Topic: Best modern front end

[fjing60]

Hey guys will be starting my cb750 project soon. Its a 1971 750. I was wondering what are the pros and cons with both the CBR and the GSX-R front ends? Why would you choose one from another?

[calj737]

Availability. Cost of either. Brand preference.

They are essentially equal products in their own right. Swapping them onto a '71k will never yield discernible difference between the 2 choices as the 750 is the great equalizer. There does seem to be more parts available for the GSXRs, so components may be cheaper.

[hondachary]

I managed to find a 99 R1 without an engine for $250...I wasn't planning on doing a swap until I found it for so cheap. It's missing brakes so I'll be spending a bit more to get it complete but I'll still probably be under $400... then conversion bearings $100, new hub $350 and I'm set.... hopefully 

[calj737]

sounds like a great start to something fun, cool and "yours"!

[754]

 Should take the 35 dollar bearings after you get a stem made up..
 There are ways around the 350 dollar hub..if you want to run wire wheels..start with stock 750 hub and build spacers for 6 bolt rotors.

[ChopSticks]

Are there any direct swap conversion options? (other than new bearings)

I read in another thread that the GSXR fork was too short?

[calj737]

GSXR forks are not too short, but the triples have a different offset. Perhaps "early" year GSXRs might be shorter, but easily from 2001 - they are of equal length.

[ChopSticks]

GSXR forks are not too short, but the triples have a different offset. Perhaps "early" year GSXRs might be shorter, but easily from 2001 - they are of equal length.

Oh was just wondering because I was reading this thread where the stem was too short

http://forums.sohc4.net/index.php?topic=127168.0

I guess ultimately is there any set of modern forks that will bolt right on to a 750 with only needing to change the bearings?

[jaguar]

Anyone actually sit down and do the math on these swaps?

Honestly don't see the quantitative point.

[Retro Rocket]

Anyone actually sit down and do the math on these swaps?

Honestly don't see the quantitative point.

Yes, i have Jag, its all dependent on what wheels are used as well, the GSXR is also a very light bike so spring rates should be looked at for a "proper" installation. Personally, I don't like the upside down look on older bikes, I've gone for 43mm GSXR1100K forks, right side up and an excellent array of adjustment, these front ends are a very popular mod for classic racers here and retain a stockish look....  Frame bracing is also another thing to factor in, the newer forks and brakes put a lot more stress on the old frames, I also consistently see these front ends used with cheap crappy shocks on the rear...   If you don't care about handling them why even bother...?  Yeah, I know, it "looks good"...

[fjing60]

What do you mean upside down look?

[Don R]

USD forks, the chrome tube is on the bottom the aluminum part is on the top.

[calj737]

USD forks, the chrome tube is on the bottom the aluminum part is on the top.

Also referred to as "inverted" forks.

[754]

Anyone actually sit down and do the math on these swaps?

Honestly don't see the quantitative point.

Yes, i have Jag, its all dependent on what wheels are used as well, the GSXR is also a very light bike so spring rates should be looked at for a "proper" installation. Personally, I don't like the upside down look on older bikes, I've gone for 43mm GSXR1100K forks, right side up and an excellent array of adjustment, these front ends are a very popular mod for classic racers here and retain a stockish look....  Frame bracing is also another thing to factor in, the newer forks and brakes put a lot more stress on the old frames, I also consistently see these front ends used with cheap crappy shocks on the rear...   If you don't care about handling them why even bother...?  Yeah, I know, it "looks good"...

 Better stopping and easier maintainence.... Are two good points .
 I am thinking of running a SV 650 fork, and just discovered you can lift the front end with a stand,and remove axle by loosening 1 bolt , and the switching sockets to remove axle.. Thats it way easier. To get the forks off the ground..   

[Retro Rocket]

Anyone actually sit down and do the math on these swaps?

Honestly don't see the quantitative point.

Yes, i have Jag, its all dependent on what wheels are used as well, the GSXR is also a very light bike so spring rates should be looked at for a "proper" installation. Personally, I don't like the upside down look on older bikes, I've gone for 43mm GSXR1100K forks, right side up and an excellent array of adjustment, these front ends are a very popular mod for classic racers here and retain a stockish look....  Frame bracing is also another thing to factor in, the newer forks and brakes put a lot more stress on the old frames, I also consistently see these front ends used with cheap crappy shocks on the rear...   If you don't care about handling them why even bother...?  Yeah, I know, it "looks good"...

 Better stopping and easier maintainence.... Are two good points .
 I am thinking of running a SV 650 fork, and just discovered you can lift the front end with a stand,and remove axle by loosening 1 bolt , and the switching sockets to remove axle.. Thats it way easier. To get the forks off the ground..

Sure is Frank, I've got a set of 41mm cartridge forks i'm fitting to a 750, just trying to get bearing sizes sorted out at the moment, one bolt either side and one bolt on the end of the axle and it all slides out, very simple, tidy and quick...

[754]

The downside is you play with the speedo drive, on on our original bike the axle can stay in.but being able to lift under the forks, and not have forks flopping..i like the idea.
 I suppose tho, we could mount spools to our fender mounts.. IF the 6mm bolts can take it..they should.. The guys with 77/78 forks I guess will be again F,d..

[Retro Rocket]

Depending on what wheels you use, a speedo drive can be sorted out, I found out that a lot of Japanese model bikes use the same 2260-40 ratio {is that correct?} as the 750, so with some mods I'm sure it could be done, I have a wheel with the same speedo ratio drive, I'm going to see if i can slightly bore it out so it fits the bigger axle as soon as it arrives in the mail, there's usually a way around these things.......eventually...

[754]

No, what i meant was as you pull the axle the speedo drive falls , unike the original Honda forks.

[Retro Rocket]

No, what i meant was as you pull the axle the speedo drive falls , unike the original Honda forks.

I understand...  As long as it works, I could live with that...

[turboed13b]

Are there any direct swap conversion options? (other than new bearings)

I read in another thread that the GSXR fork was too short?

The gsxr stem is too short for the cb750. Someone makes a longer stem to press in maybe Cognito?

If you are not running the stock gsxr wheels and brakes you will have to do a lot of mixing and matching of parts to make them work or spend a ton of money on a custom hub.

[Retro Rocket]

Are there any direct swap conversion options? (other than new bearings)

I read in another thread that the GSXR fork was too short?

The gsxr stem is too short for the cb750. Someone makes a longer stem to press in maybe Cognito?

If you are not running the stock gsxr wheels and brakes you will have to do a lot of mixing and matching of parts to make them work or spend a ton of money on a custom hub.

Yeah, cognito makes the stems, I covered the spacers and mixing and matching, yep, lots of mixing and matching, I'm smack bang in the middle of one right now...  Its a bit of a hair puller at times...I like a challenge       If using later brakes you'll need spacers to match stock type wheels, it can be done, cognito's hub saves lots of screwing around....