Topic: Who has a lightened/balanced crank?

[xedge4lifex]

Im really interested in results from anyone who has put a lightened/balanced crank in their 550/750. weight? rpm? power band? who is a reputable shop to bring it to? should the pins be welded? how much would be a good price?

thanks guys
Aaron

[mec]

should the pins be welded?

thanks guys
Aaron

  its a one piece crank!

mec

[lordmoonpie]

Im really interested in results from anyone who has put a lightened/balanced crank in their 550/750. weight? rpm? power band? who is a reputable shop to bring it to? should the pins be welded? how much would be a good price?

thanks guys
Aaron

Yup, nicely lightened and balanced with the rotor - surprising how far out the rotor can imbalance an otherwise welll balanced crank. You'd need to find someone local I guess. I use Basset Down Balancing in the UK - very professional lot.
See bottom crank here to compare to top standard crank...power band moved up, revs faster and higher....great for race applications not so sure about street riding though.

[H2Eric]

I got mine done at APE via J. M. Rieck. A brilliant job and highly recommended, but I've not had the chance to test it yet.
Good luck
Eric

[MCRider]

Yes, I've run lightened and polished cranks in several engines for many years. Partly for bragging rights partly for performance. It does what is claimed. Overall lighter (thoug a diet may be more cost effective there) spins up faster, positive, negative, you lose flywheel effect making shifting a bit clumsier, etc.  It will reduce some buzziness in the handlebars and footpegs. Overall just feels like "hey I did something!".

Reducing spin weight good for road racers. Some dragracers say not so good as it interferes with a good launch. I'm sure thats a matter of riding style. But sitting in the parking lot and blipping the throttle, you'll hear the response easily over a stocker.

I've had local machine shops do it and I've had APE Performance cranks redo one. They claimed they got it balanced better than it was. Anybody can probably make it better than stock. For $225 I'd give it to APE the sponsor of this forum BTW.
http://www.racecranks.com/

Balance the rotor too. Welding not necessary on one piece cranks. That's different than on the roller bearing cranks like Z1s and GS (I think).

[Doctor_D]

I think most of us in this section of the forum have had it done. State-side folks use APE.  Long turn-around, but they know exactly what they're doing. Spins up nicely with 3lbs removed from the crank.

If you're going to reuse stock rods in a high performance application, shot peen them and use F2 rod bolts.  Don't forget to balance the big-ends and small ends either.  My rods overall weight was close, but the big-ends varied by almost 5 grams across the four rods.

[MCRider]

As to APE and turnaround, and additional backstory...

Big Jay at APE is the owner, and member of this forum. He started his business when the CB750 was King and has probably done as much with them as anyone. Now, the Hayabusa and the like is where performance shops make their real money, CB750s are a pain in the side. But Jay still has a soft spot for them, even has a special part of his website known as the "SOHC Zone" for CB750 performance parts and services. (See the banner at the top of this thread).

So, he likes to be the one that works on the CB750 parts, personally, I've heard. So you send your stuff in (I did a crank and a transmission) he's likely the one doing the work. But with the real workload a priority (gotta keep the lights on) he may have to set it aside till he gets a free moment to concentrate. I got mine back right away, i must have hit his CB750 day, others have had to wait I've heard.

This is what i've gleaned from reading his bio, and talking with the staff at the desk. Many places can do the work and are competent. If you can, I suggest using him/APE.

[Howell]

This is the crank we use in our CB500 racer , it is ligthened 4 kgs and dynamic balanced.
Conrods are from the Suzuki GSX-R 1000

[Big Jay]

Thanks for the kind words guys. We try to stay on top of these cranks, but when the busy season hits, we can have 60 cranks in here at one time.

Love the Hondas. Just did one today, but as another poster pointed out, we must do 50 hayabusas for every 750 sohc.

http://aperaceparts.com/mailers/crankmail.html

[mick7504]

The winning vote goes to Big Jay (APE)
All going to plan, this one will be rotating sometime this year.
Mick
http://forums.sohc4.net/index.php?topic=74086.0

[xedge4lifex]

@mec- ahhh im so used to the kz cranks i didnt even think of hondas having a single piece crank.

