Author Topic: Modern 600cc vs a SOHC (Read 10155 times)

Wisohc · « **on:** March 22, 2016, 12:28:53 AM »

I picked up my first SOHC about a year ago and once I finally got it back on the road I immediately noticed how the acceleration differs from a modern bike. I'm speaking mostly of how when you roll on, say third gear or so you can really feel a modern 600CC push you back off the seat but I've never felt that with my SOHC.

I always thought that's just how these old bikes are but when I searched online I hear of folks saying how fast they are and some say they're faster than the modern 600CC's.

I really have to push my bike and it feels like racing a 125CC compared to a 250CC or so. I'm usually always taching above 4500 and from there I can make it scream and get going but it's never a "I better hold on" kind of feeling (which at times I'm glad because it brakes like I think a 40 year old bike would).

Anyway, long story short. I'm wondering if I have it tuned properly. I runs great and honestly is smoother than a lot of new bikes I've been on but it sat for 10+ years before I got it and all I really had to do was clean the carbs to get it going. I did the best sync job I could with what I had (2 vacuum gauges) and the only thing I can think that I haven't done is a compression test but the bike only had 14,xxx miles when I got it and like I said runs amazing.

Deltarider · « **Reply #1 on:** March 22, 2016, 12:37:24 AM »

My advice would be, start with the easiest and make a long, nice ride on the highway @ 7000 rpm (minimum) and after an hour or so exit the highway and feel if pick-up/driveability has improved. For me it always worked. Mine is a CB500 and feels best with 2 to 3 extra degrees advance.

Retro Rocket · « **Reply #2 on:** March 22, 2016, 12:50:48 AM »

Most modern 600's have about double the HP of the old Sohc 750 so you won't get any where near the acceleration on your Sohc/4...

Terry in Australia · « **Reply #3 on:** March 22, 2016, 01:34:09 AM »

Yep, modern bikes crap all over our old bikes, they just don't have any...... "Character".....

Bailgang · « **Reply #4 on:** March 22, 2016, 01:51:29 AM »

My kids earlier cbr600 F3 would smoke my 750 and his current cbr600 F4i is even faster, the brakes work a lot better too.

Wisohc · « **Reply #5 on:** March 22, 2016, 02:29:26 AM »

Thanks guys that's what I thought but I just wanted to make sure. It does take awhile to warm up and is spotty until it reaches temp. Plus, I don't really need to be going that fast

Trevor from Warragul · « **Reply #6 on:** March 22, 2016, 03:06:05 AM »

My wife's Yamaha XJ6N is very fast, and it's a detuned R6 motor...

70CB750 · « **Reply #7 on:** March 22, 2016, 03:31:50 AM »

There is usually a sweet spot you can feel starting above 4000 rpms.

What sprocket combination are you running?

Steve_K · « **Reply #8 on:** March 22, 2016, 03:37:55 AM »

These are 40 year old bikes and even if it was new would never have a chance against a modern 600. Heck, my 86 GIXXER would stomp a CB750 or even a Z-1. Think about it, 4 value heads, water cooling, better brakes and suspension make a huge difference.

BUT, these SOHC Hondas are great fun to ride. They are just different and much more rare on the street.

Steve

ekpent · « **Reply #9 on:** March 22, 2016, 05:25:53 AM »

My Son got great satisfaction out of womping the crap out of dear old dad riding a 750 on his GSX600RR and he did not even have to get past 3rd gear. He did have a nice looking tail light way up in the distance. First time I rode the 600 I grabbed a handful of front brake like I do on the 750 and ended up sitting on the tank doing a 'stoppie' and damn near dropped it

Stev-o · « **Reply #10 on:** March 22, 2016, 05:40:22 AM »

No comparison!

DH · « **Reply #11 on:** March 22, 2016, 05:40:28 AM »

There is a lot of nostalgia surrounding the SOHC bikes. The 750 was one of the fastest and best all around of its time, and was eclipsed
fairly quickly by other bikes. The term "VS". shouldn't even be used. A modern 600 will out perform any stock SOHC,
in any area. I own one of each, and found the 600 amazing when I bought it. That said, the SOHC4 is what it is, and nobody can take the cool factor away from it. Honda hit that one out of the park IMO. When the time comes to thin the herd, my 750 will be the last to go.

