[bittercrick]

I knew Weebles wobbled but so does my C-5 Chrome.So it just got it's name it's Weeble. Last eve. I took the bike for a ride and thought i'd speed things up for a bit  i got to bout 70mph and the death wobble started ,so once back home i checked and tightened each nut and bolt then today i tried it agin 70mph and the wobble started so i held it open and it crept up to 75 mph and the wobble became worse so i backed out of it and fingered the front brake and it simmered down. I looked Weeble over agin and nothing jumps out at me, any Ideas would be apreciated. Thanx

[TWinOKC]

Check the tire pressure, owners manual says 18 front, 28 rear.   Seemed a little low to me but works good.

[Ducati Scotty]

Check the tire pressure, owners manual says 18 front, 28 rear.   Seemed a little low to me but works good.

+1.  I'm 225# and I run 18/24.   I can go 0-80 with no instability at any speed.

Scott

[prof_stack]

Yep, tire pressure.  I had the same thing on my C5.  I run 18-20 / 24-26 and there is no longer any wibbly wobblies.

You'll be pleasantly amazed how good it runs at those pressures.  But the light weight of the bike makes speeds above 70 a little nervous anyway.

[bittercrick]

Thanx for the help I'll lower it to your specs and check it out.Man I like the lively responses on our site.  bittercrick

[Desi Bike]

Mine wobbles when pressed into  headwind above 65mph. I haven't dropped the psi down yet as I don't get up above 64.5 mph very much...  I'm just a few pizza slices under 180

[bittercrick]

Ok so I set my tire psi's at 18 frt and 28 rear went for a spin and i'd say it's bout 80% better ran her up to 75+ mph and she didn't try to throw me.thank you all for the tip . These lil bikes are sensitive to any twitch of the bars and they wanna whip I think that some of it comes from the forks but see no way to mount a fork brace.I had a similar problem with my 78 GL1000 but a super brace cured it pronto.

[Arizoni]

If you weigh up in the 220+ pound area your bike's probably set about right.

If you weigh less than that you might want to drop the rear tire pressure down to around 25-26 psi.
Who knows?  You might even get to to be 95% better.

[Ducati Scotty]

The geometry of the C5 frame makes it more nimble than the G5 but it's less stable at high speeds.  Still, I'd say drop another 4 pounds of pressure in the rear.  I'm heavy and I ride with 24 PSI - no problems at all.

The AM 26 tires are very stiff so low pressures are fine.

Scott

[Andy]

Yep, tire pressure.  I had the same thing on my C5.  

Me three.  Fixed right up after dropping to the numbers in the owner's manual.

[GlennF]

These lil bikes are sensitive to any twitch of the bars and they wanna whip I think that some of it comes from the forks but see no way to mount a fork brace.I had a similar problem with my 78 GL1000 but a super brace cured it pronto.

My understanding is fixes like stronger forks and replacing the nylon bush in the swing arm mitigate the wobbles on some machines. However you are just applying  a band-aid solution to the symptoms (the wobble) rather than attacking the underlying geometry problem.

OK, I do not own a C5 but my take is it seems likely the handling is on the "edge of the envelope" to use aviation parlance and even the subtle trail/geometry/cg changes resulting from different tire pressures can effect the stability.  If sticking to recommended pressures or below puts things back in the black its probably a whole lot simpler to just keep an eye on tire pressure rather than redesigning the frame.

[Ducati Scotty]

Also, I think they put a 19" wheel on the front, though I haven't seen it on any of the 2011 C5s I've seen so far.  r80t put different tires on his bike and transformed the handling. 

I think you're right, this bike is probably fine in India where speeds are slower but is pushing it in the US where 60mph is commonplace.

Still, mine tracks fine and always has, even when I was running high pressures.  It's more comfortable with the lower pressures and handled better, but it never shimmied or shook, never felt unsafe.  I don't think we entirely understand this issue just yet.

Scott

[Land Surveyor]

18 and 24? Wow! That even sounds low for a car.  The only thing I ever ran close to that was my old trials bike,  and it had rim locks.

[Maturin]

Another possible source of wibbly wobbliness is the fork oil. It's rarely the case that there is the correct amount filled in, so maybe you'd like to check that aswell.

[Ice]

Search the threads here. IIRC one of the brothers had the same problem, caused by something mounted off a bit in the rear putting un due  stresses in the rear section.

[Land Surveyor]

If I may, I'm not familiar with the bikes myself but when I first got my PC (entirely different, I know) it used to act a bit uneasy at high speed.  My dealer, who owned one himself, cured it by lowering the front end on the forks by less than 1/2 inch.  Cured it completely.

[1 Thump]

My high speed wobble was related to a loose steering bearing cured (sort of) by tightening the the big chrome nut on the casquette.

[Ducati Scotty]

18 and 24? Wow! That even sounds low for a car.  The only thing I ever ran close to that was my old trials bike,  and it had rim locks.

The AM26 tires are really stiff.  I had a flat front tire once and barely noticed.

You can't slide the the fork tubes up or down on these bikes, the tops are screwed in to the casquette.

Scott

[gashousegorilla]

  Still, I'd say drop another 4 pounds of pressure in the rear.  I'm heavy and I ride with 24 PSI - no problems at all.

