V7 sport top speed

[czakky82]

The thread about max speed on loop frames has me wondering about original Tonti top speed?

Mostly I’m curious about V7 sport top speed but really any early round head Tonti’s.

Tkelly’s T3 (my old one) would easily get up to an indicated 110, maybe more I really don’t remember I just know that it was pulling just fine well over the ton.

My Sport hasn’t had a proper high speed run yet.

[Tkelly]

125 in a 750comparison test in 1972,faster than any other 750 s including Honda,Kawasaki,Ducati,Laverda.Cycle World got 126 from the LeMans.My t3 will probably never go 75 again while I am riding it.

[Scout63]

More important to me is how smooth and secure the Tonti feels at high speed. I’ve become a wimp in the past few decades so rarely do I break 70 mph. I took my G5 out and about today and it felt very smooth and planted at about 50.  Not much help in answering Czakky’s question.

[PeteS]

A few Road Tests recorded just over 130 for the 850 LeMans. The difference between 125 and 130 can be as little as air temp, humidity, couple of degrees of timing or fuel.

Pete

[cliffrod]

I understand my bike will & has run in the approx 120 mph range with stock-spec drivetrain.  Whether it will do 125, that would require more accurate instrumentation or measurement. Getting to the top isn’t much trouble on flat level nice roads.  Once you get there, it just goes flat.   But it’s always smooth.

I do know for a $$$fact$$$ that it will easily coast after such a WOT throttle run at a TN Highway Patrol radar-indicated 108 mph. I know because he showed me…

[Turin]

I recently took my 850T out. Ikon shocks, Fac Dampers, worth springs, bridgestone spitfire tires ( tires are a little old), no steering damper. She's very stable at high speeds on a crap section of freeway. Mind you it's a bit more interesting than riding a modern bike at those speeds.

[LowRyter]

fast enuff

[TOMB]

My Sport at the time.

I could shift into 5th gear over 100 MPH and the bike could go faster, BUT NOT ME!

I swapped with a friend, and he said the bike was still accelerating at 110 MPH.

I really liked that bike!

Last known location it was in Vermont.

TOMB

[Turin]

If I remember, the V7 sport has 8/35 gearing which would give you more Top speed than a T-3 through Cali III.

[czakky82]

Good info!

@Turin, yeah they are geared pretty high. Lazy shifting has me clicking clunking into 2nd around 45-50mph.

[bad Chad]

How much rear wheel HP did a stock v7 sport actually have?   I don't see how it could of had more than 60, and even that might be generous.  After all, it's a 757cc pushrod twin.

[PeteS]

How much rear wheel HP did a stock v7 sport actually have?   I don't see how it could of had more than 60, and even that might be generous.  After all, it's a 757cc pushrod twin.

I would guess more like 52. I saw two 850 LeMans, one supposedly with some mods make 58 at Perry Sound Sport Bike Rally on a Dynojet Dyno.

Pete

[cliffrod]

Agreed.  I thought actual rear wheel numbers I’ve seen were in the approx 50hp range.  48hp comes to mind but can’t tell you where I read it.  It’s been a long time since it mattered to me.

[moto]

In October, 2001, the magazine Classic and Motorcycle Mechanics reprinted data from contemporary (1975-1978) tests done, I think, by one of the two big British magazines (Motorcycling and The Motor Cycle). These were two-way averaged top speed values measured at a vehicle testing facility called MIRA, the Motor Industry Research Association's proving ground. I don't think more authoritative data exist. Here is a table summarizing the results for the several Tonti motorcycles tested:





The T3's two-way average top speed in the reported test was just about 117 mph (and the 850 Le Mans averaged about 123). These are the figures I trust.

One day in Idaho on a long straightaway I rode my own, basically stock T3 to its top speed. There might have been a tail wind; I didn't do a two-way average. Using my tachometer reading of 6600-6700 rpm, calibrated to over-the-road speeds later in the same day using highway mileposts and my wristwatch, and also using speed-in-gears data from a Chilton manual, I estimated that my achieved top speed had been about 115 mph. I was lying as flat as I could behind a small windscreen, and carrying a set of Wixom bags. The bike didn't exhibit instability at the top speed. My speedometer was reading much higher, of course, but I didn't write down what it showed.

As for the V7 Sport, the Chilton Motorcycle Repair Manual, 1976, reported these figures, without citing any sources:

"750 Sport/S": 130.0 mph
V850: 120.1
850T: 120.1
850-T3: 121.1

The first line is what we call the V7 Sport. I would take those numbers with a grain of salt, though I have always read that the V7 Sport was faster than the T3. 

