Author Topic: 100 mph on the Speedometer !  (Read 20982 times)

0 Members and 1 Guest are viewing this topic.

singhg5

  • Grand Gearhead
  • *****
  • Posts: 2,785
  • Karma: 0
on: March 28, 2016, 09:10:37 pm
Is it really possible to see 100 mph on my G5 ? I know RE speedos are off, but this was beyond all my expectations ;).

That is what is on the speedometer even when G5 is in neutral, standing still :D. Anyone else seen this happen to them ?

The needle swings all over 360 degrees when riding the bike. The speedo cable is fine - lubricated, and in right position.
« Last Edit: March 28, 2016, 09:32:14 pm by singhg5 »
1970's Jawa /  Yezdi
2006 Honda Nighthawk
2009 Royal Enfield Black G5


Otto_Ing

  • Guest
Reply #1 on: March 28, 2016, 09:29:02 pm
I had something like this happen to my GT. It would occur after starting the engine while the initial self-test was ongoing (where the needle goes all the way up and back to zero). After turning it off and on again it would be back to normal.


Carlsberg Wordsworth

  • Grand Gearhead
  • *****
  • Posts: 715
  • Karma: 0
Reply #2 on: March 28, 2016, 09:41:15 pm
My 1st failure would do this. Mucking about with it has it @ 30 ish mph sat on the shelf lol.

2nd has been fine for ages (4100 miles ish), first group ride out and it fails half way through ride.

I want to give mine a 3rd time lucky chance now I've poked about with it but that Koso is looming fast. I might just to have go balls in and order along with new AM26 and take the financial hit this month.



tooseevee

  • Grand Gearhead
  • *****
  • Posts: 4,571
  • Karma: 1
  • Everybody's havin' them dreams
Reply #3 on: March 28, 2016, 09:47:15 pm
Is it really possible to see 100 mph on my G5 ? I know RE speedos are off, but this was beyond all my expectations ;).

That is what is on the speedometer even when G5 is in neutral, standing still :D. Anyone else seen this happen to them ?

The needle swings all over 360 degrees when riding the bike. The speedo cable is fine - lubricated, and in right position.

            Is that a magnetic cup type speedometer?

             I'd love to have that KOSO unit Kevin has for my AVL, but heap too many furs for me + a day of discomfort to hook it all up properly.
RI USA '08 Black AVL Classic.9.8:1 ACEhead/manifold/canister. TM32/Open bottle/hot tube removed. Pertronix Coil. Fed mandates removed. Gr.TCI. Bobber seat. Battery in right side case. Decomp&all doodads removed. '30s Lucas taillight/7" visored headlight. Much blackout & wire/electrical upgrades.


Desi Bike

  • Grand Gearhead
  • *****
  • Posts: 1,176
  • Karma: 2
Reply #4 on: March 28, 2016, 09:58:25 pm
Not sure if you can get into the speedo unit itself but it sounds like maybe a broken internal spring or dried up lube. They are magnetic drive from my understanding perhaps a bit of metal junk attracted to the springs.  Sounds like you have some open heart surgery to perform.
میں نہیں چاہتا کہ ایک اچار
میں صرف اپنی موٹر سائیکل پر سوار کرنا چاہتے ہیں


gashousegorilla

  • Grand Gearhead
  • *****
  • Posts: 4,485
  • Karma: 0
Reply #5 on: March 29, 2016, 03:10:45 am
Is it really possible to see 100 mph on my G5 ? I know RE speedos are off, but this was beyond all my expectations ;).

That is what is on the speedometer even when G5 is in neutral, standing still :D. Anyone else seen this happen to them ?

The needle swings all over 360 degrees when riding the bike. The speedo cable is fine - lubricated, and in right position.

  Nice Singh !   That's it .... I'm filming YOU this Summer. ;) 

   Yeah, It's kind of what happened to mine when it went.  That threaded pub that the speedo cable screws onto.... you know, Bottom of the speedo.   I found that that whole piece seems to make contact inside the unit, and if it is loose and you can wiggle it a bit.  It will make and break whatever connection is going on in there.   I said screw it and got the Koso deal.  But, you may be able to get it apart and get right.
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


Arizoni

  • Grand Gearhead
  • *****
  • Posts: 7,412
  • Karma: 2
  • "But it's a dry heat here in Arizona
Reply #6 on: March 29, 2016, 04:29:45 am
Whoa!

