Topic: 1973 Honda cb750K3 Clutch Replacement.

[Stev-o]

I like the way you keep track of your clutch cover screws. 

I do a similar drawing but include the length of the 6mm screws as I typically switch them to SS socketheads, especially if they have been "boogered up" by a PO.

[BenelliSEI]

Great wheels, I wonder what the weight difference is, if any.

They are not very light….. Never actually measured the difference. I’m running a set of tubeless dual sport Kenda tires on them now.

[BenelliSEI]

I like the way you keep track of your clutch cover screws. 

I do a similar drawing but include the length of the 6mm screws as I typically switch them to SS socketheads, especially if they have been "boogered up" by a PO.

Nice…. I had to replace these. All of  them were damaged….. fortunately they all “popped” with the hand held impact and went straight to the scrap bin.

[HondaMan]

Great wheels, I wonder what the weight difference is, if any.

They are not very light….. Never actually measured the difference. I’m running a set of tubeless dual sport Kenda tires on them now.

They are definitely heavier than the regular spoked wheels, so using them makes the steering heavier. It's the tubless-ness feature of them that I like.
I also have a pair (I think) of the Comstar wheels, but they won't fit right on the K2.

[seanbarney41]

Great wheels, I wonder what the weight difference is, if any.

They are not very light….. Never actually measured the difference. I’m running a set of tubeless dual sport Kenda tires on them now.

They are definitely heavier than the regular spoked wheels, so using them makes the steering heavier. It's the tubless-ness feature of them that I like.
I also have a pair (I think) of the Comstar wheels, but they won't fit right on the K2.

Lesters are very close to the same weight as a stock wheel assembly.  They absolutely DO NOT make the steering heavier as I think the weight is centered more around the hubs and not sure why, but the fact that they are absolutely rounder and truer than a steel rimmed spoke wheel could ever be seems to really lighten up the handling of the whole bike.  There were many other manufacturers of similar wheels.  There are Morris and Hayashi that look very similar and they all have different pluses and minuses in use.  Yamiya sellsa six spoke variant brand new.

[HondaMan]

Great wheels, I wonder what the weight difference is, if any.

They are not very light….. Never actually measured the difference. I’m running a set of tubeless dual sport Kenda tires on them now.

They are definitely heavier than the regular spoked wheels, so using them makes the steering heavier. It's the tubless-ness feature of them that I like.
I also have a pair (I think) of the Comstar wheels, but they won't fit right on the K2.

Yamiya sellsa six spoke variant brand new.

I remember ads in the 1970s stating they were lighter, but the ones I've mounted tires on weren't, which surprised me a little. Also the 'snowflake' version I have are heavier than my empty front wheel: I'll try to find a way to weight it and compare.

Can you point me to the Yamiya wheels (so I can dream and drool?).

[seanbarney41]

Yeah, the Yamiya wheels are beautiful but pricey! 

yamiya750.com/en/products/as203g

I din't know why I can't drag and drop a workable link anymore.  Hopefully someone else can help out.  Just google Yamiya's site and  they are in there with all the other cb750 tire and wheel parts.

[BenelliSEI]

https://yamiya750.com/en/products/as203g

This might work? Makes me think the gold might look good on the cb750K3 if I ever restore it……

[MauiK3]

Very nice wheels. Does anyone know the weight difference?

[BenelliSEI]

Nice day, so opened up the shop and ran the Varadero, K1 and K3.

Rode the cb750K3 up and down (in the shop, all of 20’) and the clutch is smooth, but still feel a small “judder”. I wonder if the snubbers have failed in the rear LESTER wheel? Will check those next time! Chasing my tail.

[seanbarney41]

Very nice wheels. Does anyone know the weight difference?

Lesters weigh more but not very much more.  Lesters have seven spokes with a heavy H profile.  The Yamiya wheels are made in Japan by Enkei with 6 spokes with a + profile, very similar to Morris.  Most of the weight of your wheel assembly is the brake drum and bearings and axles.  Six  spokes are less material than seven.  I have a set of Hayashi wheels on one of my bikes which are 5 spoke.  They are certainly lighter than the stock wheels, but probably not more than a pound or 2.

Another great benefit of the Yamiya wheels is they are likely designed to run tubeless.  Most of the old brands of cast wheels are not safe to run tubeless.  For example, some Lesters are and some are not, depending on their date of manufacture.

[MauiK3]

It would be interesting to see a side by side weight comparison. Same tire mounted on the two wheels, one spoked, one a (for example) Yamiya cast wheel. Bearings installed. The axle and brake assembly (on the rear) are constants so can be left out.

[BenelliSEI]

They look great but are not perfect. When I mounted the dual sport Kendas I remember checking the bare wheel balances before fitting tires and then mounting the lightest part of the new tire to the heaviest part of the rim. They still needed significant weight. They are well machined and run very true.

Next project is to pull the rear off and see if the cush drive rubbers are deteriorating. I first fitted these wheels to my cb750K8 (original 17” wheel). Most likely just moved the cush rubbers over from the original spoke wheel. I wonder if they are different than the earlier 18” style?

[Stev-o]

Very nice wheels. Does anyone know the weight difference?

Lesters weigh more but not very much more.  Lesters have seven spokes with a heavy H profile.  The Yamiya wheels are made in Japan by Enkei with 6 spokes with a + profile, very similar to Morris.  Most of the weight of your wheel assembly is the brake drum and bearings and axles.  Six  spokes are less material than seven.  I have a set of Hayashi wheels on one of my bikes which are 5 spoke. 

Hey Sean...your "snow bike" has Lester's?



