wristpin needle bearing question
- Thread starter Thunderhead289
- Start date
mapbike
Well-Known Member
Well.... I've been in email conversation twice today with juicemotoparts and here is what they told me, so im gonna put the parts in my oldest engine which has remains in stock form since 2009 because the vibess with this engine were so bad I figured there was no need to modify for high rpms, it may crater on me but if it does, Ill just put a dax drilled crank in it and freshen the whole thing up head to toe, this engine has well over 2000 miles on it now and runs strong for a stock engine just vibrates pretty bad above 28-29 mph even with a 32T on a 24" wheel.
The "two friends" they mentioned in the email to me are a fella nam d Dave and Fred ( maker of the Fred Heads) there is a members only club on facebook called " china girl lovers club " and they both posted bad results from engines that had ran the titanium wrist pin one was said to have only lasted 10 miles before the piston was hitting the head.....
Hi Shan,
Your items went out*today*via USPS First Class mail. Sorry for the hold up as we've been a*tad backed up on orders since we returned, and we've also been having*some trouble with our titanium supplier. As for our titanium wrist pins, we have*only had 2 customers complain about the titanium wrist pins over the 30 bikes*that we have installed them on. Coincidentally the two bicycles were not*broken in, and had stock needle bearings. This can be a problem, and is the*reason why we recommend that you use higher grade needle bearing, AND/OR*bushings. Also, we know that the bearings from these china engines are*pretty darn crappy and any performance mods that you make are likely to*reduce the life of them drastically. The aluminum wrist pin bushing that you*ordered is an experimental one which means that we have not thoroughly*tested it's effects over an extended period of time. We more than invite*you to give us some feedback over the course of a few months, if you would*like to. It would also be nice to point the two friends of yours whose*engines "hand-grenaded" in our direction, as I would like to ask them a*few questions and help out if I can. Hope this helps and let us know if*there is anything else we can do. Thanks for your business again Shan.--
*Yours Truly,
The Juice Team @JuiceMotoParts.com
Time to get Juiced!
Last edited:
mapbike
Well-Known Member
Yeah the aluminum bushing raised my eyebrow also.....lol
But if its high enough grade and the tolerance is right along with at least one hole for increased lubrication it might and I do mean might work in a lower compression low to medium rpm application. ... of course I may be completely dead wrong about this, but what is the piston made of? Aluminum.... it is what is called a floating wrist pin because it also spins in the aluminum piston, now it does have about twice the bearing surface than the wrist pin bearing or bushing does, but has anyone as of yet heard of a failure on these engine between the aluminum piston and the steel wrist pin?
These are just questions running through my head which may be bunk questions but I'm still curious just the same and will give the set up a test and see what my results end up being.... hey... if I have to pedal home or call for help it wont be the first time or probably the last...lol!
I plan to go alumunim on titanium first and then if the wrist pin survives that Ill switch to the brass bushing for a few miles, if pin survives that then Ill go with good quality needle bearing and see if this is the one that kills it..... otta be fun... dang aint it fun to tinker...!
Map
Last edited:
mapbike
Well-Known Member
Interesting.....
mapbike
Well-Known Member
Edited: Aluminum bushing is bad idea.. tried it and it failed quickly....
