Author Topic: A CB750 race bike build... (Read 13763 times)

johno · « **Reply #50 on:** July 02, 2021, 06:03:48 PM »

Keep working Santiago, your my winter entertainment

You get 10 out of 10 for that side cover, well done.
oh if you come across any type of R/H hanger grab it and pm me

cheers johno

Santiago · « **Reply #51 on:** July 02, 2021, 06:27:04 PM »

The plan is to blast the side cover with some chunky crushed glass blasting media to give it a 'cast' look. And the RH hanger was a complete fluke, Pete Sales (who sold it) runs a parts business and usually charges moonbeams for his parts, I'm pretty sure he didn't know what it was, I didn't twig until it turned up in the post, I just thought I was buying a spare LH side. Its certainly made sorting the brakes easier.

johno · « **Reply #52 on:** July 02, 2021, 06:48:37 PM »

When I looked through your engine plan you were undecided on a couple of things, namely primary chain tensioners and cam chain tensioners, have you committed to anything yet?
I run the old cycle X "white" tensioners for both but don't have enough run time on them to check their wear rate but am buying their new cam chain tensioner which looks the best Ive seen so I'm waiting for Slick Willie to thrash the guts out of his 750 heavyweight in the US to see how good it is

slikwilli420 · « **Reply #53 on:** July 02, 2021, 06:56:24 PM »

Quote from: johno on July 02, 2021, 06:48:37 PM

When I looked through your engine plan you were undecided on a couple of things, namely primary chain tensioners and cam chain tensioners, have you committed to anything yet?
I run the old cycle X "white" tensioners for both but don't have enough run time on them to check their wear rate but am buying their new cam chain tensioner which looks the best Ive seen so I'm waiting for Slick Willie to thrash the guts out of his 750 heavyweight in the US to see how good it is

Fingers crossed I'll get to thrash it in a double header weekend coming up at the end of the month.

Santiago · « **Reply #54 on:** July 02, 2021, 08:55:14 PM »

Quote from: johno on July 02, 2021, 06:48:37 PM

When I looked through your engine plan you were undecided on a couple of things, namely primary chain tensioners and cam chain tensioners, have you committed to anything yet?
I run the old cycle X "white" tensioners for both but don't have enough run time on them to check their wear rate but am buying their new cam chain tensioner which looks the best Ive seen so I'm waiting for Slick Willie to thrash the guts out of his 750 heavyweight in the US to see how good it is

Hi Johno, yep, the motor is all done, I ended up buying the Cycle X 'old' style cam chain tensioner and also their primary tensioner where the Honda wheel is replaced by a (teflon I guess) manufactured wheel (which appears to no longer be available). No doubt the new Cycle X cam tensioner is an improvement, however my bike will be a seldom used classic racer not doing big miles or ridden like a MotoGP bike by a lightweight young jockey who knows no fear, , so I'm pretty happy that what I have will do the business. Saying that, I am also building a Bimota HB1 replica (kind of in tandem with this CR homage bike) and I plan to buy the new Cycle X tensioners for that engine. But that is probably for next year. There is a local craftsman who is going to build me a HB1 frame based on measurements I took from the real HB1 in Motorcycle Mecca, a museum in Invercargill. He has ordered the steel tube (cold rolled seamless mild steel), and I've given him wheels, forks, shocks, tank and seat (from Airtech) and empty engine cases for him to set up in his jig.

Santiago · « **Reply #55 on:** July 02, 2021, 09:00:52 PM »

A few more pics of the ignition cover, its not perfect but is pretty close, anyway it will be behind the fairing. Still got bolts to make and need to blast the cover, not sure if I will paint it the dark grey Cerakote like on the engine cases. The Electrex world ignition plate will get painted dark grey to match the engine.

Santiago · « **Reply #56 on:** July 03, 2021, 02:09:43 AM »

Got the mudguard bracket scribed out and cut out, now to roll it and tweak it...I saw a picture on the FB CR750 group from a guy on Greece who had some real parts, so I'm using it for reference. 1.5mm mild steel, probably too thin but my cheapo bench mounted Chinese roller set won't handle steel any thicker than that. See what tomorow brings...

Santiago · « **Reply #57 on:** July 04, 2021, 01:40:30 AM »

Kind of almost finished. Probably a bit high and too much gap under the guard, not sure if I'm going to make a shorter hoop or not. Probably just run with the first attempt and the rivet counters can be damned 🤣. Once I weld on the stays I'm committed....

Santiago · « **Reply #58 on:** July 06, 2021, 02:48:03 AM »

Just a wee job done today, modified a Yamaha TZ tank band to look a bit like the Honda one.

Santiago · « **Reply #59 on:** July 07, 2021, 01:32:27 AM »

Strap in position and the tab bonded on. God enough for a 'homage' not a replica 🤣

Santiago · « **Reply #60 on:** July 07, 2021, 01:45:24 AM »

Also working on the brake cable, I acquired a 'replica' cable with the replica foot pegs, hangers and levers I bought from the guy whose project it originally was, no way on earth was the cable ever going to fit the wheel / lever combo. I desoldered the nipple on the brake end, made a new spacer adjuster that fitted the lug on the brake plate out of stainless. Also made an adapter sleeve out of stainless for the footrest end so that it would locate properly in the lug on the footpeg bracket. Tomorrow I'll make a new brass nipple and solder it on. I also need to make a custom bolt to fit through the brake lever bush and lug on the footpeg bracket. I'll need to ream the bronze bush that came with the lever to the same size as the hole in the bracket, which is just under 9mm. Whoever made them intended to use an 8mm stainless bolt (which came with the set up), but the hole in the bush is about 8.4mm, the hole in the bracket is 8.95mm, and the shank on the 8mm bolt is under at around 7.95mm. Plus it has to locate the exhaust hangers. Its all as loose as hell. So I'll make all the holes the same size and turn up a bolt from some 13mm stainless bar to have a 9mm shank but 8 x 1.25mm metric threads to take a nut, plain washer and a spring washer (trying to avoid nylocs to be more in keeping with what Honda probably used).

