, Bill Jr., along with Dave Ekins, had been the first to ride solo from Tijuana to La Paz, Mexico, on their very stock 250 Scramblers.

The last story is back to CR750 parts.  Before the internet, before Craigslist, there was a local free-ad paper called the Recycler.  One day, I found a listing for a CB750 gas tank, new in a factory box - aluminum. I called up, and he gave me the part number on the box, 17500-300-000, early-early number, no color code.  Not a  970 number. 

So I went to take a look at it, and yes, it was an exact replica of a CB750 tank, painted in red with the gold striping.  I'm pretty sure it had a flip up aluminum cap, with a little tab off to the side for safety wire, but not positive.  The owner had stumbled across it in a warehouse or something, but he wanted $1000, a huge sum back in the '80s. I walked away, and later tried to call him and make an offer, but got no response.

Bob Hansen was a So Cal local, and I met up with him at one of the motorcycle swap meets.  I asked him about the tank, and he said, yes, they had 10 tanks made, just in case the AMA wouldn't let them race with the long tanks. So there were 10 unused tanks floating around somewhere.....

Thanks for reading/listening.
« Last Edit: October 07, 2021, 05:40:39 am by pekingduck »

Offline H2Eric

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Re: The 1970 Daytona CR750s.
« Reply #883 on: October 20, 2021, 02:47:12 am »
I'm looking for a rear RHS brake cable for a Cr750, I messaged Daniel Mercier and got no reply.
If I can't find one I'm going to have to make one, Ive checked out Venhill and other cable companies pages but can't find
the parts required, so short of having to machine all the metal parts can anyone make a suggestion or know someone who might be able point me in the right direction?

Cheers
Paul

Daniel has suffered with the Covid outbreak and I understand that his business has been sold. However, there is a new website www.motojlmreplica.com  Not sure if Daniel is back in business or if this is the new owners. Might be worth making contact through the new web site.
Eric
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Kawasaki 750H2B
Suzuki GS750
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Offline slikwilli420

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Re: The 1970 Daytona CR750s.
« Reply #884 on: October 23, 2021, 02:18:02 am »
I'm beginning bike prep for AHRMA's return to the high banks of Daytona in January and was wondering about gearing? I'm currently running 17/48 and adjust a bit from there but that's my general baseline. That all goes out the window at Daytona of course. What did the original Daytona bikes use for gearing? My first guess is that I'll be in the 17/44 range.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline napoleonb

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Re: The 1970 Daytona CR750s.
« Reply #885 on: October 23, 2021, 02:19:42 am »
This is out of a partslist, so not for the Daytona bikes but it gives you a good understanding of the kit racers.
« Last Edit: October 23, 2021, 02:25:26 am by napoleonb »

Offline napoleonb

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Re: The 1970 Daytona CR750s.
« Reply #886 on: October 23, 2021, 02:23:00 am »
This one from an RSC partslist isnt very readable, but 17 teeth front and 42/43/44 back.

Offline H2Eric

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Re: The 1970 Daytona CR750s.
« Reply #887 on: October 24, 2021, 04:31:13 am »
Cycle magazine (Oct 1970) quotes the gear ratios for CR parts list as follows;
5th 5.09
4th 5.95
3rd 6.70
2nd 7.86
1st 9.54
Figures are for a standard 2.812 final drive reduction. Gearbox sprockets of 17T and 18T and rear wheel sprockets of 44T, 46T and 48T were offered for customers to play with.

I have a Nova A set transmission in my CR750 with ratios of;
1st   18 – 37   2.055:1   
2nd   22 – 33   1.500:1
3rd   25 – 31   1.240:1
4th   31 – 33   1.065:1
5th   32 – 31   0.969:1
Overall reduction 1st – 5th   52.8%
I tried a 17T / 45T combination to start with, but found it too high geared, probably fine for the Daytona banking though and could be a good starting point.