Well, I installed the Titanium wrist pin along with the Aluminum bushing today, not sure what grade or type of aluminum they use to make that bushing but that stuff is hard, was barely able to even scratch it with a fine ignition point file, it has three holes drilled for oiling, the tolerance between the pin and bushing was really close, that concerned me because of expansion when it heats up, but that hasn't seemed to be an issue so far, I went ahead and done some port work on the engine while I has it down so the rpm potential would be improved some since it was a bone stock jug with burs in the ports, OK, long story short... after reassembly the engine fired right up and the port work did a lot to improve throttle response, I cautiously left my private road and kicked it up to 30mph, vibes were comfortable and minimal at this speed and at 31mph not bad but vibes noticeably increased so I backed it back down to almost a perfect 30mph and it was just humming right along, at two times I kicked it up to its plateau top speed of 36.3mph vibes are crazy at that speed with this engine, its very obvious to me that the crank being extremely untrue is the problem with this engine and always has been, I road the bike comfortably at the 30 mph speed for 12.8 miles and it ran great, the porting made a huge difference on the area hills also, loads of power pulling my 215lbs with a 32T sprocket on the 24' rear wheel, I think I will probably go back to the 26" wheel and a 36T sprocket on this bike in the near future, so.... for now the engine is running good, not a click in it, a bit smoother than it was before, but it has a bad untrue crank that no amount of external tweaks will remedy, but for a 30mph cruiser it works nice now with the ability to quickly hit 35mph for short vibrating burst if needed....LOL, I discovered that this engine is a tight case engine like the ones Fred is seeking, wow if I only had one of Freds trued and balanced cranks in this engine, it would be a dream....., next post below will be weight measurements I took today for multiple pin and bushing-bearing weights before I installed the Titanium Pin & Aluminum Bushing that may not hold up for long.... running 100:1 Opti2 and so far it has never let me down so we'll see how this bushing holds up, may be to soft and hammer out in another 10-20 miles or maybe not.. I'm very curious about this.
Map
Well, I installed the Titanium wrist pin along with the Aluminum bushing today, not sure what grade or type of aluminum they use to make that bushing but that stuff is hard, was barely able to even scratch it with a fine ignition point file, it has three holes drilled for oiling, the tolerance between the pin and bushing was really close, that concerned me because of expansion when it heats up, but that hasn't seemed to be an issue so far, I went ahead and done some port work on the engine while I has it down so the rpm potential would be improved some since it was a bone stock jug with burs in the ports, OK, long story short... after reassembly the engine fired right up and the port work did a lot to improve throttle response, I cautiously left my private road and kicked it up to 30mph, vibes were comfortable and minimal at this speed and at 31mph not bad but vibes noticeably increased so I backed it back down to almost a perfect 30mph and it was just humming right along, at two times I kicked it up to its plateau top speed of 36.3mph vibes are crazy at that speed with this engine, its very obvious to me that the crank being extremely untrue is the problem with this engine and always has been, I road the bike comfortably at the 30 mph speed for 12.8 miles and it ran great, the porting made a huge difference on the area hills also, loads of power pulling my 215lbs with a 32T sprocket on the 24' rear wheel, I think I will probably go back to the 26" wheel and a 36T sprocket on this bike in the near future, so.... for now the engine is running good, not a click in it, a bit smoother than it was before, but it has a bad untrue crank that no amount of external tweaks will remedy, but for a 30mph cruiser it works nice now with the ability to quickly hit 35mph for short vibrating burst if needed....LOL, I discovered that this engine is a tight case engine like the ones Fred is seeking, wow if I only had one of Freds trued and balanced cranks in this engine, it would be a dream....., next post below will be weight measurements I took today for multiple pin and bushing-bearing weights before I installed the Titanium Pin & Aluminum Bushing that may not hold up for long.... running 100:1 Opti2 and so far it has never let me down so we'll see how this bushing holds up, may be to soft and hammer out in another 10-20 miles or maybe not.. I'm very curious about this.
Map
Last edited:
mapbike
Well-Known Member
OK weight measurements (Steel pin + Needle Bearing = 20 grams) --- (Steel pin + Bronze Bushing = 24 grams) --- (Steel pin + Aluminum Bushing = 16 grams) --- (Titanium pin + Needle Bearing = 12 grams) --- (Titanium pin + Bronze Bushing = 18 grams) --- (Titanium pin + Aluminum Bushing = 10 grams) --- (Titanium pin = 8 grams) --- (Steel pin = 14 grams) --- ( Needle Bearing = 4-6 grams depending on bearing) --- (Bronze Bushing = 10 grams) --- (Aluminum Bushing = 2 grams)
Here are the weights and combinations of weights I measured today, the Bronze Bushing on the Titanium pin is still lighter than a steel pin and a stock wrist pin needle bearing by 2 grams, the high grade Japanese needle bearing I got from bearingdirect is 2 grams lighter so the weight with it on a steel pin is the same weight as the Bronze bushing on the Titanium pin. we shall see how this all hold s up, I'll be measuring miles traveled on a gps everytime I ride the bike up till I get 100 or so miles on it and then she's coming apart for inspection if it last that long...lol!
