Topic: Seeking rim advice for ´76 CB750f cafe

[rangerdave1]

I am Seeking advice regarding wheels for ´76 CB750f cafe build i am getting ready to start.

I want to keep spoke wheels and trying to decide between rebuilding my wheels with stock d.i.d steel rims or changing them out for aluminum rims. I plan on taking my hubs and polishing them and would like to build the wheels myself. I would love to go a little wider with the rims however looks like that is more trouble then it's worth.

Firstly, other then looks, is there a real advantage to going with aluminium rims? What kind of weight savings are to be expected?? And will ot even be noticable?


I have been searching online and have found buchanan's which seems to be the best route however its out of my price range, especially with shipping to Canada, exchage rate and duties...

Are there cheaper ways to build wheels with aluminium rims? What are people using? Excel rims? Other brands? If so which ones??

I also found what seems like a decent price for a set of rims and spokes from 4into1.com however not sure if these rims are any good and unfortunately the kit comes with zinc spokes instead of stainless.    https://4into1.com/rising-sun-rim-spoke-set-silver-honda-cb750f-1975-1976/)



Any help would be appreciated.

[754]

Where in Canada ?

[slikwilli420]

Steel rims seem completely pointless to me unless doing a restoration. Go with 2.5 front and 3.0 rear and it will have a great look and give plenty of tire choices.

[rangerdave1]

Where in Canada ?

I am in Nova Scotia

[rangerdave1]

Steel rims seem completely pointless to me unless doing a restoration. Go with 2.5 front and 3.0 rear and it will have a great look and give plenty of tire choices.

Any recommendations on which brand of rims?

[slikwilli420]

I like Borrani wheels but Sun and Excel are very nice as well. Hoops and spokes will run you at least $600 regardless of brand chosen. Not cheap but a great way to get custom wheels for your ride.

[Bankerdanny]

If you don't mind a 17" rear rather than an 18, the aluminum rims from a '75-'77 GL1000 Goldwing will work. The front wheel is a direct bolt on (you will need to swap over your rotor and speedo drive) and the back rim laces right up with standard GL1000 spokes. The GL rear can often be found in the US for not a lot of money and should be relatively common in Canada too.

[calj737]

You’ll never discern the weight difference between ally or steel rims riding your bike. However, ally won’t rust and that alone is the number one reason I’d opt for ally rims. Especially in Nova Scotia. Same is true for stainless spokes versus zinc plated.

Excel rims are excellent quality, as are the Sun rims. With rims, you get what you pay for. They will either be true and round, or uneven, out of round, and the spoke holes jiggered. Your choice.

[seanbarney41]

You’ll never discern the weight difference between ally or steel rims riding your bike.

strongly disagree...the wheel assembly is THE most important place to save weight, because they are spinning...better acceleration, better braking, and easier direction changes

[calj737]

You’ll never discern the weight difference between ally or steel rims riding your bike.

strongly disagree...the wheel assembly is THE most important place to save weight, because they are spinning...better acceleration, better braking, and easier direction changes

Whats the weight difference than between stock sized steel and ally rims? Adding a second rotor adds substantially more weight than a simple rim change. I guarantee you its not even 2lbs difference, and thats being generous. Hell, modern tires probably weigh more in difference than a rim change.

Anyone riding a 40 year old close to 500# bike on the street will never ride the difference in rim weights.

[rangerdave1]

Thanks for the replies.

I am still having a hard time finding information on which rims to look for. I'm curious if aluminium rims require the same length spokes as the factory rims providing I stay with the same diameter wheels... Also, I assume the width listed on the stock rims is the internal width, do aluminum rims also sell the wheels based on the internal width dimension???


I would be happy to stick with the original size in the front and it's mostly the rear width I would like to widen a bit..

 I found cycle exchange has a 2.5" wide rear rim, does anyone have experience with this rim? I assume I could go up to a 130 tire since the rim is a little wider.

[calj737]

Spoke lengths are the same as long as the rim is the same style, versus drop centered etc. A 3.5” rear rim width will fit just fine, and handle a 130 tire quite nicely. I don’t know the rims from CycleX, but 4into1 also has some inexpensive ally rims on their website.

[Alan F.]

I wouldn't sweat over zinc plated spokes, it probably took years parked out in the elements for most stock spokes to start rusting. The main difference between zinc plated spokes and stainless spokes is you can polish stainless spokes.

Once you wrap your head around building and truing spoked wheels and learn how to calculate spoke lengths to lace any hub to any appropriate rim, the mystery will be gone and it'll be just another thing to leave stock or go wild with.

Recommended reading: http://earlymotor.com/leon/misc/html/spoke.htm

[754]

 750 A alloy rims bolt right on.
 If you have a rim in hand you are thinking of buying, measure across where spoke nipples exit, then compare to yours. Keep in mind not all rims are drilled at the angles you need and make sure they are 40 spoke.

[754]

Small differences matter.
 Old Scrambler von here,  set a record at Bonneville in late August. His competition was .15 of a mile an hour slower, so he lost the record. Small difference meant win or lose
 I remember changing jetting on my 72 750, then being able to keep up with my buddy, i could not before.
Small change makes a difference.
 So on rims if they are lighter,  you can accelerate slightly quicker   and it will handle better.
And if they are truer than steel, the ride can be smoother.

 So yes small differences matter and they add up.

