Wiggles_dad

This is a simple question. I have an 87 Schwinn High Sierra, which has a 6 speed freewheel. The IRD 7 speed freewheel has a different stack height than the 6 speed. Would I be able to upgrade to a 7 speed from a 6 speed? Thanks!

due ruote 

Often, but not always, this is possible. You might need to add a small spacer. Does the 6 speed on there now look like it has some extra room?

WNG

The general answer is YES, because both freewheels specified 126mm OLD spacing. But sometimes the drive side could use another 1mm of space when a 7 speed freewheel is used....not all brands are the same height. The trick is to take a washer off the NDS of the axle and add it to the DS under the locknut. You can redish the rim, but some forgo it since it's 1mm deflection.

Chitown_Mike

I did this on an old Trek 800 and had to run a spacer to keep the chain from catching the seat stays/chain stays because of how close things are. I wish I had a picture to post but it worked.

Blylan

Did you have to re-dish as well?
Ive been looking into replacing my freewheel, and anytime a spacer is mentioned, re-dishing is usually advised.
Im not prepared to redish myself, it feels very daunting, But i wasnt sure how absolutely necessary it would be after something like this.

Thanks!

bikemig 

It's only 1 mm so you could forgo this. Alternatively you could get a longer axle suitable for a 130 mm rear wheel and add 1 mm of spacing on either side. Assuming this is a steel frame, it's no big deal to go from 126mm to 128 mm; you just push open the drop outs a bit when inserting the rear wheel.

jimmuller 

It isn't. You can do it on the bike if you wish. Check the center of the tire tread against the brake mounting bolt by sighting down from above. That will give you a starting viewpoint. Go around the wheel giving each spoke 1/8 turn, tightening the right, loosening the left. Remember to take spoke twist into account. Check again. It may take several trips around the wheel. When you are satisfied with the dish amount, check it for lateral trueness. If it was close to start with it will be close, but you may need to tweak, especially because not all the spoke twist up the same amount. Go for a ride.

eschlwc

^ and remember which way to turn the nipples to tighten and loosen.

it's a bit like removing the left pedal with a wrench when kneeling on the right hand side of the bike.

wait, what?

zukahn1

To avoid redishing you can also just add 1mm spacer to both sides, which may result in a tight but very exceptiable wheel fit.

Michael Angelo 

IRD freewheels sit further in on the hub, meaning that is might just work with out any mods. That said, check for enough spoke to Derailleur cage clearance in low gear.

Wiggles_dad

The IRD 6 speed freewheels have a stack height of 31.5mm and the 7 speeds are 34.1mm.

zukahn1

Both are slightley shorter than classic 6 which measure about 34.

dddd

I've never seen a seven speed freewheel that wasn't wider across the cogs than any six-speed freewheel.

Having said that, I usually expect any seven-speed freewheel to have sufficient clearance on a factory stock-spaced 126mm hub, i.e. one that has not been tinkered with.

SJX426 

it is somewhat hit and miss. You will need to test it for your frame. My 83 Colnago didn't need adjustment at all and with friction shifting, wasn't an issue. Same is true with my 94 Burley Tandem but it needs a 7 spd bar con to work as the indexed 6 won't. I have what i need execpt the time!

bikemig 

That has not been my experience.

top506

Mine either.
Sometimes you can get away with a spacer or two.
Sometimes you have to re-dish.
Sometimes you get lucky and it screws right on with no problems.

Top

kehomer

I replaced the standard Shimano 6 sp freewheel with an IRD 7 sp 32t on my Panasonic Touring bike. Also replaced the old 80s Shimano triple with a compact Sugino triple. Worked really well. Those steep hills didn't seem so steep anymore.

John E

I had no trouble running a 13-26 7-speed freewheel on the Bianchi in place of the original 14-26 standard 6-speed, but this was on different rear hubs, since one was Italian-threaded, and the other was ISO-threaded, and I am (overly?) cautious about the class B fit.

I have had the same experience as others on some hub/frame/freewheel combinations, but nothing 1 or 2 mm of additional right-side spacing would not fix.

I believe the official OLD for a 7-speed is 128mm; standard 6 was 126mm.

Chitown_Mike

Did I? No.

Should I have? Meh, maybe? I don't run knobby tires, I have some Conti Double Fighter IIs on the rims so they are a tame side tread and fit into the frame. The rear tire is kicked out a bit but nothing that effects the riding or handling. The bike is a hodge-podge of parts that it doesn't all match anyway, but it rides real well without much of an issue.