Donnelly X’Plor MSO 650Bx50 Tubeless Ready Clincher Tyre Review by Tim Taylor

Donnelly X’Plor MSO 650Bx50 Tubeless Ready Clincher Tyre Review by Tim Taylor

With the sun yet to rise over the Derwent River in Tasmania, Australia, I had already started the mammoth task. I had embarked on an Audax Super Series, a GT series for short. For those readers who are unfamiliar with what a Super Series is exactly, it comprises of four rides in a week: a 200 km, 300 km, 400 km and finally a 600 km ride. The GT series being held in Tasmania included the extra challenge of climbing. For the total series I climbed roughly 17,000 metres.

The tyre I chose for this task was the Donnelly X’Plor MSO 650Bx50 Tubeless Ready Clincher. Why? They were recommended to me by a friend whose opinion I value highly. It was the first time in my 10 year endurance cycling career I was running the 650B wheel size.

 close up Donnelly X’Plor MSO 650Bx50

The tyres were mounted to DT Swiss FR560 rims which I built into a Shutter Precision Dynamo front hub, the rear hub was a Chris King. I use Stan's No Tubes rim tape, wrapped twice and WTB valves. At 35 PSI the X’Plor MSO measured 55mm.

The tyres mounted without any need for tyre levers, fuss, worry or problems whatsoever. Simple, straight forward. I used a Blackburn Chamber Tubeless Pump to inflate and seat the bead. No problems. Then finally filled with Orange Seal EnduranceSsealant. Tubeless setup as it should be: simple.

It become apparent very early on that these tyres don’t like high pressure. By high pressure I mean in excess of 40 PSI which is well under the sidewall recommend range of 35 PSI–55 PSI. I am a fairly large gentleman weighing in around 100kg, so can never run tyres at super low pressure for fear of bottoming out the rim. After a few trials I found the sweet spot for the X’Plor MSO tyres to be 35 PSI in the rear and 30 PSI in the front. For the GT series I was carrying extra gear such as thermal top, rain jacket and extra food and water which added 5kg to the bike weight for a total of approximately 15kg. If I wasn’t carrying the extra gear I would be comfortable to drop another five out of the front and rear to run 25 PSI in the front and 30 PSI in the rear.

Kevin Gravel Bike

Once that air has been let out, they are comfy. On the rough bitumen roads I smiled and wondered how I have ridden the kilometres I have without these tyres or wheel size. There was no jarring or discomfort felt in the hands through the handlebars. By the end of the series I had no issues ie: numb hands or fingers A lot can be said for the bike (Curve Cycling GXR – Kevin of Steel) and setup/posture as well. The tyres provided a comfortable ride but not so comfortable as to give you the feeling of being delicate. Instead they give you a feeling of confidence and reliability.

On gravel, which I only found a few times, they did everything I asked of them. Cornering, tick; fast downhill, tick; fun, tick. As the gravel wasn’t particularly rocky, instead more hard packed dirt road, a 32mm road tyre would have been fine. But they oozed confidence and willed you to take them further off into the wilderness.

These tyres suited my riding style, ticking along between 25km/h and 30km/h. Anything in the high thirties I found they were hard work to keep that pace and also a tad noisy. Not so noisy as to be annoying – more a low murmur. The longest I cycled with minimal breaks was a tad under 40 hours on the 600km. The road noise/buzz by the end was not noticeable or that could be the fact I had become accustomed to their sound. I found that with the loaded weight and if I stayed within the lower end of the recommended pressure range, they were pretty flawless and met expectations.

The GT series was completed successfully. The tyres looked like they hadn’t been ridden, other than the rear showing some signs of wear –1,700 km later. 

Donnelly X’Plor MSO 650Bx50 tread pattern

Since finishing the series, I have managed to put a 25mm slash in the rear tyre, which required a tube as the slash was too large for the sealant to seal. Looking at the slash, any tyre of this nature would have succumbed to whatever I cycled over. A Schwalbe Marathon Plus type touring tyre would have stood a much better chance. For purely road riding I wouldn’t mind trying a more road orientated, slick tyre to see what differences there would be and have something to compare them with.


For versatility, where one day you are riding all road, next you are tackling gravel, these tyres are a tick. Remember, lower pressure is what I found to be key.

About the author:

I have been cycling for the past 10 years. In that time, I have cycled in excess of 100,000 km. 70,000 km of that has been Audax/Randonneuring. The biggest undertaking has been a 4 month, 11,000 km cycling trip in 2018 combining the 2016 Race To The Rock route, 2017 Race To The Rock route and the Indian Pacific Wheel Race route across Australia.

Disclaimer: I am not sponsored by any person or company.

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