Modern vs Classic

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Now I’d like to know the weight difference between the 961 engine and bare frame vs that of the original and modern Manx.

How much weight do you all think could be shaved from a modern 961 in a race spec only non street bike. Removing all street gear and removing all unnecessary weight?

I need to weigh my commando and dominator. Isn’t obvious the Domi is lighter. But not sure by how much. I’m not certain, but the Domi swing arm may even be heavier, it has more tubing compared to the commando. But it does have a lighter single rear shock vs 2 for the commando.

Anyone know the weight savings of the BST carbon fiber wheels vs the stock aluminum steel spoked wheels? I’d guess at least 10-15 pounds total.
What about track only race tyres? Less weight?
Certainly less rotating mass.

I don’t think the 961 needs more HP /Tq To beat a Manx of any vintage, the 961 needs less weight.

But....

I really wish someone, somewhere would offer a race spec 961 engine and trans.
Im curious how a 961 Domi could be built into a full spec race bike to compete against other vintage bikes.

I’m also wondering how a stock 961 Commando would compare to a stock 961 Dominator same day. Same track. Same rider.
 
italia said:
Ken, I appreciate your response and am not questioning your experience. Though considerable over the last 15 years, I've spent somewhat less time than you on tracks, but on the half dozen modern tracks I've been on, drum brakes (at least the ones I have experience with) would be a considerable hindrance TO ME, as most of MY overtaking of other bikes tends to be on the brakes.

Maybe I'm underestimating the ability of the Manx' TLS & SLS drum brakes to refrain from fading, and providing consistency in hard pre-corner entry braking, corner after corner, lap after lap, so take my comments with a grain of salt if you have experience with those specific brakes, and my assumptions are off base.

Sure, being much lighter is a HUGE advantage to the Manx.

Even with your adept point about lightness and agility though, I’d still probably take a 480 lb 80hp 961cc bike with Ohlins suspension and great brakes, over a 310 lb 54HP 498cc classic with drum brakes. YMMV, and godspeed to you for being faster on a classic.
Click to expand...

A good explanation, and I appreciate you responding so considerately. My apologies for getting a bit huffy about your post. I think I took it too personally. In any case, this thread has certainly produced some interesting info from which we can all draw our own conclusions.

And to be fair about it, I retired from racing 27 years ago, so my personal experience is a bit dated. But I did keep a team going for some serious AHRMA racing for another 10 years or so with other (mostly faster :D ) riders on my race bikes. Good times, but in the past now.

Ken
 
Scott, IMHO the 961 will never be a lightweight, I looked hard at mine and concluded you gotta get serious if you wanna lose more than the obvious.

As already mentioned, the easy stuff includes:
Cat removal.
Lighter silencers or 2:1. Get a 2:1 fabricated in Ti would be good.
Lithium battery
Mirrors
Indicators
Carbon wheels, inc removal of inner tubes.

Other areas that came to my mind, but require more work are:
Footrest plates and hangers, removal and re design
Removal of stock seat and sub frame and fabrication of lighter
Removal of ABS equipment if applicable
Removal of starter motor and associated ancillaries (if serious about race / track use)
Ditto lights and other road gear
Lighter fuel tank.

And FWIW I don’t agree the 961 ‘doesn’t need more power’. I think if you dyno’d yours you might get a shock! Dyno reports seem to vary from high 50s to low 70s rwhp. The low 70s figure was with airbox and exhaust mods, plus a Power Commander ign IIRC.

I don’t think it is ‘black magic’ to get more power. I think a knowledge person could look at the head, valves, piston, cam and come up with a plan quite easily. Any such plan is likely to require bigger / better injector bodies or carbs, and removal of the airbox. You’re in the right part of the world to tap into some serious ‘2 valve pushrod’ tuning knowledge from the race car fraternity.

If you could shed 80-100 lbs AND get the power to a genuine 80-90 rwhp I think you’d have something very special and fun to ride.

But its gonna be a proper ‘project’. This isn’t a ‘from the catalogue’ kinda thing.

So, you’re gonna have to get innovative, and very willing with your credit card ...

But... you did say that you want a project...!
 
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It's kinda like what you told me in another thread Nigel - if you're addicted to trying to get low lap times go and buy a cheap 600. Or run the 961 with a couple of mods for ground clearance and breathing and challenge yourself to get the best out of it at your local track.
 
Clive said:
It's kinda like what you told me in another thread Nigel - if you're addicted to trying to get low lap times go and buy a cheap 600. Or run the 961 with a couple of mods for ground clearance and breathing and challenge yourself to get the best out of it at your local track.
Click to expand...

Indeed, and I’d choose the latter purely for the grin factor! I thoroughly enjoyed taking my 961 on the track and have occasionally found myself looking at second hand ones now that prices have come down, contemplating using one as a track day toy.

But the one point you’re not factoring in here Clive is Scott’s level of OCD...!
 
Fast Eddie said:
Indeed, and I’d choose the latter purely for the grin factor! I thoroughly enjoyed taking my 961 on the track and have occasionally found myself looking at second hand ones now that prices have come down, contemplating using one as a track day toy.

But the one point you’re not factoring in here Clive is Scott’s level of OCD...!
Click to expand...
Yep - I have a session with Jamie Whittam booked at Mallory in April on the 961 which should be fun. Personally I would not want to be on a bike coming out of each corner on the back wheel so the extra weight but good handling & brakes suits me.

