My girlfriend has an early 90s Razesa that I'd like to change the rear sprockets on. It's a standard 39/53 double with a corncob (11/17) in the rear, attached to a SunTour Cyclone threaded hub. Components are early 90s Campy Athena, including downtube indexed shifters. She's not time trialing, so I'd like to widen the gear ratio to giver her something more suited to her riding style. It appears that Shimanos were essentially the industry standard, but would they work with the Campy shifters?

You can use a Sunrace 7s 13-25t freewheel with that derailer and shifter, but will need to use 9s chain for it to index smoothly, since the spacing on Suntour/Sunrace freewheels is a little different than Campy intended.

There is a "B" tension gizmo inside of the top knuckle of the rear derailer. Removing the derailer exposes the toothed stop that you will want to move forward to make the derailer move rearward for the larger freewheel.

I doubt that a larger freewheel can be found to work with this derailer, but I have to admit that I didn't try one. Possibly a 28t would work, I don't know, but a longer chain is needed, one link longer for every two extra teeth on the largest cog.

Don't forget to put some light grease inside the indexing shifter, down inside where the two indexing springs and notched indexing ring are are. These shifters work quite well if kept lubed, and these Synchro systems work better than they ever did back in the day using today's chains. I used Shimano 9s chain btw, and the shifting across the freewheel range is crisp and smooth.
It will also help to use a new, lined piece of cable housing at the rear derailer. Properly-fitting ferrules are important, so don't lose the originals and use modern Brake cable housing if that is what fits your derailer and stepped ferrule best. Keep this housing as short as practical, given the new positioning of the derailer after the bigger freewheel goes on. I so often see overly-long loops of housing out back that do nothing for indexing accuracy. Double-sprung derailers need added length to accommodate the swing of the derailer body, but yours doesn't.

Here's what a shortest-practical housing looks like, the first two shown are even accommodating double-sprung pivots (yours is fixed).
The third photo shows a derailer just like yours, together with a 13-25t Sunrace freewheel. The cable housing shown is a bit longer than necessary but works fine.

What brand freewheel is it currently using? If it is a Sachs Aris or a Regina, there is a chance I could help you out by re-gearing your current freewheel body. Can you put up a picture of the freewheel?

Agreed, we can't make a blanket statement without knowing more about the shifting system, as Athena was redesigned from 7 speed Syncro to dedicated 8 speed in the early 1990s. If it has Syncro levers, we'll need to know the freewheel and/or lever insert. Only if the levers are dedicated 8 speed, do we know they they will work with 7 speed SIS compatible freewheels. There are also three possible derailleurs, all with different capacities, that will affect the freewheel gearing options.

This thread certainly reinforces my love of non-indexed shift.

I think the most likely insert will be 7s for use with the Regina America 7s freewheel. As I said, the 7s Sunrace or Shimano freewheels index quite closely enough if narrower 9s chain is used.

But it is a good idea to note the color of the indexing ring when greasing the shift lever. The insert should be blue, so will be sufficiently compatible with Shimano or Sunrace 7s freewheels, among others.

Not to hijack, but what bike that? I can't quite make out what is on the downtube, is it a Lovell?

Ahhh, no, it's my custom-painted Torelli.

Decal is a little smooshed.

Picture of the Shifter lever and possibly the insert color would help.

I'm rather surprised to hear of a 11/17 freewheel. Do you have a photo of it?

DNP Epoch makes an 11-28 freewheel.
https://www.amazon.com/DNP-Epoch-Free.../dp/B007A8RPUS

It preserves your 11T high-end, and is rather relaxed on the low-end.

Expect the freewheel to run a little wide for a 7s freewheel.

Personally, I thought it had too many jumps for the smallest sprockets, 11-13-15

What are your GF's favorite gears on here current cluster? What is the highest gear she regularly uses? I would use that as a guide for picking out a new cassette. If she rarely uses the 11T and 12T, then there is a much larger selection of 13T freewheels.

I have no direct photos of the gearset at the moment, but I indeed verified tooth count. I also spent some time on Velobase looking up what exactly was on it (see notes below) - It was a time trial bike in its day, and was sitting for quite some time before I found it. She's happy with my Trek 1.5 gearing (50/34, 11/26 9-speed). An 11/28 would provide similar top and bottom ratios - granted, I doubt she'd actually use top gear, so a 13T would likely be a better fit to her riding style and intent (she's planning to commute with it).