It's now official!

Singh5 is the first to break 100 mph on his Royal Enfield and he even shifted into neutral to show us how easy it is.  ;D
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary


Sectorsteve

  • Grand Gearhead
  • *****
  • Posts: 1,350
  • Karma: 0
Reply #7 on: March 29, 2016, 01:26:29 pm
After about 40 min of highway riding my speedo needle jumps all over the place. I've got a boating app on my phone that has GPS mph. It's really accurate. When I'm going 113kph the bike speedo says 120!


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #8 on: March 29, 2016, 01:38:02 pm
Whoa!

It's now official!

Singh5 is the first to break 100 mph on his Royal Enfield and he even shifted into neutral to show us how easy it is.  ;D

That's one way to do it!
 ;D
Home of the Fireball 535 !


johno

  • Grand Gearhead
  • *****
  • Posts: 540
  • Karma: 0
  • 2012 B5 on the original Portland Dorset UK
Reply #9 on: March 29, 2016, 06:09:55 pm
I always said Enfield's look fast standing still, now we have the proof ;-)
2012 B5 Bullet
 K&N, sport muffler, 18tooth fr sprocket, Avon style fairing, 1958 pattern British army haversacks. Mitas tyres DiD chain. Carberry plate.


singhg5

  • Grand Gearhead
  • *****
  • Posts: 2,785
  • Karma: 0
Reply #10 on: March 30, 2016, 03:08:57 pm
Enjoyed all of your comments - RE people are good people :).

Took the speedo-odo-meter out and found it has the same problem as mentioned by GHG. 

The bottom half of the speedo mechanism consists of a magnetic bowl connected to speedo cable. It is NOT attached to indicator needle.

The upper half consists of a free floating speedo-cup inside the bowl and it is connected to indicator needle on the dial.

As the magnetic bowl rotates fast with the speed of the front wheel, it generates a magnetic field that turns the speedo-cup - and thus the needle at a much slower pace. The speedo-cup rotational speed will also be affected by the torsion of the return spring.

In a defective unit the speedo cup and the bowl touch each other and loose contact rapidly and repeatedly. The needle then fluctuates rapidly. (It is different from speedo cable going in and out).

The second issue is why did the needle go below zero ? Normally the speedo-cup has a tab that hits a stop - a 1" tall metal strip that hangs down from frame, above the cup. But in the defective piece, the speedo-cup moves just a fraction of mm below so that its tab does not touch the stop. The speedo-cup can then rotate in all directions 360 degrees.

Tried a few things and it seemed that the speedo was working. BUT after it was installed on the motorcycle, it went back to being in a broken state :(!

Two possible reasons - either the top half has shifted down or the bottom half is pushed up.

I think that the spindle - connected to the needle - has worn out / is thinned out / or the holes for it have enlarged a bit. So it falls slightly downward due to gravity.

The other reason can be what GHG has mentioned that the bottom half moves up/down and touches the speedo-cup.

Note of caution - the chrome ring around the speedo case is crimped tightly. To take it off the case, it has to be un-crimped which causes some damage, cuts and small nicks. 
« Last Edit: March 30, 2016, 04:22:42 pm by singhg5 »
1970's Jawa /  Yezdi
2006 Honda Nighthawk
2009 Royal Enfield Black G5


pmanaz1973

  • Grand Gearhead
  • *****
  • Posts: 729
  • Karma: 0
Reply #11 on: March 30, 2016, 08:40:55 pm
I've always wondered what the inside of one of these looks like. 

