Numeric Racings Short Shifter
#61
Dang! I was about to put mine on....may need to talk to Numeric about the failure to see if they have a fix before I get stranded.
#62
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Definitely looks like some sort of material issue. Even w/ the tapered down diameter, there's no way that it would break unless you are putting hundred+ lbs of force on the shift ****... Hopefully Numeric can talk to its supplier and sort it out.
#63
Rennlist Member
I guess I'll keep the OEM in my car on track days just in case.
Numeric supposedly did make a change of some sorts to the design, but I haven't had the chance yet to look into exactly what changed.
#64
GT3 player par excellence
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sorry to see it snap. was it made in my home country, taiwan? we cant do metal, we make world's best CF. look at all high end bikes. the manufacturer would need to step up, i see no reason for you to pay for anything.
personally i tried all the shifters under the sun. cup shifter with cup cable get my vote. no adjustment just works.
personally i tried all the shifters under the sun. cup shifter with cup cable get my vote. no adjustment just works.
#66
Rennlist Member
I took a photo of my spare (new design) and show it below as compared to my failed shift rod based on the old design. I haven't taken measurements, but you can clearly see that the new design provides a continuous taper extending from the pivot region to the rod end. It eliminates a stress riser (even though this region does not fail) but it also appears to provide more material since the rod diameter tapers down instead of being fixed.
#67
Rja the stress raiser is the dark area in the failed cross section, the material seems to be bent a lot so for some reason it has seen higher bending loads that passed it memory return point. I have just check mine out, out of interest and its straight. Possible wrong batch or poor grade austenitic material.
Have you had any bulked gear changes?
Have you had any bulked gear changes?
#68
Rennlist Member
New Shifter!
I just got mine delivered and it looks like I got the new design. Yeah!
#69
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Although no product is without failure, it is always the intention of Numeric Racing to continue to improve the design and manufacturing process of our products. We proudly stand by all products with a lifetime warranty. Please contact customer support with any RMA or warranty concerns at (727) 372 -0300. We thank each and everyone of you for the input.
#70
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#72
Another version? This is what I got a couple weeks ago in the mail from eddie.
#73
Add mine to the list of broken Numeric mount. Got 9 track days out of it before it broke. Same area broke. pics look identical to mine. Broke in the 3rd lap of my first session of a 2 day event that is 300 miles from my house .
It seems there is either a design flaw or manufacturing defect w/ the Numeric shifter. Mine failed a few weeks ago, and now another incident by another driver (same shifter, also a 997.2GT3RS) just today.
I lost a $275 lapping day and ate a vacation day to mine failing. The main shifter rod snapped into two on mine on the first lap when pulling 3->4. Luckily the Cantrell guys were present to offer assist. There was a nearby aircraft welder available to welded it back together and it was back in the car w/in an hour, but it snapped again in a different location after a few laps either because welding compromised the heat treatment or other fractures were present and I simply worked my way onto the next one. From the photo below you can see that the rod is bent some, which may have lead to fractures in the heat treated material. We called it a day, jerry-rigged the shifter back together w/ 2-part steel epoxy so I could make the trip home (shifting very gently).
My first question on seeing the part prior to initial installation was, 'why did Numeric step the diameter down so much ... is it strong enough??' Those were my actual words. It doesn't taken an engineer ... but, I was assured yes, never a problem and used in competition. Well???
I cannot see any reason why Numeric stepped down the diameter so much below the pivot, and there's a lot of mechanical leverage from above. It seems like a really bad idea, but giving the benefit of doubt, would for Numeric to provide an explanation. Hopefully not a case of function following form (i.e., because it looks cool).
I recommend to Numeric they don't step down quite so much. Even a small increase in diameter will yield significantly greater bending strength. (The inner core contributes virtually nothing by comparison so they hollow out the rod it weight savings is the driving factor -- although this would seem like overkill.) Numeric replaced the part for free, and cited possible impurities in materials as potential cause. I can accept this but stepping up the diameter will make part less susceptible to failure in such events.
I really like the Numeric shifter. It provides me with solid links all the way back to the gearbox and shifting is very precise. Also, I hate stupidly short shifters and prefer the OEM length on the RS, and the Numeric shifter allows me to retain that. There's really very little to be gained with a short shifter except a missed shift here and there which will eat up far more time than the 0.005 seconds possibly saved by reducing length of throw.
