louky

I just bought an older Nishiki mixte, model is "Custom 12". I want to do some customizing on this, including switching to 700c wheels. I assume this bike is a low/middle model. Chrome front fork tips, Diacompe center pull brakes, Althus components. I have a Trek bike that has 700 x 35 Bontrager wheels on it. I pulled the front wheel and put it on the Nishiki. It has plenty of clearance and the brake pads actually line up perfectly. I was going to try the rear wheel to see if the pads would align only to find out that the hub is much wider on the bike I was taking the 700 from. The spacing on the Nishiki measures 125mm.

What do I need to be looking for to get a 6 speed hub that would fit in this space with a 700 rim? The freewheel or freehub is also something I haven't run across. It is labeled Shimano but different from the freehubs I have been taking off recent cheap mountain bikes, and also different than the cassettes I have removed using the chain wrench and insert. Thanks in advance.

Bill Kapaun

Look up Uniglide

Kontact

That's the original Shimano cassette hub - instead of a lockring it uses a threaded outer cog. This is a little unusual in a bike of that type - usually it would just have a freewheel. 6 or 7 speed hubs with cassettes or freewheels are usually 126mm wide, like yours. Wider hubs (130mm) can accept 6, 7, 8, 9 or 10 speed freewheels or cassettes. For the 6 or 7 cassettes you add a spacer before adding the cogs. Using a wider hub won't hurt the Nishiki - you can just pull the dropouts apart to get the wheel in or permanently set (bend) the dropouts out to 130.


You need to ask yourself why you are putting a new 6 speed on the bike. If it has index shifting, then you would need to stick with 6 speed. But you may find it incredibly difficult to find true 6 speed spaced cassettes. Most 6 speed bikes used freewheels, and 6 speed index compatible freewheels are still produced. So if you need to stay with 6 speed, get some freewheel compatible wheels. They are not hard to find, new or used.

If you aren't trying to match a 6 speed index system, then consider upgrading to 7 or even 8 speed. 7 speed is also available in freewheel and cassette, and freewheel is likely to be the easier option.

You would need a 7/8 speed chain, if the bike doesn't have one already, but the crank and derailleurs will work just fine with narrower chains.

Given the kind of bike you have, I would find some decent freewheel compatible wheels and buy a Sunrace freewheel. It will not be a downgrade from what you have and will remain easy to get parts for.

Does that make sense?

dedhed

Probably a 1050 hub. Tells you it was at least above a base model or the wheel was replaced.
https://manualzz.com/doc/53869670/sh...-exploded-view

Options are a 6 speed 700 freewheel wheel or lace a 700 rim on the existing hub.
https://velomine.com/products/sun-m1...63b15e51&_ss=r


Those uniglide hubs can be "upgraded" to hyperglide.

maddog34

the Nisiki frame should actually measure 126mm.. and it can be reset/"COLDSET" to 130mm without much trouble.. a shop with frame gauges can do that for not too much cash.
restting the frame to 135mm will be tougher and require more effort....the dropouts get wider at the rear and they also need alignment..

SurferRosa

An inexpensive and quick solution for 126mm spacing would be a threaded hub for freewheel.

That pic reminds me of the Shimano thread-on freewheel I had with the hub bearings outboard of the freewheel.
[edit: yours isn't that.]

louky

I'd be glad to take some more pics.

louky

My goal on this bike is to get the handlebars up so my creaky 73yo body can comfortably ride on streets and bike paths (mostly paved, some hard pack gravel). I wanted to replace the current steel wheels due to weight and the fact that they have some rust, the finish on the rest of the bike is in excellent shape. Based on the condition of the bike I am thinking it was a garage queen. Looks like original gumwall tires, with almost no wear on the tread but gumwalls rotting. Little wear on brake pads, and you can see the condition of the rear gears.

I have found some alloy wheels online with the proper axle width that takes the thread on cassette in 27 x 1 1/4, which would be one solution as I have a set of new gumwalls that will fit them.

I could get 700c wheels that would take a standard shimano cassette in 126mm width in alloy? I know my front brakes would line up, and assume the back will not be a stopper. This might give me a much wider choice of tires and possible let me have more than 6 cogs on the rear?

There is a chance I can find this set of wheels at the co-op, but I would think the chance of finding the 27 x 1 1/4 in alloy there is much less.

BTW, is there a good way to measure the axle width on these wheels without a special tool while I am at the co-op?

Also, should I be calling this particular one a freehub or a freewheel?

Thanks!

dedhed

You need to measure the hub "OLD" not the axle, but a QR axle needs to fit within the dropout. If an axle on a QR wheel extends beyond the dropout it will not clamp correctly. Axles can be cut shorter if too long.
Measuring the OLD on a built wheel can be done with a decent ruler and a good eye. The standard dimensions are 120mm, 126, 130, 135 and some longer others for more modern and tandem frames. Eyeballing with a ruler is usually good enough to determine which it is.

SurferRosa

Thanks for the pic. It's not what I thought. Sorry for my confusing post.

Kontact

As I explained earlier, finding a 126mm cassette (freehub) wheelset new is going to be extremely unlikely. Finding a thread on freewheel wheelset will be much easier. That is true for both 700c and 27". AND, you aren't going to find any 6 speed cassettes for modern hubs. They start at 7. You will find 6 speed freewheels, though.

It will also be easier to turn a 130 freewheel hub into a 126 than it would be to do the same with a freehub/cassette wheel.

The used wheel market may have quite a lot of selection of 700c freewheel AND cassette wheelsets in 126/7 speed left over from the '90s. If you buy a cassette model, get one that takes a lockring (HG). Some will take both kinds of cassettes (UG and HG), and are threaded on the outside and inside. HG are the ones where one spline is wider than the rest.

You can still buy replacement 27" wheels and tires for all those touring/sport touring bikes of the '80s bike boom. But your selection of tires will be much poorer. Might as well go 700c.

Jeff Neese

No problem. I think you said you already found a 700C wheelset that is 126mm and that accepts a 6-speed freewheel. I just bought one of those myself for an old Fuji, from Velomine. They are very nice wheels and hubs. And there are still Shimano 6-speed freewheels available too, and Sunrace sells them also.

This is what I bought and I'd buy these again in a heartbeat. There are different rims available depending on what tires you're planning to use. These have Sun CR18 which I have on several other bikes.
Sun CR18 27" 5,6,7 Speed Freewheel hubs Road Bike Wheelset

Selection of screw-on freewheels is limited but this is what I used.
Shimano Tourney/TY MF-TZ500 6-Speed Multiple Freewheel, 14-28 Tooth

This is also available.
SHIMANO MF-TZ20 14-28 Teeth 6 Speed Freewheel

sweeks

Just a thought... I don't see why you couldn't keep the original hub, gears and derailleur and have the wheel re-built with a 700c rim.

Kontact

It's expensive. The hub is bolt-on. The cogs are no longer made.

sweeks

I suppose so. I'd have done it myself for the cost of the rim and spokes... probably still a bit expensive.
Well, it was just a thought.