HPRE

Menu

92 Guests, 3 Users
JPJP, DonK, motomataya
 

Author Topic: A warm Hello! (and your experience with the 20t sprocket)  (Read 1225 times)

Bullet Whisperer

  • Grand Gearhead
  • *****
  • Posts: 880
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #15 on: June 12, 2017, 02:41:03 am »
I think 20 t would be too much. The standard gearing on an Electra X is about right. Here is some on board footage of one fitted with 'S' cams and shortened barrel. the ports were left standard.
 B.W.

https://youtu.be/obBjjB4nPiw

elysianforest

  • Neophyte
  • *
  • Posts: 24
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #16 on: June 12, 2017, 12:09:24 pm »
Hey B.W. - I really dig your video. Thank you.

I think I'm getting the idea that some of you are not getting the same testicle destroying vibrational zone between 60-70 mph that I am. This leads me to believe there may be things other than a sprocket change I need to do to correct the issue...

In truth, I pretty well love the gearing as it is if it weren't for the fact that I feel like my manhood (and much of the rest of me) was in a Jacob's Ladder sequence at the most convenient cruising speeds.

Any thoughts?

And btw- I asked about the Clipper because I saw a cam set from 1956 go on eBay that looked remarkably like the S cams- 40 tooth and all.

Thanks!

-Forest

Bullet Whisperer

  • Grand Gearhead
  • *****
  • Posts: 880
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #17 on: June 12, 2017, 02:58:00 pm »
I think some of the Indian Enfields - whatever model - vibrate because of their relatively early inlet valve closing point, causing there to be high cylinder pressures to overcome before firing the piston downwards again, causing more of a jolt than if the valve shut a little later. Every bike I have retarded the inlet timing on has run a little smoother and revved higher  ;)
 B.W.

Arizoni

  • Grand Gearhead
  • *****
  • Posts: 6,648
  • Karma: 2
  • "But it's a dry heat here in Arizona
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #18 on: June 12, 2017, 04:39:06 pm »
elysianforest

If the vibs are that bad, be sure to check the cylinder head steady.  Also check the lower engine mount bolts to make sure they are tight.

The cylinder head steady which runs from the back of the cylinder head up to the frame is a weak place on all of the Royal Enfields.

If it cracks or if the bolts are not tight, the bike will have some really serious vibration at various speeds.
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary

Adrian II

  • Grand Gearhead
  • *****
  • Posts: 987
  • Karma: 0
  • Sharing my ignorance with anyone who needs it
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #19 on: June 12, 2017, 07:40:31 pm »
Quote
The cylinder head steady which runs from the back of the cylinder head up to the frame is a weak place on all of the Royal Enfields.

It's just a piece of light-gauge pressed 3mm strip steel, one of my bikes managed to break two of them. I made the replacement from a piece of 6mm steel strip which should last a lot longer.

Something doesn't seem quite right about yours if the vibes are really bad, mine had some vibes as any single will but hit a sweet spot around 70mph on the stock 18T sprocket.

A.
Grumpy Brit still seeking 500 AVL Bullet perfection! Will let you know if I get anywhere near...

elysianforest

  • Neophyte
  • *
  • Posts: 24
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #20 on: June 13, 2017, 01:43:55 am »
Something doesn't seem quite right about yours

The picture is becoming clearer as my previous assumptions are falling away. I believe it was the venerable Samuel L. Jackson who said, "Everybody knows, when you make an assumption, you make an ass out of you and umption!"

Thank you Arizoni for chiming in some excellent suggestions. Bolts seem to be tight, though... I wish it were so simple.

I do think I may feel a bit more in my nether regions due to the sprung leather saddle a previous owner had fitted in that it's not sprung toward the front - and I imagine there's a bit less padding than a stock saddle. Ah, what we endure for style!

BW may be on to something. It certainly couldn't hurt to try. I'm assuming (there I go again) I would dial back the intake cam a tooth or so?
« Last Edit: June 13, 2017, 01:54:55 am by elysianforest »

elysianforest

  • Neophyte
  • *
  • Posts: 24
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #21 on: June 18, 2017, 07:30:41 pm »
Yeehaw! Arizoni was right!

Took off the gas tank today while working on some wiring and was surprised to hear a "chink!" on the floor. The head steady was snapped just under the bolt head. I swear it looked solid when I checked before - if I had loosened then retightened that bolt instead of just torquing on it to make sure it was tight I might have found that earlier.

I happen to have a stick of .25" x 1" steel... Guess I'll have to finally set up my vise. I'm very pleased. Hopefully this will improve matters a good deal.

I'm still going to try retarding the intake at the next oil change. I'm interested to see if that smooths things even more.

Thanks guys!

