Miyata 1000 650b Conversion
 

Hello,

i was wondering if it is possible to switch 27 inch wheels from a 1982 Miyata 1000 to 650b?
it's been on my mind for a while. The bike already rides great, probably the most comfortable bike I've ever ridden, but all this talk of 650b makes me curious to increase the comfort. I've been told tjat 700c is just as good if I get a more supple and wide tire, but a lot of threads seem to agree that 650b rides different than 700c.

the miyata has cantilever brakes if that helps. I'm not too sure on the specifics of the geometry and can't post pictures since I am relatively new.
thanks!

You can't just use longer brakes when the rim drops to the other side of the cantilever pivot. I think I'd start with a different bike if I wanted to dabble in the 650b territory.

+ 1 on this advice.

I think what I'd do- in order

Try a set of Swift Tire Sand Canyon tires in 1 3/8".

Go to 700C- You should be able to get some 700c x 35s on there- plus fenders- maybe 38s without fenders. Depending on what cantilevers brakes you have on there- it may be just a matter of putting the 700C wheels on. If your brakes don't adjust enough- do some reading around and/or ask questions.

I wouldn't even consider 650B until trying it out on another bike- without canti studs. That being said, I'm considering a 650B conversion on one of my bikes.

650B = 584mm diameter; 27" = 630mm diameter, so you'd be looking at lowering your brake pads by 23mm (46mm/2). That's likely beyond the adjustment range of any canti-brake.

https://www.brgstore.com/en/brake-ca...ors-elevn.html

I think these might work.

Won't work on steel bikes with braze-on posts.
 

A Miyata 1000 has a steel frame, right? Steel bikes typically have one-piece canti posts, so no, they won't work. As was recommended, you should find a different frame for 650B conversion.

16mm might not be enough.
I put 700cs on an 81 miyata and it required very little tweeking of the brakes. 27-700c would be a 4mm drop 700c to 650b would be a 19mm drop. Its more than i would spend to try it but 700- 650b would work i bet. I may try it eventually.

those 559s are the bomb. Lots of stopping power.

Another option. Still only moves 16mm.

BE-1 BRAKE POST EXTENDERS NEW - Promax Components

Another possibility is to grind the posts off and rebraze new posts to fit either cantilevers or centerpulls. It has been done by at least one BF member, and you might find it on one of the 650B threads on this forum. It probably isn't worth it on the Miyata, because the Miyata 1000 is just right as it is. However there are lots of other frames without braze ons that can be readily converted if you want to try 650Bs.

As someone with several 27" wheeled bikes, and as someone who's recently switched over my main bike from 27" to 700x x 35- There's a world of difference in the ride of a tire with substantial air volume and supple casing.

A majority of the problems with having a bike with 27" wheels is finding good tires. Most 27" bikes were built when narrow tires at high pressure were thought to be a good thing- With wider, high volume, more supple 650B and 700C tires at lower pressures- people have figured out that a comfortable ride doesn't mean getting jarred around every road bump. But that hasn't really been reflected in whatever 27" tires that are available.

With 27" wheels the the only 2 sizes that are commonly available are 1 1/8" and 1 1/4". Nominally 28 and 32mm. There's not too many companies making non-knobby 1 3/8" tires- those are nominally 37mm.

The easiest and cheapest thing would be to try out the Sand Canyon tires- they're ostensibly 27 x 1 3/8". I don't think they are- but they are bigger and wider than 1 1/4" Paselas. I think they are cushier than the Paselas- I've run them everywhere from 35-75 PSI- they're nice tires.

https://cimg8.ibsrv.net/gimg/bikefor...eabca7f2c4.jpg

https://cimg1.ibsrv.net/gimg/bikefor...c2eedb12e9.jpg

https://cimg0.ibsrv.net/gimg/bikefor...f285befe0e.jpg




For me, personally- I changed my 1985 Trek 720 over to 700C and chose to use Compass Bon Jon Pass tires at 35mm. I run them around 35-40 PSI and they ride fantastic! (if you ride them at 90 PSI- you're on a bouncy balloon). I was still able to fit the larger tires under the same fender setup as I did with my 27" tires. I'm quite happy with these tires- and when I did get my Miyata 1000LT- I chose the same tires for that bike as well.


https://cimg8.ibsrv.net/gimg/bikefor...5b5ca9e98d.jpg




The Miyata 1000 is a world class bike- one of the very very best touring bikes ever- regardless of the year/model. IMO- most of the "improvement" of 650B is having cushy tires- not the actual circumference of the wheel. I would strongly urge you to try more voluminous tires and try converting to 700C and using voluminous, supple tires.

700c

+1

You can probably find some cantilevers that work on 700c wheels. My Centurion Pro Tour has brazed on centerpull posts, so I just had to find some longer reach centerpulls that would work. Dropping a few mm in rim size from 27 to 700c gives more clearance for fat tires.

https://cimg2.ibsrv.net/gimg/bikefor...63b20446f6.jpg

Having both 650b and 700c bikes, it seems that the tire patch size on 700c X 35 is equivalent to 650b x 38 - one "tire size" difference, and the cushion of the ride is about the same. So 650b x 42 would be same ride as 700c x 38, etc.

I do enjoy 700×35 paselas on my bob. I have an 81 miyata 1000 an its difficult to get 700x35 and fenders in there.* Smooth riding bike tho no matter.

I've actually done what you're wondering about to a bike very similar to your Miyata 1000. My bike is a 1982 Trek 720, bought new 37 years ago and my daily driver since.

Originally a 27 inch wheel, I de-brazed the cantilever bosses 20 years ago when converting to 700c. A crack in the front fork a couple of years ago gave me the opportunity/excuse

to go to 650b. Since the bike's primary use nowadays is commuting, I went with Sturmey Archer drum brakes, thus getting around the brake reach problem. Never having used

drums before, I was a little apprehensive about them. I even went with the larger 90mm size for the front wheel, just in case they weren't up to the job. Needn't have worried;

they are more than up to the task. In fact, they were so good that I did a 650b conversion to our tandem, using SA 90mm up front and disc in back.


Drums stop consistently fine, rain or shine; better than any rim brakes I've ever used. Easy to install and maintain. Keeps the bike much cleaner in heavy weather.

Yes, they are heavier, but, really, who cares?


With 700c, I was only able to go with 33mm tires with fenders. With 650b, 42mm with fenders. As others have said, big difference in the ride.

Give it a shot. You've got a classic there. Happy trails.