'73 Honda Tires: Sprockets forum: Grassroots Motorsports Magazine

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Oct. 10, 2011 9:25 p.m. Youngguns New Reader

Okay, to start off, I've been here before, I'm returning :] Things got a little complicated, and well, I just now got a motorcycle. She's a 1973 Honda CB450.

Now, to the point. I think the back tire on her is original, and well, the front one needs replaced as well. I was wondering if I could get some information on some good tires for her. I'd be running her mainly in late spring/summer/early fall and of course, the occasional warm day in the winter here in Maryland.

I'd also like getting some help with the tire sizes. The rear tire seems original from '73 and says "MN 90-18". The guy at the local Harley shop translated this to "110-90-18". The front says "3.25-19". The local guy said the tire will most likely be "90-90-19". I would just like to know if these are correct or not, and if not what is.

I guess I should add that I don't want cheap tires, I want some that will still grab the road during that slippery period when it first starts raining.

*Oh! The rims are spoked; tubed tires of course!

Thanks for all help! Much appreciated!
Oct. 10, 2011 9:55 p.m. Rusnak_322 HalfDork

I went back and forth with this on my CB360.

If you want todays performance, pick a tire in your size and go. There is no problem running a tube in a radial tire.

Avon makes some great tires. The Roadrider is very popular with the cafe racers.
Oct. 11, 2011 7:08 a.m. 44Dwarf Dork

Most catalogs have a metric to inch chart and will list new tires for it. Take a look around the valve stem you should find a stamp of the rim size it might be inch or it might look like W2 etc theres charts in the catalog for what tire properly fits that rim too. Get modern tire that close to same sizes as stock you'll be fine. You can go little wider but don't go overboard.
Oct. 11, 2011 7:39 a.m. PHeller Dork

You can get vintage look tires that are brand new in the same size. These are usually pretty cheap, 40-60 bucks.

Or you can get expensive $90 modern look tires.
Oct. 11, 2011 8:48 a.m. pilotbraden Dork

On my RD 350 I can't go much bigger due to rubbing on the swing arm. Your Honda will probably be similar. Find someone with a similar machine and see what they run or buy tires locally so you can test fit them. Also wider tires do not necessarily mean better performance on a motorcycle. Be cautious with new tires, the mold release agents are slippery.
Oct. 11, 2011 8:51 a.m. 4g63t HalfDork

Any tire will be better than what's on there!! I pretty much stick to KZ1000s and CB750s and I like Bridgestone BT45s. Dunlop D404s would also be good for your use, and be budget friendly.
Oct. 11, 2011 6:21 p.m. stuart in mn SuperDork

The rear tire isn't original to the bike, it's old enough that it would have had an inch size tire on it - probably 3.50-18 or 4.00-18. That doesn't really make any difference, as the tire that's on there is old enough it needs to be changed anyway.

I suspect your choices will be limited, since those tires are pretty skinny by today's standards. I'd go to bikebandit.com or denniskirk.com and search by size to see what's available.

The current sizes the mechanic gave you appear to be correct. There are a number of conversion charts on line, here's one: http://www.weeksmotorcycle.com/tire-size-conversion-chart.html
Oct. 11, 2011 7:35 p.m. Rusnak_322 HalfDork

There are actually lots of tires out there. From modern rubber in radial and bias ply to cruise and touring tires to vintage reproductions in either street or race compounds. Also dirt track tread.
Oct. 11, 2011 8:40 p.m. Rusnak_322 HalfDork

I went with Kenda K657 Challenger tires. 100/90H-18 front and 120/90H-18 rear.

I liked them because they are not too modern looking. Some of the tires look like they should be on a supersport bike. They got great reviews, but I don't plan on going too crazy when riding this bike. Anyway, all the good roads are at least 60 miles away and I don't see too many 120+ mile rides on this thing.

these look beefy because the bias ply side wall is so much taller then the radial tires.I did go up one size on the front and two on the rear. The rear easily clear the swingarm, but it will not clear the brake rod if put all the way forward.
Oct. 11, 2011 9:38 p.m. Curmudgeon SuperDork

I went with Shinko 712's which look almost exactly like those Kendas. I think they are both a knockoff of an older Metzeler design. In the 300 or so miles I have put on them, I have had no complaints. I just mounted them and didn't even balance them, no vibes up to 90MPH (the fastest I've been so far).
Oct. 12, 2011 10:45 p.m. Youngguns New Reader

Okay! Thank you everyone for your help. I'm glad to have discovered my tire sizes in metric. So pretty much, any 110/90 tire will fit the back, and any 110/90 will fit the front?

There were a lot of suggestions thrown out there, and I guess I'm looking for the best tire that combines grip and price. I don't care about modern or classic looks. Just affordable, good tires.

Oh, and where would I find tubes to go with the tires? How are tubes measured? Same way?
Oct. 13, 2011 6:31 a.m. 44Dwarf Dork

Tubes run by same sizes but with a range listed uyou might see 100-250/18 this would fit a 18 inch rim with 100 up to a 250 width and truth be told alot wider but get one that sized right.
Oct. 13, 2011 5:37 p.m. 4g63t HalfDork

120/80-18 on the rear and 100/90-19 on the front. You get tubes at the same bike shop you get the tires at. change the tubes too.
Oct. 14, 2011 2:58 p.m. motomoron HalfDork

On my RD400F Daytona Special I ended up going w/ Bridgestone BT45s. 90/90-18 F, 110/90-18 R. I haven't gone crazy on it but I've worn the chicken strips to an acceptably narrow width ans they're quite nice.

I'm and ex-motorcycle roadracer and appreciate good tires - for cheap tires these are quite good. Better that the Metzeler ME33-ME99/ME55 we used forever. Probably as good or better than Avon Super Venoms.