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To Restore OEM or to Mod during Restoration ?

Posted: Fri May 03, 2024 8:35 pm
by BritOnABike
So I am about to pull the trigger and buy my first 1979 CBX to restore and ride. Seller (original owner) and I have agreed on a $6k sales price and it comes with a minty fresh original 6 into 2 OEM exhaust system - if I decide to take off the KERKER pipes which she is currently wearing. I’ll be doing the restoration myself - except for possibly a carb rebuild which I might farm out to a CBX specialist / carb expert. My main questions revolve around wether or not to leave it stock or to do the usual recommended suspension and brake upgrades now as part of the restoration. SO How bad is the handling and braking of a stock 1979 CBX Supersport ? What can I expect? For a comparison I have a BMW K1600GTL a Honda ST1300P as well as a Suzuki GSF1250 Bandit. Hence I am no stranger to heavy powerful motorcycles……

This CBX will need new fork oil ... so the forks will be pulled anyway ...Master cylinder needs rebuild or replacement or upgrade swap. Brakes need to be completely redone anyway. Owner stated that the OEM rear shocks were never very good and the bike 'wandered' through corners at speed !!!

I figure my options, if I leave it stock, with be to add new RaceTech front fork internals , and a new pair of custom Olins rear springs. Galfer Steel braided lines front and rear and upgrade my brake pads. So the bike basically stays the same just with more modern suspension internals.

This is the cheapest and quickest upgrade but will I be happy with the result ? compared to :

The next option is to replace the stock skinny front forks and replace with thicker 39mm ones (and internals) and also do a rear swing arm swap from a later CBX or CB1100F as well as upgrade to twin pot brake calipers and then add the RaceTech suspension components and SS braided lines plus better pads etc.

More money , more time but will the result be considerably better than the first option ?

I want the brakes and suspension to be as good as possible but I have nothing to compare them too and I have no desire to just throw money at a restoration project in the hopes that I’ll be happy with the result ….. so for those of you ‘in the know’ what say you ?

Leave it stock, with new internals or do the upgrade modifications to the suspension and brakes?

Does anyone know how these upgrade modifications will affect future resale value ? With 26k miles on the bike it’s never going to be a museum piece especially as I plan to ride it a lot.

Thanks in advance for your insight.
And if you want to see pics of the bike please check my first post here :
viewtopic.php?f=108&t=12747

Re: To Restore OEM or to Mod during Restoration ?

Posted: Sat May 04, 2024 7:33 am
by Rick Pope
Yes, the early CBXs do weave when pressed in the corners. This can be largely overcome by leaning forward a bit and loading the front more. Lower bars help here.

As for mods, I had stock front fork but 7,5w oil, filled to 6 1/2" from the top with springs out and fork collapsed. Progressive rear shocks sprung for my weight. Braided lines with good pads. This resulted in a bike that rode and handled nicely, but keep in mind, it's not a modern bike.

Re: To Restore OEM or to Mod during Restoration ?

Posted: Sat May 04, 2024 2:22 pm
by BritOnABike
Thank you for the reply ! Much appreciated -

Re: To Restore OEM or to Mod during Restoration ?

Posted: Sat May 04, 2024 2:43 pm
by BritOnABike
So as far as handling and braking comparisons how does a 1979 Stock CBX with upgraded brakes and suspension (no fork or swing arm swap ) compares to modern bikes ? If I rated my current bikes I'd say my BMW K1600GTL has the best brakes, my Honda ST1300 handles the best but only because it has $2500 worth of RaceTech upgrade suspension added to it .... and my Suzuki Bandit GSF 1250 is a very close 3rd place as a very decent all rounder ... each bike has ABS although I pride myself on being an expert with the brakes and thus rarely engage the abs system on any of my bikes.

So would it be fair too rate well sorted CBX brakes as a 6 out of 10 if I gave my K1600 GTL a 10 out of 10 ?

And if I go big and add twin pot calipers and new bigger forks plus the swing arm upgrade is it possible to get the handling and braking up into the 7 or even 8 out of 10 ? or am I dreaming .....

I know an 80's super bike will never compete with modern bikes but as a professional motorcycle instructor I am safety obsessed and I won't enjoy owning a bike that doesn't stop properly or handle as good as I can make it ....

Ultimately I guess it's all a bit subjective - So to those of you who have some comparisons I'd be interested to hear your advice and thoughts on the subject. Cheers.
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Re: To Restore OEM or to Mod during Restoration ?

Posted: Sun May 05, 2024 12:00 pm
by Larry Zimmer
I'm no particular reference for your request. However, one thing I would do is replace the head stem bearings with tapered rollers. And, you can shop locally: https://cbxperformance.com/products/ols ... t-1979-cbx
Editorial comment: Whoever designed any steering stem with ball bearings should be barred from engineering forever!!

Re: To Restore OEM or to Mod during Restoration ?

Posted: Sun May 05, 2024 1:28 pm
by BritOnABike
Thank you! I appreciate the advice and the reply ! I wish you continued safe riding.

Re: To Restore OEM or to Mod during Restoration ?

Posted: Sun May 05, 2024 5:45 pm
by daves79x
Actually Larry, all CBXs do have tapered roller steering bearings from the factory. Unfortunately, by 20,000 miles, they too are worn out.

Dave

Re: To Restore OEM or to Mod during Restoration ?

Posted: Mon May 06, 2024 11:50 am
by Larry Zimmer
my boo-boo, Dave. For whatever reason, I thought the 79 used balls with a change in 80.

Re: To Restore OEM or to Mod during Restoration ?

Posted: Wed May 08, 2024 2:53 pm
by NobleHops
Another area to spruce up is the swingarm bushings and rear shocks. Our friend Bob Franzke at www.cbxperformance.com sells lovely bronze bushings (hone them to fit) and the Ikon 7610-1413 shocks will absolutely transform the rear suspension performance.

Re: To Restore OEM or to Mod during Restoration ?

Posted: Sun May 12, 2024 2:39 am
by BritOnABike
Thank you for the suggestions. Much appreciated.