Aliexpress Sprag DC4127(3C) Width?

Also, Aliexpress flips me off, setting to "ships from US".
Trying to find it now



All set, TY. I hAd used Ali before for electrical plugs for the Tenere

Try the flag top right and in a bit, click on the small arrow and select ship to and the currency.

When you google an aliexpress item it sticks to the listing settings google found, so be prepared to click on that flag a lot.

kommando said:

Try the flag top right and in a bit, click on the small arrow and select ship to and the currency.

When you google an aliexpress item it sticks to the listing settings google found, so be prepared to click on that flag a lot.

Click to expand...

Thank you.

I was notified yesterday that my new sprag had cleared US customs. Ordered from "Bearing Factory Store" Aliexpress 5-23-24 cleared 5-29-24, six days!
I have been assured that the size is correct. Nevertheless, I will be measuring upon arrival!

Edfury828 said:

I was notified yesterday that my new sprag had cleared US customs. Ordered from "Bearing Factory Store" Aliexpress 5-23-24 cleared 5-29-24, six days!
I have been assured that the size is correct. Nevertheless, I will be measuring upon arrival!

Click to expand...

My new sprag arrived last night, 5-31-24 making 8 days from ordering to my doorstep.

Measuring the width I got 0.530" or 13.463 mm. Not sure how to measure the ID and OD with the moving dog bone things? Right now my primary is assembled with my old sprag in place, so I'm not sure when I'll be getting back to installing this new and improved (?) one.

I am attaching a couple of pics as it occurred to me that we may all be getting different sprags depending on Ali vendors or sellers. I'm not sure what to make of the brown colored metal clip looking thing on top or the brown "spring" on the inner circumference, it just lays over itself at the top....

I have no knowledge on what constitutes a good reliable sprag vs a weak one. Just trying to document what I can. As far as this new one goes, only one way to find out! I will be changing out my stock one soon, since they are known to fail. Meanwhile, I will keep this new one with me just in case...

This has worked for me without issue and for a few years .

Ron Hulton said:

This has worked for me without issue and for a few years .

Click to expand...

Wow, three years ago and counting, that's great! It looks like a twin to my new one. Maybe they are from one consistent source after all? And thanks for stating your experience Ron, I think that really nails it down!

Do you happen to recall the name of the seller you bought it from on Aliexpress? As stated above, mine is from "Factory Bearing Store".

The two I previously recieved, which were the wrong parts in correctly labeled (in very fine print) boxes, we're from "Special Bearing Store".

No hard feelings, just trying to document the source of my bad parts and ensuing travails. (I should've checked all dimensions myself before installing, that was a huge mistake on my part.)

I'm at work now, but will try to get the ID and OD on mine as you did, tonight.

Sellers on AliExpress come and go, if their rating drops they restart under a different name.

Edfury828 said:

Wow, three years ago and counting, that's great! It looks like a twin to my new one. Maybe they are from one consistent source after all? And thanks for stating your experience Ron, I think that really nails it down!

Do you happen to recall the name of the seller you bought it from on Aliexpress? As stated above, mine is from "Factory Bearing Store".

The two I previously recieved, which were the wrong parts in correctly labeled (in very fine print) boxes, we're from "Special Bearing Store".

No hard feelings, just trying to document the source of my bad parts and ensuing travails. (I should've checked all dimensions myself before installing, that was a huge mistake on my part.)

I'm at work now, but will try to get the ID and OD on mine as you did, tonight.

Click to expand...

My Ali Express sprag was installed in 2017. I kept track of the number of starts up to 500, which occurred a few years ago now.

Glen

Here is a post from 2019, after two and a half years of use.

• Aug 6, 2019

• 
  
• Add bookmark
• #2

The 18 tooth Chinese Sprag I purchased on Ali Express is working well. It has been in place for two and a half years now.
It was priced at $17 US. The seller was "Freewheels"
It's been working so well that I purchased a couple of spares. This seems to be the best way to insure that the first one will keep working forever!

I haven't used the kickstart on that bike in 2 1/2 years.
Starter is a 4 pole with big cables. It spins the engine fast, starts in a flash.
The bike has a tiny isolated booster battery in the circuit for full ignition voltage on cold starting. ( ancient low voltage sensitive Boyer)

Glen

worntorn said:

My Ali Express sprag was installed in 2017. I kept track of the number of starts up to 500, which occurred a few years ago now.

Glen

Here is a post from 2019, after two and a half years of use.

• Aug 6, 2019
• 
  
• Add bookmark
• #2

The 18 tooth Chinese Sprag I purchased on Ali Express is working well. It has been in place for two and a half years now.
It was priced at $17 US. The seller was "Freewheels"
It's been working so well that I purchased a couple of spares. This seems to be the best way to insure that the first one will keep working forever!

