Author Topic: 35mm Betor Forks from Mid-Ohio  (Read 7944 times)

0 Members and 1 Guest are viewing this topic.

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
35mm Betor Forks from Mid-Ohio
« on: July 25, 2011, 12:50:42 PM »
Just picked up some 35mm Betor forks for my '76 750 SuperSport and would like to know a bit about them. They look just like the Ceriani GP forks and I understand that they are simply a copy of the Cerianis and are about 1.5" longer than my stock 750f forks. I have a few questions about them. First, how is the quality compared to Ceriani? Where can I find parts (seals, seal dust covers, performance springs, and for caps) for these Betor forks? Is there any issue with running these on my 750f as far as overall bike weight is concerned? I ride solo and I just really like vintage speed parts and wanted something different. Any and all comments welcome.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,711
  • Big ideas....
Re: 35mm Betor Forks from Mid-Ohio
« Reply #1 on: July 25, 2011, 01:01:48 PM »
Here is one place  http://durelleracing.com/store/index.php?main_page=index&cPath=33_37
 It was so hot there I couldn't get through half that swap meet. I also noticed there was a good amount of junk there. I'd say that ebay, Craigs List, the internet in general have made swap meets a lot less than what they used to be. ::)
« Last Edit: July 25, 2011, 01:05:25 PM by MRieck »
Owner of the "Million Dollar CB"

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #2 on: July 26, 2011, 12:27:27 AM »
 I have not seen Betors that look like the Cerianis, but they are a nice light fork.
 Are they the ones with long dustcaps over the seal area, and with fender/brake mounts ? And is the stem needle bearings with eccentic bearing holders ?
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #3 on: July 26, 2011, 05:28:54 AM »
Yes, correct. They are the street version with the fender mounts and the long dust caps. One side has a smaller hole than the other for the axle, so I will have to have something made up. They also have the cast aluminum top and bottom clamps that are identical. The spread is about 1/8" less between forks, and the legs are full width all the way down to the axle, unlike honda forks where they are skinnier at the axle clamp area, so I figure I have two options. First option is to ditch the speedo and just make up a spacer to replace it, or to get new billet triple clamps, which, aside from cost, do not look quite right on a bike that is being composed of all vintage speed parts. These forks seem very robust, but most references online link Betor forks to dirt riding and I would like to know if these ones are appropriate for a larger bike, such as my 750F. I will try to post a picture later so everyone can see exactly what Im talking about.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #4 on: July 26, 2011, 09:57:02 AM »
 I ran them on my iceracer 750 way back, but only used the legs on stock 750 trees (another option for you) so I did not tun speedo drive.
 A lot of there forks were used on CanAm bikes and in that case are marked Bombardier). They are nice and light. CanAm used needle bearings in reversible holders, to change the rake.. cool..
 Your stock 750 K 6 hole hub, has a few brake rotor options. Yamaha brakes fit, as well as the big Ducati floaters.. you could set up a nice btake if you do a bit of fabbing/machining.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #5 on: July 26, 2011, 12:49:18 PM »
Right now my plan is to stick with my lester rim with dual discs, get the discs thinned on the outside, and fab up some bracketry to hold two grimeca or lockheed calipers. I know this setup will weigh a bit, but Im going for the overall look of vintage speed parts as opposed to something that is truely setup for race.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #6 on: July 27, 2011, 07:45:03 AM »
 Run stock trees if it gets too tight, I think Yamaha hubs are narrower but 36 hole , right bolt pattern.
 I weighed;
 1 leg assembly Betor with fender mnt..7 lbs
 1 leg assembly cb 750 F or K .. 9 lbs
 Ceriani double mount, complete fork with trees and stem...16 lbs..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #7 on: July 27, 2011, 11:33:32 AM »
This forks sound robust enough, and in doing some searching, seem like pretty high quality. There are multiple spring rates available for these forks. How do I know which one to use? They range from 42#/Inch to 48#/Inch. I am about 250#, and the bike is used mostly for around town spirited riding. Is there a formula to figure out what rate is appropriate? I would also like to keep the original trees, so is there any downside to ditching the speedo and just making a spacer, aside from not knowing how fast your going?
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #8 on: July 27, 2011, 09:17:37 PM »
 I dont blame you for wanting to run the trees..do you need a stem, and you may need to make steering stops.
 I sort of assumed you wanted a speedo, a lot of  folks do.. I dont..if I get away with it.. but run a tach
 Just find out your rpm needed in 3 for 25 or 30 mph, maybe 45 mph and then 55 or whatever legal speed is in 5th.. then the only problem sometimes is knowing what gear you are in..
 Plus I bet you dont want to carve up the axle area (lower leg) to get a speeedo drive in there.
 You can always run a bicycle speedo off the back wheel..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #9 on: July 28, 2011, 05:35:07 AM »
All very good points 754. I would like to keep from modifying the actual fork leg if at all possible. Do you have a recommendation for a bicycle speedo that others have used? What about spring rates for the forks based on the bike's size as well as my weight? I would assume that I might want something on the stiffer side, but I just dont know.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #10 on: July 28, 2011, 08:13:31 AM »
 I did change mine, but it was 300 + years ago, they may have come from CanAm.
 At that time, I ran a set of Betor legs without fender mounts in stock trees.. still have them.
 Springs from a 750 or 500 fork, may fit they look similar.
 I have seen  3 or 4 versions of the Betor legs, recently picked up a 71 Bultaco Pursang frame with Betors and they are a lot different , not great shape either..
 
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #11 on: August 10, 2011, 07:03:57 PM »
Finally got around to posting some pics of the forks. All I need is some patience and someone with a lathe to make me an axle and a new steering stem and I will be in business.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #12 on: August 10, 2011, 10:33:31 PM »
 are you going to run the tal boots, or a fork brace..?

 Is your stem, too fat or too skinny? Sometimes you can turn it down or shim it..
 If you are real;ly stuck I could make something, but not  in the next month..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #13 on: August 11, 2011, 05:45:08 AM »
754, Im up in the air about boots or fork brace. My stock Honda setup currently has an old Daytona fork brace thats pretty sweet. I think I might go with the tall boots and a smaller GP style front fender. As far as steering stems go, it will need to be taller, and I would like to have one made that utilizes the all balls tapered bearing I already have, and also be able to keep the top sleeved nut that came with the forks. I will also need to come up with a two piece axle that will go through the large hole and thread into a shaft that goes through the small hole side to tighten against the wheel bearings, then I can tighten the pinch bolts. Too many ideas, not enough access to a machine shop.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,050
Re: 35mm Betor Forks from Mid-Ohio
« Reply #14 on: August 11, 2011, 08:31:06 AM »
 Usually there is a bigger step on the axle for the big hole, then its bearing size for the middle and whatever goes thru the samall side. You threads are on small end,  torque up the axle, then clamp.
 If you want more rigidity you may want to bore out small end.. Yamaha for example uses a 17mm axle I think, and Honda is 15mm, small by todays standards.

Axles are huge today and more rigid.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,357
Re: 35mm Betor Forks from Mid-Ohio
« Reply #15 on: August 11, 2011, 08:38:36 AM »
If I jump up to a larger axle, will I be able to get wheel bearings that are the same OD but the bigger ID? I dont want to modify my Lesters at all. As for the axle idea, that was what I was thinking with the two pieces that lock together on the bearings, then the pinch bolts on the forks to hold it all together. I really need to find a local machinist that does stuff on the side so I dont break the bank.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html