woodenidol

So not being too bright, I figured my new 7 speed freewheel would screw on to my present 6 speed hub and be ready to go. Ummm, not so fast little buck a roo! Its wider than the 6 speed and bumps against the frame, well nearly.

What do I need, a new wheel? Am I doing something silly and just not seeing the big picture? I got the 7 speed so I could keep the wheel (maybe should have asked some questions, lol) and not have to spread the frame. Did I oops?

Help a fledgeling old bike upgrader please.

Kevin

EjustE

Need more detail about the hub and the freewheel (include all the markings on your old 6sp and your new 7sp as well as the make, model and year of your bike). You might have a threading incompatibility issue

khatfull

https://www.sheldonbrown.com/harris/freewheels.html

"6 Speed to 7 Speed - If your bike currently has a regular-spaced 6-speed freewheel, you can generally upgrade to 7-speed with little trouble. Since the sprockets are closer together on a 7-speed freewheel, the overall width is only very slightly wider than a regular-spaced 6-speed. You might need to add a thin washer to the right side of your axle to keep the chain from rubbing the frame in the highest gear.

I'm thinking of doing the very same thing, and have been looking at Sheldon's site extensively. Be sure to update your thread with your results.

Bianchigirll 

Hi woodenidol. yes we need more info. odds are pretty good you can respace and redish your existing wheel. wether or not you have to have your frame 'set' or just deal with the hub being slightly wider we shall have to see after the hub gets respaced.

what kind of wheel/hub, bike, and shifting? is this index?

woodenidol

Looks like a Mallard hub? Difficult to see, its pretty faint. New mega range 14/28, shimano freewheel. Threads on fine, spun right on. I looked at the freewheels after, the 7 is a cog wider, I guess I naively thought the cogs were spaced closer together.

It was a 1987 shimano 105 indexed. I purchased a 7 speed brifter set to upgrade.

woodenidol

Removed 7 speed freewheel and compared to old 6 speed freewheel. The new freewheel is approximatly 3mm wider.

Bianchigirll 

28T? can a short cage 105 handle that? we all make dumb mistakes like that from time to time. you need to respace the hub and maybe a new axle. perhaps you can just move a spacer from the nondrive to the drive side. or even split that spacer and move half of it. then redish the wheel

woodenidol

The specs show it as a 28 tooth max from what I found on one site.

Ahhh, I believe I see what you are talking about. There appears to be be a small spacer on each side of the hub, between the locknut and the hub body. It appears to be roughly 1 mm. Suggestion is I move that to the freewheel side to give more clearance?

woodenidol

Hmmmm, the frame doesnt seem like it will need spread, as its a bit loose as is. Im wondering if my axle is too short now though. there isnt much room for a washer on it. Not sure how much axle should be protruding into the drops.

EjustE

Alright...

you might have additional issues in this project:

-Those brifters (and need to know which ones they are) were very likely made to work with super SLR brakes. Make sure you got super SLR brakes (dual pivot on)
-Need more info about what RD you have. Long cage 105 RDs were spec'd for 27 teeth max (but will be fine with 28). Also, not knowing what your brifters are, and assuming that your RD is something like 105x, you might have issues there

roccobike

woodenidol, hang in there. I've made the change from downtube to brifters several times and it's always worth it.
If the 7-speed freewheel is wider than the 6 speed, you will almost certainly have to put an additional spacer on the right side to move the axle lock nut further to the right, thus creating some space between the frame and the freewheel. When you do this, you will almost certainly need to redish the wheel because you've moved the wheel center to the left.
You will be happy with the 7 speed brifters. I find I ride the conversion to brifter bikes more than the bikes I left original.

woodenidol

Hmmm, well I need to check the brakes, I knew it may be an issue, and seems that is a cheap enough fix if I have to get some new ones. I will have to read up on redishing the wheel, as I understand the basic concept, but not sure if I just need to have that done.

Looks like this will be learning experience!

woodenidol

Per VeloBase.com this is my RD. ..................Shimano RD-1050, 105

It appears to handle a 28 tooth rear cog, the wrap is one shy of what I will have, but others have said that is not really an issue. From what I read, the pull is the same as modern RD, so I was thinking, it would work with the Sora 7 speed shifters. Im starting to wonder if I just should have changed to a 9 or ten speed and changed the crank also.

Brake levers are listed as SLR, no super in the description. Brakes are listed as single pivot, so I guess those are out too. Pity, nice looking brakes.