I haven't used the kickstart on that bike in 2 1/2 years.
Starter is a 4 pole with big cables. It spins the engine fast, starts in a flash.
The bike has a tiny isolated booster battery in the circuit for full ignition voltage on cold starting. ( ancient low voltage sensitive Boyer)

Glen

Click to expand...

Looks like you got yours pretty well sorted Glen! I'm thinking mine should be pretty good now too, just need to verify...

my old sprag OD is 2.268" with 1.635" ID and again, my width was 0.516"

My new sprag OD is 2.277" with 1.634" ID and 0.533" width.

Having come this far, I couldn't leave the old sprag in, even though it is perfectly serviceable, so I tore the primary down last night once again, and put in the new sprag. It went in really nice, tight and firm with a clockwise rotation that felt like a new bearing and spontaneous lock up when attempting to turn counter clockwise.

All that is left is to put the oil in and fire up! Maybe tonight???

Edfury828 said:

Looks like you got yours pretty well sorted Glen! I'm thinking mine should be pretty good now too, just need to verify...

my old sprag OD is 2.268" with 1.635" ID and again, my width was 0.516"

My new sprag OD is 2.277" with 1.634" ID and 0.533" width.

Having come this far, I couldn't leave the old sprag in, even though it is perfectly serviceable, so I tore the primary down last night once again, and put in the new sprag. It went in really nice, tight and firm with a clockwise rotation that felt like a new bearing and spontaneous lock up when attempting to turn counter clockwise.

All that is left is to put the oil in and fire up! Maybe tonight???

Click to expand...

Did you buy a spare ?

Ron Hulton said:

Did you buy a spare ?

Click to expand...

Not yet, after buying two wrong parts in right boxes from the previous seller, I decided to buy the one I have now. If all is good then order another from the same seller. So far, so good! If the test ride is good too I'll get that spare!

Good fit.

As I mentioned earlier, I got 13 in total from 2 different suppliers? Factories? 8 from 1 and 5 from the other. They are all DC4127 3c. The 2 types differ slightly on the outer tolerance. The one I am using is a slightly tighter fit the original sprag and the one I got 5 of ! 8 for £90. Can't hurt too much ? Anyone know where the real ? ones are manufactured ? Roy.

I have got another box straight from a Chinese Company direct. $9 each, plus postage. Will measure all three from different manufacturers and see how much they differ. If someone can give me definitive dimensions of one that works well utilising stock drive gear I'll see if any of the many I have fit the bill. As my (rgm belt drive) drive wheel was machined out marginally I don't need ones with the original specs. Roy.

The yaki said:

I have got another box straight from a Chinese Company direct. $9 each, plus postage. Will measure all three from different manufacturers and see how much they differ. If someone can give me definitive dimensions of one that works well utilising stock drive gear I'll see if any of the many I have fit the bill. As my (rgm belt drive) drive wheel was machined out marginally I don't need ones with the original specs. Roy.

Click to expand...

Go back and read post # 26

Like Glen, Mine is now 5 years old and works like a dream, I bought a couple of spares 2 years ago and now one is in a local bike the other is sat on my parts shelf.

I got my replacement aliexpress sprag installed about a month ago and it instantly felt really right. Considering I have no other sprag experience than what is in this thread, it may seem unlikely, but I could just feel how nice it was rolling clockwise like a new bearing and instantly locking when attempting to turn counter (anti-) clockwise. I could see too, the depth of the starter drive gear as it meshed with the anti-kickback gear was just as with the (assumed) original sprag.

Incidentally, I found it odd that what appears to be the correct gear alignment has the starter drive gear about 1/16" (eyeballed) deeper or offset from the anti-kickback gear. That's one thing that fooled me with the sprag which was too wide, it put those two gears together in perfect alignment. It looked really good, but that was wrong! At least on my engine, the correct position iss offset. I will include pics to illustrate.

I just barely had time to load up and haul my bike across the state for our annual NWNO camp out. Naturally, my truck had a defective one year old fan clutch on the way (thanks ebay!) Which I replaced with a "lifetime guaranteed" part at a handy auto parts store parking lot, making for a late arrival.

The next day I was finally able to test ride and the sprag worked great! I probably started it about a dozen times in the 38 miles which I was able to go (doh!). Unfortunately my Mikuni had gotten gunked up inside due to sitting unused for many (assumed) years. I had replaced a brand new looking set of Dunlaps after buying the bike due to 2002 manufacturing dates, so it hasn't been ridden much in the last 22 years!

It was mainly the idle circuit killing the engine at idle which provided the plentiful opportunities to keep testing testing the ali-sprag. It worked great! The carb on the other hand, will be needing some TLC...

I have plenty of these mentioned ! Roy

I have plenty of these mentioned ! Roy.