vintagerando

I have a 6 speed free-wheel on now but want to move to a 7 speed. What issues will arise when I do this? Do I need to move the spacing of the cones in the hub? And will adjustments need to be made on the rear derailleur? Are there other issues that I will need to address? Thanks.

le mans

yeah you'll need a wider spacer on the drive side, then check to see if it's not too wide for the drop outs, if so a bit of manipulation might be in order. then you could check for wheel dish too, yes you'll need to install a 7 spd shifter then adjust the derailluer

dabac

Since 7-speed freewheels are notorious for axles bending/breaking, I wouldn't be too keen on that change.
Better either be a lighter-than-average rider or only stay on nice roads.

CliffordK

It is pretty common to upgrade 5 or 6 speed freewheels with 7 speed, with benefits of shift gates and

A little bit of the ease of doing it will depend on your bike.

Do you have friction or indexed shifting? With friction shifting, no changes will be needed with your shifters. Indexed could be a problem. Anytime you replace a freewheel, you should always adjust the derailleur, even if it is a similar one to the one you removed. It isn't a big deal, just reset the limit screws. There is lots of info on the web to do it.

Is this a road bike or MTB? If you are careful with what you run over on a road bike, the axle should be just fine. I've always thought that MTBs came with pre-bent axles as I've yet to find one without a bent axle.

How much of the axle sticks out beyond the edge of the freewheel? You may be able to just screw on the 7 speed freewheel without problems, but more likely you'll have to move some spacers around. Do you have any washers or spacers on the left side of the hub? These may need to be moved to the right side. You will only need minimal clearance to the right of the freewheel.

It would be a good time to repack the bearings too.

When you move the spacers, it will throw the dishing off on the rear wheel. 1mm or so might not be a big deal, but any more than that, and you should re-dish the wheel. Not something that is insurmountable by a home-mechanic.

I believe that DNP Epoch is the only vendor to sell an 11T, 7 speed freewheel. However, those freewheels have a little more back-spacing than others and mount wideer than other freewheels (meaning more spacers to move from the left to right).

Bike tinker man

if the extra 7th spocket (low gear) is bigger than previous one on 6, then you may need a longer arm on the RD, also depending on the size jump it might have an effect on chain lenght i.e. be too short.

Both the above comments will only apply if there is a large jump say from 25th to 30+

Slash5

You should check the present width of your hub at the lock nuts. If it's 120 mm your freewheel won't fit without a new axle (probably) and adding spacers. If it's 126 mm the 7 speed freewheel should work. Assuming it is a road bike.

bikemig 

You realize that the OP is not changing the spacing of the rear triangle by going from 6 to 7, right? Depending on the width of the freewheel, the OP might need an extra 1 mm spacer on the freewheel side to avoid chain rub.

Plus, you're not right about 7 speed freewheels being "notorious" for breaking axles; the problem became more serious with the move to 130 mm rear drop outs and 8 on the back.

bikemig 

This is an easy conversion. The biggest potential problem is that if the 7 is wider than the 6, you may end up with some chain rub. Usually a 1 mm spacer on the freewheel side will fix that problem. The wheel won't be quite centered but not a big deal.

If running indexing, there will be shifter problems in going from 6 to 7 which can be fixed (assuming you are running shimano, things get more complicated with suntour).

If you change the size of the freewheel, you may have some issues with derailleur capacity and chain length that you'll need to be aware of.

dsbrantjr

You should always check for the ability to shift into the big chainring/big cog combination without straining anything, by turning the cranks slowly and gently by hand, when you make a change like this.

Aubergine 

I just did this very thing. I had to move a couple thin washers from the off side of the hub to the drive side, and adjust the cones a bit to re-center the axle. I put the wheel in the truing stand and tightened the drive side spokes to center the rim. I thought about skipping this step, but the spokes were a bit loose and the wheel was slightly out of true. So recentering the wheel was worth while.

fietsbob

Not many , the 7 speed freewheel was made to N+1 cogs on bikes with 6 speed freewheels already , Narrower Chain.

I use them Interchangeably on bikes with 126 wide Frames and Modified Freewheel Hubs on Newer 130 frames ..
\

Sedisport chains came in at the time of the 6>7 transition, the Bushingless chain Type
that is Universal on derailleur Type chains Now.

I assume the shifters are Friction.. and You will adjust the stroke Limit screws on the RD a little..

vintagerando

So, so I am hearing "its easy, you should do it" and "it complex, don't do it".

vintagerando

This is a road bike. Its friction. The rear derailleur is a early 1980s Campy Super Record. I am not sure which spacers are discusssed here in a couple posts. Spacers on the axle of the hub? Or spacer on the freewheel? I will have to research what "dishing" is. Thanks/

bikemig 

The spacers are axle spacers. You don't need to monkey with the freewheel. It comes on and off as a unit. Typically a 7 speed freewheel will be a bit wider than a 6 which is why you may have an issue with chain rub. If you do, then you have to add about a 1 mm spacer to the freewheel side of the axle.

