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Ambo 4 speed 75-80 mph cruising?

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tubehead View Drop Down
Falcone
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    Posted: 04 Jul 2017 at 13:51
I meet up with a another Ambo rider today who had upgraded to a 5 speed gear box .He seemed to think
the 4 speed is working too hard once you are cruising over 70mph.
I find mine is really happy at 75 to 80 mph and is actually vibrating less at those speeds than 60.
Has anyone on here upgraded to the 5 speed?
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Loopian View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Loopian Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jul 2017 at 15:12
I've got a 4 speed v7 special although I originally wanted a Eldorado 5 speed, so I spent some time looking at the difference between a 5 and 4 speed box. From what I remember I'm fairly confident in saying that their is no difference between a 4 speed "fourth" and a 5 speed "fifth" it's just the ratios in between.
On the American forums there seems to be a lot of fondness for the 4 speed box. I must admit it has taken a fair few miles for me to get use to it, but as with the bike as a whole I get immense satisfaction from getting it right, of course I still get the occasional false neutral.
Cheers Ian
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tubehead Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jul 2017 at 16:17
Originally posted by Loopian Loopian wrote:

I've got a 4 speed v7 special although I originally wanted a Eldorado 5 speed, so I spent some time looking at the difference between a 5 and 4 speed box. From what I remember I'm fairly confident in saying that their is no difference between a 4 speed "fourth" and a 5 speed "fifth" it's just the ratios in between.
On the American forums there seems to be a lot of fondness for the 4 speed box. I must admit it has taken a fair few miles for me to get use to it, but as with the bike as a whole I get immense satisfaction from getting it right, of course I still get the occasional false neutral.
Cheers Ian


That's interesting Ian I will check out the ratios as the guy I meet today was under the impression he has an overdrive 5th gear.I have no rev counter on my model so cannot even be sure what revs I am doing at 75 mph.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jul 2017 at 16:29
I'm lucky enough to have two Loops.A four-speed V7 Special and a five-speed GT850.According to Guzziology fitting a five speed to a 750 is not ideal because it will be over geared.This is due to the different ratios in the final drive box.My V7 Special had a five speed fitted when I bought it but unfortunately, the box blew up soon afterwards.I obtained a four-speed box from Gutsibits,re-built it and found that the bike was then noticeably "snappier" than before.
It seems from reading Greg Bender and Dave Richardson that the four-speed is the more robust box and the less lightly to give problems.I also like the fact that the selector spring on the four-speed can be replaced without dismantling the gearbox.You could do it on the side of the road if necessary.
As with the five-speed, it is important to get the selector drum shimming right on the four-speed.Upward changes are like butter, downward changes erm,less so.

http://www.thisoldtractor.com/moto_guzzi_loopframe_model_differences.html

Oh, and the 750 four-speed cruises at 80MPH no sweat.

Edited by Dave P. - 04 Jul 2017 at 16:36
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1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Loopian View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Loopian Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jul 2017 at 17:18
Are it looks like I'm mistaken, although the gear box ratios for the top gears are the same in the gearbox they are not the same overall. I should have really started to realise by now, that these days memory is not what it used to be! Thanks Mr P.
Cheers Ian
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jul 2017 at 17:40
You are very welcome Ian.Of course, you can't determine which overall gearing you have without dismantling the rear drive.Your ring and pinion set may be the original 8/35, which not being available for years could have been replaced by an 8/37 set as used on the 850's, giving lower gearing.I'd like to get my hands on an 8/35 set for the 850GT to give it slightly longer legs.

CORRECTION The 8/35 set is available; 400 euros.

Edited by Dave P. - 04 Jul 2017 at 18:10
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote ranton_rambler Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jul 2017 at 18:42
You could just take the drive box off and count the input / output rotations.
 
I'm happy with gearing on my 850GT and it will sit at 80mph no problem, but people say the 4-speed is "just right"
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tubehead Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 2017 at 02:39
Based on opinion here I think I will just stick with the 4 speed.Mine has a bit of gear whine at exactly 40 mph in top  but is silent everywhere else I am not sure if that warrants any attention yet because it changes nicely and is otherwise spot on.




Edited by tubehead - 05 Jul 2017 at 02:42
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Dave P. View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 2017 at 07:39
The four speeds are known to whine.If yours whines only at 40mph you've got a good one.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GUZZIPETE Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jul 2017 at 20:49
I thought I'd read in Guzziology that 4th on 4speed was actually a higher ratio than 5th on a 5 speed?
1971 Moto Guzzi V7 Special
1974 Laverda 750 SF2
1979 Laverda 3CL

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 2017 at 12:12
Overall gear ratios according to Greg Bender are;
4 Speed 1-4.510
5 Speed 1-4.284

Making the 5 speed slightly higher.

Edited by Dave P. - 19 Jul 2017 at 12:16
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GUZZIPETE Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 2017 at 12:27
That's interesting Dave. I think the I may have misinterpreted Dave Richardson's text.

In section 10, page 11, he says "The four speed transmission actually covers a greater range from first to fourth than the later five-speeds do from first to fifth". 

I understood that to be that 4th was a higher ratio on a 4-speed than 5th on a 5-speed. But it could also mean that 1st could be a lower ratio, which would also increase the "range" of ratios, disregarding the highest gear ratio on either box.

He may mean that the gaps between the ratios are greater with the 4 speed.

Pete.
1971 Moto Guzzi V7 Special
1974 Laverda 750 SF2
1979 Laverda 3CL

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 2017 at 12:39
Hi Pete.Yes, the four speed has a lower first gear than the five and the top gear ratios' are the same on both at 1-0.750. Confusing ain't it.

The gaps are certainly wider on the four speed box.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GUZZIPETE Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 2017 at 13:26
Thanks Dave, that's cleared it up, I thinkErmm.

Whilst we're on the subject, my Loop box is quite whiney, much more so than the Tonti. The bike has done about 45k miles. Are they commonly whiney?
1971 Moto Guzzi V7 Special
1974 Laverda 750 SF2
1979 Laverda 3CL

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 2017 at 13:44
When I first fitted a four-speed box to my 1971 V7 Special(it came with a self-destructing five speed) I was quite concerned about the whining sound.I thought that I'd done something wrong when I rebuilt the box.However,after reading everything I could find on the subject I was satisfied that they do indeed all do that.Especially the very early straight cut examples.Aparrantly when the California police had an early V700 on evaluation they thought that the siren was permanently switched on!
Maybe Amboman could comment.What say you, Charlie?
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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