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CB450 SC Nighthawk triple tree specifications??

Albert

Well-known Member
Joined
Aug 11, 2020
Total Posts
84
Total likes
8
Location
Cuba
Hi guys, I need to know as much specs as possible like the distance between the center of tubes holes, offset, steering stem lenght, etc
Thanks
 
Might help to post your intentions. You can't measure using your bike?
rake and trail may be in the service manual.

edit: can mods move to the sohc section? [Done]
 
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Inspired by Jim's no nonsense reply

lower clamp from a cb400t

stem 205mm from bottom of race to top of threads
tubes are 140mm apart
looks like tubes were 32mm dia
that would make it 172mm center to center?
 
OK, up to 43* now. Looking like a heat wave starting:lol:
Fork tube centers = 171mm
Offset = 47mm
Stem lengths measured from the bottom washer under the race and seal:
Total= 222mm
Bottom of top threads = 202
Top of threads for load nut = 192mm
Bottom of threads for load nut = 180mm
These are as close as I can measure and may be +/- 1-2 mm's on the spread and offset, stem lengths are correct.
Forks on all of the SOHC 400/450 series are 33mm
 
Thank you so much for your answer, was really helpfull
 
Here's the thing: I'm customizing my bike with a new set of Yamaha XS650 wheels wich are the best option for what I want to do, according to Stephen whom by the way I'd like to say thanks because he's been really helpfull. I bought that bike with a complete front (forks, triple tree kit and wheel ) from a Kymco Venox, not with the OEM parts, these forks are 41mm width and the wheel has 3" rim width. So I'd like to keep the 41mm forks width but with the Yamaha wheels wich are an almost exact match, just have to make new spacers according to Stephen, so with the change of the front wheel and the forks I need to find a new set of Triple trees that I can fit (The same specs as the OEM ones but for forks with 41mm) and as I don't have the OEM ones I don't have the specs to use as a guide on finding the right triple trees... that was the reason of my question.
 
Sounds like a good project.
Do you need xs650 triple clamp details for your front wheel spacing?
i have 2 sets of 650 and 1 xs750 dual disc set I can check the tube spacing.
I'm not sure the calipers on the kymco forks are a direct swap or you need to modify too?
 
Albert..... My recommending the XS 650 wheels was because they can be easily fitted in the stock forks and swingarm of the DOHC CB 450 K with minor mods.....

I have NO IDEA if they are suitable in the Kymco forks, narrowed or not, particularly in reference to axle diameter.......and, the rear axle slots in your CB 450 SC swingarm will have to be widened (about 2 mm I believe) due to the larger axle diameter of the XS 650 rear wheel......

The initial impression you conveyed was mostly about employing different rotors, not about retaining the 41mm fork diameter and changing fork width.....
 
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BTW, A 1984 XS 650 "Special" has the disc rear brake 16" wheel you wanted....... Get the caliper with it if you can.....
AND.. a 1980 XS400 special also has a 16" cast rear (drum brake), but with the correct axle diameter to fit your stock swingarm (IIRC)....
 
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Albert..... My recommending the XS 650 wheels was because they can be easily fitted in the stock forks and swingarm of the DOHC CB 450 K with minor mods.....

I have NO IDEA if they are suitable in the Kymco forks, narrowed or not, particularly in reference to axle diameter.......and, the rear axle slots in your CB 450 SC swingarm will have to be widened (about 2 mm I believe) due to the larger axle diameter of the XS 650 rear wheel......

The initial impression you conveyed was mostly about employing different rotors, not about retaining the 41mm fork diameter and changing fork width.....


