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Author Topic: top speed query  (Read 3853 times)

livingdeadhead

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top speed query
« on: April 21, 2014, 11:24:39 AM »
my bike is a 79 us import , and has the 85 mph speedo , when i get to 85 i'm showing 5,750 revs , if i rev it out to 7,000 what do you estimate i'm doing (all on a private road of course  ;))

Offline Luca

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Re: top speed query
« Reply #1 on: April 21, 2014, 12:25:08 PM »
85mph/5750rpm= .01478261mph per 1RPM

.01478261 X 7000 = 103.478mph calculated speed

As for actual speed, a GPS is your best bet.  The speedo won't know when your back tire is slipping, nor is it necessarily accurate to begin with
'82 R65LS
'01 K1200RS

livingdeadhead

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Re: top speed query
« Reply #2 on: April 21, 2014, 12:34:25 PM »
just wanted to know the top speed indicated at max revs , just when it starts pulling really strong ... i run out of speedo ! lol hey the super blackbird never had this problem  ;D

Offline Tony Smith

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Re: top speed query
« Reply #3 on: April 21, 2014, 07:37:18 PM »
175 km/h (109 mph). On the best day it ever had, freshly tuned and with a specially bred, bullet shaped test rider. Your "mileage" will vary.

The only bike I've ever owned that consistently "ran out of speedo" was a 1975 Honda CB400F, but then it had a Poweroll stroke kit and 4 Henry Abe Honda 100 to 138 pistons and sleeves, combined with bigger valves and the carbs from a CB500. Actual displacement was just shy of 700cc.
 
The speedo used to wind around to the "o" in "Honda".

The thing was as tough as old boots too. Shortly after I screwed it together the idler gear retaining bolt backed off the jack shaft and machined a hole though the side of the engine case - fixed by applying correct torque and green Loctite, the hole filled with a section of coke can and Araldite, that was the only thing that ever went wrong after the conversion, generally it just totally behaved itself and received only normal maintenance.
 
The little Honda was great fun and capable of greatly embarrassing bikes that were notionally much bigger and faster. I sold it on and used to see it still getting around town up to 15 years later. The last time I saw it I inquired if the owner was interested in selling, he wasn't sadly. In 1990 I left Townsville, I've often wondered if it is still extant.
1978 R100RS| 1981 R100RS (JPS) | 1984 R65 | 1992 KLE500 | 2002 R1150GSA |

livingdeadhead

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Re: top speed query
« Reply #4 on: April 22, 2014, 04:46:05 AM »
i had a 400 4 , best sohc 4 they made i think , mind you the cam bearings were a weak spot on all of em , down to owners not changing the oil! seen a few of those bodged with araldite .

Offline montmil

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Re: top speed query
« Reply #5 on: April 22, 2014, 08:29:25 AM »
My late father once solved a construction and zoning issue for a client friend but would not accept payment for the work. Couple days later, he found a brand new Honda CB400F sitting in his living room!

He requested I take it and ride it for him to, "...keep the oil circulating and the battery up." Smooth as a Singer sewing machine.
Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

clonmore1

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Re: top speed query
« Reply #6 on: April 22, 2014, 11:55:29 AM »
"Singer sewing machine" wow, a blast of the past with that Monte!

Do we still have Singer sewing machines?

Offline montmil

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Re: top speed query
« Reply #7 on: April 22, 2014, 12:03:27 PM »
Quote
"Singer sewing machine" wow, a blast of the past with that Monte!

Do we still have Singer sewing machines?

You bet'cha.  [smiley=thumbup.gif]
Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Offline Tony Smith

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Re: top speed query
« Reply #8 on: April 22, 2014, 02:51:00 PM »
Quote
"Singer sewing machine" wow, a blast of the past with that Monte!

Do we still have Singer sewing machines?

yes, and used regularly. Ours is an old treadle machine that has been factory converted to mount an electric motor, has a shaped piece of iron mongery that inserts into a receptacle at the front of the case, you use your knee to turn the motor on and off. Personally i'd rather have a working treadle.
1978 R100RS| 1981 R100RS (JPS) | 1984 R65 | 1992 KLE500 | 2002 R1150GSA |

livingdeadhead

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Re: top speed query
« Reply #9 on: April 22, 2014, 03:17:04 PM »
singers were much better made than hondas imho !

