Zebra Tempest

Hello all,

With all the biking I did last summer, I needed to replace my chain on a 1986 Zebra Tempest. With the new chain, the 1st gear skips like crazy, and the the other gears skip a bit.

So, I think this means I need a new freewheel (This freewheel probably has close to 10,000 miles on it).

The freewheel i have is a Suntour (or is it Sunrace?) 6-speed 14-30. What is the best replacement for this? I really can't have fewer teeth than 30 on the large ring.

Thanks for any help!

clubman 

It's getting harder to find good 30 tooth freewheels. Take the best you can afford...unless it's crap of course. Newer models shift easy but Suntours can be forever (10,000 miles is forever.)

ramzilla

The shiny silver Sunrace freewheels work very well. (Built to Shimano HG specs). And, are usually a very good value at a reasonable price.

Soody

Shimano Freewheel Tourney TZ500 14-34 6-Speed

very cheap, like $25. Worth a shot to see if your derailer can shift it. It might. Or switch to something that can. Lower gears can be a big quality of life improvement.

JohnDThompson 

Pretty sure I still have these, someplace. The gold-color one is 14-28, the brown one is 14-32. PM if interested and we can work something out (if I can find them):

capnjonny 

Or you could try a Shimano Mega Range 7 speed. The 6 lower gears are pretty tightly spaced and good for most riding and the 34 tooth big cog can climb walls.

sovende

What was the reason for replacing the chain in the first place? Were you having any issues? Maybe putting the old chain back into service will remedy your problem . Does the Tempest utilize an “indexed” shifter for the rear derailleur? I’m not familiar with the Zebra product line . Pics of the original freewheel might let the “experts” here on the forum see just how much wear the teeth have suffered.
If the consensus is that a new freewheel is warranted, the other replies point out many options. As mentioned, going to freewheels with more teeth on the largest cog may require a different rear derailleur and perhaps a longer chain. Also, if the Shimano MEGA range 7 cog freewheel is used, I believe that you’d need a 7 speed indexed shifter or switch to the friction mode.

Zebra Tempest

Jeez, i want to upload the pictures, but I can't right now, since I'm new to the forums. Looks like I'll browse around and post 5 more times today

dddd

Two alternatives to freewheel replacement are:

1) replace the chain with a fresher used chain (assuming the existing chain is worn out, likely it is).

2) Clip the sharp driven-side corners off each tooth of any sprocket that allows skipping.
Just 1mm will almost always do it, as shown on the one tooth below (at 12:00) with the corner beveled off.
Better to angle the bevel at a more-vertical 35 degrees to the driven side of the tooth instead of the ~45 degrees shown! This allows the chain rollers to fall between teeth under heavy load instead of hanging up on the sharp corner, which otherwise causes "failure to engage" and thus leads to skipping.
Be sure not to over-do this, keep the bevels tiny, smaller than shown! I use a Dremel tool with a stone worn down to 3/8" to 1/2" diameter and can do a couple of sprockets worth in minutes without removing the wheel from the bike. I've had to do this in emergency conditions after heading out the door (to an organized ride) on a fresh build so discovered how fast I could do it!

Zebra Tempest

Thanks for the responses. I couldn't reply yesterday with pictures, because I was under 10 posts!

Here are some quick pictures I took of the freewheel. I can take the wheel off if, that would help. (I also have a dremel tool, like dddd suggested).

I had the old chain swapped at a shop, so I don't have it any more. I only have brand new chains.
The large chain ring (low gear), is the main one that is skipping.

So what do you think? Is it savable? This is the only bike I've had since I was 15, so thanks for your help.

tgot 

I did this 6->7 change, including the megarange. It's tight spaces 14-24 6speeds plus bonus 34! If I were to do it again I might have shipped around for a 7-speed with more even jumps.

If you're already using friction shifters, it's less of a change.

Edit: I did need to add a 1mm spacer to clear the frame. I didn't worry about any dishing change from that.

Zebra Tempest

I have friction shifters, so that's no problem. That 14-24+34, is interesting. Does it work well, it's a 40% jump from 24-34! My current freewheel has 14, 16, 19, 22, 26,30. So I guess with that megarange proposal (14, 16, 18, 20, 22, 24, 34),
My 30 -->34, (13% easier)
My 26 --> 24 (8% harder)

Did you need a new derailleur to support the 34?

tgot 

Also potentially of interest would be to know if the B-screw is all the way in, or not. And, how much space is there between the jockey wheel and biggest cog, with the 30t you have.

If there's space or more adjustment to fit a 32t, trying a 7speed 13-32t might be the answer. $60 from IRD, looks like. I didn't see 6-spd with 32t max but I didn't look for long.

Alternate thought: Are you 52-42 up front? If so, and you're stuck with 28t rear, going to 52-39 would get back the current low.

tgot 

I did. It had been a short-cage with only 28t max, I think. I ended up with *also* a wolf link, which I think would have let me use the prior derailleur. The inexpensive Alivio RD I used was supposed to handle 34t, but I couldn't get it adjusted right to have clearance, it struggled to get into the 34 before I added the wolf link.

