noobinsf 

I bought a new Sunrace 7 speed freewheel recently for a 6-to-7-speed conversion, and I noticed that it spins less easily than the original Suntour (I think a "Winner" model, not sure, don't have it in front of me). The original Suntour will just spin and spin, while the Sunrace feels like it's fighting something. (I have not used the Sunrace while riding, as the build is in progress.) I flushed the Sunrace with WD-40 and added Phil Tenacious Oil, but to no apparent difference.

This sparked the question -- what are the factors in freewheel rolling resistance? Bearing quality? Assembly? I feel like I've eliminated lube viscosity, but maybe I need to work on it more? I dunno -- thoughts?

rhm

I'm sure bearing quality, lubrication, the number of pawls, the strength of the pawl springs, etc, all play a role. More important, to my mind, is the fact that it doesn't matter unless you're coasting. As long as you're pedaling, none of the parts of the freewheel are moving

JohnDThompson 

Freewheel drag is unlikely to have any significant performance penalty; if there's enough drag to affect performance, you'll have problems with the chain tension while coasting. And if it still bothers you, don't coast. :

The Golden Boy 

Since it is new, it may have to "break in" for a few hundred miles.

When I got my Phil freehub- they said it'll take at least 400 miles for it to settle in- in that time whenever I rolled the bike the cranks would turn with it. It still sometimes does it, but it's loosened up.

dddd

I've had new Sunrace freewheels that had plenty of thick grease in them, and it was very much a chore to free them up!

And after I got the freewheel to where I could get some fluid to go through it, it then showed it's lack of smooth bearings.

The grease was definitely a problem when coasting, caused the chain to sag.

I can only recommend some kind of forced air, solvent or hot water as possible ways to blast some free space into where copious thick grease now exists. So it's a "plumbing" problem, so as to force something fluid through the space between the inner and outer freewheel body halves.

Nobody else has ever made as modern, inexpensive and good-looking of a "close"-ratio 7s freewheel as Sunrace's 13-25t, so the shortcomings must be forgiven.

old's'cool

Sunrace 13-28 FTW!

verktyg 

thanks John, best laugh of the day.

verktyg

SurferRosa

I would never recommend removing good grease from a new freewheel.

But, I guess you can always buy another one.

Darth Lefty 

pastorbobnlnh 

I recently acquired the tool to remove the lockring on the Sunrace pictured above. Believe it or not, it was not available in the US. However, the head manager of Sunrace-Sturmey Archer USA special ordered it for me and sent it to me for free! He was impressed with the service I offered and understood that servicing a Sunrace freewheel would be impossible without the lockring tool. I've not had a chance to use it yet. Just waiting for the opportunity.

To the OP's original question: Your Suntour Winner spun smoothly because there was no more grease left in the bearing races. The Sunrace was "stiff" or "sticky" initially, because they tend to be over-greased by the machines in the assembly process. Grease on the ratchet teeth and the pawls can really impact performance. However, with that said, even when I hand apply the correct amount of grease to just the race, a vintage Suntour, Regina, Shimano, etc., also feel "stiff" or "sticky."

This does not impact performance and dissipates after use (as @The Golden Boy mentions above with his Phil freehub). Since the Sunrace still felt tight after flushing it with WD-40 and adding Phil Oil, my guess would be that it lacks a proper spacer(s) between the retaining ring/outer bearing race and the inner body stop.

As an aside, and not to be contrary nor disrespecting of our great C&V community which have recommended or practice the "flush and dribble" method of freewheel service, I only recommend grease in the bearing races, and never oil of any kind.

Kabuki12

I agree! I have used the "flush and oil" method and it works , but as old as most of my freewheels are , I have to wonder if it is just a temporary fix. The Regina you just sent me and the Regina you did for my daughter's Raleigh are sooooo smooth and for the reasonable cost of your service, I would definitely have a professional(Pastor Bob) "rebuild" the freewheel rather than any thing else . I have a new Shimano that I can use while you rebuild if I have problems. Joe joesvintageroadbikes.wordpress

jeirvine 

Cool. Would you mind posting a pic of the tool?

pastorbobnlnh 

John, it is on the Sunrace website here: This is the stock photo since mine is at home and I've never had a reason to take a picture yet.


Thank you @Kabuki12, you are so kind. If any one is interested, his daughter is the cover "rider" on the homepage of the Freewheel Spa website.

Now--- back to Holy Week preparations!

canklecat

Ah, so there is a SunRace freewheel tool. My 7-speed 14-28 is very slightly loose and I couldn't find a tool for it. It's not too bad and not critical so I moved it to my errand bike that gets ridden only a few times a month and a few miles.

The SunRace chromed 13-25 has been very good so far, and runs and shifts more smoothly than the original Suntour on my GPX Accushift RD/shifter. I'm trying to find the chromed 13-28 version of that same model.

noobinsf 

You mean this one? This is the one I have:

https://www.ebay.com/itm/SUNRACE-MF-...item2f15885bfc

EDIT: Never mind -- I see that link leads to the one with zinc finish, and I realize I'm not sure if I have zinc or chromed, as I didn't know both finishes were available. Carry on...

noobinsf 

Thanks everyone for your advice on this...

canklecat

Yeah, it's hard to tell from online photos whether it's chromed or zinc plated unless the seller includes the full model designation. Most vendors skip that info, which is how I ended up with a carbon steel and zinc plated SunRace freewheel. The item didn't match the photo.

The chromed 7-speed 13-25 SunRace for road bikes is the MFR30 ("R" for road), or just the R30, and the chromed version is designated by something with a C in it: C, CQ, CS, CP, there doesn't appear to be any key on the SunRace site for interpreting those. The CV seems to refer to freewheels with zinc and blued carbon steel cogs.

The chromed 7-speed 13-28 I'm looking for is categorized as a mountain bike freewheel, MFM30, or M30. But the MFM3S 7CS zinc plated freewheel appears to be otherwise identical so I might settle for it.

old's'cool

First of all, many thanks for sharing info about the Sunrace tool.
Second, I concur completely with proper servicing of the freewheel according to the design intent. I have a practice of not departing from the design intent of a particular device unless I know better based on my own specialized knowledge, or at least have a particular reason for doing so and have reasonable technical understanding of the risk I am taking on.
Now when it comes to oil vs grease, the difference is, oil does not adhere to any surface but rather flows continuously in accordance to gravitational or other acceleration. That means, unless it is contained within seals, or is being continuously replenished ("total loss" system), eventually there will be no oil left where it is needed, and there will be puddles and patches of oil where it is not needed. Grease , by contrast, when in serviceable condition, adheres to surfaces and does not flow under typical gravitational or machinery accelerations. Certain greases even incorporate special formulations that make them somewhat fibrous, so that they cling to and wrap around spinning machine elements, such as ball bearings, much as cooked spaghetti might do when twirled on a fork.