Clutch ISCG Chain Guide Adaptor

The not-so-minor details


Cluch ISCG Chain Guide Adaptor


Clutch MTB Solutions




It works. The best way we have found to get a full chain guide on a press fit bottom bracket frame.


Tight installation and will leave a few marks on the bottom bracket shell.

Flow recently received the Clutch ISCG Chain Guide Adaptor to test.  The simple outcome from the testing is that it works, and works really well.

The introduction of pressfit bottom brackets without ISCG tabs on certain Giant bikes has been an issue for many riders. This design oversight does have an impact on rider experience and chain security problems.  The introduction of Shimano Shadow Plus and SRAM Type 2 derailleurs has alleviated this issue somewhat however full chain security was still an issue. [private]

Enter the Clutch adaptor.

The Clutch ISCG Chain Guide Adaptor is designed specifically for Giant mountain bikes which use pressfit bottom brackets and is important as it enables a full chain guide to be used. Without the adaptor, only a top-guide-only chain device can be used, however for some riding and rough conditions a top-guide-only isn’t enough chain security.

The adaptor currently fits Giant 1×10 set-ups for: Reign, Anthem, Anthem-X 29″, Trance-X 26″ and 29″.  We installed the adaptor to a 2012 Giant Reign with a 38-tooth front chainring and an e*thirteen TRS+ chain device.

Our test bike set-up.

Installation of the adaptor only took around 5 minutes at most.  It was a simple process of removing the cranks, inserting the adaptor over the bottom bracket shell, aligning as per directions, and tightening the pinch bolt to 5NM.  The only hassle we had was the need to jam a lever into the adaptor to spread the opening wide enough to fit over the bottom bracket shell – it’s a very tight fit.

The Clutch in action.  It simply fits over the bottom bracket shell.

The installation and interface with the e*thriteen was a little fiddly and took a bit longer, however installation of any chain device on any bike can me problematic at the best of times.  Flow did not choose to use a chain device with a bashguard as we rarely hit our chainrings and have been without for years with little problems.

We did not tighten the pinch bolt more than the 5NM as recommended and it did not move.

Out on the trails the adaptor held the chain device in place with no problems noted. We did not get any chain device movement and knocks and bottoming out on the bottom roller did not induce any movement of the adaptor or chain device.

In our First Bite Gaby Mayo suggest we: ‘Also, once installed, lay a 2×4 on the chain guide & whack it with a hammer’.  Whilst we wouldn’t normally do such non real-world testing we thought it prudent given the scepticism the adaptor has received.  So, in the sprit of good testing, we did just that – gave it a good whack on the bottom roller.  The whacks started getting harder and harder and still there was no movement.  Only under a very huge eye-squinting whack did it move ever so factionally.

It’s important to remember that this adaptor replaces the previous top-guide-only option and the amount of force applied in our “whack” test would have certainly moved a top guide much, much more – if not broken it.

Flow has found the adaptor to be an excellent product that is simple to install and worked very well.  No problems were noted on the trails the our chain security on our test bike has been fixed.  For only $40 dollars we think it’s a very worthy investment.

There were several other questions asked of the adaptor in our First Bite and lucky for you a representative from Clutch MTB did jump online and answer your questions.

At the moment the adaptor is designed and tested on Giant bikes only however it may work on other frames.  Also, it should not be installed on carbon fames.

Tolerances are very tight hence why the current adaptor is designed for one bike suspension design.






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