How wide is wide for mountain bike rims? We're set up to test 3 wheels with 3 different internal rim widths to find out.
Words: Ben Morrison
Photos: Nick Waygood
The question about how wide is too wide and how narrow is too narrow is one that has plagued mankind since the dawn of creation... well in the case of mountain bike wheels this is perhaps a more recent question, that has for the older readers out there almost come full circle if you remember the days of the Sun Double Wides and Sun Mammoth Fat rims of the late 90s.
With tyre development and rim development now becoming more hand in hand than ever before we are seeing tyres specifically being made for the now more trendy wider rims. Because of this we decided to perform our own set of tests to find a bit of balance in this world of standards and trends we call mountain biking.
In order to do this, we partnered with DT Swiss who supplied us with their 3 most popular selling rim widths hand built to DT Swiss 350 hubs. So we had the XM 481, XM 421 and the XR 361 rims. Hubs and spokes were the same. Dt Swiss have done a lot of work developing the right rims and wheels for moountain biking, and they truly feel we should all 'Go Wide'. The idea is that a wider rim allows better support for a tyre and greater internal volume which should allow for lower pressure without more sidewall squirm.
On the side of tyres Onza supplied us with their IBEX in 27.5 x 2.4" in their FR trail casing.
For the duration of the test we will be using the same size tyres and model on all rim widths and to help with setting up a baseline for our test we will be using the same Rocky Mountain Altitude fitted with a Shock Wiz across 3 trails all of which offer different conditions.
The interest and excitement with tests like this are not just confined to AMB staff with many readers chiming in on social media asking questions as things progress with even the likes of experienced and highly talented riders like Chris Kovarik chiming in to offer advice!
Don't miss the feature in our next issue - we'll have a test of the carbon DT Swiss XMC 1200 super wheels coming soon too.