Sunlite Alloy Seat Post Clamp with Rack Mount

This is a great idea for mounting rear racks onto bikes that don't have lots of braze-ons. This Sunlite is the second rack-mount clamp I've owned and the one I currently use. I had bought another where the rack-mount holes are up at the same level as the set clamp bolt. The vertical offset on this Sunlite clamp allowed me to angle the rack supports downward a little more and avoid a pinch point between the supports and the rack's deck. Those few millimeters of offset let me turn an acceptable setup into something I am truly happy with.

I bought this to improve the point of contact my rack has onto my bike frame. The smaller size, 28.6mm, perfectly fit into my seat post with some grease and light prying to open the clamp and slide it into place. Although my seat post is around 3mm smaller, this clamp would not slide on easily, as I mentioned I only needed to open it slightly for it to shimmy into place. I preferred this as it meant it would be secure even if the tightening screw came loose for whatever reason. The material felt pretty hefty and my screws from my rack screwed in perfectly and tightly to this clamp.

Replaced stock seat post lever clamp with this clamp with good results, so far. If the clamp does not clamp with enough force, I will use a Dremel Tool to remove the inside lip and lower the clamp on the frame, then use the stock lever clamp to secure the seat post.

While it's totally my fault for ordering the wrong size, I just want to warn others that "diameter" means across, not circumference (around). No, I'm not a COMPLETE idiot but after reading all the reviews that warned to measure- I did, and it came out to exactly one of the options so I thought I had it right. As a bike newbie (and obviously a math moron), I didn't understand that you have to take the seat off to get a correct measurement, that's on me. I wasn't very happy to spend $3.90 to send it back, wait a week for a new one, and I still haven't gotten my refund yet (seven days now) so make DERN sure you measure right the first time! I haven't even installed it yet (there are no directions) so once I figure out how it's supposed to go and check it out, I'll update. So much for my rack warranty! By the time I get it on (if I do it tomorrow) I'll have less than 2 weeks left to test the rack (I ordered both at the same time but the rack was Prime so I got it about a week before I got the wrong adapter, took another week to get the right one).UPDATE: I don't know EXACTLY how stupid I am but I'm getting a glimpse and it's not good. I DID take the seat off, I DID measure again, and then I ordered another wrong size! Bad news, the next smaller size also didn't fit, also wasn't prime, and cost more than this one did! It also cost $4.90 to send back (the return label said it was 2 lbs but it couldn't possibly weigh more than a few ounces)! I sent it back 10 days ago (received by UPS March 15, 1:18am, today is March 25, 9:10pm, and they got it yesterday 1:11pm) and I still haven't gotten a refund. (I did get my refund for the first one I sent back after I contacted Amazon and they contacted the seller. along with an apology email.) Great, so then I ordered the smallest size (even a blind squirrel, am I right?) and it IS Prime! It cost even more than the previous two larger ones but at least I didn't have to wait a week for it! It fits perfectly and is exactly what I needed. I can't comment on how well it works yet as, after almost a month of trying to get the right size, I still haven't had a chance to test it yet. I will say though that my bike seat has never been tighter (I could never get it tight enough with my quick-release seat clamp) so I'm happy about that! I'm also very pleased that the rack I bought went on without a hitch and seems quite secure (I got the "Ibera PakRak Bicycle Touring Carrier Plus+, Frame-Mounted for Heavier Top & Side Loads, Height Adjustable, Fender Board, for 26"-29" Frames" (https://smile.amazon.com/gp/product/B00DWKUAZK/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1). I'll update again once I put some serious weight on it and really give it a good test.

Does exactly what it's supposed to. Feels durable enough I don't anticipate needing to replace it for a few years, if ever.

The seat post clamp was just what I needed to mount a rear bike rack to my NCM Moscow E-bike. All when well until I attempted to install a bike rack support strap using a 5mm socket head bolt to the right side threaded hole. The hole had not been properly tapped and I was required to dig out my tap and die set and properly tap the hole. The left side hole was properly tapped. With the exception of the improperly tapped left side hole the seat post clamp performed as expected.

Replaced a quick release clamp with this when I converted to a dropper post. I really should have gotten one of these long ago. The quick release clamp holding my rear rack was not ideal and this just solves it. Yes, it replaces your quick release clamp. If you need to often remove your saddle/post, probably not for you. If you don't often change it, much better.The thread pitch for the rear seat rack attachment is M5x1 IIRC. I took it with me to the hardware store to get the socket head cap screws needed but it would have been nice if it came with them.

Product arrived quickly in good condition. Brought this product because my Diamondback mountain bike did not have mounting holes for my ibera bike rack near the seat post. I clamped the Seat Post Clamp over the bike frame where the seat post slides into the bike. Make sure the Seat Post Clamp is tight enough to hold the bike rack securely, but NOT too tight if you need to adjust the height of the seat: otherwise you will need to loosen the Seat Post Clamp to adjust the height of the seat. The Seat Post Clamp has two mounting holes to attach my bike rack to it. The bike rack fitted perfectly after a little trial and error tightening the Seat Post Clamp. I am able to adjust the seat height without loosening the clamp.