I purchased this item from Niagara Cycle Works and received it promptly. Their price was more appealing than RDS Bikes. This type of instrument was common years ago but the older ones were made of metal and had a small diameter metal wheel attached to the spokes. The disc was perforated near the outside edge and a metal gear meshed with the disc to drive the speedometer cable which in turn operated the speedometer and odometer. This made in China product is genuine plastic. While not the quality of the old American models, it operates very well and for the money I am most satisfied with it. It is easy to read while riding compared to the electronic models which can be very difficult due to light reflection. The installation is very simple. Noting a complaint regarding lack of instructions, here is how installation is done: The accessory has 3 basic parts - the head (as pictured above), the drive cable and the drive gear assembly. Starting at the bottom, the drive gear has a metal arm that protrudes through the spokes. This, in turn, rotates a small wheel that powers a gear that rotates the cable that runs up to the head. (it remains to be seen how well this will hold up over time as the remainder of the drive gear is plastic)
Unbolt the front wheel after deciding if you want the head on the right or left side of your handle bars. The drive gear can be mounted on the left or right side of the axle There is a plastic cap that screws on the end where the cable is not inserted, the cable can be inserted from 2 directions, just one is needed, insert it into the top side and the cap goes to the bottom. Unbolt the front wheel and remove it. Recenter the axle slightly to compensate for the space used by drive gear attachment. Slide a washer (provided) onto the axle, the drive gear, a second washer and then reattach the wheel to the fork. It might take a bit of pulling to slightly spread the fork. Position the drive gear so that the cable can go straight into the drive gear attachment, tighten your front axle bolts - but - not too tight as you do not want to break the plastic gear housing. The cable screws in on the top side. Mount the head on the handle bars, screw the other end of the cable into the head and you are in business! One more thing: To keep the cable from snagging onto something, I used a couple of plastic cable ties to bring the cable tight up against the side of the fork. As the handle bars and front fork turn in unison, there is no binding of the cable. Would I buy anogther one? I would without hesitation should the need arise. I have seen replacement drive gears advertised for a few dollars, so no sweat if the drive gear apparatus wears out. Not being interested in 15 or so functions that the electronic models offer, this one suits me just fine. Hope this helps anybody with questions of how these are installed. 4 stars

I got a bicycle in mid June and purchased this Speedometer Pyramid Pro 26/27 with Resettable Odometer about a month later. I was riding almost every day between 15 and 22 miles and liked seeing the length of my rides and checking the time it took for these rides. This guage is easy to read and while it worked it was a joy to see the miles ticking along. It no longer is resettable as the third digit to the left does not move in coordination with the other slots. It is no longer an accurate odometer as the other slots don't work either most of the time. Not a reliable odometer although the speed still works. I would have loved this product if it had not malfunctioned after only 3 months. 3 stars

The product came in a timely fashion and seems neat, however it came with no instructions. I emailed the company through Amazon and did not receive a reply. My son is very disappointed that his new accessory doesn't work and I am very disappointed that the company will not support their product. 1 star

I purchased this item to keep track of the miles I ride my bike each time I go to the park. It is very nice to know if I have ridden 10, 15, 20 miles. And the speed I am riding is also nice to know. This item is reasonably easy to install. It is very easy to read. I am glad I have this item on my bike. However, on some English racing style bikes which have the fast, easy off front tire, this item may not work. This item appears to be made for bikes where the front wheel is permantly bolted fork. If the front wheel has the fast remove handle, there may be a problem installing the cable. 4 stars

As a previous reviewer indicated, this comes with no instructions, though I did not find it too difficult to install. The only problem I had was figuring out which side of the bike to mount the rotating tooth that engages with the spokes. If you do it on the wrong side, then you have to take it off and re-mount it on the others side of the wheel. So, I assembled the entire speedometer and simple held the end that connects to the wheel up to the wheel with the bike upside down. I then gave the wheel a good spin while holding the speedometer up to either side of the wheel to see which way was correct. The other thing to note is that it is in KM/H and KM, not MPH and Miles. So, be ready to multiply the readings by 0.6 for a quick conversion. 4 stars