Any opportunity to shim the needle up a bit of the cup down?  Thin brass or aluminum washer maybe?  Might be a temporary fix, but might work?
1984 XL350R
1991 XR250L
1976 Harley XLH 1000
1993 CBR 600
1976 Norton Commando 850
1972 BMW R75/5
2014 Royal Enfield C5


gashousegorilla

  • Grand Gearhead
  • *****
  • Posts: 4,485
  • Karma: 0
Reply #12 on: March 30, 2016, 10:14:18 pm
Enjoyed all of your comments - RE people are good people :).

Took the speedo-odo-meter out and found it has the same problem as mentioned by GHG. 

The bottom half of the speedo mechanism consists of a magnetic bowl connected to speedo cable. It is NOT attached to indicator needle.

The upper half consists of a free floating speedo-cup inside the bowl and it is connected to indicator needle on the dial.

As the magnetic bowl rotates fast with the speed of the front wheel, it generates a magnetic field that turns the speedo-cup - and thus the needle at a much slower pace. The speedo-cup rotational speed will also be affected by the torsion of the return spring.

In a defective unit the speedo cup and the bowl touch each other and loose contact rapidly and repeatedly. The needle then fluctuates rapidly. (It is different from speedo cable going in and out).

The second issue is why did the needle go below zero ? Normally the speedo-cup has a tab that hits a stop - a 1" tall metal strip that hangs down from frame, above the cup. But in the defective piece, the speedo-cup moves just a fraction of mm below so that its tab does not touch the stop. The speedo-cup can then rotate in all directions 360 degrees.

Tried a few things and it seemed that the speedo was working. BUT after it was installed on the motorcycle, it went back to being in a broken state :(!

Two possible reasons - either the top half has shifted down or the bottom half is pushed up.

I think that the spindle - connected to the needle - has worn out / is thinned out / or the holes for it have enlarged a bit. So it falls slightly downward due to gravity.

The other reason can be what GHG has mentioned that the bottom half moves up/down and touches the speedo-cup.

Note of caution - the chrome ring around the speedo case is crimped tightly. To take it off the case, it has to be un-crimped which causes some damage, cuts and small nicks.

   Very cool explanation Singh, thanks.   I'm thinking if it's that bottom threaded loose pub piece causing it ?  Perhaps you could silver solder it to the bottom case of the speedo so it doesn't move on you ?  Or maybe silver solder or epoxy an extension onto and along side that little stop there ?
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


singhg5

  • Grand Gearhead
  • *****
  • Posts: 2,785
  • Karma: 0
Reply #13 on: March 30, 2016, 11:22:39 pm
I've always wondered what the inside of one of these looks like. 

Any opportunity to shim the needle up a bit of the cup down?  Thin brass or aluminum washer maybe?  Might be a temporary fix, but might work?

   Very cool explanation Singh, thanks.   I'm thinking if it's that bottom threaded loose pub piece causing it ?  Perhaps you could silver solder it to the bottom case of the speedo so it doesn't move on you ?
 
Or maybe silver solder or epoxy an extension onto and along side that little stop there ?

The stop bar can be extended with solder or epoxy - at least theoretically in this IMAGINARY picture 2512B below. That can take care of stopping the indicator needle from turning below zero.

The other problem is different, because the threaded pub is solidly attached to the frame.

BUT the inner rotating cylinder, in which the end of speedo cable is inserted, moves slightly up/down - I think it is normal play of about 1 mm or <1 mm. If that gap is reduced by a very thin washer, it will stop upward movement of magnetic bowl - BUT that will also hinder its free rotation.
« Last Edit: March 30, 2016, 11:25:25 pm by singhg5 »
1970's Jawa /  Yezdi
2006 Honda Nighthawk
2009 Royal Enfield Black G5


Desi Bike

  • Grand Gearhead
  • *****
  • Posts: 1,176
  • Karma: 2
Reply #14 on: March 31, 2016, 12:55:47 am
Would slightly bending the framework around the mechanism accomplish the adjustment?  It would have to be minimal so as to not affect the odometer gear spindle.
« Last Edit: March 31, 2016, 01:02:12 am by Desi Bike »
میں نہیں چاہتا کہ ایک اچار
میں صرف اپنی موٹر سائیکل پر سوار کرنا چاہتے ہیں