Topic: 77 f2 - comstar-to-spoke conversion possible?

[yoomit]

77 cb750 f2...dual fronts, rear disc.
is it possible to swap out the comstars for spokes? 
i'm not finding many posts here that indicate that this is do-able.

suggestions?

[yoomit]

bump.

anyone??

[MRieck]

 I've done it using an earlier hub, modified early rotors and the F2 calipers. There is some machine work involved

[yoomit]

eh, sounds like more work than i have time for.
tks for the input!

[doobiebro]

The 1975 and 1976 F model came with spoked wheels, although the front had a single caliper/disk.  You may find a set of these and then do the mod to put a second caliper/disk on the front.

[Geeto67]

The f2 has much better brakes than the previous cb750s, why would you want to go backwards for the sake of style?

If anything I would upgrade the F2 calipers with twin pot calipers off the DOHC bikes from 1981-1982

[Egil]

The 79 CB900F has  the same diameter (size) on the front fork legs and will fit straight in to the  top bridge,if you go for those options .
You can choose from newer the caliper that have 2 cylinders insted of the original one cylinder slide caliper.
Please corrects me if 

[Geeto67]

The 79 CB900F has  the same diameter (size) on the front fork legs and will fit straight in to the  top bridge,if you go for those options .
You can choose from newer the caliper that have 2 cylinders insted of the original one cylinder slide caliper.
Please corrects me if 

We didn't get the 900F here in the states until 1981 and by then the forks had grown to 37mm. We did get the 750F here in 1979 but the single pot calipers on the 1979-1980 cb750Fs don't really work any better than the 77-78 CB750F single pot calipers. Honda did not switch over to the twin piston calipers until 1981 on the 900F (and some of the 750s - I think it was a midyear switch). You find them most often on the 1982 models here in the states. I don't know if the cb1100F calipers will work since the discs and wheel are different.

I have converted my 1979 cb750F to twin pots and it just bolts on despite the different forks. I am currently converting my 78 SS and so far the rear is the only one I can say with certainty is a bolt on. The front looks like it is but I just haven't actually bolted it on yet.

[Egil]

Have sent you a mail whit picture that's are to big for post on the the forum  , sorry to the rest of the users

[yoomit]

not trying to lose braking power over aesthetics.  if i can't retain the dual discs upfront while attempting to convert to spokes, then this idea is dead.
i was hoping for weight savings front and back by switching to an aluminum spoke set.

[Egil]

Think there are something on the forum about your problem's take a Search in the forum

[Geeto67]

The problem with SOHC wire wheels and brakes is in the caliper not the rotor or wheel. It is a fact of life. Probably the best balance of weight reduction and stopping power that is a bolt on is your current stock setup. Even the comstar F single pots are much better than the spoked wheel single pot calipers. Just evolution of design.

If you absolutely want spoke wheels and don't want to give up your current stopping power you could adapt a 1975-76 Goldwing front end. It is a bolt on as long as you get the triple trees. However as far as weight savings are concerned the alloy rim does little to stem the weight penalty of 37mm forks, two huge discs, and calipers that look like the came off a car. This was the ultimate back in the day upgrade and considering the front end was designed to stop a bike that weighed half as much more than a cb750 it is slight overkill....but then again there is no kill like overkill.

You can convert a 73+ K or early F spoked wheel setup to dual disc but the problem is you are still stuck with those K calipers which are not as good as your F calipers so you are not really making any headway and most likely you are going to loose your speedo drive in the process. this and the gw front end both have the weight penalty of a tube in the tire.

IF you just want the lightest weight and best stopping power as a bolt on, a tubeless comstar and a set of 1981-82 twin pot calipers is the ticket.

[Kevin400F]

I've been thinking about disassembling a Comstar, saving only the inner hub and brake discs, then having two bolt-on discs fabricated to serve as flanges for conventional wire spokes.   Aluminum alloy 1/4" thick should be sufficient, replicating the spoke hole circle of, say, a CB400F rear hub to permit OEM-length spokes to be used with an 18" alloy rim.

Kevin in TX

[eurban]

Gotta have spokes?-for the front I would consider either taking MRieck's approach or find a suitable early complete GL1000 (spoked) front end.  Brake quality is pretty much the same as the F2/F3 setup and the alloy DID rim is a nice piece.  Not overkill IMO.  I don't believe that there is much weight difference between the F2/F3 calipers and the GL pieces but I do believe the rotors are heavier.  The forks are certainly heavier but the unsprung portions (the legs) are not. . . . .  The GL setup looks nice.