In photos below:
- First photo shows broken shifter.
- Second photo shows welded shifter (which failed again in a different location). Why is the diameter on this part stepped down so much?? Seems unnecessary. You don't need to be 'power shifting' like a drag racer to introduce quite a bit of stress into this region given the significant mechanical leverage that exists above the pivot point (not seen here).
I lost a $275 lapping day and ate a vacation day to mine failing. The main shifter rod snapped into two on mine on the first lap when pulling 3->4. Luckily the Cantrell guys were present to offer assist. There was a nearby aircraft welder available to welded it back together and it was back in the car w/in an hour, but it snapped again in a different location after a few laps either because welding compromised the heat treatment or other fractures were present and I simply worked my way onto the next one. From the photo below you can see that the rod is bent some, which may have lead to fractures in the heat treated material. We called it a day, jerry-rigged the shifter back together w/ 2-part steel epoxy so I could make the trip home (shifting very gently).
My first question on seeing the part prior to initial installation was, 'why did Numeric step the diameter down so much ... is it strong enough??' Those were my actual words. It doesn't taken an engineer ... but, I was assured yes, never a problem and used in competition. Well???
I cannot see any reason why Numeric stepped down the diameter so much below the pivot, and there's a lot of mechanical leverage from above. It seems like a really bad idea, but giving the benefit of doubt, would for Numeric to provide an explanation. Hopefully not a case of function following form (i.e., because it looks cool).
I recommend to Numeric they don't step down quite so much. Even a small increase in diameter will yield significantly greater bending strength. (The inner core contributes virtually nothing by comparison so they hollow out the rod it weight savings is the driving factor -- although this would seem like overkill.) Numeric replaced the part for free, and cited possible impurities in materials as potential cause. I can accept this but stepping up the diameter will make part less susceptible to failure in such events.
I really like the Numeric shifter. It provides me with solid links all the way back to the gearbox and shifting is very precise. Also, I hate stupidly short shifters and prefer the OEM length on the RS, and the Numeric shifter allows me to retain that. There's really very little to be gained with a short shifter except a missed shift here and there which will eat up far more time than the 0.005 seconds possibly saved by reducing length of throw.
In photos below:
- First photo shows broken shifter.
- Second photo shows welded shifter (which failed again in a different location). Why is the diameter on this part stepped down so much?? Seems unnecessary. You don't need to be 'power shifting' like a drag racer to introduce quite a bit of stress into this region given the significant mechanical leverage that exists above the pivot point (not seen here).
Last edited by 4forme; 09-11-2013 at 12:25 PM.
#74
I have a spare now, though not a freebee.
#75
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We at Numeric Racing are saddened to hear about your recent misfortune at the track and express our sincerest apology for any troubles. We take pride in manufacturing all of our products and stand behind them 100% with a lifetime warranty! Out of all the shifters sold there have been only three recorded cases of this flaw. This being the third, the other two levers were sent out to a metallurgical expert to have the material tested for any impurities or flaws. The results concluded a large sulfur pocket within the steel bar that caused the steel to be weak in that particular area. Fortunately, due to the size of our manufacturing company we were able to isolate the incident quickly and prevent any chance of reoccurrence in the future. We narrowed down the actual bar of steel and acquired the majority of material back. Our new levers use 316L which is a much stronger material that I can assure all of our customers will not fail. The Numeric Shifter is one of the best products on the market preferred and used by many winning race teams. It would be unnecessary to remove the shifter when all parts are completely under warranty and the replacement lever will take about 5 minutes to install. We obviously cannot take back your unfortunate weekend. However, I can promise you that we will continue to take great care of you! Our records indicate that you have not contacted us directly for this matter or purchased through 6speedonline. To further assist you please contact our company with all the information needed to expedite your warranty. For all other Numeric customers with early model levers and would prefer an updated model, please contact us direct to arrange an exchange. Thank you.
Add mine to the list of broken Numeric mount. Got 9 track days out of it before it broke. Same area broke. pics look identical to mine. Broke in the 3rd lap of my first session of a 2 day event that is 300 miles from my house . Not only has it cost me the price of the mount and install, but now have to pay to reinstall oem piece and ruined the weekend for me. All in all Numeric owes me $1,600. Thanks Numeric!
Do NOT buy their mount.
Do NOT buy their mount.