How fast does it take to enter a speed wobble?

[Rogero]

Hi,

So I'm getting more and more comfortable riding, and have started taking my bike to and from work. I take it out of town first, circle around and come back - turning my 15 minutes commute into a full hour when it's possible - very fun.

I go through stretches of 80km/h (50mph) zones, and usually ride them at about 60mph (funnest speed for me right now - wide open road, no traffic)

BUT - a friend was giving me a story of when he used to ride. In telling his story, he talks about hitting a speed wobble at about 60mph. That scared me. Another friend had told me about his experience with a speed wobble, but that was north of 80mph.

I'm guessing it's a bike dependent question, but can you really start a speed wobble at as low as 60mph? Any experience on a Harley Softail and whether it'll get into a speed wobble, and at what speeds? I honestly don't think I'll ever get past 70 mph. I'm scared of faster speeds, but much much more scared of the tickets that go with speeds over 70mph.

Any comments (as usually) are awesome.

r

[Amdonim]

Wobble is not something that normally just happens on modern bikes. It's usually caused by things such as improper luggage loads (i.e. putting 30 lbs worth of stuff in the left saddle bag and leaving the right empty), worn/damaged steering components, or learning back and taking a nap at speed. I guess it could also happen from one of your tires being massively unbalanced. I'm sure it could happen at very high speeds (way triple digits) and that's why they sell steering dampers for sport bikes, but I don't think it's something you're going to run into.

[Johnj]

Back in the day I did a minor tune-up on a Norton 750. I completed all the tasks and took the bike for a test ride. It started a speed wobble at about 50mph and didn't stop till I did. All the rubber bushing in the "isolastic frame" had gone bad. I never did get paid for that job.

[InAsia]

Hi,

So I'm getting more and more comfortable riding, and have started taking my bike to and from work. I take it out of town first, circle around and come back - turning my 15 minutes commute into a full hour when it's possible - very fun.

I go through stretches of 80km/h (50mph) zones, and usually ride them at about 60mph (funnest speed for me right now - wide open road, no traffic)

BUT - a friend was giving me a story of when he used to ride. In telling his story, he talks about hitting a speed wobble at about 60mph. That scared me. Another friend had told me about his experience with a speed wobble, but that was north of 80mph.

I'm guessing it's a bike dependent question, but can you really start a speed wobble at as low as 60mph? Any experience on a Harley Softail and whether it'll get into a speed wobble, and at what speeds? I honestly don't think I'll ever get past 70 mph. I'm scared of faster speeds, but much much more scared of the tickets that go with speeds over 70mph.

Any comments (as usually) are awesome.

r

It ain't that bad.....I drove a long "O Ring" trip across country reaching 100 mph are some points recently...It's moreso the wind that can get annoying for me......Wind in your faceand sound volume increase quite a bit.

Then again, my old bike might not have "speed wobble" as much as some older, less well-maintained bikes.

[fireguzzi]

Unless something is really wrong with the bike, or you give some really really bad steering inputs, I think it would be really hard to get your soft tail to get into a speed wobble. The rake of the forks is a very stable design and the gyroscopic effect of the wheel tends to keep things straight. Again unless something really violent happens I would not waste a moments thought about it while riding. Too many more important things to worry about then that. Things like suicidal deer and homicidal teenage girls with electrical devices in their ear.

[Johnj]

homicidal teenage girls with electrical devices in their ear.

HUBA HUBA

[Wrider]

Unless the bearings are bad on your HD it's not going to speed wobble. Sportbikes are MUCH more prone because of the steep rake and lack of trail. Plus with modern bikes, the only way you get speed wobble is bad bearings, or on a sportbike pulling HARD out of a corner then letting off the throttle hard.
If you do ever get it though from acceleration/cornering, KEEP ON THE GAS. Braking tends to make it worse. Except on the Isolastic frame I'm sure, then it'd just be worse no matter what you did!

[SBK15]

Surprisingly my Ninja 250 hasn't had a speed wobble yet. I've had it up to about 95 (so far ) and it didn't wobble. It's just that smooth. Now my 650 Dual sport had BADDD speed wobbles. It would do it just about anytime I gunned it over 40mph.. But it was also on street/trail tires

[JC Viper]

I dunno, my Vulcan 500 has speed wobbles when doing 70 in 3rd gear. Punch it into 4th or 5th and the wobbles go away when the RPM drops.

Sometimes a skinny front wheel on uneven pavement can do that, soft front forks too. many sport bikes today have better lower center of gravity so not much problems there. Classic cruisers definitely look like they don't suffer from it given their long wheelbase and thick front tires.

[Zagnut]

Sounds like it might be tire cupping. The edges of your tire tread get worn at different rates and cause a wobble above certain speeds. I believe its caused (or at least caused in part) by riding on underinflated tires over time... at any rate... wobble at speed is not normal and there is a problem.
Is it the front tire wobbling?. If it's tire cupping, you need a new front tire.. It could also be one of the other things mentioned. Get it checked out and solved. You have enough working against you when you ride, you don't need added hazards.