Changing tires for race day

Tally Ho

Got an XC race coming up that's 30Km long, 1/2 of which is on fast hardpack singletrack (rocky in places), the other 1/2 on tarmac including some short and steep hills. My question is this, I'm running front and back UST Tubeless racing ralphs 2.1 (26er) on a hard tail, and considering switching both just for the race day to some 2.1 crossmarks with tubes that I've got spare. I'm hoping for 2 things if I do this:

1. A little less weight than the UST Ralphs and the performance enhancement from that.
2. Less rolling resistance on the tarmac and hardpack from the Crossmarks than the Racing Ralphs, therefore faster and more energy efficient.

I'm not worried about the puncture protection as the course is an easy one technically (in Hong Kong) and without thorns. I'm also willing to accept a little less cornering grip, and rear tire bite from the crossmarks if they are noticably faster on the straights. Any advice/suggestions on the above would be appreciated. If the change would not make a noticable difference then I'll just leave the UST Racing Ralphs on. But my suspicion is that the crossmarks will be faster on the tarmac in particular.

Thanks.

rockmonkeysc

Check out the course on race day and fit tyres to suit. If it's wet don't forget that even if it still looks solid it could get churned up very quickly.

The Rookie

For fast rolling on tarmac and hardpack DRY surfaces the Michelin Dry Mountains 2's are just about unbeatable, come in at a not too heavy 620g as well.

njee20

Sod that! That's 150g heavier than a (non-UST) Racing Ralph!

Furious Fred would be my tyre of choice for that sort of terrain, 300g each.

If you're used to the Ralphs, use those. If you know how the Crossmarks perform I'd be changing them, and aiming to run them tubeless to save a bit more weight over the Ralphs.

Monty Dog

You'll probably lose more in rolling resistance by switching to tubes than you will gain by fitting a lighter tyre. Running tubeless with sealant gives you the benefit of improved puncture protection too.

Tally Ho

Thanks for all the good advice, work stuff meant I did not have much free time to experiment or faff, so decided to go with the crossmarks and tubes. I gave them a spin tonight on the road, they seem faster rolling for sure, at least on the road. I think its that centre tread that's almost continuous that contributes to making them fly in dry hard pak or road. Feels like a good choice for Saturday's race, they'll suit this course well as the steep hilly bits are all on the road part, the off road singletrack is twisty but reasonably flat so all should be good.

Wish me luck! Thanks.

rockmonkeysc

The Rookie wrote:

For fast rolling on tarmac and hardpack DRY surfaces the Michelin Dry Mountains 2's are just about unbeatable, come in at a not too heavy 620g as well.

Thats as heavy as my 2.2" Rubber Queens.

WindyG

Why not run the crossmark tubeless, I have one tubeless on the rear of my Anthem without any problems i'll only change it when the when it can't cope with the weather conditions.

Tally Ho

@WindyG, only because of time constraints to do the fitting before the race, otherwise that would have been a good option. Given more time I would have also taken njee20"s suggestion and put on some Furious Fred's, but I could not find anyone in Hong Kong who stocked them, and ordering online would not have arrived in time.

Greer_

UST tyre?! I ran racing ralph evos for a while last year (standard sdidewall) and they were grand! Trying out rocket rons at the moment! No need for UST options IMO though, I don't see the need for them and they're too heavy!