The factory Work Shop Manual reports these top speeds:
T3: 121.1 mph [as 195 kph]
850T: 114.3 [as 184 kph for "max speed solo; also 125.5 [as 202 kph] for "max speed at max rpm"
V7 Sport/S: 128.0 mph [as "206 = 130 mph", which conversion is wrong; 206 kph is 128.0 mph].

From this it looks like the Chilton manual copied the Work Shop Manual figure of 121.1 for the T3, took the incorrectly converted 130 mph figure for the V7 Sport/S, and may have averaged the two top speed figures for the 850T: 0.6213712*(184+202)/2 = 119.9, probably making a minor calculation error. There is no reason, however, to use the theoretical top speed at maximum rpm in the calculation.

So the appropriate conclusion from the Work Shop Manual is T3 = 121.1, 850T = 114.3, V7 Sport/S = 128. But I don't trust these factory figures over the MIRA results.

I have never understood why riders don't test the top speeds of their motorcycles. If they are afraid, why have such a fast bike? :)

Moto

[Turin]

I have never understood why riders don't test the top speeds of their motorcycles. If they are afraid, why have such a fast bike? :)

Moto

Ever take a bug or a rock top the kneecap or the neck at triple digit+++ speeds?    I don't think I've ever maxed out one of my bikes, either because of fear or sympathy to the machine.

[czakky82]

Either way I appreciate the bench racing!

[Gliderjohn]

I would guess that RW HP was somewhere in thew 40s. My T-3 has the 1,000cc kit, V-7 Sport cam, port and polish work, and 36mm carbs. it showed just over 56HP on a dyno.
GliderJohn

[cliffrod]

That coasting-at-108 experience happened over 20 yrs ago, when my life and the realities of such stuff were much different.  Back then, such things could be resolved without life-altering consequences like immediate loss of license, vehicle impound, SR22 insurance, etc if you weren’t stupid with the authorities.  So, to date, that was my last ticket. 

My life is much different now.  I have little interest in doing stuff like that anymore because I clearly understand that me doing dumb stuff may kill or maim innocent people who are loved by others. 

But, towards Turin’s post, I didn’t believe my V7 Sport was straining or stressed at top speed.  Engine (bottom end) was fresh and top end wasn’t old.  The bike just ran up until I assumed it ran out of carbs. Then it flattened out.  It was very smooth, nothing frantic & probably the most smooth of any engine/vehicle I had ever had at such level.  Really great.  I believe I could have maintained that rpm level for a much longer time with no issues.  But we were coming into Knox County on I-40w, where I knew there would likely be more traffic, less ideal roads and probably a THP in that same spot on the county line shooting radar like they often do so I had better quit while I was ahead…. Should have quit sooner, because I was correct about everything.

[moto]

Ever take a bug or a rock top the kneecap or the neck at triple digit+++ speeds?    I don't think I've ever maxed out one of my bikes, either because of fear or sympathy to the machine.

No. I mentioned I was hunkered behind a small windscreen, and there were no vehicles at all to throw up rocks. Idaho is distinctly bugless compared to our Southern states, barring the occasional locust (grasshopper) swarms that make even 30 mph difficult. You have to choose your venue. This two-lane desert road with over a mile of visibility was the opposite of an Interstate highway (where I don’t dare to go faster than traffic). But enough about me. It was great fun.

[Gliderjohn]

That was a nice thing of belonging to a glider club with a private runway. During non-flying times I could take my bikes out on it and do what I wanted (7,000'x150) with few concerns. Ran the Norge 8V up to 140 indicated with bags and top case on. Smooth and rock solid control. Was still pulling a bit before I ran out of room. After the motor mods on the T-3 ran the T-3 up to 115 indicated with top case and wife on board. Think it would have also pulled a bit more with more space. The 140 on the Norge felt like 70 on an interstate. The 115 on the T-3 felt, well like 115 on a T-3. Was stable and quite smooth just overall felt much faster with more noise.
GliderJohn

[huub]

I had my V7sport on the dyno a couple of times , stock it made 50 RWHP and 53 with a set of PHF 32 mm carbs.
most of the power is in the upper rev range (a hot cam and short stroke do that )
so you need to make good use of the gearbox to get anywhere in a hurry.
it comfortably revs over 7500 and still produces good power.
a different power delivery than my le mans

had my V7sport up to 120 ( GPS) mph , not sure if there was more coming, i ran out of straight road.