zenolee

Just scored a green Miyata Six Ten beauty for $180. I put some Tektro ergo brake levers on and replaced the seat. The tires are gumwall Kenda 27"x1 3/8. I don't think that's original but they are almost new. I plan on doing one more thing: replace the cassette with a Shimano 7 Speed Megarange. Other than that I will just ride it as is. I was thinking of getting a Nitto Technomic to raise the handlebar a little more towards seat height but I will see if I can get used to the slightly more aggressive position. My plan is to do some light overnight touring on this. I tried to post a picture but I don't have enough posts!

EDIT: I have enough posts

John Nolan 

I wouldn't be too quick to add a Megarange. The triple on the Six Ten allows for pretty low gears.

52telecaster

Welcome to the fold. Miyatas rock. Dont know if u need the megarange but i till say they work very well.

The Golden Boy 

You might have some trouble with the 7 speed freewheel- as it was probably designed for a 5 speed rear end. You can usually get 6 speed to fit.

I’m looking forward to pix! I fully support the use of the Technomic- beware, on smaller bikes, there’s less headtube- so the stem can seem to be WAY up there.

Good luck!

post more!

due ruote 

A Technomic Deluxe Is a good choice if you need more height but not as much as a Technomic - the quill is 190mm instead of 225. It’s also possible to cut a Technomic down a bit, but you would likely need a different bolt if you take much off.

https://www.benscycle.com/nitto-ntc-...ng_870/product

As seen here:

zenolee

When I looked up the original Suntour derailleur specs, it said it was capable of supporting 34t

It's due to arrive today so I will let you know.

The Golden Boy 

Dude, you need to post more.

Which Suntour rear derailleur are we talking about?

zenolee

Unfortunately I can't post any links or pictures until I pass the 10 post limit. It's SunTour MounTech

Specs copied from website:

• Derailleur brands: SunTour
• Categories: SunTour - the mountain bike gears, SunTour - Frank Berto and the curse of Duopar
• Country: Japan
• Date of introduction: 1982
• Date of this example: 1982 (two letter date code is YE)
• Model no.: 4900
• Weight: 273g
• Maximum cog: 34 teeth (Source: Sutherlands fourth edition)
• Total capacity: 34 teeth (Source: Sutherlands fourth edition)
• Pulley centre to centre: 65mm
• Index compatibility: friction
• Chain width: 3/32”
• Logic: top normal
• B pivot: three pivots, rear unsprung and the other two sprung
• Materials: largely aluminium with steel pulley cage plates, link element plate and inner parallelogram plate

zenolee

I haven't measured but the spacing is typically 126mm and the 7-speed Shimano freewheel is 130mm. I've already done the conversion on my Zebrakenko from 5 to 7 and when I remount the wheel, I just have to add a little umph to get it back but otherwise no problems. No need for cold setting.

The Golden Boy 

If you’ve got that first generation Mountech- the one with the upper pulley built into the unit- find something else to replace it with- there’s a gazillion other derailleurs out there that don’t present the possibility of catastrophic failure like these do.

zenolee

I am a few posts shy of being able to post pics. Is there a way of identifying how the upper pulley is "built into" the unit?

thumpism 

The Golden Boy 

That gives me the heebies just thinking about that.

The Golden Boy 

Google “Mountech.”

The ones with the block lettering have the upper pulley captive in the arm. Those are bad.

The ones with the script lettering have a standard upper pulley system. Those aren’t quite as bad- not quite “good” though. I had one with the huge 13T lower pulley. I wanted to love it because it was so quirky weird/cool. But it just didn’t shift “Suntour” well. IMO- the triple pivot idea was totally unnecessary with the slant parallelogram. And ask yourself what you need a spring loaded, captive pulley for... I have one of the Suntour triple pulley derailleur that shifts GREAT. Much better concept - but SIS was about to steal the show.

The Golden Boy 

BTW- If you’re wondering what’s so bad about the design - there’s no way to service or even know you need to service the upper pulley unless you do that ^.

And then dirt and grit get in there, and then the pulley seizes, and the derailleur goes into the spokes.

dddd

From my experience with a 1984 Mountech (the one with the internal spring), and having rebuilt that one early on, I wouldn't expect trouble from it unless you are mountain-biking or riding in a very dirty environment.

As bad as people say they are, mine survived years of use after my initial six months of hard off-road use, and after which I did milder riding mostly on the road, but still with many trail rides thrown in.

I consider the early rear Mountech to be disposable when the top pulley becomes very worn in terms of it's bushing freeplay, since I can't remember ever identifying a convenient source for such a replacement pulley.

The Golden Boy 

My 84 Stumpjumper Sport came with a Mountech RD and Specialized hubs with Saturae rims... It came to me with a circa 1994 XT RD with a circa 1994 LX / Weinmann wheel- but most of the rest of it was stock. While I didn't ask the PO about what happened to the rear end- he did say he mostly just commuted with it.

zenolee

I have the infamous Mountech it seems.

It looks clean. The bike itself seems pristine. It has the original freewheel, from what I can tell, and it is hardly worn. I will keep an eye out for the suspected mechanical failure and also keep an eye out casually for another RD

zenolee

Finally passed the 10 post limit so I've edited the first post with a picture

thumpism 

Drive side photos, please!

I'm not saying that, I'm just saying what I'm sure many others are thinking.

Nice bike.

52telecaster

Great bike!

The Golden Boy 

Sweet, and beautiful bike!




Drive Side Pix!

zenolee

Drive side pic, as requested

btw, I had a chain failure and repaired it by removing 4 links so I had to stay mostly in granny gear for most of the day for my 40 mile ride

ryansu

Nice bike OP. Btw if a 7 speed mega range is too wide to fit they do make a 6 speed - picture attached to show how I know - went through this in March. If you need a new chain I recommend A SRAM PC 830 with quick link in my experience they work very well with 5,6 and 7 speed bikes.

In my case a 7 speed FW would kinda sorta fit but not with enough room to shift into the smallest cog, the 6 speed works fine on my 84 Novara Randonee, Enjoy the 610, I don't think you will find many negative comments about Miyata's on this forum, I have had to two pass through my hands and enjoyed them both.




TZ30 on the left is the 6 speed

dddd

Looking at these 14-34t freewheels and their cog sizes, I don't see how the 7sp one is any more useful than the 6s one, unless the bike perhaps already had a 7s SIS shifter on it!