The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Boycie1150 on November 16, 2011, 01:39:48 PM

Title: Continental tyres
Post by: Boycie1150 on November 16, 2011, 01:39:48 PM
Does anyone out there run Continental Go tyres on their 65?

When I rebuilt my bike earlier this year, (subject of another thread), I put a set of Conti Go's on it. I am not entirely impressed as the rear is not far off having to replaced after only a smidgeon over two thousand miles use. One, I am not a boy racer type, and two, I have had bikes with twice and three times the power this bike has got wear their rear tyre out in three times the distance. At least.

So, either this is a VERY soft compound, or the tread depth amounts to bugger all when it was new. Either way, I am not impressed. Now, I have to explain to the wife why I need another 85 to 90 quid for a new tyre!!! >:(

I wil have to use another one on the rear, as the front is still only just worn, but after that, I will go back with Metzelers, as I used to run years ago.

ANd before anyone asks, no, it wasn't wrongly inflated!!! ;D :D I check tyre pressures before every ride.

As I say, anyone got any comment?

CHeers peeps

P
Title: Re: Continental tyres
Post by: montmil on November 16, 2011, 01:52:26 PM
Just out of curiosity, what pressures do you run in the Contis?

Monte
Title: Re: Continental tyres
Post by: nhmaf on November 16, 2011, 02:19:21 PM
2000 miles seems VERY short life indeed.   I run 35-38 PSI in my BT45 tires and they still have quite a bit of life left almost 5000 miles on them.

I gave up on Continental tires myself back in the mid-80s.   They were decent traction-wise, but also seemed to wear out very fast back then, and I was not locking up tires, doing burnouts, and only riding 400cc and 650cc bikes back then.
Title: Re: Continental tyres
Post by: bruce_launceston on November 16, 2011, 02:30:20 PM
I would put a Bridgestone BT45 on the rear and keep the Conti front untill it needs replacing.
I'm not aware of any requirement to match tyres front and back?

I've been getting good mileage from the Bridgestones although I have a Pirelli Sport Demon on the rear at the moment, also seems a good tyre.
Title: Re: Continental tyres
Post by: tvrla on November 16, 2011, 11:10:05 PM
Haven't used the Contis, so no help there, but I'm not impressed with the Metzelers either: good grip though short lived.

I've been running the Bridgestones as well - cheapest tires I can find at about $60 and last the longest. They handle well too. I run either the S11 or BT45s.
Title: Re: Continental tyres
Post by: steve hawkins on November 17, 2011, 02:34:38 AM
I have used Contis as a favourite and have them fitted to my bikes currently.  

I am not doing a lot of mileage at the moment for one reason or another, but recall thinking the very same myself the last time I changed them.  But it is only a gut feeling and I have no numbers to back that feeling.

I am going to have to cahnge the one on the back of the R100 soon and that bike has not done much other than local work this year.

Cheers
Title: Re: Continental tyres
Post by: Julio A. on November 17, 2011, 05:24:21 AM
35-38? I follow the Sticker under the seat which specifically suggests to inflate the tires at 30-32 at the maximum load.
Title: Re: Continental tyres
Post by: Barry on November 17, 2011, 06:55:57 AM
A tire that wears that quick can't be right. I have almost 5000 miles on a Pirelli City Demon and the damn thing won't wear out. I still have 5mm of tread left. My front tire has 7000 miles and is down to 3.5mm  Not the greatest tires in the world but aimed at the same market as the Conti Go.
Title: Re: Continental tyres
Post by: montmil on November 17, 2011, 07:06:54 AM
Quote
35-38? I follow the Sticker under the seat which specifically suggests to inflate the tires at 30-32 at the maximum load.

Julio, this tire pressure issue has been bounced around the forum a few times in the past.

Our vintage bikes came with, what is now, vintage tire tech rubber. The fender sticker provides tire pressure suggestions for those old school tires. New materials and technology within the motorcycle tire industry permit higher tire pressures to achieve optimum performance.

I run 38psi front and 41psi rear in my Bridgestone S11 Spitfires. Excellent grip, handling and wear... which I discovered I really needed while riding those Three Sisters.

Monte
Title: Re: Continental tyres
Post by: clonmore1 on November 17, 2011, 08:18:54 AM
Montmil,

That makes perfect sense, old stickers old tyre tech!

That's why we have this forum for info like that - priceless ;)
Title: Re: Continental tyres
Post by: nhmaf on November 17, 2011, 08:22:19 AM
+1 with Monte - that sticker is 30 years old, right?   The tire technology of that period *Required* running at lower pressures because one had to count on some sidewall flex of the stiff rubber to maintain tire contact patch.   Modern tires of current construction have different shape, different carcass construction and sidewall/tread design, and sticky rubber compounds and maintain their contact patch much better when full inflated at the normal, higher modern pressures.   They will also run cooler and you'll get better fuel economy.

