CB125F Tyres & Sizes

Hi everyone,

I've been looking into alternatives to the OEM chinese things on my 125, i found this thread from last year:

https://www.themotorbikeforum.co.uk/viewtopic.php?t=60093

where folks are talking about ContiGos - but Continental don't seem to think they do a ContiGo in the 'right' sizes, which is an 80/100 18 at the front and a 90/90 18 at the back:

https://www.continental-tires.com/motorcycle/tires/motorcycle-tires/allround/contigo-light-motorcycles

Would i just put the 2.75 18 on the front and the 3.00 18 on the back in that case? are they basically close enough to the original sizes that it won't be noticeable?

Cheers!

What a great question (and a silly choice of front size by Honda!). As you are probably aware there is a lot of choice in 90/90-18, this will have a very similar circumference to the 80/100-18 but it depends if the slightly fatter tyre will fit without rubbing - only you can see what kind of clearance you have around the front tyre as it is. 3.00-18 is virtually the same as 90/90, but 2.75 won't be tall enough.

The first number is the width of the tyre, the second number is the height which is a percentage of the width. So a 90/90 is 10mm wider than the 80-100, do you have more than 5mm clearance either side? I bet you do.

Thanks for the reply so if i'm reading you right, what we're basically saying is that if there's space enough for the extra width, just put a 90/90 (or 3.00) on both ends?

Yep. The bike won't be quite as flickable because of the fatter tyre but you do get a choice of much nicer tyres so overall I'd go that way every time.

In 90/90-18 I can personally vouch for the Michelin Pilot Activ being excellent, with the Metzeler ME22 being a bit rubbish in the wet and Pirelli City Demons/Heidenau K44 being outright awful. In 3.00-18 I like the Metzeler ME77 and Heidenau K65 very much. Proper aftermarket ContiGo!'s are also worth a look, far superior to the terrible things that come on new Hondas - I have tried both and know they are not the same animal at all despite having the same name.

Hi

sorry if this is a bit of a necro post, but i have a 2021 Honda CB125F with standard cheapo tyres of 80/100-18 front & 90/90-18 rear. although i know it's a small bike and don't expect it to be too planted anyway, but i find that especially in wetter conditions the front tyre grip just feels a tad too squirelly for my liking on bends, as it does on cobbles, so i take it much slower than i probably need to. i replaced the rear tyre a few months ago coz of a puncture with the same tyre it came with as standard, and upped the rear preload which helped, but my questions are these:

1. if i'm reading the above comments correctly, can i use contiGo's 90/90-18 on both front & rear - i think theres well enough space to fit
2. would i be safe just replacing just the front with a 90/90 for now as it's going to need replacing soon, and then the real one later with a 90/90 when due? seeing as it's only about 500 miles old. would 'mixing' cause any possible issues

any help or comments would be appreciated. Thanks

Stick with the standard sizes and buy a decent brand of tyre would be my sugestion, do not buy cheap crap you want a tyre you can feel confident in and grips when you need it.