Topic: Cognito Moto CB750 cafe with GSX-R forks

[Retro Rocket]

Swingarm is too long, all that trouble to get the geometry right at the front and nothing at the back, not being harsh but front and rear geometry effect both ends of the bike... Good steering front with a slower steering rear compounded by the wider tires.... The bike looks cool but i'm not a fan of the combination of suspension mods sorry...

[CognitoMoto]

Swingarm is too long, all that trouble to get the geometry right at the front and nothing at the back, not being harsh but front and rear geometry effect both ends of the bike... Good steering front with a slower steering rear compounded by the wider tires.... The bike looks cool but i'm not a fan of the combination of suspension mods sorry...

That's a stock cb550 swingarm.

Little side by side




www.CognitoMoto.com

[riverfever]

I'm pretty new here and don't have a ton of experience where there's a motor between 2 wheels but I looked at a lot of builders before deciding to buy my own bike and start on a project. I know you don't have a long list of bikes to show but I love how this one, your 550, and the pic of the 350 I've seen are different enough that they don't look like cookie cutters and they have a nice mix of old and new. I didn't care for the tank on this one at first but once you stand back and see the overall lines on the bike and seat...it fits.

[Retro Rocket]

Swingarm is too long, all that trouble to get the geometry right at the front and nothing at the back, not being harsh but front and rear geometry effect both ends of the bike... Good steering front with a slower steering rear compounded by the wider tires.... The bike looks cool but i'm not a fan of the combination of suspension mods sorry...

That's a stock cb550 swingarm.

Little side by side




www.CognitoMoto.com

The 17 inch rear wheel makes it look worse than it is, a lot of the 500-550 racers use the 750 swingarm because its shorter and  it quickens up the handling of the little bikes..

[CognitoMoto]

Swingarm is too long, all that trouble to get the geometry right at the front and nothing at the back, not being harsh but front and rear geometry effect both ends of the bike... Good steering front with a slower steering rear compounded by the wider tires.... The bike looks cool but i'm not a fan of the combination of suspension mods sorry...

That's a stock cb550 swingarm.

Little side by side




www.CognitoMoto.com

The 17 inch rear wheel makes it look worse than it is, a lot of the 500-550 racers use the 750 swingarm because its shorter and  it quickens up the handling of the little bikes..

The seats like 22" so it's a bit shorter than stock. It is deceiving


www.CognitoMoto.com

[SOHC4 Cafe Racer Fan]

Okay, Devin, get yourself over to the Bike of the Month Nomination thread and accept your nomination, so we can make BOTM a horse race!

[CognitoMoto]

Okay, Devin, get yourself over to the Bike of the Month Nomination thread and accept your nomination, so we can make BOTM a horse race!

Haha sorry. Got it and thank you!


www.CognitoMoto.com

[MarshallCS]

Can we vote on bike of the year yet?




Absolutely stunning work. I know it's probably the most simple part, but I absolutely love the footpeg brackets. Hurry up and start selling them for a 78-750F!

[timbo750]

Great bike, just found the thread recently and have been reading it from the start. I would love to see your ideas on the cowl for the rear and I am hoping it will fit over the existing seat. I had a VFR years ago with the removable cowl, it stopped people asking for a ride around the block when you visited someone after being out for a ride.

[RustyOlive]

WOW!! another stunning build.
congrats man.
you are really turning out some pretty sweet bikes and sexy parts to boot!! =)

[SOHC4 Cafe Racer Fan]

Devin,

What are you using to cycle through the different display functions of the Motogadget gauge?  One of their buttons?  If so, where did you mount it?  Also, did you stick with a stock key or the M-Lock?

[CognitoMoto]

Reply 182: m-key, m-button and m-unit.

I'd like to see where he mounted the control button too. I looked over my stuff today again (finally ripping out all the wiring on my 550 Friday re-wiring with MG gear). I noticed my new gauge came with the micro switch, but I ordered the small single button for my bracket.

I suspect Devin hid it somewhere discreet.

I used that little chrome button I sell since the m unit button is a little goofy. Mount it on handle bar. I mounted under seat but didn't realize it would need to be accessed regularly while riding.

The m-unit is mounted under the tank. The tank was has a large opening underneath so it clears and I'm able to hide it on the back bone of the bike. The other thing is that it allowed me to run the switches directly into the m-unit and no extra wires were needed.


www.CognitoMoto.com

[CognitoMoto]

Great bike, just found the thread recently and have been reading it from the start. I would love to see your ideas on the cowl for the rear and I am hoping it will fit over the existing seat. I had a VFR years ago with the removable cowl, it stopped people asking for a ride around the block when you visited someone after being out for a ride.

Can we vote on bike of the year yet?




Absolutely stunning work. I know it's probably the most simple part, but I absolutely love the footpeg brackets. Hurry up and start selling them for a 78-750F!