If my front BT45 tire gets down to 25PSI it will develop a slight wobble in the 40-45MPH speed range.   I make sure that my tire pressures are both in the mid-30s before I take off for a ride.
Title: Re: Continental tyres
Post by: clonmore1 on November 17, 2011, 08:30:26 AM
nhmaf,

More expertise, it's all going in to my small brain for regurgitation later...

Thanks
 :)
Title: Re: Continental tyres
Post by: Barry on November 17, 2011, 08:37:22 AM
There is a thing on the net at the moment about universal tire pressures for all makes of tire and all bikes. You don't have to think about it just put in something like 36/42 and forget about increasing the pressure when two up or loaded. Personally I don't believe in a universal pressure regardless of what the bike and rider weigh. Fora start they are talking about modern superbikes with radial tires.

The easy and proper answer to the tire pressure issue is to look at the manufacturers web site. Every one I've ever looked at has a tire selector tool which will recommend a specific tire for your bike and they always list pressures.  Who knows better than the people that designed and made the tires. Some riders will use higher pressures still claiming improved handling. Fine as long as you don't go above the maximum rated pressure but you shouldn't go lower than the web site recommendation. If you really want to do your own thing test it with the 10/20 rule. Measure the tire pressures Hot after a hard ride. The front pressure should have increased 10% from cold and the rear 20%.

If your pressures have gone up more than that they were too low to start with and if they didn't show that much increase you had them too high. The 10/20 rule worked close enough for me when I used the manufacturer's recommended cold pressures.
Title: Re: Continental tyres
Post by: steven m on November 17, 2011, 09:32:30 AM
When I increased the pressure from 32/36 to 37/40 in my Avon tires, which I thought might be a bit high, I discovered the bike handled AND had better ride quality, plus, on my brief grooved freeway excursions, ugh, the wobbling, wiggles, whatever you want to call it, was drastically reduced.  That alone is worth the price of admission...

As is usually the case, in agreement with Monte.

Steve
Title: Re: Continental tyres
Post by: tvrla on November 17, 2011, 12:14:05 PM
Barry - I've heard it's right around 10% for both tires. It was actually something like 9% for the front and 12% for the rear. But who has a gauge that accurate?

I'll have to do the actual test now, because I used to run the higher pressures, but recently started using the lower values in the low 30s. I like the ride better now than before.

And I don't think a universal pressure is a good idea - heavier riders will need to run more pressure, as well as when loaded for touring or with a passenger or at high speeds. The killer is tire flex which causes heat build up and will destroy a tire. A blowout is a wonderous thing!

Over-inflation reduces contact patch, doesn't allow the tire to heat up to correct operating temps - thus not as sticky, and gives a harsher ride.
Title: Re: Continental tyres
Post by: Barry on November 17, 2011, 12:42:04 PM
I don't suppose the difference between front and back is a hard and fast rule but the explanation I heard was the driving wheel does more work putting the power down on the road. More slip and therefore more heating occurs as a result. If I put my hand on the tires after a run the back is always warmer than the front.

Don't remember where I first learned about the 10/20 rule but a quick Google produced this and others although they may all be traceable back to the same source. Believe the rule is not necessarily applicable to radial tires which being more efficient don't heat as much.

http://www.bmwmcnj.com/Articles/TirePressure.html

There's an odd sounding claim that carrying a passenger actually reduces rear tire wear because the extra weight reduces slip. If true that's another reason for increasing the rear tire pressure when running two up. Not just to support the extra weight but because the difference between cold and hot running pressures is not going to be as big.

Edit: Checking back in my notes I actually recorded the cold/hot pressure rise once and got increases of 9.5% and 17.4%. Near enough 10/20 given I don't ride that hard.



Title: Re: Continental tyres
Post by: Boycie1150 on November 17, 2011, 02:47:02 PM
Bloody 'ell, that got some comments!!! Thanks chaps.

Just out of curiosity, what pressures do you run in the Contis?

Monte


Monte, I have been running them around the 27/31 mark. Which is higher than the original pressures recommended. However, others have made the very good point that these are modern tyres and constructed differently. I have just checked the Continental Tyres website and these are recommended to be run at 31 front and 36 rear, which is significantly higher.

Now ordinarily, one would think that running higher pressures would increase wear, but I am going to try this and see what happens. There is still wear left on the tyre, so I will can at least see what the effect on handling is.

Cheers, I will update for those that might want it.

Other than that, the bike is going really well. It has a slight oil leak from one of the front seals, but nothing to worrying. I suspect that a seal has gone a bit 'dry'. It looks like a simple job to replace it anyway, so I will sort that in due course.

Managed to something like 55 miles to the gallon out of the other weekend on a long run, by keeping it around the 65 mph mark. Well happy.

Phil
Title: Re: Continental tyres
Post by: Barry on November 17, 2011, 03:23:23 PM
Phil

Curious about your 55 MPG. You don't so where you hail from so is it Imperial or US gallons. 55 is a good result if Imperial and an exceptional result if the gallons are US.


As there are a couple of clues I'd put money on Imperial.




