With a slim aluminum backplate and tiny slider, OneUp's $45 USD chain guide is about as minimalist as a guide can get. The Canadian company says that their 35 gram guide doubles the usable life of narrow-wide chain rings by increasing security (NW chain rings lose some of their retention power as their teeth wear) thereby saving riders money in the long run while also acting as a lightweight bit of insurance.
There's not much to the pared down OneUp chain guide, but what is there is pretty clever. Because there's no skid or lower slider, the guide's aluminum backplate can bolt to just two of the bike's three ISCG-05 chain guide tabs - there is no ISCG version - and like any guide, the mounting holes are slotted to allow it to be clocked correctly on your bike. Height adjustments are made by loosening a single aluminum bolt that holds the guide's upper element in place. This section slides vertically on the backplate, and there are laser etched height markings to make setup mostly a no-brainer.
OneUp Chain Guide Details
• Intended use: keeping your chain on
• ISCG 05 mounting only
• Aluminum backplate
• Compatability: 26t - 38t chain rings
• 5.5mm of chainline adjustment
• Black and green sliders incl.
• Weight: 35 grams (w/ hardware)
• MSRP: $45 USD
The slider, which OneUp says is glass reinforced thermoplastic, attaches to the upper element with a single 4mm hex bolt, and a fin that's shaped into the back of it helps to keep it from ever rotating. It's all pretty simple, and very nicely made, but it's how OneUp went about making the slider horizontally adjustable that's interesting.
Rather than space out the backplate from the frame as per the norm, or build in some sort of slotted adjustment, OneUp went with thin spacers that fit in between the slider and the backplate. Each one is about a millimeter thick, and dimples on the spacers help to keep everything aligned. A gauge is included that tells you how many spacers to use, or you can just sight it from above.
Installation and Setup
Do you own a single 4mm hex key? Then you've got this. The guide attaches to your bike's ISCG 05 chain guide tabs, but because it only bolts onto the forward two mounts, you can install it without having to remove your drive-side crank. This is a huge plus for someone who doesn't enjoy, or doesn't feel comfortable, working on their own bike, and it greatly speeds up installation. And, if you have to remove your crank for whatever reason after the guide is on your bike, you can just rotate up or remove the slider rather than having to take the whole thing off.
Before bolting the backplate on, and before installing the slider, use a 4mm hex key to set the height of the slider to match whatever size chain ring you're using. You're doing this now because some chain ring and crank combos can block access to this aluminum bolt once the guide is on the bike. Clock the backplate until the flat edge where the slider is going to sit is horizontal to the ground, and then snug up the two steel, countersunk ISCG 05 mounting bolts to 5Nm.
While most other chain guides ask you to space the entire backplate out from the frame, which can be a finicky, annoying job to get correct, OneUp supplies thin plastic spacers that go between the slider and the backplate. The guide also comes with a nifty little stepped feeler gauge that, by holding it up against the backplate, tells you exactly how many spacers to use to have the slider centered over the chain ring. I mounted the guide onto an older Stumpjumper that has even older SRAM cranks and a Blackspire chain ring and ended up having to use three spacers.
After the guide was installed, I realized that I'd need to raise it up slightly higher than would have been ideal; otherwise the chain ring tabs for the crank would rub on the slider. I was able to fit a 4mm hex key through to reach the adjustment bolt and get it sorted, but the slider did end up sitting a touch high. Performance
The pint-sized OneUp chain guide is obviously not about offering chain ring protection or even adding tension to the chain, rather it's a 35 gram piece of insurance that has no interference on your drivetrain. The slider is wide enough that there was no contact between it and the chain, and the cutout in the side of it allowed crud to escape rather than pile up and possibly cause an issue. The short length of the slider also keeps it from interfering with your bike's chain stay or swingarm, and all of the above makes it pretty much invisible once it's on your bike. In fact, it spent a few months on a test rider's bike, and he actually forgot it was there.
As you've probably guessed, there were no dropped chains while the OneUp guide was on the bike, despite the slider having to sit a bit higher due to it needing to clear the crank's spider. Then again, the bike was already fitted with a clutch-equipped derailleur and a narrow-wide chain ring, and the rider couldn't recall the last time he lost a chain. But, at just 35 grams, there's not really much reason to not keep using the little guide if it doesn't cause any issues. Pinkbike’s Take:
|The OneUp chain guide weighs just 35 grams and costs $45 USD, making it a pretty reasonable component to consider using, and let's not forget that it's basically invisible while doing its job. I'd say that it's the minimum amount of insurance for someone who might be doing a few enduro races, or simply a smart add-on for anyone who would rather not worry about dropping a chain, but also doesn't need full-sized protection. - Mike Levy|
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