The AM 26 tires are very stiff so low pressures are fine.

Scott

 Totally agree with Scotty here. 28 psi in the rear is still a bit high.  Try 18-22 front, 24-26 rear.

 

Search the threads here. IIRC one of the brothers had the same problem, caused by something mounted off a bit in the rear putting un due  stresses in the rear section.

  Ice, that was holes drilled incorrectly, wrong place and short, on the rear fender. Causing stress on the fender stays, and making it so the front of the fender (notch) did not sit in the rubber bush. Causing the tail to sway at high speed.Which was felt at the bars, as the bike oscillated. Finding and correcting that solved about 75 % of the problem. Reducing the tire pressure finished it off.

 Just to add,  reinforcing the swing arm, adding a steering damper, making a hidden fork brace, putting on a 19" front wheel, etc.  etc..  Did not solve my high speed instability problem.

[olhogrider]

Sometimes gusty crosswinds can make mine behave badly but since i lowered the tire pressures it handles great. More like a Ducati than a Hog. If you find the bike twitching, try taking your hands off the bars. See how much is "pilot induced occilations".

[Ducati Scotty]

Just to add,  reinforcing the swing arm, adding a steering damper, making a hidden fork brace, putting on a 19" front wheel, etc.  etc..  Did not solve my high speed instability problem.

I guess there you have it.  If your frame isn't out of whack and nothing is loose, set your tire pressure right.  If you want to check your frame just unbolt the two bolts that hold one side of the rear fender to the strut.  If it doesn't spring way out of place you're just fine.

It should be noted too that GHG had the earlier style rear fender and struts.  His struts have little tabs that bolted to the fender.  The later models have bolts from inside the fender that go right into tapped holes in the strut, no tabs.  I don't know if that matters but I thought it was worth mentioning.

Scott

[prof_stack]

I guess there you have it.  If your frame isn't out of whack and nothing is loose, set your tire pressure right.  If you want to check your frame just unbolt the two bolts that hold one side of the rear fender to the strut.  If it doesn't spring way out of place you're just fine.

It should be noted too that GHG had the earlier style rear fender and struts.  His struts have little tabs that bolted to the fender.  The later models have bolts from inside the fender that go right into tapped holes in the strut, no tabs.  I don't know if that matters but I thought it was worth mentioning.

Scott

+1

[gashousegorilla]

Or.......Just get tires like r80rt got,with a taller-softer side wall, when his wore out.

[bittercrick]

Olhogrider you sugested taking my hands off the bars I already tried that at the same time ran over a tiny bump in the road and man she got the wobbles quick I really don't wanna find out if I have ta dodge a rabbit or somethin at speed I think Weeble would come onglued it's that touchy.just used to the other bikes in my stable i guess.Peers to me the best thing to do is forget what 40 odd years of riding has tought me and adapt to the Bullet way ..hee hee

[prof_stack]

....just used to the other bikes in my stable i guess.  Peers to me the best thing to do is forget what 40 odd years of riding has tought me and adapt to the Bullet way ..hee hee

+1

Last night I took the new Guzzi for a 60 mile ride and marveled how rock steady it is at freeway speeds (break-in says to keep it under 5k rpm, good for 80mph, heh).  It is not much heavier than the C5. 

So, you have to learn about your Enfield up close and personal.

[Land Surveyor]

Gotta ask.  Which Guzzi?

I absolutely love the California Retro.

[prof_stack]

Gotta ask.  Which Guzzi?  I absolutely love the California Retro.

Check the "What I did on the Enfield today..." thread from yesterday for a pic and explanation of the deal I got on the Breva 750.

Tire pressure:  the Guzzi rec's 36/39 psi.  The C5 rec's ~18/24.

[Ducati Scotty]

I find that riding the C5 is an experience in low pressure

[prof_stack]

I find that riding the C5 is an experience in low pressure

[GSS]

I knew Weebles wobbled but so does my C-5 Chrome.So it just got it's name it's Weeble. Last eve. I took the bike for a ride and thought i'd speed things up for a bit  i got to bout 70mph and the death wobble started ,so once back home i checked and tightened each nut and bolt then today i tried it agin 70mph and the wobble started so i held it open and it crept up to 75 mph and the wobble became worse so i backed out of it and fingered the front brake and it simmered down. I looked Weeble over agin and nothing jumps out at me, any Ideas would be apreciated. Thanx

I spent a bit of effort in tuning up several things and have a rock steady C5.  Had great help from ScooterBob and r80rt.  I will post a list of things in a couple of days that will hopefully summarize all the issues.

[olhogrider]

Olhogrider you sugested taking my hands off the bars I already tried that at the same time ran over a tiny bump in the road and man she got the wobbles

Was this before or after setting the proper tire pressure?

[bittercrick]

It was after air was adjusted,even on a smooth hyway if you take one hand off the bars she wants to wobble.so it's 2 hands and don't do anything sudden.

[olhogrider]

It was after air was adjusted,even on a smooth hyway if you take one hand off the bars she wants to wobble.so it's 2 hands and don't do anything sudden.

Now you got me thinking bent or badly out of balance wheel, rear alignment maybe? Hmmm