Arizoni

  • Grand Gearhead
  • *****
  • Posts: 6,648
  • Karma: 2
  • "But it's a dry heat here in Arizona
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #22 on: June 19, 2017, 12:54:43 pm »
IMO, cam timing can effect torque, max engine speeds and several other things but vibration isn't one of them.

I suspect that after you replace your broken head steady you will find that move of the vibration goes away so, IMO, messing with the cam timing is best left undone.

Yes.  I know that big singles vibrate but IMO, Royal Enfields single is not as bad as several twins I've ridden.

Be sure to tighten the bolts on your new head steady firmly.
That thing doesn't just keep the top of the engine from vibrating back and forth.  It also stiffens the frame a lot because the engine is a structural part of the frame design.

Let us know if your motorcycles vibrations get better. :)
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary

Bullet Whisperer

  • Grand Gearhead
  • *****
  • Posts: 880
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #23 on: June 19, 2017, 05:14:02 pm »
IMO, cam timing can effect torque, max engine speeds and several other things but vibration isn't one of them.

I suspect that after you replace your broken head steady you will find that move of the vibration goes away so, IMO, messing with the cam timing is best left undone.

Every Indian Bullet I have retarded the inlet cam timing on so far [except standard 350's] Has been a better, smoother and faster machine for it and there have been quite a few, including several 'iron' 500's a few AVL's and a 612  ;)
 B.W.

Mick Bailey

  • Scooter
  • **
  • Posts: 83
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #24 on: June 20, 2017, 07:57:17 am »
When it comes to gearing, don't forget tyre profile. In the UK at least, the standard tyres on an Electra X are metric sized and 90 aspect. The original fitting for Enfields was imperial and 100 aspect. So when comparing sprockets and gearing between the Electra and older bullets, this also needs to be taken into consideration. I recently fitted my wife's Electra with Heidenau imperial-size tyres and it's made quite a difference to the gearing. The extra sidewall height does mean the seat height increases a bit. Ok, the comparison is between new Heidenau and part-worn Avon Roadriders, but the imminent tyre change on my own Electra will be to an imperial fitment. They also ride the potholed English roads better than the Avons.

elysianforest

  • Neophyte
  • *
  • Posts: 24
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #25 on: June 20, 2017, 07:33:44 pm »
I will definitely let you all know how and if things improve. I'm taking a little forced hiatus from even working on it in the garage because temps here have been around 115 Fahrenheit. I'm pretty good up to 105 and I will do 110, but that's where I draw the line!

I would have to think that if the engine is behaving as B.W. describes some of them do that retarding the intake timing would indeed smooth things up a bit. If the valve is closing before the crank is bringing the piston back up, it seems like there would be an ever so slight vacuum to overcome. That probably wouldn't make a huge difference for the most part, but I could easily see how it might limit revs and cause some resonance. Anyway, as has been said earlier, it won't hurt to try - at worst I might lose a PSI or two of compression if the valve closes a bit late.

Thanks for the input on the tires, Mick (tyres is the better spelling to separate noun from verb - but alas, I am on the other side of the pond). Though the tread on my Avons is still very good, the cracks in the sidewall indicate they may be a bit long in the tooth, so I might be able widen that diameter a little sooner than later. A very good suggestion - while I do love the look of that Speedmaster, I don't have particular notions about the Safety Mileage.

Mick Bailey

  • Scooter
  • **
  • Posts: 83
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #26 on: June 21, 2017, 03:32:25 am »
The Heidenau tyres fitted to my wife's bike are K34 - universal front/rear. Front is 3.25-19 and rear 3.50-19. They're a vintage pattern, but modern compound. I don't know if you have them in the US, but worth a look. They also fit the mudguard profile better than the metric sizes. I gave up on the Avon Roadrider - 6 tyres in all. They split between the tread and had a web of crazing on the sidewalls. They were removed well before we got any reasonable life out of them.

elysianforest

  • Neophyte
  • *
  • Posts: 24
  • Karma: 0
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #27 on: June 27, 2017, 09:39:56 pm »
elysianforest

If the vibs are that bad, be sure to check the cylinder head steady.

Arizoni saves the day! Thank you. It's really like a whole different bike. There is still some vibration of course, but not much at all in the most important places. ;)

I've never owned a single before, and I guess I just thought they were that bad and that's why the sprocket changes were so popular. Live and learn!

Here is the bar I bent up to replace the broken head steady... I was going to paint it black, but decided I kinda liked the look of the raw steel. I may still paint it, we'll see...

Arizoni

  • Grand Gearhead
  • *****
  • Posts: 6,648
  • Karma: 2
  • "But it's a dry heat here in Arizona
Re: A warm Hello! (and your experience with the 20t sprocket)
« Reply #28 on: June 28, 2017, 01:19:26 pm »
Now, THAT is one hell of a head steady.

Actually, it is what Royal Enfield should have used in that job.
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary