dbarkdoll_imp
Been there
Using the original tank or a custom one?
Single Sided Swingarm
- Thread starter Cafe Project_imp
- Start date
Cafe Project_imp
First service completed
Thread starter
Original tank so far. It was dented and I am filling in the Honda badge relief and removing the badges. I don't like the filler cap so I may end up with a different tank at some point.
So, I weighed the Honda and Ducati rear ends. It was a little surprising - maybe. All in pounds....
Honda:
Swing arm - 21.4
Wheel, tire, sprocket - 39.8
Shocks and axle - 9.4
Honda Total - 70.6 pounds
Ducati:
Swing arm - 27.6
Tire and shocks - 22.8
Wheel - 8
Ducati total - 58.4 pounds
The Ducati swing arm is heavier but the Honda wheel, tire and shock group is made of lead. So the rear is already 12.2 pounds lighter, all from unsprung weight.
So, I weighed the Honda and Ducati rear ends. It was a little surprising - maybe. All in pounds....
Honda:
Swing arm - 21.4
Wheel, tire, sprocket - 39.8
Shocks and axle - 9.4
Honda Total - 70.6 pounds
Ducati:
Swing arm - 27.6
Tire and shocks - 22.8
Wheel - 8
Ducati total - 58.4 pounds
The Ducati swing arm is heavier but the Honda wheel, tire and shock group is made of lead. So the rear is already 12.2 pounds lighter, all from unsprung weight.
jtopiso_imp
Been there
What Honda wheel are you comparing it to?
jtopsio, he's talking about the OEM Honda wheel for the CB1100, isn't he?
jtopiso_imp
Been there
wire spoked, cast...Cormanus_imp said:
Cast.
jtopiso_imp
Been there
It amazes me how two wheels (with tyre) of similar size and techonolgy (cast aluminium, I assume) show such a difference in weight.Cormanus_imp said:
PowerDubs_imp
Road warrior
Well, the #'s he listed are not the same.
One he has the tire with the wheel, the other without. No mention of Ducati sprocket. Etc.
In theory, if the bike is still apart, he could separate and give more comparable numbers.
He also mentions 12.2 unsprung- but that isn't true- there is a midway point in the suspension that transitions from sprung to unsprung, both on the shocks and swing arm/linkages. Are you going to feel it? Nah... but just a clarification to a mentioned technicality.
The rear sprocket on the Cb is steel. Quick and easy to drop weight by going to aluminum. Not drastic, but easy.
Biggest comp would be direct weight of wheel/tire/sprocket as an assembly- that is what is being moved up and down..
One he has the tire with the wheel, the other without. No mention of Ducati sprocket. Etc.
In theory, if the bike is still apart, he could separate and give more comparable numbers.
He also mentions 12.2 unsprung- but that isn't true- there is a midway point in the suspension that transitions from sprung to unsprung, both on the shocks and swing arm/linkages. Are you going to feel it? Nah... but just a clarification to a mentioned technicality.
The rear sprocket on the Cb is steel. Quick and easy to drop weight by going to aluminum. Not drastic, but easy.
Biggest comp would be direct weight of wheel/tire/sprocket as an assembly- that is what is being moved up and down..
Cafe Project_imp
First service completed
Thread starter
The numbers are actually the same. If you add them all up, the total equals the same set of parts for each bike i.e. wheel, tire, sprocket, brake disc, shocks and linkage, axle/hub and swing arm.
Check the picture. The Ducati sprocket/disc is part of the swing arm hub and on the Honda it's attached to the wheel assembly. That's why the Ducati swing arm is heavy and the Honda wheel is heavy. But add everything up and it's the same set of parts. Ducati is way lighter.
Different bikes with different design parameters.
I agree about the unsprung weight comment, but that would be too hard to work out exactly. It's close enough - for me.
Check the picture. The Ducati sprocket/disc is part of the swing arm hub and on the Honda it's attached to the wheel assembly. That's why the Ducati swing arm is heavy and the Honda wheel is heavy. But add everything up and it's the same set of parts. Ducati is way lighter.
Different bikes with different design parameters.
I agree about the unsprung weight comment, but that would be too hard to work out exactly. It's close enough - for me.
PowerDubs_imp
Road warrior
Wow- never paid enough attention to notice how they built that. Pretty cool!!
Just trying to figure out where the actual weight difference is since it is grouped differently.
Example- if you pulled the sprocket and rotor off the duc arm, how much closer would it be to the CB arm.
Likewise if you pulled the rotor and sprocket off the cb tire/wheel, then compared.
Piece by piece is the best way to pinpoint the lard.
Sent from my iPhone using Tapatalk
Just trying to figure out where the actual weight difference is since it is grouped differently.
Example- if you pulled the sprocket and rotor off the duc arm, how much closer would it be to the CB arm.
Likewise if you pulled the rotor and sprocket off the cb tire/wheel, then compared.
Piece by piece is the best way to pinpoint the lard.
Sent from my iPhone using Tapatalk
jtopiso_imp
Been there
It's a nice piece of engineering indeed. Thanks for the nice pic, "Cafe Project"PowerDubs_imp said:
I would assume the ducati arm must be a bit heavier anyway, as it has to support some bending and torsion loads, while the honda is almost only under tensile/compressive loads.
Of course, this extra stiffness required for the ducati arm is achieved by geometry (increased cross section) and not just adding material, but being both hollow, the Honda is smaller so it will be lighter.
Then you save from going from a dual spring/damper to a monoshock (plus rocker and droplink).
A very nice design form ducati that will make that CB not only lighter, but also look great!
jtopiso_imp
Been there
So... what happened with this project?
I'd love to see more pics!
I'd love to see more pics!
Cafe Project_imp
First service completed
Thread starter
Had an issue with powder coating the rear wheel. Took weeks. I have been out of the country for a while too, so progress has been slow. Anyhow....some pics.
Lots of caveats here: the seat and rear subframe are going to be ditched. I have a seat pan that I am working with. The trees and triple clamps are the prototypes that don't really fit. I didn't want to use the super sexy CognitoMoto parts just to test fit things. The rear suspension top mounts and spacers are just mock ups right now. There are a couple of issues too. The clutch master cylinder gets in the way of the clipons and needs some fettling. The front brake lines don't fit - braided hoses on the way. Plus a million other little things.
I am happy with the general direction....
Lots of caveats here: the seat and rear subframe are going to be ditched. I have a seat pan that I am working with. The trees and triple clamps are the prototypes that don't really fit. I didn't want to use the super sexy CognitoMoto parts just to test fit things. The rear suspension top mounts and spacers are just mock ups right now. There are a couple of issues too. The clutch master cylinder gets in the way of the clipons and needs some fettling. The front brake lines don't fit - braided hoses on the way. Plus a million other little things.
I am happy with the general direction....
It’s coming together, Café Project. Nice work.
Jim21680_imp
Been there
Awesome! Awesome!! Awesome!!!
GoldOxide_imp
Road warrior
That ... is sumthin'.
jtopiso_imp
Been there
Impressive!
dbarkdoll_imp
Been there
Sounds like a lot left to do, but as you said, general direction is the right one. Looks amazing, very very cool stance and overall demeanor. I am a sucker for gold USD forks, lol. Best of luck moving forward!
peterbaron
Road warrior
peterbaron_imp said:+1 for courage....but worry about CB look after
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