Ideally the rim is centered between the locknuts on the axle. If you add a 1 mm spacer, then it is no longer centered but it's no big deal. You can just ignore this.

Bottom line is that you may need to pick up a 1 mm spacer to make this work. Best bet for a 7 speed freewheel is one from IRD but they are expensive:

Cassettes / Freewheels ? Interloc Racing Design / IRD

Older versions of this freewheel apparently suffered from some issues but I believe this has been fixed. I don't know the width of the freewheel. I tried to get this info from IRD as I'm thinking of buying one but still waiting on an answer.

CliffordK

Many hubs have both spacers on the right and left.

Campy often used oversized cones on the left, so maybe not requiring large spacers. However, at least the older hubs often had a washer between the locknut and cones. You can move this washer from the left to the right side of the hub.

Or, you could just add a small 1mm or so spacer to the right side of the axle (and possibly re-centering the axle). But, this may also make the wheel fit a bit tightly between your dropouts, which may or may not be an issue.

The first thing might be to just find a 7 spd freewheel and try it out. You should be able to at least locate a very cheap used MTB freewheel to test.

As mentioned, the DNP Epoc 11T freewheels do run a bit wide if you choose that route.

Another thing to consider is threading. I think people mix Italian, English, and US/ISO threaded freewheels. Beware of French hubs and freewheels.
Traditional Thread-on Freewheels

vintagerando

Ok, so we are taking about a spacer for the freewheel. I think some of the other posts were discussing spacers on the axle. but, I need a 1 mm freewheel spacer? Right? I have a box of old freewheels...gotta be a spacer in that darn box. Whats why we save all this junk, right.

Tim_Iowa

No, we are talking about axle spacers.

You can't put a spacer behind the freewheel; it screws on.

le mans

there's a bit of engineering to consider, ya gotta ask yourself do you really need an extra gear?

i play around with scrap bikes that people give away, fix them up and flip them. if it hasn't got a rear wheel or it's too far damaged, i'll use another one, & if it's got the wrong freewheel i fit one orginally intended for the bike - space it accordingly [check the dish]

CliffordK

Cassettes require spacers.
Freewheels do not.

Axle spacers may be needed to make the axle stick out further to prevent rubbing.

dabac

Overall spacing doesn't matter in this case.
The distance from DS bearing race to locknut is what matters, as that's where they tend to bend.
If the OP has to add more spacers between cone and locknut, the OP is increasing the risk of the axle bending/breaking.

fietsbob

Sight unseen and OP being of an Unknown skill level of mechanic , That is what a Text based forum can do <guess>

By the way adding the 8th in a Freewheel does increase the Axle bending potential
as it is the 7 speed narrower spacing, adding one more cog in width..

BITD Sun Tour Introduced the 'Ultra 6' it was a narrower spaced Freewheel to replace a 5 speed in a 120 frame

7 speeds do similar in a standard spaced 6 speed in a 126 frame..

Adding that 8th is when Free-hubs really came in to be more reliable..
right axle bearing moved to the outboard end of the driver so axle better supported..

dabac

Easy or difficult depends on your skill level.

It will require the ability to remove an old f/w, which might be on ridiculously tight.

There's a high possibility that you will need to move a washer/spacer from the NDS to the DS side of the axle.
That would require knowing how to adjust cup & cone hubs.
(An ugly fix, only useful for a small adjustment, is to add a washer outside the locknut. On a q/r wheel, this would be quite annoying everytime the wheel is removed and reinserted.)

So, if you know how to remove stubborn freewheels and how to adjust cup & cone hubs, then it's easy - assuming the f/w comes off w/o too much of a fight.

vintagerando

Its not the extra gear I really want. The freewheel that's on now is a Sunrace B0525, the largest cog is 24 or 25.....I have a very nice Sach with a 28t largest. I wanted to get that 28t to help with hills

le mans

ahh, i have a few 7 gear freewheels that has an extra large low gear sprocket, i want use for a roadster, so i know where you're coming from.. but this roadster is already set up for 7 speeds :-D



https://www.youtube.com/watch?v=rj3bYJ7zyLc

bikemig 

It may be zero or it may be 1 mm. People ran 7 speeds for a long time without a huge number of problems; the problems became more pronounced with 8 speeds.

So yeah I'm disputing your claim that 7 speed freewheels were "notorious" back in the day when they were more commonly used for breaking axles running 126 mm in the rear.

There are some problems with the current freewheel set ups because they use cheap axles (heck they get spec'd on cheap bikes) but there's a solution for that, just get a high quality axle.

You don't need to run 7 speed freewheel bikes on nice roads ridden only by little old ladies to avoid breaking axles.

I'll also agree that this became a more pronounced or serious problem with the move to 8 speed and 130 mm dropouts. Cassettes are a better design.