I had always issues with all kind of grommets but never with the U ones. I tried to assemble the small T and they fit, but were too short. I think it is okay to go for the U ones from mbs. You don't need to change the U's as often as any other grommets. Just my 2 cents.
From my experience they fit snug and tight at the top of the frames (last 2 mains). At the bottom they are not as firm but fit snug. I recommend to wide them with an awl before stringing (generally an advice for the shared holes) and then you don't have issues that they would fall out. During stringing you need to hold them when you pull the mains, but I always had these issues with various rackets, so to me it is normal. Why don't you give your stringer the exact number of grommets to put them into your racket?
So how many strong jobs can these handle? Is it a case of rotate change every time or can they stay in place for 2 or 3 jobs?
with the T & square grommets (small + big) you won't need to rotate grommets ever. Only replace them. The Red T grommets should easily last beyond 3 string jobs. IMO The Square grommet for the shared holes should last fairly long too. I'm monitoring how durable the flared side is over time (I flare all my shared holes). I didn't notice any heavy notching (28 lbs) on the outside of the grommet proving that it is way better than the standard round grommet. I have the same thoughts and opinions for the 2.1mm small single Square grommet too. My only question is whether the plastic material used for the red grommet is different from the black grommet. To me it appears that the red one is more durable? Or am i just seeing things.
I have to warn you that the initial cost of these grommets appear to be more expensive than the MBS grommets, but as you can see from the photos posted previously on the thread, the number of grommets you get (Red T + Square Head ones) in a bottle is A LOT. I've been filling some of my old MBS ziplock bags to get a better idea of the amount of grommets. Trust me...once you order, you probably won't order again for quite some time. These grommets offer terrific value and have been something I've been looking/waiting for as a stringer to offer better protection to rackets as more string jobs requested are creeping closer to the high 20s' to low 30 lbs mark.
I find that around the lower main string holes 8-9-11 I forget the exact one, but with the standard 4-knot Yonex pattern, it does place quite a bit of stress on those shared holes, this is especially true for racquets where it's designed with a channel like ZF2.
Nice kwun! I wanted to restring my last BS12 but the delivery guy left my package in the warehouse, so grommets arrive Monday instead. As for your signature line... LMAO
I may need to revise my order when you're stocked up! All us stringers here appreciate all the R&D you are doing!
Same here. I'm already considering a new order to make up for my botched order (I botched it up myself)).
i have one suggestion. 2.1mm T-grommet with a ridge on the head like the way ZF2 has it. This will save time fishing the string through a covered grommet hole on some rackets.
@kwun So T-grommets with the ridge/extruded bit to separate the paths of the string? That would be awesome! And a pair of pictures that show what kwun is talking about. @JJ0907 You should consider doing this. For the 2.1 & 2.6mm grommets. 如果你可以設計有“镶”的T-墊圈我肯定會買!
@mikomi , that's exactly what i am talking about. we don't need to have a whole strip like the ZF2, just add the ridge to the existing t-grommet will be sufficient. I will replace all my client's grommet at that place. it will make our lives so much better.
Just dreaming of the possibility makes me giddy. But it shouldn't be limited to the 2.1mm grommets. the larger +2.6mm grommets too!