collapse

www.dimecitycycles.com


www.restocycle.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.bisonmotorsports.com

www.speedmotoco.com

www.cognitomoto.com

www.townmoto.com

www.sparckmoto.com

www.Moto-Madness.com

www.pistonsociety.com

QUESTIONS ABOUT THE SITE? TROUBLE REGISTERING? ADMIN@DOTHETON.COM

Author Topic: Comstars + gsx-r front end  (Read 3375 times)

Offline rs_ss350

  • Posts: 56
Re: Comstars + gsx-r front end
« Reply #120 on: Jul 07, 2017, 15:39:49 »
Photobucket really pulled a fast one.....and they won't let me download my albums (over 12yrs worth, 4000 images) to go back and fix every post I've ever made. pretty irritating.

aw man that is a raw deal, holding your pics for ransom.  looks like they want $399 to unlock you!

thanks for reposting the pics, sent you a PM...
1979 CB750K - 10th Anniversary Limited Edition
1982 CB750K - Cafe/brat project under construction
1977 CB750K - another project!

Member of Moto Guild SF

Offline crazypj

  • Posts: 12410
  • Split personality, I fake being smart
Re: Comstars + gsx-r front end
« Reply #121 on: Jul 07, 2017, 15:44:00 »
I tried downloading my pics and it didn't work either. Yep, they are holding them for ransom and want $399 a year
'you can take my word for it or argue until you find out I'm right'
I gave my girlfriend an orgasm the other night, but, she spat it back at me
 Some humans would do anything to see if it was possible to do it. If you put a large switch in some cave somewhere, with a sign on it saying 'End-of-the-World Switch. PLEASE DO NOT TOUCH', the paint wouldn't even have time to dry
 It’s not worth doing something unless someone, somewhere, would much rather you weren’t doing it  (Terry Pratchett)
CB360's,  http://www.dotheton.com/forum/index.php?topic=11736.0
XS650,  http://www.dotheton.com/forum/index.php?topic=11922.0

Offline rs_ss350

  • Posts: 56
Re: Comstars + gsx-r front end
« Reply #122 on: Jul 08, 2017, 16:16:44 »
OK, so I have been thinking about this a lot - and I have to choose a new wheel.  I'm considering the old comstar from the GL1000, but am a little hesitant to do so without being able to measure the spoke width.  If anyone has a set, some measurements would be great! The caliper spacing is 40mm. 

Ideally I would also want to use the matching rear wheel, with drum brake.  Does anyone know if that's possible or have you done it before?

I also started looking around at other mag wheels I might like to use, contemporary to my year model.  I came across the wheels from The Kawasaki KZ750, same model year (82).  I was lucky enough to have a guy working one right next to me in the shop this morning.  I measured the the rims and there is plenty of clearance.  I assume the process for fitting them would be the same as what has already been discussed here.  The only question, similar to above, would I be able to use a rear wheel from the KZ on my CB?

Thanks!
1979 CB750K - 10th Anniversary Limited Edition
1982 CB750K - Cafe/brat project under construction
1977 CB750K - another project!

Member of Moto Guild SF

Offline focusinprogress

  • Posts: 910
  • City Limit Moto:Parts-Service-Apparel (716)8038606
    • City Limit Moto
Re: Comstars + gsx-r front end
« Reply #123 on: Jul 10, 2017, 09:33:29 »
front wheel would be similar work yes. According to Partzilla, the rear wheel bearings for the '82 KZ750 are SKF6303 which are 17mm axle......your CB750 uses a 20mm axle.....

The part could be remedied with different wheel bearings, a quick search says 1204 or 2204 bearings are the right SIZE, but I didn't get into looking at load specs.

You'd also need custom centering spacers to run the KZ wheel, and may also have to mill down or add a spacer to the cush drive to get chain alignment.

all in all, not impossible.....but also not just bolt-n-go.

I think I have a KZ mag front 19" wheel kicking around, if you need some measurements.

For all your gear needs, check out CityLimitMoto.com
DTT10 code for 10% off at checkout


Offline Joseph New York

  • Posts: 83
Re: Comstars + gsx-r front end
« Reply #125 on: Jul 15, 2017, 14:18:15 »
Wish I saw this post earlier could have helped. I didn't read all pages so excuse me if I'm repeating something.