There is also a B set (available from CycleX) which has ratios of;
1st   17 – 38   2.235:1   
2nd   22 – 34   1.545:1
3rd   25 – 31   1.240:1
4th   31 – 33   1.065:1
5th   33 – 31   0.939:1
Overall reduction 1st – 5th   58.0%

Good luck and keep us posted
Eric
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Honda CB750K3
Kawasaki 750H2B
Suzuki GS750
Honda CB175
Honda CB350F
Yamaha R1

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Offline johno

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Re: The 1970 Daytona CR750s.
« Reply #888 on: December 06, 2021, 03:39:48 pm »
Hi Matt,
 for what its worth I read somewhere the Hanson outfoxed the Honda team by running standard gears or at least the first gear as compared to the extremely tall CR ratio first gear and that it resulted in him pulling a hole shot on everyone else. ????? when you watch the start on old footage it kinda makes sense. I don't know how that impacted on other parts of the track such as the tightest corner ? and I haven't been there to watch bikes so don't know. The only other comment on that subject was M3 racing commented that at the tightest corner their gun rider used the gears aggressively to back the bike in and several times they popped the primary chains out the top of the cases.
So Matt I can't wait to hear your feedback about the great track and Im truly excited for you , good luck
cheers Johno
GRASSHOPPER SOHC HONDAS ARE THE MEANING OF LIFE.

Offline Old Scrambler

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Re: The 1970 Daytona CR750s.
« Reply #889 on: December 14, 2021, 09:50:34 am »
Yes to the stock Honda tranny on Mann's bike...........coming out of the banking is a downhill boost of speed..........so set your rev-limiter at the highest that you're comfortable with...........and maybe use the F2 5th gear for a little added power.   
Dennis in Wisconsin
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Offline slikwilli420

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Re: The 1970 Daytona CR750s.
« Reply #890 on: December 14, 2021, 11:28:47 am »
Yes to the stock Honda tranny on Mann's bike...........coming out of the banking is a downhill boost of speed..........so set your rev-limiter at the highest that you're comfortable with...........and maybe use the F2 5th gear for a little added power.

Both bikes have what Kenny calls the French transmission which is the F gear swap onto a K trans. Im running 17/42 on the superbike and 17/44 on the Sportsman bike to start the weekend. I have tooth counts all the way up to 48 for both. Based on what I am hearing from more experienced guys that have raced Daytona, I should be 2 or so teeth lower than what I normally run, which is 48 rear for the S750 and 46 rear for the Superbike, but Im starting very conservatively. The other consideration is the draft, which apparently can quickly add 1000rpm to your top speed, so if I can gear the bike to run around 8500 on my own and I pull a draft up to 9500 I will still be in the safe zone for revs.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline westfieldandy

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Re: The 1970 Daytona CR750s.
« Reply #891 on: January 06, 2022, 08:52:44 am »
Hi

The b set ratios offered by Nova, were developed from the racing we did here in uk, They supported us during our 3 years racing and amended a lot of stuff including the ratios to suit our 750cc short circuit engine,  The original Nova close ratios were far too close, and caught Rob (the rider) out as we had to gear the bike different to maintain top speed giving a terrible long first gear, which left him behind at the start of races.

I am not sure all the changes with dog clearance and the mainshaft, have been implemented in the box they now sell as they have had a big turnover of staff, But the box started out terrible and ended up fantastic, for us anyway, 

Offline napoleonb

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Re: The 1970 Daytona CR750s.
« Reply #892 on: February 20, 2023, 06:32:14 am »
Did the 4 Daytona race bikes have aluminum rear brake stopper arms?
Most RC factory bikes and even the later Sumiya factory bikes have an aluminum arm which look to be identical in layout (not length offcourse) between them.

For the life of me I can't find good quality pictures of the Daytona bikes proving me wrong or right.

Offline bigutah

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Re: The 1970 Daytona CR750s.
« Reply #893 on: September 04, 2023, 10:56:26 am »

My CR750


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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: The 1970 Daytona CR750s.
« Reply #894 on: September 04, 2023, 07:13:21 pm »
VERY nice!
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline MRieck

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Re: The 1970 Daytona CR750s.
« Reply #895 on: September 05, 2023, 04:33:45 pm »
I agree.
Owner of the "Million Dollar CB"

Offline bigutah

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Re: The 1970 Daytona CR750s.
« Reply #896 on: October 10, 2023, 03:21:27 am »

Girlfriend says I won’t leave the garage much these days….wonder why?


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Offline bigutah

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Re: The 1970 Daytona CR750s.
« Reply #897 on: October 10, 2023, 03:57:03 am »

Installed a set of CR31 Ticklers I scored on FB marketplace. Some of the #$%* you find on there is unreal. JMR block is next.


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