Handlbar Shake

[heathy]

Johnny, everyone is entitled to an opinion, it's a free country after all. In fact the range of knowledge available on sites like this are what make them so usefull. However not all information is necessarily going to be of benefit to people, but let's assume the majority can make an informed decision having done a little research.
The reasons I disagree with your advice were set out in my last post but due to my inept editing skills got placed in the middle of the box with your quote in, don't know if you spotted this.
With regard to taking your advice, it wasn't me who was looking for it! I in fact had a new 2008 bike with conti trail attacks. The front was faulty and changed for a good one which was fine. Had three previous gs's with a range of tyres and none with any problems at all. Now running roadsmarts which are brill.

The point I'm making is nobody should need to run pressures nearly 30 percent higher than recommended in order to make the bike ride correctly, the gs is a great bike and it does work really well, handling wise, assuming its all working correctly. Caveat this for über fat buggers! My previous comments re grip level, comfort and insurance validity are my biggest concerns about your previous advice and I'm sure readers will make their own minds up about a suitable course of action if they find themselves in this predicament.

 

[JohnnyBoxer]

Johnny, everyone is entitled to an opinion, it's a free country after all. In fact the range of knowledge available on sites like this are what make them so usefull. However not all information is necessarily going to be of benefit to people, but let's assume the majority can make an informed decision having done a little research.
The reasons I disagree with your advice were set out in my last post but due to my inept editing skills got placed in the middle of the box with your quote in, don't know if you spotted this.
With regard to taking your advice, it wasn't me who was looking for it! I in fact had a new 2008 bike with conti trail attacks. The front was faulty and changed for a good one which was fine. Had three previous gs's with a range of tyres and none with any problems at all. Now running roadsmarts which are brill.

The point I'm making is nobody should need to run pressures nearly 30 percent higher than recommended in order to make the bike ride correctly, the gs is a great bike and it does work really well, handling wise, assuming its all working correctly. Caveat this for über fat buggers! My previous comments re grip level, comfort and insurance validity are my biggest concerns about your previous advice and I'm sure readers will make their own minds up about a suitable course of action if they find themselves in this predicament.

Read and understood

As for psi recommendations, there seems to be difference of opinion between the tyre manufacturer (in person and staff directly employed by them in their race-truck) and the info in the manual, supplied by the bike manufacturer

Personally I agree it's a pain to have to alter tyre pressures to compensate, but so is having to return to have a tyre changed, especially when you're on the wrong side of the Channel in my case

Over the years, I've had numerous front tyres of differing brands that exhibited the 'shimmy', that I wouldn't bother taking it back now (that's my choice and not necessarily my advice)

Even on a 'known' good 'trail style' front tyre on the GS, I can still get a slight 'shimmy', so much so.......... it doesn't bother me anymore

However someone new to a GS, may well be perturbed and rightly so

If you really want to 'feel the tyres' on the road, then ride a GSA with TKC's

 

[Deleted account 211025001]

That's very interesting JB. I have to say that I only ever use the 'recommended pressures' as a starting point and just as I adjust the suspension to suit me and the type of riding I'm doing, so too I set pressures up to suit.

Most tyres I've run on the GS have ended up at higher pressures than the standard WMB recommendation and yes, it is possible to feel the difference.

heathy - I run my dirt bikes at between 15 and 20psi (F&R) and my SM at 27psi (F&R). Are you seriously suggesting that I would have problems with insurance because I'm running pressures so far off what might be recommended

Andres

PS This thread does, again, make me wonder why peeps run pseudo off road tyres on their GS If you go off road fit TKCs/Heidis and if you ride on the road fit road tyres - simple

 

[heathy]

heathy - I run my dirt bikes at between 15 and 20psi (F&R) and my SM at 27psi (F&R). Are you seriously suggesting that I would have problems with insurance because I'm running pressures so far off what might be recommended QUOTE]

Well, to start with, this thread was about conti trail attacks, ie a road tyre, so let's keep it in context. And yes, if an accident investigator were to check your bike and find it was not within the manufacturers recommended range and that caused or was a contributory factor in the accident then i think you may have a problem. Manufacturers specify and tell you to check pressures regularly for a reason ie performance and safety. If in doubt give your insurer a call, speak to claims advice and ask them to confirm the position in writing so you know your ok.

 

[heathy]

heathy - I run my dirt bikes at between 15 and 20psi (F&R) and my SM at 27psi (F&R). Are you seriously suggesting that I would have problems with insurance because I'm running pressures so far off what might be recommended QUOTE]

Well, to start with, this thread was about conti trail attacks, ie a road tyre, so let's keep it in context. And yes, if an accident investigator were to check your bike and find it was not within the manufacturers recommended range and that caused or was a contributory factor in the accident then i think you may have a problem. Manufacturers specify and tell you to check pressures regularly for a reason ie performance and safety. If in doubt give your insurer a call, speak to claims advice and ask them to confirm the position in writing so you know you're ok.