You´re right about that, and I´m sorry if I didn´t tell about the Kymco forks, I really don´t remember if I mentioned it to you or not, anyway in order to replace the wheels I´ll also have to replace the front forks because in first place I´ll set the front wheel with dual disc brakes as I mentioned you and kymco forks only fits for one brake caliper, also fork tube centers are at 214mm wich is more wider than the Honda OEM, so I must also get a new pair of front forks with a triple tree set, thing is I´d like to keep the currently 41 fork diameters because the OEM ones for Yamaha XS650 and Honda CB450 are thinner, it´s not that I think that those are bad forks at all, but with my little knowledge about bikes I know 41mm forks are stronger, not to mention that my bike will look much better. And anyway I also searched the web for a new pair of front forks for CB450 Nighthawk or for the Yamaha XS650 and those and I couldn´t find any new, at least not in a fair price, and that´s a part I´d like to buy "brand new" so I decided to go with a pair of Showa 2008-2010 Honda CBF600 front forks, new and OEM (at least according to the seller) in a fair price ($267) Now I need the triple trees with the right specs to fit the new forks, the wheel, etc. A bit of a work but... that´s what I want to accomplish and I think that with your help together with the rest of the group I think I can do it
 
Sounds like a good project.
Do you need xs650 triple clamp details for your front wheel spacing?
i have 2 sets of 650 and 1 xs750 dual disc set I can check the tube spacing.
I'm not sure the calipers on the kymco forks are a direct swap or you need to modify too?

Yes, of course those specs would be an aditional data to have in mind and I really appreciate all your help, in my recent reply to Stephen I detailed a bit more about my idea, but just to add more details these are the specs for the Showa forks I have in mind

Length: 765mm
Fork diameter: 41mm
Distance between holes for calipers: 80mm

I realized that these forks are shorter than the OEM Yamaha or Honda forks we´ve been talking about, but as I´m also going to replace the rear shocks for a pair of brand new Progressive Suspension wich are 1" shorter, that means I'll be only lowering the front of the bike 1.18" according to my calculations. If I'm wrong about something please correct me

820mm OEM Honda CB450
-765mm New Showa forks
----------------------
55mm difference
-25mm 1" shorter rear shocks
----------------------
30mm (1.18")

I know this means less trail, don't know exactly the difference, but if I get the triple trees with a bit less offset I can increase the trail again to keep it in the right parameters. I'm I correct?
 
CBF600? we didn't get those in the States, but here https://www.cmsnl.com/honda-cbf600s...5/stem-sub-assy-str_53219merr60/#.X8QjczlOmyU
Looks like it wasn't used on any US spec bikes.

The front axle appears to be the same as all of the 600 Hornets, including the 599 that we did get in the States.

The 599 lower triple appears to be the same part, but even having logged in to CMSNL I can't reference them as compatible.https://www.cmsnl.com/honda-cb600f-...sub-assy-str_53219mbzk00/#pageproductModelfit

In my experience, as long as that hollow axle is the same part, everything will interchange from wheel and bearings and spacers to speedometer drive if equipped to brakes to triple trees.

I forget which thread it was but someone bolted on a CBR600 front end and it fit like a glove.
I think it was Redeemer1972 from the HondaRebel forum, he's got a big bore 450 Rebel project in the works for several years now.
 
Looks like the cbf600 specs

Caster Angle: 26°
Trail: 110mm

I checked cb450sc in the FSM but forgot what the numbers were.

I have a bike with a front end swap off something more aggressive and hate the handling. I don't drive it just for that reason. I really like the way the stock Nighthawk handles. If I were to upgrade the front end I would probably model it after longdistancerider setup.

When I had the Nighthawk, i found it handled city street and open highway well, and performed reliably and predictably in tight lane splitting situations, and the ability to be jamming 40mph past stopped cars, hit the brakes and bounce into the next lane to pass a slower motorcycle.

edit: 450 Nighthawk caster angle 60, trail 130mm
 
Looks like the cbf600 specs

Caster Angle: 26°
Trail: 110mm

I checked cb450sc in the FSM but forgot what the numbers were.

I have a bike with a front end swap off something more aggressive and hate the handling. I don't drive it just for that reason. I really like the way the stock Nighthawk handles. If I were to upgrade the front end I would probably model it after longdistancerider setup.

When I had the Nighthawk, i found it handled city street and open highway well, and performed reliably and predictably in tight lane splitting situations, and the ability to be jamming 40mph past stopped cars, hit the brakes and bounce into the next lane to pass a slower motorcycle.

edit: 450 Nighthawk caster angle 60, trail 130mm
Honda did some strange numbers in some of the FSM's, actual caster angle is 30* (90-60=30)
 
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