Don R · « **Reply #12 on:** March 22, 2016, 08:17:00 AM »

It's like comparing a 300 horse 327 chevy to a modern LS Corvette engine. The 327 is still awesome for what it is but really can't compete.

mrfish2 · « **Reply #13 on:** March 22, 2016, 08:33:27 AM »

I bought a 2015 Yamaha FZ-09 the other week, and with triple the horsepower and triple the torque compared to my 550 there really is no comparison. Even in 6th gear I have to hold on when whacking the throttle open on the FZ, but my 550 will always be cooler. A lot more people like the old bikes, even if they are slow. And when you combine them with a loud pipe (like Kerker or MotoGP Werks) it just makes them that much more fun

strynboen · « **Reply #14 on:** March 22, 2016, 08:52:16 AM »

delta is head on..
.a auer or 2..on the heighvay...at the start of the seson..and all old oil and dirt is burned off...and it starts,, idel and runs just better for more month..
..if it not can take that..its not worth to hold it.

firebane · « **Reply #15 on:** March 22, 2016, 09:13:00 AM »

CB750s are like a fine wine... The older they get the more fine they become. Everyone has a modern 600cc bike and there is absolutely NOT uniqueness to them at all.

No you won't stand a change against any modern bike no matter what but do you want fast and boring or slow and fun?

Bailgang · « **Reply #16 on:** March 22, 2016, 02:18:54 PM »

Quote from: ekpent on March 22, 2016, 05:25:53 AM

My Son got great satisfaction out of womping the crap out of dear old dad riding a 750 on his GSX600RR and he did not even have to get past 3rd gear. He did have a nice looking tail light way up in the distance. First time I rode the 600 I grabbed a handful of front brake like I do on the 750 and ended up sitting on the tank doing a 'stoppie' and damn near dropped it

My kids cbr600 is a blast to ride but I've still got too much kid in me to be owning one for myself, I'd just get into way too much trouble. Late last year my kid picked up an older cbr900, I can't wait to try that beast out.

I know what you mean about the brakes, not only are me feet always searching for the foot pegs when I first get on his bike but I always have to remind myself to be aware of the brakes as well.

dusterdude · « **Reply #17 on:** March 22, 2016, 05:50:52 PM »

Quote from: Bailgang on March 22, 2016, 01:51:29 AM

My kids earlier cbr600 F3 would smoke my 750 and his current cbr600 F4i is even faster, the brakes work a lot better too.

Mine too

Sent from my LG-D850 using Tapatalk

FunJimmy · « **Reply #18 on:** March 22, 2016, 06:18:33 PM »

Let's see, 40 years of development, twin cam, multi valve, fuel injection, electronic engine managment, higher compression, better metallurgy and tighter tolerances. Ya, should be close.

Terry in Australia · « **Reply #19 on:** March 22, 2016, 09:46:31 PM »

Funnily enough, I remember all of the above being said when my CB750 was new......

Desert-SOHC · « **Reply #20 on:** March 22, 2016, 10:17:11 PM »

Nothin beats the sound of a SOHC singin!! It's not fast by today standards, but then when they roamed the streets in the early 70's they were the Kings at the stop lights on Whittier Blvd.

Garage_guy_chris · « **Reply #21 on:** March 22, 2016, 10:39:24 PM »

Thanks for bursting that bubble guys.... I felt my 750 (albeit a lightly hot roded 836) was a pretty quick bike! I figured a 600 was a lot of revs and HP but not so much torque also with a really tall gear set compared to a 750. While the 750 is more even between torque and HP with similar torque to a 600 and nice useable short gearing. All that being said I figured it might resemble a race to 60-80 miles an hour then the 600 would walk away

At the end of the day I would really like to try out some bigger bikes, when summer comes and the Honda Test rides starts up i would love to try the CBR650R, CBR600RR, VFR800, maybe even a liter bike... (doubt Im ready for that)

Wisohc · « **Reply #22 on:** March 22, 2016, 10:50:46 PM »

70CB750 - I'm not sure what sprocket combo I am running but I'm guessing it's stock.

Guess I'm a bit older than I thought.... When I say modern I'm thinking like 94 and up on the inline 4 cylinders. Anyway....

Mostly of what I'm thinking about when I talk about performance comparison is that the CB has absolutely no power band. At least not in the way a modern bike or possibly a DOHC would have. I've wondered if it's the DOHC that provides that extra pull when rolling on the throttle.

Still thought the SOHC is super cool and more than fast enough. Modern-ish 600's are too easy to get in trouble on and really don't have any nostalgia to them.

harisuluv · « **Reply #23 on:** March 22, 2016, 11:14:30 PM »

A CB750 was my first SOHC experience. I also thought it was fast, but compared to today's bikes it's a real dog. I used to hear stories about RD350s beating CB750s back in the day and part of me just couldn't believe it.

Then I got an RZ350, and it would destroy any 750 I've ever owned. It's not even modern, it's an '85 and it's a 350cc.

It's kind of a tough pill to swallow, but they're not "fast" relative to what's out there anymore.

teotdk · « **Reply #24 on:** March 23, 2016, 01:33:48 AM »

You just hve to go the other way... i started to built bikes with a '58 Simson AWO 425... Really really great bike.. next was a cb 500 Four.. the accelaration was madness.... Won't get any better! HP doesn't beat the sound and awesomeness of the SOHC...

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Author Topic: Modern 600cc vs a SOHC (Read 10155 times)

DH