I chalked some of that up to my inexperienced wrenching. But I think that bike also has a shorter hangar than other bikes.

The jump to 34 is big. I don't do it under load! I moved from 14-24 6 to 14-34 7, so the 34 was the extra bailout and the rest stayed the same. But that wouldn't be my first choice, if I were doing it again.

Zebra Tempest

I have 52-40 upfront. So the 39 might help.

What is IRD?

tgot 

IRD was a brand of freewheel that had a 13-32t 7spd in stock.

Zebra Tempest

thanks for the offer. I might be interested in that brown one. They look in great shape, right? I going to try to fix mine first.

tgot 

I looked again at the pictures, with the claw-mount rear derailleur I don't know if there's any adjustability, the way there is for the B-screw. Is there any equivalent, usually?

Maybe shift into the 30t and post a picture showing the space between jockey wheel and sprocket?

If you can't get a 30t large, a 32t is more likely to fit than the 34t. The IRD brand has spacing of

13 - 15 - 18 - 21 - 24 - 28 - 32 Teeth

which Is much nicer I think than the Shimano 14-24+34.

I had thought that there were more freewheel choices, but lots are listed but 'out of stock' or unavailable.

Changing 40t to 39t in the front is going to be a small change, ~2.5%. Probably only worth it if you decide that 10000 miles is a good time to swap chainrings also.

Zebra Tempest

dddd, you convinced me to give this a try. Can't hurt, since I can't use the freewheel anyway.

So, I have dremel 3000. Which tool would you recommend?
I have the 932 and 954. Or should i get a different one?
https://us.dremel.com/en_US/products...grinding-stone
https://us.dremel.com/en_US/products...rinding-stones

It seems fairly straight-forward.
Seems like I should just clip the sharp corners on the drive-side that are a bit pointed.

tgot 

I looked again at the pictures, with the claw-mount rear derailleur I don't know if there's any adjustability, the way there is for the B-screw. Is there any equivalent, usually?

Maybe shift into the 30t and post a picture showing the space between jockey wheel and sprocket?

If you can't get a 30t large, a 32t is more likely to fit than the 34t. The IRD brand has spacing of

13 - 15 - 18 - 21 - 24 - 28 - 32 Teeth

which Is much nicer I think than the Shimano 14-24+34.

I had thought that there were more freewheel choices, but lots are listed but 'out of stock' or unavailable. Searching is basically poisoned by sales listings for unavailable items.

Changing 40t to 39t in the front is going to be a small change, ~2.5%. Probably only worth it if you decide that 10000 miles is a good time to swap chainrings also.

tgot 

I realize the 7-speed option is a lot more taking on a bike-hobby, vs. just riding.

But, I was on bikeparts dot com and happened to see that new Microshift 6/7 speed long-cage RD, with the claw attachment, were only $13. Listed max is 32t, so that may or may not be enough depending on the freewheel you choose.

Zebra Tempest

Thanks for checking this out for me. That is a super cheap derailleur. I could pair that to the IRD

• speed|range|cogs: 7sp|13-32t|13,15,17,21,24,28,32

That IRD is a bit expensive for some reason ($80). But at least that means I get free shipping

I'm going to try to fix my current freewheel. If that doesn't work, that's a great option. I do like 24,28,32 as my low gears. Clearly i need the low gears, since the lowest gear is the one that wore out on my current freewheel.


I'm pasting hear pictures of my current freewheel and the derailleur

rear derailleur on lowest gear

Worn freewheel. The lowest gear is the worst.

spacing
on the lowest gear.

tgot 

The dremel idea is certainly cool. That would scare me, but I guess all you have to lose is the freewheel that's worn out anyway.

Good luck!

alexnagui

You could also try to disassemble the cogs and flip the biggest sprocket. That would definitely prevent the chain from skipping but shifting might become worse. You are not really supposed to do that because the teeth on Suntour freewheels are beveled only on one side so they are asymmetrical. However, I did this once with a Suntour Perfect freewheel myselft and I swear it shifted just fine, it was a 14-21 or 24 freewheel though, so no big sprockets. Also, I flipped that bike so I haven't done much riding on it.
Anyway, I think it's worth trying.

dddd

The "side" bevels do matter on the middle cogs, but this is a good idea here with this being an "end" cog, which allows the limit screw to control the shift.

I would duplicate the bevel on the less-beveled side of the teeth using a bench grinder or file, probably will shift exactly as before.

For anyone wanting to do my wear-correcting bevel method to the driven side of the tooth, removing even a slight part of the "wear hook point" will effect a noticeable improvement (with additional grinding then done only if a first tiny bit of grinding doesn't solve the problem under heaviest load). In other words don't over-do it with the bevels(!) on the first go, and be prepared to cut a little further with a subsequent bit of Dremel grinding. Luckily this can be done in a minute or two, with the wheel still on the bike, just wear eye protection and work in a well-lit area.