I may be the odd man out, but I dont like mag wheels on my vintage bikes that came with spoke wheels. I've sold a couple sets of Lesters that I acquired over the years.
However, I did the mags that came stock on my KZ1000 & my GPz550, which had Enki's.

[HondaMan]

For weight differences: don't forget to "lose" the weight of the tube when going into the cast wheels.
Although at the cost of these wheels, the lighter wallet incurred may make up some of the difference, too?

[seanbarney41]

Very nice wheels. Does anyone know the weight difference?

Lesters weigh more but not very much more.  Lesters have seven spokes with a heavy H profile.  The Yamiya wheels are made in Japan by Enkei with 6 spokes with a + profile, very similar to Morris.  Most of the weight of your wheel assembly is the brake drum and bearings and axles.  Six  spokes are less material than seven.  I have a set of Hayashi wheels on one of my bikes which are 5 spoke. 

Hey Sean...your "snow bike" has Lester's?



I may be the odd man out, but I dont like mag wheels on my vintage bikes that came with spoke wheels. I've sold a couple sets of Lesters that I acquired over the years.
However, I did the mags that came stock on my KZ1000 & my GPz550, which had Enki's.

ha ha ha...no Steve-O  count those spokes!  Lesters are all 7 spoke.  These are 5  Made by Hayashi in Japan

I understand about your love of spoked wheels, Steve-O.  People just seem to equate vintage with spoked.  I just feel like Honda (and most Japanese bikes of the era) kinda just cheaped out with the chromed steel rim.  I have found that the bulk of Japanese bikes' reputation for poor handling should lead one to the typically abused and neglected loose spoked, wobbly, out of balance steel wheel with standard spokes.  But few ever make the connection other than attempting to cover the situation with a quick sandblasting and some black powder coat.  Or just ignore the situation altogether and agree "yeah these Japanese bikes don't handle so good"  Looking at the participants of this thread, I realize I am preaching to the choir.  Everyone following here has some of the nicest and thorough builds I have seen.  Quality aluminum rims, such as found on European bikes, or some Excel by Takasago, or even some GL/750 auto aluminum rims laced up with some Buchanon's heavy duty spokes is some other great ways to go !

[seanbarney41]

For weight differences: don't forget to "lose" the weight of the tube when going into the cast wheels.
Although at the cost of these wheels, the lighter wallet incurred may make up some of the difference, too?

But watch out there...as I mentioned earlier most of the early cast wheels do not have the proper safety bead that prevents a tubeless tire from coming off the bead in the event of deflation.  There are even many Lesters that have "tubeless" cast in that were made before this bead profile was invented. and thus are truly unsafe to run tubeless.  Also, as far as the cost of these wheels, 10 years ago a set of 18"/19" Lester's was $800 to $1200.  Now, you can find the same set of wheels for $500 or less.  I just bought a NOS set of Henry Abe star spoke wheels for $150.

[Kingmambo]

One thing I forgot to mention….. I’ve seen people struggle to remove the main clutch cover. Usually because someone has been over zealous with some horrible sealer. First, use a hand held impact driver to loosen ALL the retaining screws and remove. Got them ALL?

Assuming you have the chrome top cover off and the clutch cable removed, loosen the lock nut on the centre clutch actuating mechanism. Use a good size flat blade screw driver and turn the clutch adjuster IN. Easily pushes the cover away from the engine cases without any beating or banging.

You raise a good point on the hand-held impact. I wasn’t able to find a set which contained JIS bits but I did find a set of JIS bits on Amazon for like $12. It makes life so much easier.

[HondaMan]

For weight differences: don't forget to "lose" the weight of the tube when going into the cast wheels.
Although at the cost of these wheels, the lighter wallet incurred may make up some of the difference, too?

But watch out there...as I mentioned earlier most of the early cast wheels do not have the proper safety bead that prevents a tubeless tire from coming off the bead in the event of deflation.  There are even many Lesters that have "tubeless" cast in that were made before this bead profile was invented. and thus are truly unsafe to run tubeless.  Also, as far as the cost of these wheels, 10 years ago a set of 18"/19" Lester's was $800 to $1200.  Now, you can find the same set of wheels for $500 or less.  I just bought a NOS set of Henry Abe star spoke wheels for $150.

Great info, SB, thanks! I don't know a lot about the cast wheels as I've done spoked, HD spoked, alternate rims, etc., all these years. I only know I've long liked them (especially the Lesters) but never could afford a set. With modern tires and far too many non-Americans dumping boxes of screws & nails out of the back of their tailgate-less pickup trucks around here, a tubeless set would make a nice addition to my steed, now.

[BenelliSEI]

One thing I forgot to mention….. I’ve seen people struggle to remove the main clutch cover. Usually because someone has been over zealous with some horrible sealer. First, use a hand held impact driver to loosen ALL the retaining screws and remove. Got them ALL?

Assuming you have the chrome top cover off and the clutch cable removed, loosen the lock nut on the centre clutch actuating mechanism. Use a good size flat blade screw driver and turn the clutch adjuster IN. Easily pushes the cover away from the engine cases without any beating or banging.

You raise a good point on the hand-held impact. I wasn’t able to find a set which contained JIS bits but I did find a set of JIS bits on Amazon for like $12. It makes life so much easier.

This set from vintagecb750.com is not labeled as JIS but the third one from the left fits perfectly in all my case screws and has lasted for ever.

[BenelliSEI]

As posted elsewhere where I did pull the rear Lester apart and found a very small amount of play in the cush drive. Ordered a new set of rubbers and will see if that tightens it up.

[MauiK3]

Hopefully a little less free play in the rear cush drive will help.

[BenelliSEI]

Hopefully a little less free play in the rear cush drive will help.

Steve… I hope so. I’ve pretty much changed averything else.