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Tyres again sorry
Posted: Sun Feb 13, 2022 1:46 pm
by Doctor T
At the moment i have PR4 none GT tyres fitted to the RT. After inspecting the front for a slow leak which i cant find. I have also found the front is cupped and the rear, although loads of tread depth left it is slightly squared off.
I've read loads on sites regarding BMW RT tyres but can not find a definite answer on whether to fit GT version tyres or not. Some have copied emails that they have received from manufacturers saying you need GT tyres and others say their rear standard tyre is good enough.
Comments from owners are split 50/50. Looking at manufacturers spec's are varied as well. Some state that they use a slightly harder centre compound and others say they add an extra ply.
Most of the RT that i have seen seem to be running standard rated tyres. What are your thoughts on the subject?. Am not looking for a tyre recommendation list, just GT or NOT
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 2:30 pm
by Steve398
I'm just in the process of changing from PR4 to 5GT. Personally I've not been a lover of the 4's but that's down to a personal choice, that's what was fitted when I bought the bike.
I've always fitted the GT versions because we do 2-up European touring, and as I understand it the additional ply is there to accommodate the weight, however tyre specialists
Two Tyres offer this -
What’s the difference between the Michelin Road 5 and Road 5 GT?
The difference is the way the ply is laid on top of each other. Michelin use a different construction method called Dual Angle Technology (2AT). In doing that, they don’t need to use additional steel belts like some other manufacturers do for their GT tyres. This approach creates a 15% stiffer cornering rigidity. If they added beading i.e. steel wires it would add 700 grams of weight of the tyre which Michelin want to avoid and so with this construction method it increases rigidity but keeps the weight down.
The Michelin Road 5 GT is a Sport Touring tyre offering riders:
- A new benchmark in wet weather performance for the sport touring market.
- Amazing stopping performance, with a 50% worn tyre achieving the same braking distance as a brand new Pilot Road 4 in testing.
- Excellent durability for many miles of happy riding.
- Follows on from the popular Pilot Road 4 and Pilot Road 3
- Designed for larger motorcycles
- The Road 5 GT has been designed specifically for the following bikes:
- BMW R850 RT, R1150 RT, K1200 GT, K1200 RS, R1200 RT, K1300 GT, K1600 GT / GTL
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 2:37 pm
by David.
IMO, tyre cupping and squaring off is more likely to be down to tyre pressures, loading and how the bike is used rather than just the tyre itself.
I've also had email correspondence with Michelin, their recommendation was, "I should fit GT tyres". However, I was also told that if I did not want to purchase these, "I could fit (in this case) Pilot Road 2 without any issues".
Bearing in mind that the BMW recommended rear PR2 version code (B) is now not available, I went ahead and fitted a standard tyre. I've suffered no ill effects with this set up. Have also used non-BMW recommended PR1's without any problems, using them two-up plus luggage.
If I wanted to use a particular tyre which had a specific BMW fitment e.g. GT, then I would use it. If the tyre choice didn't have the correct version code, it wouldn't bother me.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 2:50 pm
by Doctor T
Thank you, David. This is the information i was looking for. The previous owner did a lot of motorway miles hence the squaring off. Cupping i usually put it down to braking on a heavy bike and yes pressures do come it to it.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 2:51 pm
by Casbar
I've shared this email before, but this was in response to me asking if I should use the GT tyres before the 5GT came out
Thanks for the interest in Michelin tyres for your bike.[/font][/color]
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The Pilot Road 4 GT was developed while working closely with BMW to adapt the standard Pilot Road 4 to better suit the particular demands of the R 1200 RT and a short list of other bikes. Michelin were not entirely happy with the handling of the bike when using the standard tyres, in particular when/if the bike was pushed quite hard, and we engineered a solution to ensure rider satisfaction.[/color][/font][/size]
[/color][/font][/size]
The solution was to create a new casing construction with optimised ply angles, made possible by a new assembly process to increase cornering stiffness. Cornering stifness has increased by 15% without resorting to increasing the number of casing plies which otherwise would have added approx 700g to the weight of the tyre. This construction guarantees the stability of the bike at speed without sacrificing comfort.[/color][/font][/size]
[/color][/font][/size]
The Pilot Road 4 GT remains our recommended fitment for your bike, and the standard Road 5 tyres are not recommended. We are developing a Road 5 GT tyre, but it will not be available in 2018.[/color][/font][/size]
[/color][/font][/size]
I hope that this helps,[/color][/font][/size]
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Best regards,[/color][/font][/size]
[/color][/font][/size]
[/font][/size]
Engineering Support – Operational Marketing[/color][/font][/size]
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Europe North and Russi[/color][/font][/size]
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Also on the cupping question, Michelin recommended that you run the fronts at a couple of pounds more, so I've always run mine at 38. This helped with cupping. Theory being BMW recommended pressures can not be the same for every tyre, in fact pressures should be adjusted depending on temps etc, when doing track work I always used a pyrometer to measure temp and adjusted pressure relevant to tyre temp. On the road this would not be practical though.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 3:30 pm
by Doctor T
You said. "Theory being BMW recommended pressures can not be the same for every tyre". Different styles of riding, the rider's weight, etc. You have to take this all into account on tyre pressures. Most of the bikes ive owned ive always had to play around with pressures.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 3:54 pm
by David.
