Comstars + gsx-r front end

Joseph New York said:
Yes! Glad I help contribute to this feat, looks sweet!

Is that a 19" wheel??

What's the plans for the rotors?
Click to expand...

It is 19" wheel. For rotors I've got a set of these http://m.ebay.com/itm/99-07-SUZUKI-HAYABUSA-GSX1300R-ROTORS-FRONT-BRAKE-DISC-WHEEL-OEM-STRAIGHT/252966078859?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Using 5mm caliper spacers to match diameter and I've got the adapters designed up and ready for cnc.
 
erock85 said:
Sorry I totally flaked out on this question, I actually never saw it, but yes that sounds correct
Click to expand...

No worries! I measured and did the math a hundred times and it seemed to make sense :). Thanks to you and all on the thread for all the help thus far!
 
1fasgsxr said:
So.....RS (Rally sport)SS (Super sport) ? ;D
Click to expand...

almost! RS = my initials, SS350 = super sport 350 Camaro... my old handle from nastyz28.com i use on all message boards
 
I've ordered my rotor adapters - I got 4 instead of 2 because it's more cost effective. If anyone here wants to do the EXACT same setup i can sell you my extra 2 at cheaper than you might get on your own (unless you have your own access to cnc). In any case, PM me if interested. I gotta wait 17 days to confirm that they actually work, so maybe wait till then :)
 
Adapters have arrived and looking good. They fit on the wheel, and the rotors fit, so that's good... now let's see if i measured the widths properly :)

rotor-adapter1.jpg


rotor-adapter2.jpg


rotor-adapter3.jpg
 
focusinprogress said:
Have you guys ever installed bearings on a comstar wheel....where as you're pounding one bearing into place the other one starts pounding out if you don't put the retainer in? That's what I'm saying is the concern....the wheel is essentially free to move across the outer race of the bearings without the retainer in place.
Click to expand...


That only happens before wheel has axle and is fitted in forks. When fully assembled the various spacers hold bearings 'down' to base of recess
 
Just wanted to wrap this thread up with some final pics everything installed. I've got an extra set of rotor adapters - if anyone wants to do the same setup, let me know!

gsxr-adapter.jpg


gsxr-adapter-rotor.jpg


gsxr-rotors-installed.jpg


gsxr-forks-right.jpg


gsxr-forks-left.jpg
 
Gsxr forks...
Cbr forks....

No matter what they are.
“Upside down” forks looks the dogs nuts on any older bike. Shame people want £300 quid plus for a old pair. Seen bent pairs go for £100


Sent from my iPhone using DO THE TON
 
Realistically, there are only two Japanese manufacturers who supply the 'Big 4'.
Some of the manufacturer build requests are a bit weird though.
The picture of the Blue Kawasaki few years ago with fork leg snapping is only unusual because it was captured, the screwed on fork bottoms often came loose and leaked, I saw more than a few with cracks developing (and I 'don't do' Kawasaki's)
 
Hi Everyone,

I'm working myself on a fork swap for my 1979 CB750 KZ, and found this topic to be a gold mine! Apologize in advance for my english, I'm french...

Bought the bike 10month ago and was so far focusing on having it running on it's four cylinders, which is now done! Carbs reassembly, change of gaskets, change of valves shims, and now pending a proper carb sync..
Attached a picture of the bike as it is now, not a fan of the look but still ok for the 2 000$ I had it.
Currently I'm trying to purchase the GSXR fork or R6 fork, so few questions here to anticipate and avoid potential mistakes...

I saw different way of doing the swap on the thread, and few questions below:
- is the CB750 stem able to fit with the triple clamp of the USD fork without major adjustement? I saw it's feasible by machining & welding slighly the bottom clamp, but not really sure about it. Otherwise, conversion stem from Cognito seems to be THE best option to go for...
- in terms of geometry, does it change the behaviour of the bike significantly? Or is it just minor? considering I will be riding it as a pleasure bike (no track or agressive riding planned so far^^), if it's minor I can cope with it :) I will change the rear shocks as well, so it might be a way to adjust the stance / balance if needed
- is it best to keep the CB750 axle or to go for the USD one? Machining of the inner diameter of the wheel kinda affraid me a little bit...
- how is the steering radius after conversion? does it need special attention?

I also saw some of you having extra conversion hub / spacer available, so if it's possible to purchase for reasonnable price I would be more than happy to do the deal! ;D ;D I do not know machinist around there and the few I approached were giving crazy high prices...

Thank's for your help (especially @RS_SS350 & @focusinprogress who already gave me a lot of help!) and future feedbacks! I'll keep you posted about the evolution of the build

cheers
 

Attachments

  • 20171209_144851.jpg
    20171209_144851.jpg
    2.6 MB · Views: 358
- in terms of geometry, does it change the behaviour of the bike significantly? Or is it just minor? considering I will be riding it as a pleasure bike (no track or agressive riding planned so far^^),
Modern sportbikes have less offset (forks are more or less inline with steering stem) so you will end up with more trail making bike slower to turn. Forks are often shorter than old style as well which may compensate as you'll have a steeper head angle- is it best to keep the CB750 axle or to go for the USD one?
Use largest diameter axle you can, original would be best as it's now possible to get odd size bearings for conversions
 
thanks for the informations!

For the ability to turn, is it something that can be compensated with the rear shocks? And how sensitive will be this change in turn capacity? I'm not an experimented rider, so I might not even feel it if it is only "slight"...

Yep, understood for the wheel axle! Will try to figure it out.

Regarding the stem, any information about how to proceed?
 
you may also lose steering radius due to forks contacting your fuel tank. geometry also heavily depends on front wheel/tire size as well. there are some good calculator sites available to help with the math for rake and trail where you can input stock numbers then play around with fork length, offset, and tire/wheel size to see how it gets impacted for riding.
 
@focusinprogress
yep, I know that and will most likely need to work on the stopper of either the CB frame, or fork tee.
Do you mind sharing the link to those calculator?

Also, just bough a GSXR - 600 fork from 2005 for a good deal! 8) 8) GSXR 2005 rotors in 300mm are also coming soon, so I'm now starting the assembly sketch off all that!!

For the sake of precision, I'd like to make a small CAD of the assembly, but I can't find a 3D model of the Comstar wheel...
Does anyone here has that specific part? I found a GSXR fork, caliper & frame 3D model already on Grabcad
 
LeMarseillais said:
@focusinprogress
yep, I know that and will most likely need to work on the stopper of either the CB frame, or fork tee.
Do you mind sharing the link to those calculator?

Also, just bough a GSXR - 600 fork from 2005 for a good deal! 8) 8) GSXR 2005 rotors in 300mm are also coming soon, so I'm now starting the assembly sketch off all that!!

For the sake of precision, I'd like to make a small CAD of the assembly, but I can't find a 3D model of the Comstar wheel...
Does anyone here has that specific part? I found a GSXR fork, caliper & frame 3D model already on Grabcad
Click to expand...

https://www.rbracing-rsr.com/rakeandtrail.html
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light
    • www.jadusmotorcycleparts.com
    www.lostapostle.ca/
    www.sparckmoto.com

    Spread the Love

    Back
    Top Bottom