What you said a while back did set me thinking; a Seeley rolling chassis with a recammed and carbed 961 lump would be rather interesting against a Manx...
 
Fast Eddie said:
Scott, IMHO the 961 will never be a lightweight, I looked hard at mine and concluded you gotta get serious if you wanna lose more than the obvious.

As already mentioned, the easy stuff includes:
Cat removal.
Lighter silencers or 2:1. Get a 2:1 fabricated in Ti would be good.
Lithium battery
Mirrors
Indicators
Carbon wheels, inc removal of inner tubes.

Other areas that came to my mind, but require more work are:
Footrest plates and hangers, removal and re design
Removal of stock seat and sub frame and fabrication of lighter
Removal of ABS equipment if applicable
Removal of starter motor and associated ancillaries (if serious about race / track use)
Ditto lights and other road gear
Lighter fuel tank.

And FWIW I don’t agree the 961 ‘doesn’t need more power’. I think if you dyno’d yours you might get a shock! Dyno reports seem to vary from high 50s to low 70s rwhp. The low 70s figure was with airbox and exhaust mods, plus a Power Commander ign IIRC.

I don’t think it is ‘black magic’ to get more power. I think a knowledge person could look at the head, valves, piston, cam and come up with a plan quite easily. Any such plan is likely to require bigger / better injector bodies or carbs, and removal of the airbox. You’re in the right part of the world to tap into some serious ‘2 valve pushrod’ tuning knowledge from the race car fraternity.

If you could shed 80-100 lbs AND get the power to a genuine 80-90 rwhp I think you’d have something very special and fun to ride.

But its gonna be a proper ‘project’. This isn’t a ‘from the catalogue’ kinda thing.

So, you’re gonna have to get innovative, and very willing with your credit card ...

But... you did say that you want a project...!
Click to expand...
Yves, do you need a new project for lockdown!!??
 
Clive said:
Yep - I have a session with Jamie Whittam booked at Mallory in April on the 961 which should be fun. Personally I would not want to be on a bike coming out of each corner on the back wheel so the extra weight but good handling & brakes suits me.

What you said a while back did set me thinking; a Seeley rolling chassis with a recammed and carbed 961 lump would be rather interesting against a Manx...
Click to expand...
Did I say that about a Seeley chassis? If so, just goes to show you should drink and type...!

It would need a complete re-design to house the 961 power train. So much so it wouldn’t really be a Seeley any more !
 
Fast Eddie said:
Did I say that about a Seeley chassis? If so, just goes to show you should drink and type...!

It would need a complete re-design to house the 961 power train. So much so it wouldn’t really be a Seeley any more !
Click to expand...
I don't think you actually suggested putting the 961 engine in the Seeley chassis so I'll forget that idea.

Back to a 'switch on when you need it' low pressure Rotrex type supercharger with a brushless motor in place of the airbox and lipo battery pack under the pillion hump.....
 
Why compare a racing bike from years ago to a present day road bike? I agree it's an interesting question,and I'd love to see it played out on a track though
But really it should be a road bike IE the first dominator being a twin cylinder road bike
 
Clive, Mr Whittam is the man! So down to Earth and unassuming, yet such vast ability and experience.

Interesting trivia: he’s building a Rickman Metisse with a Triumph engine in it, just for fun.

You’ll love that day. Are you riding the 961 or renting a ‘disposable plastic motorcycle‘ from them for the day ?
 
Fast Eddie said:
Clive, Mr Whittam is the man! So down to Earth and unassuming, yet such vast ability and experience.

Interesting trivia: he’s building a Rickman Metisse with a Triumph engine in it, just for fun.

You’ll love that day. Are you riding the 961 or renting a ‘disposable plastic motorcycle‘ from them for the day ?
Click to expand...
Most probably the 961 - there is a new 400 class in the CRMC eligibility rules so I am toying with the idea of a buzzy 400 like a gsxr or nc23 or zxr400.
 
An NC24 was my introduction to Mr Honda's legendary reliability and build quality...
Kept me biking through the 'lean' years as at the time they were two a penny, so nothing to gained by selling....
 
If you‘re the right build, an NC30 is a fabulous, fabulous, machine and virtually unbreakable.

If thats what you’re thinking of racing Clive, I’d ask what they can rent you. Compared to a 400cc race bike, going round Mallory on a 961 will be rather like going round in a long wheel base Transit...
 
Fast Eddie said:
If you‘re the right build, an NC30 is a fabulous, fabulous, machine and virtually unbreakable.

If thats what you’re thinking of racing Clive, I’d ask what they can rent you. Compared to a 400cc race bike, going round Mallory on a 961 will be rather like going round in a long wheel base Transit...
Click to expand...
Diesel?
 
Fast Eddie said:
Clive, Mr Whittam is the man! So down to Earth and unassuming, yet such vast ability and experience.

Interesting trivia: he’s building a Rickman Metisse with a Triumph engine in it, just for fun.

You’ll love that day. Are you riding the 961 or renting a ‘disposable plastic motorcycle‘ from them for the day ?
Click to expand...
Awesome bloke, hell of a racer in his day and with such a unique riding style - always entertaining. Not bad for a Yorkshireman! Was a bit of a Foggy (Lancastrian of course :) ) groupie throughout his career and came across Jamie a few times I think. My memory is shocking! I’ve had this signed pic knocking around my garage for decades - no idea where I got it from!

Enjoy the day Clive - should be a blast!

Modern vs Classic
 
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