guygadois 

I have a bike with 120 spacing (steel frame). I would like to see if I could use some Dura Ace 8 Speed brifters on it. My thought is to use a Shimano 7 speed freewheel and 8 speed brifters and adjust the limit screws to accept the 7 speed (with an extra useless click). Can this be done? Can I achieve this with 120 spacing in the back without stretching the rear triangle?

-GG-

toytech

you would have to cold set the rear drops almost certainly I would imagine, I don't think a 7 or 8 cog set will fit otherwise, although I might be wrong. You may at least have to squeeze in a 126mm rear wheel, although a 130 will give you more options (like the 8th cog..) your existing deraillers may be able to take the adjustment and work with the brifters. My own Arabesque Shimano 600's work fine with 105 8 speed brifters but they are at their limits.

EjustE

hold it for a sec.

120mm rear spacing can accommodate up to a 5-speed. (126mm for a 6 or 7.) So you would need to stretch it to get that 7 in there.

As far as the compatibility with the brifters go with the extra click, that is doable, but you will have to work really hard to make it happen. Easiest way to do that is to get an 8 sp RD and short it out (either way for the outer gears) to a 7 sp movement. Short cage RDs tend to be nicer towards this. Another consideration is compatibility of the freewheel/cassette with the RD. Ultraglide might not play nice in this set up...

Good luck

tradtimbo

You will be able to fit a 126mm OLD hub in there, no sweat. A steel frame will flex 3mm on each side without a problem. You don't need to cold set it unless you want to fit a 130mm OLD.

If you decide to take this route, then it is possible to take a hub with 130mm OLD and remove the spacer on the left to make it a 126mm OLD hub. Many Shimano hubs have this spacer (like Ultegras-5600). Others do not, so you have to check.

Now, all of sudden, you can re-dish the wheel over 2mm and put on your 8 speed cassette and have all 8 speeds! You could even put on a 9 or 10 speed cassette if you want to "upgrade" your brifters. The wheel integrity is slightly compromised, but nothing to worry about. Its still plenty strong.

Your options are limitless. Good luck. No need to go with Uniglide. Replaceent cassetts for Uni's are getting hard to come by.

guygadois 

One thing I need to mention is that I need to use my existing wheels as they are 24" and I don't have another option for wheels. So, if I stretch the frame the wheels won't fit, correct?

tradtimbo

so a 7 speed freewheel with 8 speed brifters on a hub with OLD of 120mm? If it is a hub meant for a 5-speed freewheel, or a "ultra" 6 speed freewheel, you'll need to add a 6mm spacer to the right side for a 7 speed freewheel to fit without the chain rubbing on the frame while on the smallest cog. You'll also need to re-dish the wheel. The shifting will work the way you describe, but it will not be optimal. The spacing for 8 speed indexing is slightly smaller than the spacing for 7 speed cogs. It works, but it is tricky to adjust just right.

guygadois 

Thanks for your response. I was under the impression that if I sap out the axle for a 126 length and put on a 7 speed freewheel this could work. With the 126 axle I would add 3mm of spacing to each side to avoid redishing the wheel. Then I would only use 7 of the 8 gears and clicks in the brifters.

What do you think?

Cheers

-GG-

robertkat

Actually if you pick up a Suntour freewheel in "Ultra" spacing, you can fit a 6 speed on a 120mm rear. That was the whole point for the Ultra six freewheels. Might have to re-space the hub slightly. You can find them on ebay for good prices, often times NIB.

guygadois 

That could be a good idea but my goal is to take the kids to SIS shifting thinking it would be easier for them to learn.

tradtimbo

You might need to add both the spacers to the right side, but what you say is worth a shot. Give it a try. Worse comes to worst and you'll have to add both spacers to the right and re-dish. The problem will be the chain or cog rubbing on the frame.

Your shifting idea will work, but you have to get the adjustment perfect because the spacing of the 7 speed cogs is slightly (0.3mm) different from the 8 sp brifters.

Go for it and let us know how it goes. Cheers!

Cheers

DieselDan

Ultra 6 has the same spacing as 7 and 8 speed.

Zaphod Beeblebrox 

Learning Friction is pretty easy...start em out with thumb or stem shifters. Brifters aren't really easy at all IMO...there's alot of functions going on in your hand all at once there.

There's a way to swap an 8 speed Freehub Body on a 126mm 7 Speed freehub.

If you just want indexing on a 120mm hub you could just screw on a 5 speed freewheel and use a 6 or 7 speed index shifter, set the limit screws and it'll work as a 5 speed. There is such an animal as a 5 speed SIS shifter as well.

sciencemonster

I put a 6 speed Shimano freewheel and SIS stem shifters on my wife's bike and it works fine. Not sure if the shifter was 6 or 7 speed...don't know if it makes a difference. The shifters were 12 dollars off eBay. The derailleur is late model Campy; not sure if that makes a difference.