[scottly]

You’ll never discern the weight difference between ally or steel rims riding your bike.

strongly disagree...the wheel assembly is THE most important place to save weight, because they are spinning...better acceleration, better braking, and easier direction changes

Whats the weight difference than between stock sized steel and ally rims? Adding a second rotor adds substantially more weight than a simple rim change. I guarantee you its not even 2lbs difference, and thats being generous. Hell, modern tires probably weigh more in difference than a rim change.

Anyone riding a 40 year old close to 500# bike on the street will never ride the difference in rim weights.

It's not so much the total weight savings, as much as where it's placed, Cal. Two pounds at a radius of 9 1/2" has much more flywheel effect than the same two pounds at a radius of 5".

[Farley121]

  I would actually love to know the weight difference between the two metals.  Someone must have weighed a steel vs alum rim.

[754]

On same size piece aluminum is 1/3 the weight of steel.
 But due to construction sometimes being different, it may be more like 1/2 the weight..
 A  SHOULDERED alloy rim  would be heavier than a shoulderless for example.

[calj737]

It's not so much the total weight savings, as much as where it's placed, Cal. Two pounds at a radius of 9 1/2" has much more flywheel effect than the same two pounds at a radius of 5".

TIL nothing. The flaw in your analogy is that the weight delta is distributed throughout the entire mass of the rim, not in a specific location. And as Frank also points out, simply because a rim is ally and not steel, doesn’t guarantee a weight savings due to construction cross section. Ally is lighter in a given equal mass, but in order to obtain the equal strength, more mass is required using ally.

I stand by my assertion that anyone riding a 40 year old SOHC on the street, won’t ride the difference. On a track where weight matters, sure, it can be hugely advantageous since all areas are addressed. But for a “cafe” bike, give me a break 

[rangerdave1]

If the weight savings are only 2 or 3 pounds, I can't see myself feeling that difference on the streets. As already mentioned, I'm sure the the difference would be noticed on a race course as you're pushing the bike to it's limit in that environment. I have two other faster bikes anyway so this build is not as much for performance as it is for style.

To me the advantage to steel rims are that they stay shinny without any added work and have the classic look. The disadvantage to me is that I'm very limited to the sizes available and can't seem to find a 3" rim for the rear. Spoke selection will also be easier with steel rims since I'd be able to order stock replacements in zinc, SS, or chrome..

Alumimum rims are lighter, look a tad bit more modern and look stunning when polished. However they are much more expensive, likely require custom length spokes, and require alot more maintenance to keep looking good...


Do aluminum rims have a locking lip? If you seal the nipples, can you run tubeless?? If they can be run tubeless, I see that as an advantage but I doubt its a reasonable option without some experimenting and likely some leaks...

Is there anyone that has found steel chrome rims in 18x3"


 

 

[calj737]

Most ally rims are anodized, so polishing isn’t required unless you tear them up. Two best advantages to ally rims are potential weight savings (for the correct application) and anti corrosion benefits. Spokes are the same provided the rim style is the same. Cost is a factor, but, there are some inexpensive ally rims out there just as there are inexpensive steel rims. Cost is all about quality on both. Quality of chrome, circularity, tolerances, etc.

As a rule, ally costs more than steel, simple as that. Manufacturing techniques are similar, and finishing them both involves extra steps.

You can find both steel and ally rims in wider sections. Spoked rims as a rule are not tubeless. Some have run tubeless tires on spoked rims with no ill effect, but the lip design of a spoked rim differs from a tubeless mag. Be aware of that. You can run a tubeless tire on a spoked wheel with a tube, rim tape cover the nipples, and some care.

[SOHC4 Cafe Racer Fan]

I'd recommend aluminum rims over steel unless you are doing a factory original restoration or you don't have the extra dollars for aluminum wheels.  FYI -- you can get the exact size front wheel from a 75-77 GL1000 in aluminum, and simply swap the brake rotors -- the hub is identical.

[scottly]

  I would actually love to know the weight difference between the two metals.  Someone must have weighed a steel vs alum rim.

From a post a couple of years ago:

"I actually just measured the weight of my stock rear steel rim compared to my new excel aluminum shoulder rim two weeks ago.  It's not apple to apples as I got a wider aluminum rim (18 x 2.5 vs. the stock 18 x.215 steel rim), but it gives you a general idea.

Not super accurate, but I hopped on the scale holding the steel rim, and then hopped on holding the aluminum rim: total weight savings was 1.8lbs.

I know, I thought it would be more.  I assume you'd save a little more weight if you stick with the stock size... maybe a little more if you get the non-shouldered rims... not sure?  But, I wouldn't expect a huge weight savings - I'm guessing 2-3 lbs savings max.

All that said, saving 2lbs of rotational mass around a 18" diameter is pretty significant."

[scottly]

It's not so much the total weight savings, as much as where it's placed, Cal. Two pounds at a radius of 9 1/2" has much more flywheel effect than the same two pounds at a radius of 5".

TIL nothing. The flaw in your analogy is that the weight delta is distributed throughout the entire mass of the rim, not in a specific location.

Weight delta? Two pounds at a mean radius of 9" requires an energy of 61 ft/lbs to accelerate from zero RPM to 800 RPM, (approximately 60-65 MPH, depending on the tire diameter) and the same energy to slow it down from 800 RPM to zero. This is the amount of energy to lift 61 pounds one foot, or one pound 61 feet.

[PGF550F]

Getting pretty heated up over discussions about what makes or breaks a good rim job...