Tyre question...

[derek badger]

Cross posting this here to get a wider audience. While I understand what the numbers mean and that it might change the riding characteristics on a factory bike, this is for a MX bike supermoto conversion . And yes, I know they are quite narrow rims but that's what I'm using.

3.0 front rim, 3.5 rear. OEM fitment is 100/80-17 and 130/70-17, it's currently got Conti Twist SMs on there, which look fucking awful. I can get much more choice if go for 110/70-17 and 140/70/-17. Chain clearance shouldn't be an issue.

Any thoughts from the masses?

Current short list is Dunlop GPR-300's or Pirelli Diablo Rosso 2's (available in both OEM size and 100/140 width), or the budget Pirelli Angel City's.

[Potter]

FWIW I put Pirelli Diablo Rosso 2's on every bike that they will fit on.

I have them on my bikes in the UK and here, they perform way better than I can ride in the rain/wet/dry/sunny/etc and I used them on my track TZR250.
The only time I've ever had something even came close to a slide was at the end of a trackday when it was 45c and the track temp must have been way above that.

There might be better tyres out there, but those work for me and I trust them, so that's what goes on my bikes.

[derek badger]

...any comment with regards to the question about sizes?

[Potter]

...any comment with regards to the question about sizes?

You mean in relation to the rims?

Personally I'd put the standard sizes on, if you go for a wider tyre then AFAIK it will steepen the profile on a smaller rim, but that might not be a bad thing on a SM that will spend a lot of it's time leaned over.

I don't know enough about it to offer any more worthwhile comment than that, sorry.

[singlesman]

For what it’s worth I remember running 110 fronts on a 3.0” RG 500 front Dymag with no issues, but it was an awful long time ago and at an age when you just rode anything as hard as you could, not too much thought went into it

[DefTrap]

I've run bikes with wider tyres than is standard for the rims. As far as function goes, it was fine, although I was hardly racing it. As far as legality goes, mot man wasn't bothered, the difference wasn't huge or even massively noticeable.

Later I changed it back to standard

[Scuffmark]

There's a useful guide here...

https://www.maxxis.co.uk/know-your-tyre ... s-and-rims

[Druid]

This chart confirms that your tyre choices will fit ok

https://ridewrightwheels.com/pages/moto ... ment-chart

I have no ides what difference it will make to the handling though

[Nobby]

...any comment with regards to the question about sizes?

130 would be too small on the rear rim. 140 would be a nice fit.
110 on the front

[derek badger]

Right, cheers all. I've ordered the Diablo Rosso II's. £150 posted. Just need to get some new tubes now.

[Tricky]

Am a bit late to the party here, but as others have said, 110/70 will be fine on a 3" and I'd say anything from a 130 to a 150 on a 3.5" rear dependany on profile you want

In fact of course the big number is not the whole story, as a 140 is the commonly available size is actually wider than a 150 - the 150/60 is standard fitment on the rear of KTM 390s, but I'm replacing it with a 140/70 on my little RC390 track bike- purely as that's the size that my tyre of choice comes in, and it worked so well on my previous 390 Duke.
Front is a 110/70 and thinking about it, I'm almost certain the tyres currently on there are Rosso IIs (they are the OE ones) - sounds like you're already sorted, but if not and you want them and don't mind waiting a few weeks until I get off my arse and get them off and the Dunlop Alpha SPs I've got for it on there, you are welcome to them - the bike has done approx 900 miles so almost as good as new

[derek badger]

Gah. Cheers fella, thanks for the offer. Placed the order this morning though!

[Le_Fromage_Grande]

For those rim sizes 110 front and 140 rear sound right, you could get away with 120 front, 150 rear, but 110/140 is better.