 

[Deleted account 211025001]

Well, to start with, this thread was about conti trail attacks, ie a road tyre, so let's keep it in context. And yes, if an accident investigator were to check your bike and find it was not within the manufacturers recommended range and that caused or was a contributory factor in the accident then i think you may have a problem. Manufacturers specify and tell you to check pressures regularly for a reason ie performance and safety. If in doubt give your insurer a call, speak to claims advice and ask them to confirm the position in writing so you know your ok.

No, Trail Attacks are not a (pure) road tyre, they are a dual purpose tyre (what I refer to as a pseudo off road tyre).

Re the insurance issues I think I'll take the risk

Andres

 

[heathy]

(what I refer to as a pseudo off road tyre).

Re the insurance issues I think I'll take the risk

Andres

You plonker, look up the meaning of "pseudo" and then get a big cloth to wipe the egg off your face.
Re the insurance, then you're a bigger idiot than your grasp of the English language suggests.

 

[Deleted account 211025001]

You plonker, look up the meaning of "pseudo" and then get a big cloth to wipe the egg off your face.
Re the insurance, then you're a bigger idiot than your grasp of the English language suggests.

pseu·do 
adjective
1.
not actually but having the appearance of; pretended; false or spurious; sham.
2.
almost, approaching, or trying to be.



Andres

 

[JohnnyBoxer]

You plonker, look up the meaning of "pseudo" and then get a big cloth to wipe the egg off your face.
Re the insurance, then you're a bigger idiot than your grasp of the English language suggests.

CTA are not the only tyres that exhibit the 'shimmy' though, so discussing other tyres is extremely relevant

 

[KevinW]

[catches up with thread] Oh dear.

The tyre is being replaced FOC tomorrow so alls well that ends well...hopefully!

We had a great weekend in the Alps despite the shake. Report here.

Kevin

 

[KevinW]

About 8.5k miles later the shake is back.

I like the way the TAs feel when it's not shaking so I'm sitting here reading tyre threads wondering whether to get another TA front or try something else...

Kevin

 

[cookie]

About 8.5k miles later the shake is back.

...and there's the reason i've never experience the shimmy

 

[KevinW]

...and there's the reason i've never experience the shimmy

You haven't yet ridden 8.5k miles?

(Actually, given the 'right' tyre you can experience the problem from almost no miles at all as per my opening post)

Kevin

 

[cookie]

You haven't yet ridden 8.5k miles?

not on one Trail Attack.

 

[Bendy toy]

Information from a mechanical engineering lecture by Damian Harty 2-wheel specialist at Prodrive.

Front wheels on ALL bikes have a speed where the self centring effect of the suspension trail is a little over-corrected by the tyre. The tyre pulls the wheel into line but overshoots then pulls it back. At slow speeds there isnt enough force to over shoot. At higher speeds not enough time, so every bike has a speed where the steering wiggles. On a kicked out cruiser it can be under 30. On a steep angle sports bike more like 60. Something middling will do it between 30 and 45. Higher tyre pressures raise the critical frequency.

However, it should never become a full on wobble. Simply the rider's weight on the bars should be enough to damp it out.

When it becomes serious on a bike with ordinary tele forks the usual cause is knotchy or stiff steering bearings.

To my mind, the telelever may be less critical as it has a bit less steering mass and the head bearings are not used in the same way, but its well worth checking the steering bearings.

 

[jwpzx9r]

About 8.5k miles later the shake is back.

I like the way the TAs feel when it's not shaking so I'm sitting here reading tyre threads wondering whether to get another TA front or try something else...

Kevin

Surely the tyre is about shagged at 8.5k ?

 

[KevinW]

Surely the tyre is about shagged at 8.5k ?

I would think so, that's why it's going to be replaced.

It felt fine up until about 500 miles ago but went off on our way home. There's a surprising amount of tread left - about 2.5mm in the centre of the tyre - but I assume it's now distorted.

Kevin

 

[Nice 'n' Fat]

Surely the tyre is about shagged at 8.5k ?

I got 19,000 miles out of my first front Trail Attack

 

[jwpzx9r]

I got 19,000 miles out of my first front Trail Attack

Not going to say impossible because you did .... but you must ride it like a nun on sedatives or wheelie it everywhere. To ride a bike at anything like an exciting speed you must use the front to a pretty large extent. I get about
5k from a rear max you are getting four fronts to one rear I now expect to hear that 19k is nothing and 10k from a rear is normal... not when you start the engine its not.

 

[Nice 'n' Fat]

I'm still on the original front brake pads at 42,000 miles too

Am I doing something wrong?