Map
Here are the weights and combinations of weights I measured today, the Bronze Bushing on the Titanium pin is still lighter than a steel pin and a stock wrist pin needle bearing by 2 grams, the high grade Japanese needle bearing I got from bearingdirect is 2 grams lighter so the weight with it on a steel pin is the same weight as the Bronze bushing on the Titanium pin. we shall see how this all hold s up, I'll be measuring miles traveled on a gps everytime I ride the bike up till I get 100 or so miles on it and then she's coming apart for inspection if it last that long...lol!
Map
mapbike
Well-Known Member
You're welcome Kioshk I'm gonna ride it as much as I can and document the miles until I get 100 or so miles on it and then she'll come back apart the check for noticeable wear.
gonna be interesting, I have another engine that may get the same set up depending on how this one does.
Map
gonna be interesting, I have another engine that may get the same set up depending on how this one does.
Map
mapbike
Well-Known Member
I'm running an Aluminum Bushing on the pin and I am running Opti2 oil with a bit of Maxima 927 Castor in the mix, so far I have put 12.8 GPS'd miles on it with no negative signs, of course that could all change in a blink of an eye, Juice told me they 28 bikes still going with the Titanium Wrist pins in them, of course I don't know how they know they're all still going, they did tell me they have had two reports of problems with the pin so time will tell, even with a superior to many lubricant like Opti2, that wont help a bit if the material gets hammered o heck from being to soft, I'm just gonna ride the bike as if I knew it had everything I would have in my others and put it through the paces to see what happens, no way I see it lasting as long as a good steel pin, but with the right set up it might do pretty good for a while....shrug... we'll see..???????
map
mapbike
Well-Known Member
Update.... ALUMINUM BUSHING on TITANIUM WRIST PIN ...... ( FAILURE )......
Just wanted to say that the aluminum bushing didn't make it, I was concerned about it the entire time, but tried to think about the possibility that it may last a while and why it might possbly last a while..... well my first thoughts on it were confirmed after about 50 miles of really hard running, wristpin would have held up fine with bronze bushing it seems but the aluminum bushing totally failed, and ruin d rist pin when bushing allowed con rod to run against wrist pin, ruined piston after about 20 minutes of beating the pin out of piston, everything else was in good shape so I put and newpiston pin and needle bearing in and reassembled the engine and give it a few miles of running today, runs good again but the vi es are still just ridiculous with it above mid 20's mph.
My final conclusion to this little experiment is..... run a steel wristpin and a high quality needle bearing, dont junk up the top end trying to make up for a badly untrue and unbalanced crank, if a seriously bad vibration issue excistwith a china girl engine deal with it by a replacement dax Gen IV lower or the same lower from Neil aka: motorbicycleracing, my dax engine builds are a pure pleasure because of the extra smooth low vibe experience I've had with them, ill be contacting juisemotoparts to inform them of my experience so they will hopefully stop selling the bushings.
I wanted to do all of this for answering questions that someone may ask concerning these parts.... now we know.
Map
Just wanted to say that the aluminum bushing didn't make it, I was concerned about it the entire time, but tried to think about the possibility that it may last a while and why it might possbly last a while..... well my first thoughts on it were confirmed after about 50 miles of really hard running, wristpin would have held up fine with bronze bushing it seems but the aluminum bushing totally failed, and ruin d rist pin when bushing allowed con rod to run against wrist pin, ruined piston after about 20 minutes of beating the pin out of piston, everything else was in good shape so I put and newpiston pin and needle bearing in and reassembled the engine and give it a few miles of running today, runs good again but the vi es are still just ridiculous with it above mid 20's mph.
My final conclusion to this little experiment is..... run a steel wristpin and a high quality needle bearing, dont junk up the top end trying to make up for a badly untrue and unbalanced crank, if a seriously bad vibration issue excistwith a china girl engine deal with it by a replacement dax Gen IV lower or the same lower from Neil aka: motorbicycleracing, my dax engine builds are a pure pleasure because of the extra smooth low vibe experience I've had with them, ill be contacting juisemotoparts to inform them of my experience so they will hopefully stop selling the bushings.
