Topic: Cognito Moto CB750 cafe with GSX-R forks

[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...

[CognitoMoto]

Hit a couple shows this past weekend and got some great pics thanks to Miguel Rivera

https://m.flickr.com/#/photos/magspipes/sets/72157644990304094/




New gauge setup





















www.CognitoMoto.com

[calj737]

750 turned out really nice, Devin. Pictures are great, but don't do the thing justice compared to in-person. One of these days, we will have to get them out for rip ride and some local BBQ

[ggrant]

Looks great.
Cant find that battery...

[Retro Rocket]

Love the gauge set up, simple and tidy...

[jojo]

so now that youve had the opportunity to ride both the 550 and the 750, which do you prefer and why?

[SOHC4 Cafe Racer Fan]

so now that youve had the opportunity to ride both the 550 and the 750, which do you prefer and why?

Is this a trick question!?

[CognitoMoto]

so now that youve had the opportunity to ride both the 550 and the 750, which do you prefer and why?

Hahahaha you had to ask...

I haven't had much seat time on the 750 yet so my answers may change in time.

My first thoughts on the cb750 was that it felt incredibly lighter than I expected and smooth. I'm very pleased. The gsxr600 forks used have dampening and rebound adjustment that I'm still playing with but it's got enough range adjustment to find what's needed. The FOX shocks are really nice match and the bike doesn't feel too stiff.

The motor on the 750 is a lot smoother than the 550 and the vibration is less throughout the bike. The 750 has more power and it's noticeable.

The knee dents in the tank and foot peg position makes the cb750 more comfortable to ride.

Both a really nice to ride but I just have a personal bond with the cb550. If I had to sell one tomorrow it would be the 750 for no good reason.


www.CognitoMoto.com

[SOHC4 Cafe Racer Fan]

so now that youve had the opportunity to ride both the 550 and the 750, which do you prefer and why?

Hahahaha you had to ask...

I haven't had much seat time on the 750 yet so my answers may change in time.

My first thoughts on the cb750 was that it felt incredibly lighter than I expected and smooth. I'm very pleased. The gsxr600 forks used have dampening and rebound adjustment that I'm still playing with but it's got enough range adjustment to find what's needed. The FOX shocks are really nice match and the bike doesn't feel too stiff.

The motor on the 750 is a lot smoother than the 550 and the vibration is less throughout the bike. The 750 has more power and it's noticeable.

The knee dents in the tank and foot peg position makes the cb750 more comfortable to ride.

Both a really nice to ride but I just have a personal bond with the cb550. If I had to sell one tomorrow it would be the 750 for no good reason.


www.CognitoMoto.com

There is no replacement for displacement unless you transplant a modern 550 engine into a CB550 frame like the Twineline Thorn bike. I WISH you could mod the 550 power plant to give you reliable long term power above 80 bhp. Then you would have the best of both worlds.

As it stands, my 836 CB750 is very smooth and has a still reliable motor with decent gusto. My 550 is stock and very lightweight, but buzzy at 75 mph and could use more torque. It's still a fun bike, but it could use more grunt than a big bore kit, porting, a cam and CR carbs will provide.

Just my $0.02!

[ggrant]

Congrats on the feature : http://www.returnofthecaferacers.com/2014/07/cognito-moto-cb750.html

It turns out the battery is in the tank i guess. Well done!

[CognitoMoto]

Congrats on the feature : http://www.returnofthecaferacers.com/2014/07/cognito-moto-cb750.html

It turns out the battery is in the tank i guess. Well done!

Thanks!

[CognitoMoto]

Time lapse of bikes final assembly.

http://bit.ly/CognitoMotoCB750video

[calj737]

Nice! You'd have finished in half the time had you not spent so much time texting and reading those pesky manuals 

Now it's time for a thread in your 350!?!?!

[SOHC4 Cafe Racer Fan]

Time lapse of bikes final assembly.

http://bit.ly/CognitoMotoCB750video

Very nice, Devin!