WOW!! another stunning build.
congrats man.
you are really turning out some pretty sweet bikes and sexy parts to boot!! =)

Thanks guys!


www.CognitoMoto.com

[CognitoMoto]

Devin,

What are you using to cycle through the different display functions of the Motogadget gauge?  One of their buttons?  If so, where did you mount it?  Also, did you stick with a stock key or the M-Lock?

I had to give up my m-lock because the distributor was out of stock and customer ordered one. I'll try it when they are back in stock.


www.CognitoMoto.com

[Syscrush]

I had to give up my m-lock to the because the distributor was out of stock and customer ordered one. I'll try it when they are back in stock.

The MotoGadget stuff is beautiful, to be sure, but for something like RFID ignition, I don't think it's worth the premium on the price.  A reader with relay that includes a transistor in the driver circuit is $15, including 2 RFID tags.  There are a few cool ideas in this thread about different ways to wire 'em:

http://www.svrider.com/forum/showthread.php?t=121880

The one that looks the most slick to me is wiring the RFID brain's ground through the clutch switch - so to start the bike, you turn the kill switch to ON, pull in the clutch, and present the tag to the antenna.  Bike is then armed until the kill switch is changed to OFF.

This is a really fantastic build.  I'm very glad to see some high-spec parts on a nicely-build old bike like this.  If I can make one suggestion, it would be to grind the casting seam off of that lower triple.  The top is so nice, the bottom looks out of place in comparison.  You KNOW you have a sweet build when something like one casting seam on one part is even noticeable.

[Syscrush]

Nice looking trees and hubs..

Not surprising you like that triple, it uses a slitless clamping scheme similar to what I first heard described by you.

[CognitoMoto]

This was done as a bit of a case study. This is a comparison of 17" vs 19" wheels and 30mm vs 50mm offsets.

Basically if you run a 19" wheel with a gsxr fork you will want to use a 50mm offset because trail increases and makes the steering heavy. 17" wheel should not use a 50mm offset because trail would be significantly reduced (not shown).

The lower image is this bike as it sits now.




www.CognitoMoto.com

[Retro Rocket]

Its cool to have those comparisons but you must add to the mix, a 17inch wheel naturally steers faster than a 19, 3.75 inches of trail makes for a quick steering bike with a 19 inch wheel, going down to a 17 inch wheel will drop the front height slightly decreasing rake and shrinking trail even more making for a dangerous combination , running a 17 inch front wheel on one of these bikes you are better off running 4 inches of trail or maybe even slightly more. I don't think most people realize how little trail the 750  Honda's actually had, most modern superbikes run around 4 inches {or slightly more} of trail. Its not quite as simple as picking a trail number and building to it, changes in wheel sizes definitely add to the equation, just like offset, rake and trail....   Its still good to see those numbers though, it can be very hard to get these measurements looking at the actual bike....

[SOHC4 Cafe Racer Fan]

Its cool to have those comparisons but you must add to the mix, a 17inch wheel naturally steers faster than a 19, 3.75 inches of trail makes for a quick steering bike with a 19 inch wheel, going down to a 17 inch wheel will drop the front height slightly decreasing rake and shrinking trail even more making for a dangerous combination , running a 17 inch front wheel on one of these bikes you are better off running 4 inches of trail or maybe even slightly more. I don't think most people realize how little trail the 750  Honda's actually had, most modern superbikes run around 4 inches {or slightly more} of trail. Its not quite as simple as picking a trail number and building to it, changes in wheel sizes definitely add to the equation, just like offset, rake and trail....   Its still good to see those numbers though, it can be very hard to get these measurements looking at the actual bike....

I'm curious as to how well 18" wheels (front and back) work with the stock GSXR trees, or whether it is preferable to adjust the offset as well on the trees. 

[Retro Rocket]

Its cool to have those comparisons but you must add to the mix, a 17inch wheel naturally steers faster than a 19, 3.75 inches of trail makes for a quick steering bike with a 19 inch wheel, going down to a 17 inch wheel will drop the front height slightly decreasing rake and shrinking trail even more making for a dangerous combination , running a 17 inch front wheel on one of these bikes you are better off running 4 inches of trail or maybe even slightly more. I don't think most people realize how little trail the 750  Honda's actually had, most modern superbikes run around 4 inches {or slightly more} of trail. Its not quite as simple as picking a trail number and building to it, changes in wheel sizes definitely add to the equation, just like offset, rake and trail....   Its still good to see those numbers though, it can be very hard to get these measurements looking at the actual bike....

I'm curious as to how well 18" wheels (front and back) work with the stock GSXR trees, or whether it is preferable to adjust the offset as well on the trees.

I will be running 18's on the front 2 of my bikes and will be using 50mm offset clamps {instead of 60 to add a little more trail}, lots of racers use 18's on the front of the 750's... 