Offline Tony Smith

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Re: top speed query
« Reply #10 on: April 22, 2014, 07:40:17 PM »
Quote
singers were much better made than hondas imho !

Oh I disagree with that rather a lot. Singer sewing machines required an army of specially trained sewing machine mechanics to keep them singing along.

Whereas Honda motorcycles were easily able to be worked on by existing personnel trained to work on other motorcycles and were in fact so well made that Honda spear-headed a general "dumbing-down" of the general cohort of motorcycle mechanics.
 
I am in awe of Honda's engineering prowess in that they can now introduce a brand new model (CB550 as an example) and be so sure of their metalurgy/casting and machining standards that the first service (which is an oil change and inspection only) is not due till 24,000km.

My brother dropped in last week in the course of his 9,500km in 10 day trip across Australia and back again, riding his 2007 model Honda Blackbird. It had 160,000km on the dial when it left Sydney, heading to Darwin via Cairns, on arrival in Cairns I helped him change a blown headlight bulb.

In the course of that little amusing saga I pointed out that in the time it took us to change the bulb I could have done a complete tune and service on any of our BMWs, gone to the pub, got pissed and been chucked for being drunk and obnoxious.

In the light of that I inquired whether a service on the Blackbird cost less than AU$1,000. He replied that a full service was indeed around $1,000, but they only needed to be done every 50,000km, with intermediate fluid changes.

There is something to be said for any manufacturer that can produce a bike with the sort of performance a Blackbird is capable of, combined with that sort of service interval.

Singer - eat your heart out I say!
1978 R100RS| 1981 R100RS (JPS) | 1984 R65 | 1992 KLE500 | 2002 R1150GSA |

Offline Matt Chapter

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Re: top speed query
« Reply #11 on: April 23, 2014, 01:29:16 PM »
Quote
Chris S wrote on Yesterday at 11:55:29:
"Singer sewing machine" wow, a blast of the past with that Monte!

Do we still have Singer sewing machines?


You bet'cha.  

Forget the Singer, what happened to the Honda!?
'04 R1150 RT ~41000 miles
'86 R65 / '84 motor ~72000 miles. SS lines, Spiegler rotor, Progressive monoshock, Keihan silencers, a piece of Pichler fairing.
'76 CB400F ~26000 miles. non-runner!

Offline montmil

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Re: top speed query
« Reply #12 on: April 23, 2014, 01:43:29 PM »
The old man finally up and sold it!  :'( Used the cash for the down on a new BMW... automobile.
Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

livingdeadhead

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Re: top speed query
« Reply #13 on: April 24, 2014, 02:10:33 PM »
i once bought 5 cb 250s 68 69 70 models mostly stripped and some new parts , tank exhausts brightwork etc with the intention of restoring one and having spares forever , out of about 7 motors NONE had a usable cam! funnily enough the cd/cb 175 had the same cam support arrangement , i've to own one with a bad cam , their weak spot was the stand rear brake pivot area , nasty , i've also owned about 5 cb750s , and two each cb550s cb400s. never had to work on the 400/4s didnt owm 'em long enough is why , the 750s and 550s ... top ends like cheese ! down to owners not changing the oil , bodges with araldite , bronze inserts . seen the lot . xs650s were better , proper bearings for the cam. ever wondered why airhead prices are so reasonable ? much better design , better materials = last longer . yes i know modern japs last longer , but they change 'em every two years! lol , besides most are made in china thailand etc , even triumphs n harleys , which i think is a bit sad . the british goverment stopped triumph putting 'made in great britain ' on their bikes .....(takes deep breath) yes i have heard of punctuation lol

Offline Lucky_Lou

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Re: top speed query
« Reply #14 on: April 24, 2014, 02:29:28 PM »
Quote
"Singer sewing machine" wow, a blast of the past with that Monte!

Do we still have Singer sewing machines?
Yes.......................... oddly enough I used my 1880 machine today to repair a favourite pair of jeans, see my thread in misc tech discussions
 On the matter in hand we had a thread a while back debating the final drive ratios.... on a private road near me (M1) I tested Gertie a 79 and got near enough 15 mph/1000rpm bottled out at 7000rpm but felt like there was a bit more to come if needed the speedo was reading just over 105.
Lou
Oh and on the same bit of private road I tested my Honda Dream in 1975 and managed a similar result
« Last Edit: April 24, 2014, 02:32:09 PM by Lucky_Lou »
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