@lordmoonpie- your shaved and polished crank makes the world go round

@mcrider- thanks for the heads up, im definitely sold on APE now

@howell- 4kg? 8 pounds? yikes, i would assume road racing, im building a cb550 street legal race bike and attempting to get around 65hp to the rear wheel, any specs on your race bike?

@bigjay- Ill be throwing you some green and a 550 crank in the next couple months

thanks again everyone

[Howell]

@howell- 4kg? 8 pounds? yikes, i would assume road racing, im building a cb550 street legal race bike and attempting to get around 65hp to the rear wheel, any specs on your race bike?

Look here: CB500 racer

[MRieck]

@howell- 4kg? 8 pounds? yikes, i would assume road racing, im building a cb550 street legal race bike and attempting to get around 65hp to the rear wheel, any specs on your race bike?

Look here: CB500 racer

I forgot how nice job you did...great attention to detail. I personally like the use of the metal mesh on the side cover area etc.

[xedge4lifex]

@howell- 4kg? 8 pounds? yikes, i would assume road racing, im building a cb550 street legal race bike and attempting to get around 65hp to the rear wheel, any specs on your race bike?

Look here: CB500 racer

oh this is rene, yeah ive been addicted to your thread for the last year. great bike bud

[Sam Green Racing]

Yes, I've run lightened and polished cranks in several engines for many years. Partly for bragging rights partly for performance.

I had my crank gold plated and encrusted with diamonds, JUST for the Bragging rights. sorry, no pictures.

Sam.

[Sam Green Racing]

Reducing spin weight good for road racers. Some dragracers say not so good as it interferes with a good launch. I'm sure thats a matter of riding style. But sitting in the parking lot and blipping the throttle, you'll hear the response easily over a stocker.

Reducing spin weight is a matter of choice. The advantage of the heavier crank reduces the risk of bogging off the line.
If you do it in a circuit race, you will have a lot of catching up to do, not good. Do it in a drag race and you are on your way home The crank in the Bent on racing, JMR, JWEEKS drag bike was left stock, partly for cost and because it is automatic, it shouldn't bog at all. The crank was however dynamically balanced by ZINT a master crank guy from Boston. The oil gallery plugs were also removed and the inside of the crank was cleaned. The crank can act like a giant centrifugal oil filter flinging particles to the farest reaches of the oil ways and can unbalance the crank and block off the feed to the cranks journals/big end bearings. Keep it clean.


Sam.

[lordmoonpie]

Reducing spin weight good for road racers. Some dragracers say not so good as it interferes with a good launch. I'm sure thats a matter of riding style. But sitting in the parking lot and blipping the throttle, you'll hear the response easily over a stocker.

Reducing spin weight is a matter of choice. The advantage of the heavier crank reduces the risk of bogging off the line.
If you do it in a circuit race, you will have a lot of catching up to do, not good. Do it in a drag race and you are on your way home The crank in the Bent on racing, JMR, JWEEKS drag bike was left stock, partly for cost and because it is automatic, it shouldn't bog at all. The crank was however dynamically balanced by ZINT a master crank guy from Boston. The oil gallery plugs were also removed and the inside of the crank was cleaned. The crank can act like a giant centrifugal oil filter flinging particles to the farest reaches of the oil ways and can unbalance the crank and block off the feed to the cranks journals/big end bearings. Keep it clean.


Sam.

A good illustration of this was Jason Griffiths riding the Garfield 350 K4s - on short circuits the crank was lightened and balanced losing over 4lbs apparently, in the Manx GP, the crank was bog standard with just balancing. You spend so long at max revs in the IOM that the lightening is irrelevant and you need the flywheel effect for the four tricky first gear corners....

[jaguar]

does APE balance the rotors too?
any other lighter rotors then the ones cycle X was listing?

[MRieck]

does APE balance the rotors too?
any other lighter rotors then the ones cycle X was listing?

I can have 750 rotors balanced. APE doesn't list that service.