Triumphrat

DAGAD · 07-11-2009, 01:42 PM

Hi Guys. So, fitted the Conti's to my 2006 about 2000 miles ago. Felt good from the start, wet or dry roads. However while in France and 2 up with luggage the front felt a bit strange on the overrun? It also seems to do it on my own and no luggage now?
The symptoms appear to be like a tank slapper, but softer and only lightly felt through the bars. If you let go of the bars, it looks just like a mild tank slapper with the bars oscilating from side to side........ The speed seems to be about 25 / 30 mph and only if you close the throttle.
I have also noticed when under heavy braking, the front tyre seems to 'squirm', feels like the front spindle is loose and feels like you can feel the tread pattern through the bars as the wheel revolves? Tyre pressures are std. 36 / 42psi.
The Anakees never gave this feeling and to be honest, it was only the price of the Conti's which made me swap. The Anakees gave me 9000 miles and were still legal!!!!!!
Any thoughts, please?
Roy.

Skidpan · 07-12-2009, 04:48 AM

I'm no expert, so take this with a pinch of salt. Could the sensations you describe be a result of a tyre that has a 'softer' sidewall than the Anakees? Closing the throttle transfers weight to the front, braking transfers more, and if the sidewall of the tyre has more 'give', then once the wall starts to flex/rebound, could you get this oscillation? Certainly, a mild weave 'off-gas' at 25/30mph is a well-known effect on all sorts of motorcycles, a natural resonance that is amplified or disguised by head bearings, rake and trail, tyre pressures and who knows what else.
If you buy this as a possible cause of the sensation, then a stiffer sidewall caused by increasing the tyre pressure, may resolve it. I would try 2psi at a time to see how it felt. Bear in mind that eventually you will decrease the size of the tyre contact patch as a result. That could be worse than a mild weave, so choose your poison carefully.
Alternatives?
Front OR rear wheel bearings, headstock bearing adjustment, swingarm bearings, wheel balance.

BoneyMalloney · 07-12-2009, 06:18 AM

Hi Roy, that sounds terrible, i've had the Contis for a few thousand miles and with no problems. I prefer them much more than the Anakees that came with the bike.

From your description i would definately check everything Skidpan recommends, especially the wheel balancing, a weight might have been lost (they're only stuck on). Another one to check would be for a warped brake disc, a common problem. Torque up that front wheel to the correct spec and make sure the rear wheel is in line with the front. It sounds daft - but the direction of rotation arrows?

All i can say is that i've been happy with my Trail Attacks and would buy them again...

Good luck, let us know if you find a solution.

Danny500 · 07-12-2009, 11:44 AM

I was actually thinking of getting these for my bike as they're the close to the cheapest I could find... but I may just stay with the Metzlers.

I've found on all my street bikes that steering wobble's #1 cause is the rider.

Considering you're on a more street-oriented tire it may not be as forgiving as the Metz's because they're made of a softer compound with a more complete contact patch.

Before you do anything... go for a ride and try not to give as much steering input as you have.

For example: Don't lean on the bars in a corner, hold the tank with your knees to keep yourself upright and just barely guide the bars with the palms of your hands. The only thing rigid on your body should be your legs.

If changing position/technique doesn't work... then definitely try the 2psi at a time... then bearings, balance and such as previously suggested.

Outrunner · 07-12-2009, 06:38 PM

I am on my second set of Conti Trail Attacks on an 06 Tiger and I have never had/felt any of the things you describe, running mine with 36/42 psi when solo. Perhaps there is something slightly amiss with the bike?

Andy.

DAGAD · 07-13-2009, 02:34 AM

Morning all. Thanks for your input. I completely agree with all you have suggested and I will be going through it very soon starting with re tourqing and general bearing checks followed by alignment.

One thing that did concern me was balance weights. I fit and balance my own tyres, I have done this for the past 40 years. The Anakees had NO WEIGHTS on either wheel but the new rear needed 10grm, OK perfectly acceptable. However, when I balanced the front, it needed 80grm............. a COMPLETE strip of weights?????? I was concerned that my previously trusty balancer was giving me false readings? So I took the wheel bak to the place I got the tyres from to check on their balancer. No real surprise when the guy said yes, thats fine!

I have never had a tyre so far out before and also Conti do not put 'fitting marks' on their tyres. I will let you know what I find.
Roy.

DAGAD · 09-03-2009, 03:06 AM

Morning all, sorry for the delay in getting info back to you. So, all the checks complete and found nothing wrong. I did email Continental tyres and had a reply suggesting I increase the preasure up to maximum 42 psi.

Last weekend was the first opportunity I have had for a good while to get out on the Tiger. I increased the front to 38, from 36 psi and found a real difference. The squirm has almost gone under heavy braking...... nearly missed a junction and had to throw out the anchor!!! There is still that tank slapper at 40mph but noticably less.

Next, I will increaseto 40 psi and see if that totaly cures it but I think 39 will be just about right?
Roy.

Skidpan · 09-03-2009, 01:38 PM

So did Continental explain why to go for higher pressures? I'm still wondering about the softer sidewall explanation that I offered earlier, or if it's a different reason....

DAGAD · 09-04-2009, 02:45 AM

Hi Skidpan. I posted a question on their web site and nothing for almost 2 weeks. I then had a reply from Dave Humphreys at Cambrian tyres. He said that they were the importers for Conti two wheel products for the UK and my email had been forwarded from the truck division?
His obversation was under inflation and to gradually increase to a max of 42psi. If that solves the problem, fine......... If not, take it to my Triumph dealer. Not quite sure what my Triumph dealer could do for me, but I have increased the pressure as posted and it does feel better.
There was no mention of sidewall stiffness or any other reference. Going to Windy Corner tomorrow with 39psi in the front, I'll let you know.
Roy.

crowtherstephen · 09-04-2009, 06:40 AM

I have fitted Conti Road attack - they are purrrrrrfik... no problems at all, will be doing them again, well into 3000k now and still going strong, no real sign of flat spotting either.