I have a '81 CB750C that I put GSXR forks on. I too wanted to keep the comstars or a mag like wheel too. Mainly because of size and I don't like the look of GSXR wheels on a CB. When I started putting things together it became apparent that there is no way of getting the calipers to clear the comstar bars. I decided to have ISR in Sweden make custom rotors for me with 5 bolt holes, GSXR caliper offset and size, as well as buy an OEM '83 CB750SC mag wheel off eBay. Then I bought a 15mm x 10" dirt bike axel and machined two bushings and a spacer. All in all for me to keep a 18" CB mag wheel, with parts and machining cost me around 500 all in. Custom rotors was the most expensive part but they are very good discs. If your sad about having an 18" wheel over the 19", know that because of the caliper's share line, the 18" barely make it and require a little tie-back if it worries ya. But much better looking than the GSXR 17".

If you want any measurements in creating the axel and rotors let me know.

Good luck!
« Last Edit: Jul 18, 2017, 17:19:45 by Joseph New York »
CB(500/4|650|750|750/DOHC)
Norton Atlas

Offline rs_ss350

  • Posts: 56
Re: Comstars + gsx-r front end
« Reply #126 on: Jul 26, 2017, 09:59:23 »
Thanks Joseph New York - yes SC wheels was one of the options I was thinking... however i just picked up a GL comstar which is the earlier version of the comstar.  JUst got back from vacation, and will be going to the shop tonight to size it up - fingers crossed!  They are 19 wheels, and i did notice the share line might be an issue, but I figured I could probably find or have a longer line made if needed.
1979 CB750K - 10th Anniversary Limited Edition
1982 CB750K - Cafe/brat project under construction
1977 CB750K - another project!

Member of Moto Guild SF

Offline Joseph New York

  • Posts: 83
Comstars + gsx-r front end
« Reply #127 on: Jul 26, 2017, 12:20:06 »
Thanks Joseph New York - yes SC wheels was one of the options I was thinking... however i just picked up a GL comstar which is the earlier version of the comstar.  JUst got back from vacation, and will be going to the shop tonight to size it up - fingers crossed!  They are 19 wheels, and i did notice the share line might be an issue, but I figured I could probably find or have a longer line made if needed.
Well the main issue with comstars is the radial calipers clearing the sheet steel, it doesn't even come close to clearing and you can't shim radial mount calipers longitudinally like you can standard mount calipers.

Unless for some reason the comstars you found don't angle out as far toward the axel, but if they didn't I wouldn't imagine they would hold up very well. They are thin folded steel. Or if you had a really old GSXR front end that had standard mount calipers you could shim and space, but I'm not even sure that would pan out without some welding and cutting.

You'll def need a longer share line, my 18" only has 1/2" clearance which scares the shit out of me and I'm working on a longer line or tether.

Cheers


Sent from my iPhone using Tapatalk
CB(500/4|650|750|750/DOHC)
Norton Atlas

Offline crazypj

  • Posts: 12410
  • Split personality, I fake being smart
Re: Comstars + gsx-r front end
« Reply #128 on: Jul 26, 2017, 13:13:40 »
You could always shim them directly out and use large diameter disc rotors (assuming you don't already ave 320mm?)
'you can take my word for it or argue until you find out I'm right'
I gave my girlfriend an orgasm the other night, but, she spat it back at me
 Some humans would do anything to see if it was possible to do it. If you put a large switch in some cave somewhere, with a sign on it saying 'End-of-the-World Switch. PLEASE DO NOT TOUCH', the paint wouldn't even have time to dry
 It’s not worth doing something unless someone, somewhere, would much rather you weren’t doing it  (Terry Pratchett)
CB360's,  http://www.dotheton.com/forum/index.php?topic=11736.0
XS650,  http://www.dotheton.com/forum/index.php?topic=11922.0

