Continental tyres

[Barry]

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.

[Boycie1150]

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

[Barry]

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.

[Boycie1150]

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!!! Good fun though.

[rwait]

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....

[Motu]

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.

[montmil]

  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

[tvrla]

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.

[Ed Miller]

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?  

[Motu]

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.

[bruce_launceston]

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.

[Ed Miller]

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.

[Boycie1150]

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.