This is the email reply I got from Michelin.
"As per our phone call, you should fit GT tyres, for an example the MICHELIN ROAD 5 GT.
But if you are not wanting to purchase these due to price reasons, you can fit the MICHELIN ROAD 2 without any issues, but once there is no more stock of this tyre you will be forced to fit GT tyres."
Now that PR2 and PR3 are discontinued, I will not be "forced" into buying any Michelin tyre, GT or otherwise!
With so much tyre choice, I'll be fitting a pair from the BMW "official" list until such time as none of them are available anymore.
I've always run my tyres (irrespective of the manufacturer) at the BMW recommended pressures for the loading on the bike. Have never experienced any unusual wear or "cupping". Perhaps it's a problem which Michelin tyres are susceptible to.
For a 1250, from the Michelin tyre fitment guide, recommended pressures are 36/42, the same as per the BMW Rider's Manual.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 4:59 pm
by Casbar
David. wrote:
This is the email reply I got from Michelin.
"As per our phone call, you should fit GT tyres, for an example the MICHELIN ROAD 5 GT.
But if you are not wanting to purchase these due to price reasons, you can fit the MICHELIN ROAD 2 without any issues, but once there is no more stock of this tyre you will be forced to fit GT tyres."
Now that PR2 and PR3 are discontinued, I will not be "forced" into buying any Michelin tyre, GT or otherwise!
With so much tyre choice, I'll be fitting a pair from the BMW "official" list until such time as none of them are available anymore.
I've always run my tyres (irrespective of the manufacturer) at the BMW recommended pressures for the loading on the bike. Have never experienced any unusual wear or "cupping". Perhaps it's a problem which Michelin tyres are susceptible to.
For a 1250, from the Michelin tyre fitment guide, recommended pressures are 36/42, the same as per the BMW Rider's Manual.
Listen to David, he knows everything and what he doesn't know, Google does
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 5:07 pm
by BoB21
Personally for little extra cost GT always. Stiffer tyre So much safer in event of a puncture. Dont scimp on your life.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 5:49 pm
by Our Gee
Stiffer tyre = Harsh ride.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 5:55 pm
by Casbar
Not being a riding god, on the road, I have never really had an issue with any tyres on the RT. Found the Metzler's ok on my 1250, never had any moments riding all year around. Changed to Michelins 5GTs, really like them as well. Only problem I had with the Metzler's, was they were shot by around 6k, I tend to change my tyres well before the minimum tread anyway. So really haven't notices tyres giving a harsher ride, 4GTs were good and I find 5GTs good.
On the track I had preferences, but was riding more on the limits. Only tyre I really never liked was the Avon Cobras I had on a Harley once, yet others raved about them.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 6:21 pm
by Doctor T
Yes, David seems to be the BMW RT encyclopedia on here. He comes over as very knowledgeable chap on the subject. Anyway ive ordered a pair of Metzeler Roadtec 01.
Had these on a Tiger 1050 and a Pan European when they first came out. Found them excellent in the dry and i could even drag a peg in the wet. Not as long lasting as some sport/touring tyres but i am willing to pay for the grip over miles.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 6:33 pm
by David.
Doctor T wrote:Anyway I've ordered a pair of Metzeler Roadtec 01.
Which version did you go for.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 8:26 pm
by Doctor T
I went for the standard version. Not the latest SE or the HWM. Found an email reply from another site where the chap asked the same as i was wondering." Metzeler recommends the normal tyres unless you are doing the majority of pillion riding". As i ride on my ownsome and don't have a top box i think i should be fine.
I seems from what ive read across forums that H/D(HWM)tyres are for heavier bikes like K1600GT & GTL, Harley's, Goldwings and so on. Funny no manufacturer states at which weight of a bike would need to use H/D tyres. Probably to cover themselves.
I've just looked in the bike handbook and it doesn't state to use H/D tyres.
Re: Tyres again sorry
Posted: Sun Feb 13, 2022 8:46 pm
by David.
Doctor T wrote:I went for the standard version.
You've done well to find them.