I wanted to do all of this for answering questions that someone may ask concerning these parts.... now we know.
Map
Davezilla
New Member
I've seen those aluminum wrist pin bushings on their site too but decided on the bronze bushing with the titanium pin. Right now I'm running a Dax Gen 4 bottom end with my original ported top end and it would begin to vibe after about 6k rpm or so with the steel pin and needle bearing installed. Mounting my engine better and much more solid fixed that problem for me so I'm going to leave the steel ipn and needle bearing in there for now. The needle bearing is an upgraded one and not the original so I might as well get some use out of it...
While waiting on parts I've been redoing my engine mounts because I just didn't like the way it mounted and noticed that there was some play when reving the engine so I welded in some mount tabs up front to solid mount the engine to the front and then used 2 mount saddles on the rear mount with longer studs which made the rear mount a lot more rigid than with just the typical mount saddle and a steel strap to clamp around the frame. The end result was much better mounting that's very rigid now, and the vibes are gone when reved so I'm thinking my vibration problem was more of a resonance with the frame at that rpm due to the play in the mounts so I may save the titanium pin and bronze bushing for the other engine I'm building now.
Thanks for the report back on the aluminum bushing, it definitely answered my question on how long it would last as well as confirm what I was already assuming.
While waiting on parts I've been redoing my engine mounts because I just didn't like the way it mounted and noticed that there was some play when reving the engine so I welded in some mount tabs up front to solid mount the engine to the front and then used 2 mount saddles on the rear mount with longer studs which made the rear mount a lot more rigid than with just the typical mount saddle and a steel strap to clamp around the frame. The end result was much better mounting that's very rigid now, and the vibes are gone when reved so I'm thinking my vibration problem was more of a resonance with the frame at that rpm due to the play in the mounts so I may save the titanium pin and bronze bushing for the other engine I'm building now.
Thanks for the report back on the aluminum bushing, it definitely answered my question on how long it would last as well as confirm what I was already assuming.
mapbike
Well-Known Member
I figured all along there was a good chance my engine would take one for the team during this aluminum bushing experiment, I made the argument that others could possibly make saying...
"the piston itself is aluminum so why wouldn't an aluminum bushing hold up as well as the aluminum piston itself"
I can say there was a slight reduction in vibes at a certain RPM which gave me about 2-3 MPH increase before the bad vibes kicked in, but not enough difference to make switching from standard pin and bearing set up to high dollar titanium pin and bushing, another thing is that if you use a bronze bushing on the titanium pin, you really haven't gained anything about just sticking with a steel pin and high quality needle bearing, the bronze bushing is heavier than a needle bearing so it pretty much cancels out the weight savings of using the titanium pin.
my final opinion is that neither the bronze bushing or the titanium pin are worth the cost or trouble, and it has been confirmed that they wont last as long and they don't provide any benefit, cool idea but and if someone just wants a Bronze bushing for whatever reason thats fine, but if they expect any noticeable difference in how the engine runs, sounds or performs.... they're gonna be let down because I can say been there done that and it just doesn't make sense to go that route in my honest opinion.
Map
"the piston itself is aluminum so why wouldn't an aluminum bushing hold up as well as the aluminum piston itself"
I can say there was a slight reduction in vibes at a certain RPM which gave me about 2-3 MPH increase before the bad vibes kicked in, but not enough difference to make switching from standard pin and bearing set up to high dollar titanium pin and bushing, another thing is that if you use a bronze bushing on the titanium pin, you really haven't gained anything about just sticking with a steel pin and high quality needle bearing, the bronze bushing is heavier than a needle bearing so it pretty much cancels out the weight savings of using the titanium pin.
my final opinion is that neither the bronze bushing or the titanium pin are worth the cost or trouble, and it has been confirmed that they wont last as long and they don't provide any benefit, cool idea but and if someone just wants a Bronze bushing for whatever reason thats fine, but if they expect any noticeable difference in how the engine runs, sounds or performs.... they're gonna be let down because I can say been there done that and it just doesn't make sense to go that route in my honest opinion.
