Author Topic: B44 riders  (Read 869 times)

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MICKREEVES

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B44 riders
« on: 21 December, 2017, 16:09:55 »
What top speed can you get?
I can get 85 MPH on the clock.
BUT, check against a sat nav shows its only 75 MPH.
WHY?
Are they all like that?
Mick

Editor

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Re: B44 riders
« Reply #1 on: 21 December, 2017, 16:21:35 »
I think they have always been 'optimistic' but as all out bikes were of a similar age, they all read the same speeds so we all were led to believe we were doing 70+ in the outside lane overtaking other vehicles, when in reality most cars wouldn't do 70 anyway.
The other issue today is the tyres we use such as Roadriders are different OD's to the K70's back in the 60's

Greybeard

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Re: B44 riders
« Reply #2 on: 21 December, 2017, 16:42:28 »
Why the need to screw the backside of each old bike you buy, Mick? Isnt this the one that youve just had the crank rebuilt for and vibrates horrendously? I suppose at maximum revs itll soon be run-in. Hopefully youll not be using the same roads that I or any of my family (or anyone else fr that matter) use whilst youre at it :-\ Perhaps a Jap 600 and the odd track day may get these urges out of your system  ;)

Steve
Steve from East Yorkshire - Not the Greybeard of the A7/A10 forum who was not actually registered on this one when I signed up ;-)

AWJDThumper

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Re: B44 riders
« Reply #3 on: 22 December, 2017, 10:14:50 »
What top speed can you get?
I can get 85 MPH on the clock.
BUT, check against a sat nav shows its only 75 MPH.
WHY?
Are they all like that?
Mick
The manufactures have to err on the side of speedos that read high - they can't sell a bike with a low reading speedo for obvious reasons. Normally, the allowed error is +10% max but as the magnetic speedos age, the return spring weakens and they will inevitably produce a larger error. In principle, the return spring can be renewed but it would be a lot of effort for a small return. When I feel the need, I calibrate my speedos against a GPS device and then note down (and remember) the error at each 10 mph speed interval.

MICKREEVES

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Re: B44 riders
« Reply #4 on: 23 December, 2017, 08:30:57 »
Yes, I now know that my B44 speedo is 10 mph over reading. I had already recalibrated my C15 speedo, which reads 15 MPH over. (Plastic tape at 10 mph steps.
I have found it difficult to check with my satnav, which loses its battery power very soon on the bike. I will have to provide a 12 volt tapping.
Reading the small satnav speed is difficult, on the bike.

My real inquiry was to find out if ALL B44s are failing to reach the advertised top speed.
I know that my super rocket engine in featherbed frame bike would reach 100 mph 'on the clock' but I only did that once, to find out.
I never thought that speedos might read incorrectly, in those days. (1960s)
Traffic was much slower then, so my normal top speed would have been about 70, I was used to overtaking most of the time.

I travel over the country, mostly on Motorways, in my VW bus. This will keep up with the general flow - 80 to 90 MPH.
I often reach 100 mph, following sports cars or super-cars. It amuses me to think that those drivers see a white haired old geezer in a big van, on their tail!

Yes, I am naturally competitive. I was a trials rider for some years, and for most of my life i have competed  with model aircraft ( word champion 3 times, national champion 17 times.
Mick

If I wanted to just cruise along at modest speeds, I would have stayed with my little Bantam. Light and easy to manhandle.
I tried a 250cc Yamaha virago, which only weighed 300 lbs. It easily reached over 80 mph, with more to come, had I tried. But I wanted a classic BSA.

MICKREEVES

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Re: B44 riders
« Reply #5 on: 23 December, 2017, 17:02:18 »
I am not a mad speed freak. My pleasure is to make rapid progress, but safely. My no claims bonus would be 40 years plus.
A bike with power to spare is more pleasurable for normal riding, without ever using full speed..

When flying my present scale model, the skill is in making the model fly SLOWER than it wants to be, to imitate the speed of the fullsize aircraft.
So a quarter scale model of a 100 mph Sopwith biplane, would need to fly at at 25 mph. It takes little power to fly at this speed, but if the wind speed is 20 mph,
then the model should to do 45 mph into wind, and 5 mph downwind! Impossible, but we do our best.
The model has to be overpowered to achieve high scoring flight, including aerobatics.
Mick

MICKREEVES

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Re: B44 riders
« Reply #6 on: 23 December, 2017, 17:04:17 »
PS, my model flies with a 60 cc, V twin fourstroke engine. Thats why I would favour that style in a bike.
Mick

Riding B44R

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Re: B44 riders
« Reply #7 on: 22 January, 2018, 21:14:37 »
Riding a motorbike isn't about exceeding the speed limit on our roads Mick.  You want to be careful what you're stating in case a policeman reads your notes.  To state that you regularly exceed the 70 mph speed limit, I suggest isn't advisable.  Take a steady trip out on your bike, try dropping your speed to 50 mph, listen and feel the engine beneath you, proudly proceed and enjoy your ride.  You don't have to travel at those sort of speeds to enjoy a Beezer.  At 100 mph you're traveling too fast to take anything in!

Mike Farmer

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Re: B44 riders
« Reply #8 on: 23 January, 2018, 09:11:15 »
 :)

Into wind you would have a groundspeed of 5mph. Down wind you would have a groundspeed of 45mph assuming you are "dead into/downwind"

Mike 8)

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Re: B44 riders
« Reply #9 on: 23 January, 2018, 09:31:49 »
What top speed can you get?
I can get 85 MPH on the clock.
BUT, check against a sat nav shows its only 75 MPH.
WHY?
Are they all like that?
Mick
Brand new, I would have expected a B44 to do at least 10 mph faster than that. However, it's very unlikely that your bike is still producing anywhere near 30 bhp and the lower max speed reflects that.

MICKREEVES

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Re: B44 riders
« Reply #10 on: 23 January, 2018, 10:09:47 »
Why would it not produce its full power when everything appears to be in good order?

I find that car speedso read about 2/3 mph over. It would be illegal for a speedo to read under,
 so the manufacturers have be on the safe side, also allowing for variations and the effect of wea,r and changes of tyres.Mick

AWJDThumper

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Re: B44 riders
« Reply #11 on: 23 January, 2018, 11:09:49 »
With a properly rebuilt engine, I would expect it to produce the power it had when new as long as the carb and exhaust system were also as good as new. Unfortunately, as engines wear, the compression will drop as will the power, and both the combustion chamber and exhaust will coke up, again reducing the power.