I may end up with just the frame left! If that was the case, I wish I had gone 9 or 10 speed.


Ahhh, redishing the wheel seems easy enough in theory anyway.

EjustE

They made 2 kinds of RD-1050s: short cage and long cage. Which one do you have? Or: what was the biggest cog on your old freewheel?

canopus 

I don't understand, is it or is it not rubbing up against the frame? I put a 7 speed freewheel on my 126mm Campy wheels into my 1986 both of my two Cannondales and the freewheel "nearly" rubbed but 1mm clearance is still not rubbing. So I run it without any problems.

If it is rubbing, then remove the freewheel, then get a quantity of 2, 1mm spacers and add one to either side of your axle (remove the nut on each side and place it on the axle then replace the nut, then adjust the bearing preload and reinstall the freewheel and wheel into the frame. You do not need to redish the wheel if you add the needed spacing to both sides evenly. Any frame will spread the 2mm clearance with a little hand pressure (if needed at all) so there is no need to cold set the frame.

If you can't get 1mm spacers then measure your spacers and acquire a quantity needed for each side to have an extra 1mm in spacing.

Why does everything have to be so hard.....?

I wouldn't sweat the brakes until you try them.

woodenidol

26, but the short cage is listed as having a 28 tooth minimum per Velobase, unless Im reading it wrong.

woodenidol

Definatly rubbing. I will check by how much though, as what you suggest may be all it needs.

EjustE

I would not trust Velobase on that, if that is what was listed. The long cage ones were spec'd for 27 teeth max cogs. You might be reading "chain wrap". Chances are if it worked with 26 it will work with 28. You can tell if it is a long cage by looking at it

woodenidol

Think its going to need a couple mm's to get clearance., Im concerned the axle is too short now. Frame naturally is spread loose, so Im wondering if a longer axle and 2mm of spacing on each side is the way to go.

woodenidol

Well, I will have to find out. Chain wrap is listed as 27 teeth, max rear cog 28. It is a short cage, and is the RD pictured. One more thing to discover after I get the wheel set up.

Just looked at rear drops, it looks like the drive side drop out is actually bent in slightly. If it matched the left side drop out, it almost looks like it would be ok. Wonder if I need to bring it into the shop to have it aligned?

Chombi

Hmmmm..... I was able to fit a 7 speed Spidel freewheel on my 126mm spaced Vitus frame this winter. The clearance between the outboard sprocket and the dropout is close but it does fit and work with no problems.
Per my experience, 7 speed cluster spacing is also narrower than your typical 6 speed freewheel cluster to make it fit within the 126mm rear dropout spacing, so make sure you have the right narrow chain to work out with the narrower 7 speed cluster for best shifting performance. Also, make sure you also remove any spacers that might be on the hub that's causing the 7 speed freewheel too far outboard to fit. unless the design of the particular freewheel might be causing it to be too close to the rear spokes.
I don't think you need to do any wheel redising on a properly dished 126mm rear hub/wheel unless you do have a wide freewheel that might have been meant for wider rear spacing.

Chombi

miamijim

If its not rubbing its not rubbing. As long as it shifts in and out of the small cog without the chain hitting the frame your good to go. If all you need is a single 1mm washer for clearance I wouldnt worry about redishing the wheel. Heck, if thats the case throw a 1mm washer on the other side to compensate for it. You said the frames loose already so you shouldnt have to spread it.

As long as the axle extends ~1/3 of the way into the dropout you'll be OK.

woodenidol

Maybe I will try this first. its definatly rubbing, more than that actually, with the chain on that cog, its actually not able to be peddaled at all, as the frame binds the against the chain.

Zaphod Beeblebrox 

wondering the same thing....

This is a wheel that's been existing on the bike and just getting a new freewheel. So the Locknut Distance is currently correct (or pretty close)

Add spacers to the drive side until the small cog doesn't rub the stays, remove that amount of spacers from the nondrive side, Then redish the wheel.

The axle is already the correct length...it's been working all this time... you just might need to adjust it bit to the left or right to recenter it after you've added/moved spacers.

Its only 3mm difference...you can make this work.

woodenidol

Im not sure the situation is hard, so much as I evidently lack the experience in doing this to just charge ahead. smile.

There is only one spacer on each side of the hub, and it does not appear that a single mm will do the trick, but I will find out later this evening with any luck.