Santiago · « **Reply #61 on:** July 10, 2021, 01:13:58 AM »

The dry build on the back end is basically done, all the stainless bolts are done, exhaust brackets welded on, ceramic coated, spacers made, cable done, the brake lever works and the adjusters are all done. Next is the seat hoop, cutting the frame back, and mounting the oil tank. Next year. I'm away for work now.

johno · « **Reply #62 on:** July 10, 2021, 07:07:30 PM »

Awe shucks Santiago, I was just getting into the swing of things.

Just in case the plane crashes write me into your will and I'll finish the bike for you.

lol
Well done so far, your doing a great job on the fiddly bits and their always the challenge. The only problem with being away for a time is often your ideas mature and change so when you get back to the bike its a case of try something else

Stay safe on your travels Santiago, you've got serious business to get back to. Your going allright for a Kiwi lol

Santiago · « **Reply #63 on:** July 10, 2021, 07:30:17 PM »

Hard to know if you guys are taking the piss or not 🤣🤣

Santiago · « **Reply #64 on:** July 17, 2021, 01:56:25 AM »

Project delayed a few days so I got some brake lines made, turned up some stainless fittings and flared some cunifer line. I think they look ok (and it's my bike so thats all that counts 🤣)

Santiago · « **Reply #65 on:** July 18, 2021, 01:36:16 AM »

This is the first attempt at a brake hose splitter and bracket. Which is Plan A. I don't like it, so I'll go to Plan B but that will mean welding aluminium 😖😱. If that doesn't work Plan C will be to buy a professionally made replica from MotoJLMreplica. 🤣. The wire on the bracket also needs tweaking a bit to make it shorter and a bit closer to the bracket.

Sam Green Racing · « **Reply #66 on:** July 18, 2021, 02:33:22 AM »

Santiago, I used a twin feed from the master cylinder to the calipers like the ones used on later Honda's with twin discs, is this not an option ?

Santiago · « **Reply #67 on:** July 18, 2021, 02:39:55 AM »

I'd need to get longer lines and I was trying to go for a replica type set up. I will weld up a better 3 way splitter. The first attempt was a lazy arse way to do it. 🙄

Sam Green Racing · « **Reply #68 on:** July 18, 2021, 03:32:28 AM »

This was my set up if you can see it.

napoleonb · « **Reply #69 on:** July 18, 2021, 05:06:57 AM »

Quote from: Santiago on July 18, 2021, 01:36:16 AM

This is the first attempt at a brake hose splitter and bracket. Which is Plan A. I don't like it, so I'll go to Plan B but that will mean welding aluminium 😖😱. If that doesn't work Plan C will be to buy a professionally made replica from MotoJLMreplica. 🤣. The wire on the bracket also needs tweaking a bit to make it shorter and a bit closer to the bracket.

I've got a few original 970 clamps I can spare one if you're interested. That would really compliment your excellent build.

Santiago · « **Reply #70 on:** July 18, 2021, 02:09:36 PM »

Hi Napoleon B, wow, thanks, yes please, let me know how to pay etc, cheers!

Santiago · « **Reply #71 on:** July 18, 2021, 07:25:30 PM »

This is the rough draft of plan B, need to weld it up, cut the ends to suit the bracket amd tap for the lines. Just like boats, the best sort of tig welder is the one your mate owns, so I’m off to use a mates tig tomorrow. 😁

Santiago · « **Reply #72 on:** July 19, 2021, 02:15:05 AM »

Started making the bits for the clip ons, from the pictures I've seen (attached from Carco's site) they hinge on one side, clamp on the other, and appear to be a casting with a bar welded in, I'm going to try to replicate them as closely as possible by welding and bending.Having special castings made is a step too far for me.Hence this is a 'homage' not a replica 🤣

johno · « **Reply #73 on:** July 20, 2021, 05:15:34 PM »

Santiago
probably a bit late now but on the HP parts for sale thread on page 58 about half way down TT has a gen splitter for sale,
Hopefully, cheers Johno

Santiago · « **Reply #74 on:** July 21, 2021, 01:04:56 AM »

Hi Johno, thanks for the heads up, that looks like he's made one by CNC, I saw he had some replica parts from Daniel M in France as well, including a splitter, which he's sold. Dans are a casting so a bit closer to the real thing, I've ended up machining up 2 pieces and welding them together, just need to final size the T piece to suit the bracket I have bought from Nap B (I'll have one real kit part on the bike 🤣). I might clean up the welds a bit, but then again, maybe not 😖. I'm aiming to have a reasonable look alike bike to the Daytona bikes, but not a true replica as such, chasing every last detail could drive a man insane. In my mind mine will be better than some but not as good as others.🤷🏼‍♂️

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Author Topic: A CB750 race bike build... (Read 13763 times)