Tire sizes for CB77

[Tim Allman]

I have just laced up the wheels for my CB77 and now need to shop for new rubber. The front and rear tire sizes are given in inch sizes but for the most part tires are sold in metric sizes now and making this conversion is turning out to be more difficult than expected.

One of my goals in rehabilitating my machine is to make it a useful bike and I would like to put on modern tires. The questions that arise are

• Would radial tire be of any use on a bike that was not designed with them in mind?
  
  What metric sizes correspond best to the 2.75-18 and 3.00-18 sizes of the original tires?

Does anyone have experience with these issues?

Thanks.

[cknight]

Avon offers their StreetRunner series tires in 2.75-18 front, and 3.00-18 universal tread configurations. In metric sizes. I have Avon RoadRider 90/90-18 front, and 100/90-18 rear tires on my 1962 cafe' CB77. These are a bit oversize, and the front has to be deflated to fit between the front fender brackets on the forks. They ride nicely, and don't look out of place. Regards, Chase

[Seadog]

Pic, please, Chase.

[Seadog]

Chase asked me to post these for him:

All right, here's a relatively standard 1965 CB77 that I reunited with the original owner (I went to junior high school with him), then did a practical restoration on it. These are the 90/90-18 front and 100/90 rear Avons. Initially it had standard configuration Cheng Shins on it, but after a few years, he wanted tires that didn't look "so skinny". This provides a better reference for these tires with the stock fenders.

Here are also a few shots of my 1962 cafe' bike, same tires. This pretty much replicates one that I had in the early 60's. The front fender is formed aluminum, while the rear is a Airtech Ducati 350SS rear, which is about identical in cross-section to a CYB alloy rear fender. Hope that this helps.

Pictures were taken at the 2014 Riding Into History show in St. Augustine, FL.

Regards, Chase

r

[rpr851r]

Nice looking bikes.

I have just mounted a set of Heidenau tires on my brothers CB77. They look period and claim to be modern compounds. Other forum members have had good luck with them. I put a 2.75X18 K39 on the front and a 3.00X18 K33 on the rear.

Seadog-I can send you pictures to post if you PM me an e-mail address.

[DJM]

I fitted the same Hidenaus when I built my CB77 a few years ago. Very happy with them except the rear tyre didn't last too long at all, around 2500 miles before there wasn't a lot of tread left on the centre line.

I replaced it with a Mitas / Cheng Shin which I also use on my CL77 with no problems at all. I must say the rear tyres don't last that long on the CL either but the Cheng Shin tyres are a fair bit cheaper than the Hiedenaus, they do seem to last a bit longer and perform just as well.

I'm sure the rubber on both of these tyres is 'modern' whatever that means, 'softer' I suppose. They certainly seem to grip better than the old Dunlops or Avons I used back in the 1960s but don't seem to last half as long

[cknight]

Kevin at scramblercycle.com has been a good source for the Heidenaus. His site shows them to be currently out of stock, but there's a good image of them on there. Very similar to the original tires, as were the now-discontinued Cheng Shins. Regards, Chase