Exactly the direction I was looking for. I have some photos of the bike from when we first got it, and can snap a few more tonight to upload to my photo album. I've also done some more digging to identify the components. I had initially thought they were Athena, which the brakes are, but that's not the case with the shifting mechanism.


These actually appear to be C-Records from 1989-early 90s.




Athena(?), mfd 1988-1991.

This appears to be a Super Record derailleur, mfd 1979-1987.

I see now. Pretty rad paint job, IMO.

That does look a bit like a "corncob"..

But, I'm not convinced your sprocket counts are correct.

Here are a few different Shimano freewheels which would also be worth considering.

Shimano TZ-21 Tourney 7-Speed Freewheel - 14-28T

Look at the "also viewed" section.

If you go too big in the rear, you could potentially exceed the derailleur capacity

Also, it wouldn't hurt to pick up a new chain.

OK, that's 1st generation Athena with Syncro levers. It has a 30T chain wrap capacity and can accommodate a 20T to 30T large sprocket depending on the setting of the orientation of the Multi-Function System insert on the back of the mounting bolt. The blue Syncro lever insert is supposed to work well with this Athena derailleur and a Shimano 7 speed freewheel.

A wealth of knowledge, all of you.

If it's not an 11/17, I'll buy you a beer (edit: or coffee, or tea) next time you're in Tempe or I'm in Eugene. And yes the chain will be replaced with the freewheel.

Unfortunately I don't drink beer, so you may be off the hook, but I do have an aunt and uncle somewhere down in Arizona that I need to visit (during the cold/wet season up here).

If it is an 11/17 freewheel, I might be interested in buying it

I have found that the Blue insert work really well with a Regina Syncro 90s freewheel
and the Green insert works great with a Shimano Freewheel

You win: It's a Regina Extra 12/18. So, now that we have that settled, I assume that all those Shimanos you've posted no longer apply?

And going slightly off-topic, what can I do to give the brakes better feel? I've cleaned and lubed the calipers and added Kool Stop salmons, but they're not terribly confidence-inspiring. Perhaps new cables would help? The levers are pre-91 Athenas, I believe.

Oh, time to hop on the bike and start the 1000 mile ride to Arizona

What probably doesn't apply is the DNP Epoch 11-28 that I first posted.

But, your GF has to decide where she wants the top-end to cut off at. 11T (12T), 13T, 14T.

I'm not sure I've seen 12T freewheels commonly available, recently. I used to have a 12/21 (I think), but it got removed due to skipping long ago.

Anyway, that will be a personal choice.

Harder gears (11T, 12T) doesn't necessarily equate to faster riding, at least for many riders. And the larger that first sprocket, the tighter the gearing through the cassette.

So your GF isnt really enthralled with the gearing on a time trial bike, OP? My wife rides a fair amount with me, but I know that would change quickly if she had to ride a TT bike, lol.

Twenty odd bucks, and Bob's your uncle:
Opentip.com: Sun Race 327-184 7 Spd HG 13-28 Freewheel
SRAM PC-850 6/7/8 Speed Chain > Components > Drivetrain > Chains | Jenson USA

Too bad it is not a Sachs (which I can easily re-gear to achieve a wider range).

I do have a limited supply of Regina sprockets. If you sent it my way I could give it a try to re-gear into a wider range. The trick is to use your existing spacers in order to maintain the correct indexing. I believe I could keep this all under the price of these gems:

$250
NOS Regina Extra Synchro 90 7 SP Freewheel 13-31 cogs Campagnolo Compatible ISO

$123 REGINA CX/CX-S Freewheel 7 speed 13.14.15.16.17.21.25. English Thread Italy 83

And probably even less then this one even with including a cleaning and servicing of the body.

$88 NOS Regina Extra SYNCHRO 90 S 14-28 7s freewheel Campagnolo index 7-speed

what is the threading?? english or italian? Generally you can put an english freewheel on italian thread, but common wisdom is that once you do that you cannot go back to to italian

The hub has English (1 3/8" - 24) threads. Bob, I might take you up on the re-gear. Thanks gang.