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Discussion Starter #1 (Edited)
Hi guys, just after some advice. Been looking around at pics of cafes and noticed quite a few of these cafe racers (more usually brats) have chunky tires and usually a similar (looking) size on the front as the rear.
I realise that this look will be at the expense of handling and that manufacturers do tend to have an idea of what they’re doing when they select a bikes tyres, but I quite like the look.
The bike I’m working with (Kwak ER5) has its original 3 spoke alloy rims in 3.5 and 4.5 inch flavour, and was wondering what dictates what you can or can’t get away with?
Standard sizes are 110/70/17 and 130/70/17 and if I could source wires then I’d maybe go with some standard sizes rubber in an Avon Roadrunner or similar for a proper cafe look.

Anyone have any advice or can anyone point me at a selection program or repository which I can cross reference against?
Sort of thinking about maybe 120/80 or even 90 and 140/70 for a chunky look. What would be acceptable? Is there a rule of thumb? Would I get away with it?
I realise the front guard has to be changed or redesigned.
I’m not at home just now so don’t even know what clearance I have in the chain and shockers etc.
Just looking for advice (but am open to other suggestions)
Finally I know the ER isn’t a cafe racer and with a perimeter frame doesn’t even lend itself to the genre but it was cheap, I’m bored and fancy a challenge.
 

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If you are going to fit big fat bias ply motorcycle tyres based solely on appearance?
You really do not want to hear the tyre advice from the frequent flyers on this forum, none of them fit tyres based on what they can get away with.
 

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Discussion Starter #3
I never said I was, I said I was open to advice.....wanna offer any?

If it's a bad choice then I'll swerve it. I did wonder if it was just a fashion thing. My bikes will never go off road and I'd never fit knobblies on my sports bikes, I was just curious.

So stick with sticky rubber then....check. (might save me a few £/$)

Out of interest, is there a chart on the forum anywhere with recommended tyre sizes according to rim selection?
I've gone undersize on my previous Daytona T595 955i as going from a 190/50 to a 180/55 gave a taller profile and a more favourable geometry which aided tip in into the bends. I've also gone up from a 150 to a 160 on an old Bandit 600 for a fatter rear so I understand the vagaries of tyre selection and how they might effect handling etc.
 

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i understand people wanting a certain look, but you ride motorcycles long enough, i dont think a look is what 99% of seasoned riders think of.

just takes one crash or near crash to realize, fuk it, tires are one of the most important thing keeping me from the pavement. not worth it.

as far as tire sizes and rim width, usually it is best to check with the tire manufacturer what is the recommended rim width for a particilar tire.
 

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I never said I was, I said I was open to advice.....wanna offer any?

If it's a bad choice then I'll swerve it. I did wonder if it was just a fashion thing. My bikes will never go off road and I'd never fit knobblies on my sports bikes, I was just curious.

So stick with sticky rubber then....check. (might save me a few £/$)

Out of interest, is there a chart on the forum anywhere with recommended tyre sizes according to rim selection?
I've gone undersize on my previous Daytona T595 955i as going from a 190/50 to a 180/55 gave a taller profile and a more favourable geometry which aided tip in into the bends. I've also gone up from a 150 to a 160 on an old Bandit 600 for a fatter rear so I understand the vagaries of tyre selection and how they might effect handling etc.

Less to do with tread design, is all about the construction and profile of the tire carcass and the lay of the cords holding it together. The tire manufacturer specifies the appropriate rim size and design to suit the tyre or visa versa. Radial tyres out-perform bias tyres any day of the week.
Yes the size and profile when mounted on the rim will affect how quickly the bike tips into corners, because high speed motorcycle steer by leaning.
A heavier front tire and wheel combination will make your bike more prone to head shake and wobble over bumps like railway crossings or pot holes.
Tyres with tubes inside are heavier and generally require the addition of bead locks which add further weight and imbalance to the wheel.


You mentioned Avon Roadrider, imho that's a POS bias tyre with hard rubber and the tread design moulded in the wrong direction if you hope to reduce hydroplane effect on water :| worst tyres I ever mounted on my BMW. Only way somebody can rate that tyre is good would be to compare it against a shite tyre.
 

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Discussion Starter #6
Cheers guys, that’s the Sort of info I was looking for. I only mentioned the Avon’s as they’re sort of tied in with the scene or at least with the style. As mine is running alloy rims anyway there’s not much point in straying too far from standard sizes and styles. As I’ve read elsewhere, today’s tyres could win races compared with the old shite from years ago.
 

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https://blobs.continental-tires.com/www8/servlet/blob/20710/abaa6267089e0f16d873d3d9f2cd7034/technical-manual-2015-data.pdf

Here is continental tires motorcycle technical manual that I use from time to time. It has all the tires and recommended rim widths with your pertinent ones starting on page 279(bias) 282(radial). Tire size recommendations for your bike on 193.

With 17 inch wheels and nice standard width rims, you have plenty of choices.

Other tire manufacturers will have technical manual like this too.

I like complete tech manuals like this because it includes the tire circumference which can make a difference fine tuning the bike's set up and geometry.
 

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More free tyre advice:
If you ever decide to stud up a set of knobby tyres so that you can ride on ice covered rock outcrops, which is a ton of fun btw :)
Make sure you put the sheet metal screws into ALL of the knobs :|

Holy ^%$#@ did I ever go down hard yesterday! think my left knee is boogered for a couple weeks. Need to start building a knee brace today.
 

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Fuck me!! Was that you? Surely you broke something ????
Did that right at the start of a great ride day, no man neither of us was hurt at all except for my brand new helmet lol.
I was the one catching the flying motorcycles, we did it twice in a row with the same results, can't tell the 2 videos apart,
proof that if you do the same stupid shit over and over and change nothing, same shit happens again.

This one really hurt :| I took the handlebar end into my left kidney:


Pretty good tyres though eh ;)
 

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Discussion Starter #14
:D
Feck that, I'm 48 yo now, bones don't repair as easily these days and being self employed means enforced injuries take money away from the table.
 

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Discussion Starter #16
:D

Haha. I prefer to keep them rubber side down and on the queens highway. Never got into offroad / trials for some reason. Never even tried green laning. Spent 30 years on road bikes, predominantly litre sport bikes.
 

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:D

Haha. I prefer to keep them rubber side down and on the queens highway. Never got into offroad / trials for some reason. Never even tried green laning. Spent 30 years on road bikes, predominantly litre sport bikes.
Might be wise to keep it that way, once you ride a trials bike and get a little good at it, that tends to render all other forms of motorized ground transport slightly boring ;)
 

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I think the next street tires I'm rolling with is Metzler Roadtec 01 which seems to come in a very nice wide selection of sizes btw.
Anybody here ever ride on them?


Leg is healing nicely and I put more studs in the front tyre, thinking about testing it out on this tomorrow.

In theory I should be fine as long as I don't try to put a foot down.
 
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