Tyres

[Bolton440]

Howdy all, so I managed to get my 18″ 1.85 rear wheel (thanks again kk) and now I’m looking at tyres to get. The bike that I am basing mine off has an avon speed master 3.00 19 up front. On the rear tho it has a firestone which I won’t be getting as they are mega expensive and apparently not very good.
I have seen avon safety mileage but they only do a 4.00 x 18 which is not recommended for a 1.85 rim.

My question is will a 4.00 x 18 fit on a 1.85 rim and will it be safe? Also will it clear the belt? Anyone tried it? What colour socks you wearing?

Cheers!

[Michael]

Hi Bolton440,

black is beautiful 🙂

I had a look at Metzeler Technisches Reifenhandbuch 2001 and they had included a lot of Information in regards to tire and rim sizes.

A 4.00 tire on a 1.85 rim is not recommended, but they supply all technical data for it. In the end it can be mounted, but not recommended.

Clearance to belt would be fine as the narrow rim will decrease max width of the tire. so that is solved 🙂

Lowest line in the graphic.
I may help with translation if required 🙂

Cheers, Michael

PS: Sorry, can’t post Picture. Something wants to protect my Win 7 PC when I try to upload it.

[Kaptainkwak]

It appears the maximum recommended for a 1.85 rim is a 3.5 tyre Tyres on Rims . However I have run bikes with over and under sized tyres in the past without incident.

If you are interested I have a brand new Avon Roadrider 120-90-18 rear tyre mmmmm

[Michael]

This tire size is not recommended, but from my past experience it will fit to the rim and can be used without any issues.

Only thing that might be an issue, is that the curvature of the tire is not as round as the manufacturer wants it. This may lead to the fact that it is very hard to push the tire to the Limit left and right Hand side.

If you and MOT can live with that, tire size 4.00 or 120/90 should be ok.

I had a 150/80-16 on the rear rim 3.00 of an LTD. That is max width that is allowed on that rim. Was ok for approx 10.000 km 🙂
But I was not able to push that tire to the outer edges.

I am not able to push modern tires to that Limit at all 🙂

Cheers, Michael

[Kaptainkwak]

I agree there Michael. The worst case I remember doing was back in the late 70’s when I put a 2.75 Yokohama rear on my Z1000 MKII 4.00 rim. I had no major problems when riding. Being more knowledgeable I would not recommend it but it did do the job.

[Bolton440]

Awesome! Thanks guys, I guess I’ll give it a try then. I’m not particularly fussed about being able to push the tyres to the limit as I don’t really ride like a tool on my 440. Hell, even if I wanted to I doubt the old girl would be able to do it lol.

Now I know it’s possible I’ve been looking at Avon safety mileage as I really like the vintage look and they go very well with a speed master upfront.

Do you think it will look silly with the 4.00 on the rear or should I really stick with a 3.50. The main reason I wanted a 4.00 up back was to make the back end look a bit beefier.
Choices, choices.

Thanks for the offer kk but I’m gonna stick with the vintage look for this bike. Probably be a few weeks before I get tyres anyway, gonna do a bit each month til I’ve got everything ready to fit so I’m not off the road too long.

House should be going up for sale in next weeks so, house I’ve been looking at has a garage! So that’s my first priority at the moment. Fingers crossed!

Thanks again guys 🙂

[Michael]

The 4.00 should look fine on the narrow rim.
It will be a bit of “balloon tire”, which should match the desired vintage look.
Cheers, Michael

[Jon]

Hi

Bit of forward planning for me. The tyre especially on the rear looks a bit skinny by modern standards.

Any recommendations for the fattest tyres i can fit to my B2 (Mag wheels)?

[Kaptainkwak]

Hi Jon

Tyres back in the day were very skinny compared to modern standards but they were designed to do a job and in my opinion did it well. There is not much room to play with at the sides of the wheel so if you are going bigger I would suggest no more than one size up from standard. I personally stick to the original sizes. If it’s not broken don’t fix it.

KK

[Author]

Posts