Map
turnofftheradio
Member
I appreciate your advice/experience Map. Thanks for taking one for the team. I too could have argued the same points, tried and failed. You're saving smart people some time and bucks.I figured all along there was a good chance my engine would take one for the team during this aluminum bushing experiment, I made the argument that others could possibly make saying...
"the piston itself is aluminum so why wouldn't an aluminum bushing hold up as well as the aluminum piston itself"
I can say there was a slight reduction in vibes at a certain RPM which gave me about 2-3 MPH increase before the bad vibes kicked in, but not enough difference to make switching from standard pin and bearing set up to high dollar titanium pin and bushing, another thing is that if you use a bronze bushing on the titanium pin, you really haven't gained anything about just sticking with a steel pin and high quality needle bearing, the bronze bushing is heavier than a needle bearing so it pretty much cancels out the weight savings of using the titanium pin.
my final opinion is that neither the bronze bushing or the titanium pin are worth the cost or trouble, and it has been confirmed that they wont last as long and they don't provide any benefit, cool idea but and if someone just wants a Bronze bushing for whatever reason thats fine, but if they expect any noticeable difference in how the engine runs, sounds or performs.... they're gonna be let down because I can say been there done that and it just doesn't make sense to go that route in my honest opinion.
Map
Davezilla
New Member
Sounds about right... if the bronze bushing is heavy then it would be pointless to do the swap on a built engine that's already running just fine. I'll weigh everything and compare the weight against my original bearing and pin when my parts come in and report the weight difference but won't use these parts on the engine I have in the bike right now.
I might use those parts on the engine I'm building now, but may just decide to chalk it up as lesson learned and stick with the steel pin and roller bearing.
What would really impress me here for weight savings and better balance ability would be if someone with the right equipment could make a titanium rod for these, but then again, the cost might make that too impractical.
Solid mounting my engine to the frame by welding tabs for the engine to bolt directly onto really took out a lot of the vibes I was feeling at the seat and bars so I'm thinking mine was more of a resonance issue than a balance issue as it's now smoother than the first engine I had on it but this new engine was rough as **** when reved comparing to the previous one and now it's a lot smoother than it ever was. I'm sure it's still got the typical off balance that all these engines have but making the frame absorb the vibes instead of transfer them really helped in my situation.
I might use those parts on the engine I'm building now, but may just decide to chalk it up as lesson learned and stick with the steel pin and roller bearing.
What would really impress me here for weight savings and better balance ability would be if someone with the right equipment could make a titanium rod for these, but then again, the cost might make that too impractical.
Solid mounting my engine to the frame by welding tabs for the engine to bolt directly onto really took out a lot of the vibes I was feeling at the seat and bars so I'm thinking mine was more of a resonance issue than a balance issue as it's now smoother than the first engine I had on it but this new engine was rough as **** when reved comparing to the previous one and now it's a lot smoother than it ever was. I'm sure it's still got the typical off balance that all these engines have but making the frame absorb the vibes instead of transfer them really helped in my situation.
mapbike
Well-Known Member
I already did an weight comparison and here it is.
OK weight measurements (Steel pin + Needle Bearing = 20 grams) --- (Steel pin + Bronze Bushing = 24 grams) --- (Steel pin + Aluminum Bushing = 16 grams) --- (Titanium pin + Needle Bearing = 12 grams) --- (Titanium pin + Bronze Bushing = 18 grams) --- (Titanium pin + Aluminum Bushing = 10 grams) --- (Titanium pin = 8 grams) --- (Steel pin = 14 grams) --- ( Needle Bearing = 4-6 grams depending on bearing) --- (Bronze Bushing = 10 grams) --- (Aluminum Bushing = 2 grams)
There are only 2 grams to be saved between titanium pin with bronze bushing and Steel pin and quality needle bearing in my weight test.
Not enough to make any noticeable difference in my opinion.
Map
mapbike
Well-Known Member
Honestly I really don't know 60weight.
Hopefully someone else can ring in here and explain the differences.
I do know there are several type of cases because I have 4 different ones myself, ( Transfer port area looks different and either has a ramping into case or has a 90* ledge at bottom in case) but I'm not sure what the identifying method would be to know if it was a "tight case" or not.
Map