[CognitoMoto]

Its cool to have those comparisons but you must add to the mix, a 17inch wheel naturally steers faster than a 19, 3.75 inches of trail makes for a quick steering bike with a 19 inch wheel, going down to a 17 inch wheel will drop the front height slightly decreasing rake and shrinking trail even more making for a dangerous combination , running a 17 inch front wheel on one of these bikes you are better off running 4 inches of trail or maybe even slightly more. I don't think most people realize how little trail the 750  Honda's actually had, most modern superbikes run around 4 inches {or slightly more} of trail. Its not quite as simple as picking a trail number and building to it, changes in wheel sizes definitely add to the equation, just like offset, rake and trail....   Its still good to see those numbers though, it can be very hard to get these measurements looking at the actual bike....

I'm curious as to how well 18" wheels (front and back) work with the stock GSXR trees, or whether it is preferable to adjust the offset as well on the trees.

I will be running 18's on the front 2 of my bikes and will be using 50mm offset clamps {instead of 60 to add a little more trail}, lots of racers use 18's on the front of the 750's... 

How much will that lower the front end of the bike? A smaller tire will reduce rake angle and decrease trail. Changing to 50mm offset would be compensating the angle change.


www.CognitoMoto.com

[Retro Rocket]

Its cool to have those comparisons but you must add to the mix, a 17inch wheel naturally steers faster than a 19, 3.75 inches of trail makes for a quick steering bike with a 19 inch wheel, going down to a 17 inch wheel will drop the front height slightly decreasing rake and shrinking trail even more making for a dangerous combination , running a 17 inch front wheel on one of these bikes you are better off running 4 inches of trail or maybe even slightly more. I don't think most people realize how little trail the 750  Honda's actually had, most modern superbikes run around 4 inches {or slightly more} of trail. Its not quite as simple as picking a trail number and building to it, changes in wheel sizes definitely add to the equation, just like offset, rake and trail....   Its still good to see those numbers though, it can be very hard to get these measurements looking at the actual bike....

I'm curious as to how well 18" wheels (front and back) work with the stock GSXR trees, or whether it is preferable to adjust the offset as well on the trees.

I will be running 18's on the front 2 of my bikes and will be using 50mm offset clamps {instead of 60 to add a little more trail}, lots of racers use 18's on the front of the 750's... 

How much will that lower the front end of the bike? A smaller tire will reduce rake angle and decrease trail. Changing to 50mm offset would be compensating the angle change.


www.CognitoMoto.com

18 is a half inch lower than stock and 17 is an  inch lower, give and take tire profile, also the length of the forks, not sure with the upside down forks, I was just throwing the info out there as it also comes into the calculations when building a front end as does longer or shorter rear shocks....

[burlybear]

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[jojo]

Ive been riding my 750k2 with gsxr front end(stock gsxr lower triple)/ 550 swing arm for about a month now and it handles absolutely great. Steering is not as responsive as my sport bike but plenty responsive for "spirited" and fun riding while maintaining great balance. On the highway its something else, very very smooth and balanced. Im running 19" wheel up front and 18 in the rear with 14" rear shocks. Had 2 of my buddies ride it this past weekend (one rides r6, other street triple) and both said the ride is about as much fun as they have ever had on a bike. I am not very knowledgeable when it comes to suspension setups and how changes affect ride geometry but I can definitely say from experience with this particular setup (19"/18" wheels, 550 rear swing arm, gsxr 1000 forks, 14" reach shocks),and the original setup on my k2 that this one is way more fun and just as comfortable. Just my 2 cents   

forgot to mention- im running a 100/90/19 up front and a 110/90/18 on the rear..... im sure that has something to do with it.

[Retro Rocket]

Ive been riding my 750k2 with gsxr front end(stock gsxr lower triple)/ 550 swing arm for about a month now and it handles absolutely great. Steering is not as responsive as my sport bike but plenty responsive for "spirited" and fun riding while maintaining great balance. On the highway its something else, very very smooth and balanced. Im running 19" wheel up front and 18 in the rear with 14" rear shocks. Had 2 of my buddies ride it this past weekend (one rides r6, other street triple) and both said the ride is about as much fun as they have ever had on a bike. I am not very knowledgeable when it comes to suspension setups and how changes affect ride geometry but I can definitely say from experience with this particular setup (19"/18" wheels, 550 rear swing arm, gsxr 1000 forks, 14" reach shocks),and the original setup on my k2 that this one is way more fun and just as comfortable. Just my 2 cents   

forgot to mention- im running a 100/90/19 up front and a 110/90/18 on the rear..... im sure that has something to do with it.

Without knowing it you have balanced out the longer trail on the front by using a longer rear swingarm, the 550 arm is longer therefore slightly slower in handling response, like you said, the steering is slower but very stable, The use of a 19 inch front has helped this as well...