Offline Joseph New York

  • Posts: 83
Re: Comstars + gsx-r front end
« Reply #129 on: Jul 26, 2017, 18:19:42 »
You could always shim them directly out and use large diameter disc rotors (assuming you don't already ave 320mm?)
My calipers used 310mm, his could be 320... Yeah, long shim/extenders could be the only only way to get comstars to work IMO, why I didn't do it was because the rotors would have to be enormous and was worried the shimmed extensions would make the mount less sturdy. Plus machining 4 extra long mounting bolts which would cost an arm/leg. I'll def stay tuned if the PO attempts this...
CB(500/4|650|750|750/DOHC)
Norton Atlas


Offline rs_ss350

  • Posts: 56
Re: Comstars + gsx-r front end
« Reply #131 on: Jul 27, 2017, 13:08:38 »
I'm back! OK, so i test fit the early version comstar on my 07 GSX forks, and the calipers seem to clear just fine.  Now I could only really test fit it with the 15mm axle since there's no way to get the 25mm axle through the hub at the moment.  so it's a bit of a loose fit, not an exact fit, but enough to decide it might be worth pursuing.

Here's the wheel:


Definitely more clearance.  I've taken some measurements, and have questions.  Will post my diagram once I've finished it.  Any advice on how i might more accurately test fit the wheel would be most appreciated

thanks!
1979 CB750K - 10th Anniversary Limited Edition
1982 CB750K - Cafe/brat project under construction
1977 CB750K - another project!

Member of Moto Guild SF

Offline rs_ss350

  • Posts: 56
Re: Comstars + gsx-r front end
« Reply #132 on: Jul 27, 2017, 15:13:40 »
Here's the diagram with all the measurments, using the existing comstar 15mm axle as a frame of reference, then a couple of potential options for adapting the 15mm axle.  I'd rather use the 25mm gsx-r axle, but the built in collar inside the hub's got a 23.5mm ID, and unless I can accurately and evenly drill that out, not sure it's a good solution. 

The solid blue are the bearings.  You'll notice there is a slight offset in the hub for the bearing seats, which will lead to uneven spacers.

Please give me any thoughts or advice you got.  Thanks!

1979 CB750K - 10th Anniversary Limited Edition
1982 CB750K - Cafe/brat project under construction
1977 CB750K - another project!

Member of Moto Guild SF

Offline Joseph New York

  • Posts: 83
Comstars + gsx-r front end
« Reply #133 on: Jul 27, 2017, 19:57:23 »
Here's the diagram with all the measurments, using the existing comstar 15mm axle as a frame of reference, then a couple of potential options for adapting the 15mm axle.  I'd rather use the 25mm gsx-r axle, but the built in collar inside the hub's got a 23.5mm ID, and unless I can accurately and evenly drill that out, not sure it's a good solution. 

The solid blue are the bearings.  You'll notice there is a slight offset in the hub for the bearing seats, which will lead to uneven spacers.

Please give me any thoughts or advice you got.  Thanks!


What I did was grab this axle:
https://www.ebay.com/itm/222195322827
And machined a left bushing, right bushing, left spacer, and right spacer. Looking at your diagrams I see that you've done your measurements, but if you want I can send you the ODxIDxL of each. Note that no two are alike except for their IDs, and the spacers ODs. With that axel and 4 custom parts your ready to go. Also, I JD welded the bushing to the axel's fixed nut, and for the other bushing, I'm planning on cutting it in half so it clamps the axle when axel grips are tightened.

Finally, I have the spacers up against the bearings and removed the dust guards. If you don't like that idea you just have to work on a more complex solution than the 2 spacers.

Sent from my iPhone using Tapatalk
« Last Edit: Jul 27, 2017, 20:02:25 by Joseph New York »
CB(500/4|650|750|750/DOHC)
Norton Atlas

Offline rs_ss350

  • Posts: 56
Re: Comstars + gsx-r front end
« Reply #134 on: Jul 27, 2017, 20:22:24 »
Cool, if you can send me the measurements that will be cool.  I've grabbed that axle.  Thanks!
1979 CB750K - 10th Anniversary Limited Edition
1982 CB750K - Cafe/brat project under construction
1977 CB750K - another project!

Member of Moto Guild SF