Tandem Tom

I am considering the 610 for a "new project"! I think it will be what I am looking for in a randonneuring type frame. But have a question.
Has anyone done the actual 27" to 700c conversion? Did the canti brake work?Or did you have to find a replacement?
Thanks!!

RiseAlways

I've been contemplating doing the switch to 700c myself on my '83 miyata 610...just no cash for a set of wheels right now.
Here's a thread I came across a few weeks back dealing with the conversion of an old Miyata 610...

https://www.bikeforums.net/classic-vi...-610-700c.html

bear_a_bug 

I'm sure some of the 610 owners will chime in, but I have an '85 210 (first year for cantilever brakes on that model). I believe the geometry is fairly similar to the 610, and I would assume that the brake positioning would be similar, as they both had 27" wheels OEM.

I swapped over to 700c fairly easily, using the original DiaCompe brakes. I did, however, use narrower rims for the 700c (Sun M13II), which may have contributed to the ease of set up. A wider rim may have caused some brake pad positioning issues.

daf1009

My question is...why switch? You can still get a wide variety of tires for 27" and they are, a bit, more comfortable on longer rides...

mrmw

Rim width is the fly in the ointment.

Suggest Sun CR-18 rims, as they are several mm more narrow than other 700c rims but still stout when built up with double butted spokes.

Here are several cantilevers with sufficient center to center vertical brake shoe adjustment range:
--Shimano Deore BR-M550 19mm ctc
--Shimano MC-70 (early xt circa 1984) 22mm but they have some extra flexibility.
(These measurements are right from Sutherlands!)

Cyclotoine may chime in re modern Tektro's which many have tried.

My '84 Miyata 610 is plush, indeed.

bikemig 

I've had issues with getting tektros to work on my 1993 bridgestone XO-2 and I'll bet the posts on that are wider than on the miyata 610.

Tandem Tom

Thanks for the replies!!

ironwood

Can you lower the brake pads 4mm? If so, no problem. It can be done with some Miyatas, and yours is most likely made by Miyata.

The advantage of going to 700C, is that you can use some of the wider Panasonic tires sold by Somafab or Compass.

mrmw

And, you can use modern cassettes--either stock, or your own custom sized or 'Shuntour' spaced.

Most important for larger frames and riders, the rear bearing position moves outward on the axle which minimizes the potential for bent rear axles.

The Golden Boy 

Maybe I'm missing a source for stuff- but I believe "wide variety" is kind of overstretching things. When I went to the LBS for 27" tires, their selection was the $10 Kenda gumwall.

I haven't switched my 27s over yet, but I'm guessing the extra 4mm would allow for a 35mm tire, as opposed to the 4mm taller 31.75 that a 1 1/4" tire would be. I'm not good at math and calculating volume- but I would guess that 630 x 31.75 and 622 x 32mm is somewhere in the neighborhood of a wash- pretty much imperceptible to the average bear. Any differences would be in the quality of the wheel components.

A couple of years ago I switched a bike from 700C to 27" to use a set of short reach brakes. The ride GREATLY improved. I attributed the improvement in the ride to the 27" wheels. What I didn't take into consideration was that I had been using an OK rear wheel with a crappy front hub laced to a decent rim and when I went to 27, I went to good hubs on good rims- better wheels.

I believe for the extra cost of new wheels and tires, I'm OK with 27s for the time being. I'm riding 1 1/4 Pasela TGs on everything except a bike that will only fit 1 1/8. They're comfortable. If I were to switch I would probably be riding Paselas, and whatever the largest tire I could get in there- probably 35mm. But when I get the opportunity, I'll get really nice 700c wheels

The Golden Boy 

Why would you want narrower rims?

It seems to me the 27" canti posts are higher, and the farther in the brake pad goes, the more the pad is pushing down instead of directly towards the rim.

bear_a_bug 

Good point. I have never tried mounting wider 700c rims, but my thinking was that a narrower rim would allow the pads to line up squarely, rather than at a sort of "wedge" angle if the rim pushed the pads out too far.

Could just be a matter of positioning the pads better. In any case, the M13IIs seem to be working out. I do have a slight fork shudder, but that was happening back when I had 27" wheels, too.

likebike23

I think there's too much hand wringing over the whole 27 inch wheel/tire issue on this forum. The bike was designed around 27 inch wheels and will perform best if run with that size. Any perceived benefit from switching to 700C is going to be countered with poorer braking setup.