Title: Re: Continental tyres
Post by: Boycie1150 on November 17, 2011, 04:00:36 PM
Barry, in not so sunny Northants, mate.

Yes, I was impressed as well. Mind you, I was taking it easy. I wasn't in a hurry, and it was the first reasonable distance, so I didn't want to thrash it. And it was bloody foggy for the first hour of riding!

Mind you, while it might do 55 mpg when treated gently, it's a different story when one winds it up a bit!! The consumption , ehem, goes up a bit!!! ;D Good fun though.
Title: Re: Continental tyres
Post by: rwait on November 20, 2011, 07:26:14 PM
I've been running the Continental GO tires for a few years now and have gone through two sets. The rears seem to have lasted me approximately 7,000 - 8,000 miles or so.  I do approximately 8,000 miles per year, with two 2,500 mile or so trips with the bike loaded with side cases, top case, and tank bag.  I think the mileage might be somewhat low, but I have been happy with the tires overall and always get them through a place in Ohio that seems to have great prices - http://www.tiresunlimited.com/default.htm.  

I generally run 30 - 32 psi in tires...and find it interesting that some run at much higher rates.  I'll have to give this a try....
Title: Re: Continental tyres
Post by: Motu on November 21, 2011, 02:12:47 AM
I've always been one for lower pressures,I find there is more grip...the bike (bikes) feel greasy with higher pressures.

I've just fitted a 100/90x18  Spitfire to the front of the Mono to go with the S11 rear,and am hugely impressed with the result,I just hated the 90/90.  

People said my bike would handle terrible when I fitted 4.00x18 K70's front and rear,but of course I didn't do it out of ignorance.(and I run 20/25 psi in those) Whenever I went back to my wheels with standard tyres it felt nervous on entry,and always pushed wide coming out of turns. Now it handles like with the K70's - a higher corner speed and an exit line anywhere I choose.  I don't think I'll run higher than standard pressures.
Title: Re: Continental tyres
Post by: montmil on November 21, 2011, 06:57:21 AM
 ;) For readers unfamiliar with our Kiwi friend, Motu -his BMW Airhead would be happy as a clam roaring around the Springfield Mile. With respect to good neighbor Mister Rogers, can you say tracker? I knew you could.

Good to hear from you, Motu. Rock on [smiley=thumbsup.gif]

Monte
Title: Re: Continental tyres
Post by: tvrla on November 21, 2011, 07:10:21 AM
So Motu, what pressures are you running in the Bridgestones? 20/25 lbs seems kind of low - I only run those pressures in the R80G/S in the rough stuff.
Title: Re: Continental tyres
Post by: Ed Miller on November 21, 2011, 05:07:28 PM
Quote
I would put a Bridgestone BT45 on the rear and keep the Conti front untill it needs replacing.
I'm not aware of any requirement to match tyres front and back?

What size BT45 do you use on the front?  
Title: Re: Continental tyres
Post by: Motu on November 21, 2011, 11:38:00 PM
Quote
So Motu, what pressures are you running in the Bridgestones? 20/25 lbs seems kind of low - I only run those pressures in the R80G/S in the rough stuff.

I use the standard 32/34 with the Bridgestones - I wanted to run the standard size and pressure tyres as a benchmark for changes.  I use the low pressures on the K70's to get the sidewall flex they were designed for,and the 20/25 psi were the pressures they used in the day.

I'm sure the high pressure guys will love to tear this apart - one day I took the R65 for a ride,and hadn't checked the tyre pressures for some time. The bike wallowed a bit in the first few corners,but I settled down to enjoying the ride - in the end I thought it was the best it had ever handled,that 90/90 front tyre felt great.  When I got home I saw there were no chicken strips on the rear Spitfire,when it normally has about 15mm or so. A check of the rear tyre pressure show 8 psi !! ,the front about 15 psi.

It appears I like an over steering bike to one that understeers.  At 8 psi it felt like the rear tyre was just locked into the turns - mind you,with flattrack bars I might tend to think that.
Title: Re: Continental tyres
Post by: bruce_launceston on November 22, 2011, 12:43:39 AM
Hi Ed, I always run the 100/90-18 as the LS has the 2.15" wide front wheel.
The snowflake wheels are only 1.85" on the non LS R65's.
Title: Re: Continental tyres
Post by: Ed Miller on November 22, 2011, 12:02:04 PM
Quote
Hi Ed, I always run the 100/90-18 as the LS has the 2.15" wide front wheel.
The snowflake wheels are only 1.85" on the non LS R65's.

Ah.  Motorcyclesuperstore doesn't sell that size, but they have the 90/90-18 which I think I'll try.  Thanks.

Title: Re: Continental tyres
Post by: Boycie1150 on November 23, 2011, 02:46:00 PM
I rode the bike the other day with the pressures increased to 31 front and 36 rear. Certainly made a difference to the feel of the bike and I have now lost the gentle weave that I experienced at around 80mph, (not on the Queens Highway, of course, officer) ::)

I will see how it goes, thats about all I can do.