As for running wider tires, how much better and wider can you go? My Miyata built 1983 Univega Gran Turismo can fit 700x35 tires with sufficient clearance. I've got 27 inch Michelin World Tours on there now and they measure 33mm with the Araya rims. 2mm difference isn't enough to justify all of the problems with the brakes IMHO.

The tire selection issue is another one. Sure, there are not a ton of choices when it comes to 27 inch tires. There are however, enough choices to get the job done. The thing is, there is no such thing as "the best" tire for touring, gravel riding, or whatever. If you want to test my theory, just start a thread on the best tire and you'll get 100 different answers. You may need to compromise on your tire selection, but when you are riding a vintage touring bike, aren't you making compromises in one way or another?

I messed around with the 27 inch to 700C conversion thing on my Univega and couldn't get the brakes sufficiently set up with 3 sets that I tried. Just how much fooling around does one have to go through to get such a small benefit? In the end I determined that leaving the bike with 27 inch wheels was the way to go. My advice is to find yourself a nice sport touring bike with 27 inch wheels, caliper brakes, and 17 inch chainstays to mess around with. You can switch to 700C, 650B, 650A, or whatever and run 35mm-40mm tires depending on wheel size and long reach brakes are easy to find.

RiseAlways

The only issue I can foresee, and the only one I see now, is that if you are interested in any sort of touring, you're virtually screwed if you find yourself in need of a new tire or a new tube for that matter!!!!

Out of four local bike shops I called one had 27s in stock, (called a few weeks ago) but not a touring tire,..sorry but I'm not interested in "making do" with a road racing tread when I'd prefer and do better with a touring tread for grit, gravel, dirt AND pavement...

I actually just bought a set of Conti Tour Ride 27s,.. I haven't switched and I probably won't till next spring/summer when I start a "little" bit of short touring...

If you're not touring,.. stick with 27s,.. but that's just my opinion. There aren't vast amounts of 27 tires to choose from, but they're out there, not readily available at your local shop either (unless your local shop specializes in vintage bikes).

Ride on!

79pmooney

I had a Miyata 610 from probably about your year and ran it 700c with the old Mafac cantis. That setup went 27,000 miles. Roughly midway though the brakepad life, I would adjust the tilt. It wasn't until I read this thread and the one a couple of days ago that I realized I had a problem.

I have half the problem on my Peter Mooney. I had it made with the canti bosses set halfway between 27" and 700c so I could go either way. It took 44,000 miles and these threads to learn that was unacceptable. (The Miyata 610 Shimano OEM cantis went on the Mooney since they were better than the Mafacs. That was 1995. They are still there.)

Do it. Look periodically at the shoes. In 10 years you will read another thread and be reminded you have it all wrong. If you are worried, try it with a wheel you have on hand. Then you have nothing to lose and not one dollar is spent.

Ben

RiseAlways

Fantastic reply Ben!!,... fantastic!

It's pretty much like this,..
Do you stop without pinching the brake levers for dear life?...(yes)
Are your pads at 45 degree angles?....(no)

Ride on!

Lascauxcaveman 

The Miyata 1000 frame (1980) I just sold would absolutely have to get new calipers to make the jump down to 700c. Unless you like brake pads squeezing in at about a 30 degree angle from square. Bleh, wheel size change = unnecessary hassle.

Keep the 27s, and take an extra tire with you if you plan on crossing the wild Serengetti. (BTW - you'd want to do this if rolling 700c, as well) I've never been to bike shop that didn't have a few acceptable 27s in stock, and anything you want is available online.

RiseAlways

Problem is,... I've personally never seen a folding 27" tire (are they even available?),...if not,... taking an extra tire makes for a clumsy doughnut hanging somewhere. Road debris can be anything and can slice a tire. You won't be ordering online if you're touring.

Otherwise, yeah, 27s are cool,.. as I said, I just put new 27" Contis on my Miyata 610. Love em. I'm also not going long distances yet,.. yet!

Lascauxcaveman 

They are fairly common, Origin 8 still makes them in several colors, others are on ebay all the time, new or NOS.