Karoo 2 Coast - tyres

[Manx Man]

Hi Hubbers,

Got two pairs of Rekon Race - 2,35 and 2,40 - what's my best option for this race, and what pressures do people run? Or do I need narrower than 2,35?

Riding a dual suspension.

Thanks!

Manxman

[Murrob]

I’d probably go for 2.35 just as they may be a smidge lighter. 
 
Tyre pressure - check the SRAM link, put in your values and it will kick out a result https://axs.sram.com/guides/tire/pressure

M 

[HdB]

I did it last year with 2,2s front and rear (all I could find at short notice), on a hardtail, and it was fine. Probably going to use the same tyres this year, they still look ok.
I do have two new Recon Race 2,4s, which would probably be a smidge more comfortable on the rough parts.

As for pressure, I will have to check one of the calculators. Again. I can never remember, should probably write it down...

[Titleist]

I did it last year on a gravel bike with 40C's. I got a lot of proper free massages.

On 2.35, which is overkill for this race, you can easily go down to 1.8bar.

 

[Super Sywurm]

I am doing it on a hardtail, worn 2.4" Recon Races, front and rear.  I only ride 2.4" tyres on my hardtail

 

 

 

 

Edit:  I'm lying, the rear is 2.35.  Could not find a 2.4" quickly enough,  after destroying my rear tyre

Edited September 11, 2025 by Super Sywurm

[MORNE]

Ive done it on a fully rigid steel mtb on 2.6 rubber. 
 

Just ride your damn bike and enjoy the moment😅  You’re fretting over less than 2mm for a fun race.

Edited September 11, 2025 by MORNE

[Manx Man]

19 hours ago, MORNE said:

Ive done it on a fully rigid steel mtb on 2.6 rubber. 
 

Just ride your damn bike and enjoy the moment😅  You’re fretting over less than 2mm for a fun race.

Thanks for that useful response ..... I have a bike with no tyres on at the moment.

 

[RynoB]

Go 2.4 in the front and 2.35 in the rear. Depending on your weight, go 24 to 26 psi.

[MORNE]

2 hours ago, Manx Man said:

Thanks for that useful response ..... I have a bike with no tyres on at the moment.

 

Well if you really want to get that technical..what is your rim width? Because that will also determine relative rolling speed between the two sizes. A 2.35 tyre on a 30mm ID rim MIGHT square up just a tad too much and therefore provide more tread contact on the ground…and therefore more rolling resistance. The 2.3 minion SS was s perfect example of this.
A 2.4 or wider on a narrow rim..say 25mm ID will be more rounded…and run on the centre thread more…and so offer less rolling resistance depending on tread pattern.  
 

More volume = more comfort, less hangup over small bumps. less hangup on all the junk means you’ll also roll faster. Lots of variables to consider other than just thinner = faster. Then Maxxis tyres are so inconsistent size wise..i doubt there is any real difference between 2.4 and 2.35. Or maybe the 2.4 is closer to s 2.3 and the 2.3 is more like a 2.1. Thebonly Rekon i remember running close to size on a 30mm rim was the 2.6.
 

if speed and semi comfort is your goal…other than just absorbing the scenery and having jol….get 50c gravel tyres. They’ll make you mtb feel like a rocketship and offer SOME comfort.
 

if not. Just get whatever is cheaper. 2.35/2.4….it wont matter.

Edited September 12, 2025 by MORNE

[JohanDiv]

I did 4h10m @93kg on a dual suspension with 2.4 Maxxis Aspens on South Industries XC rims. 1,8bar back and 1,5bar front and bombed it on the downhills. If I was actually in shape that setup would've taken me sub 4 with ease.

Edited September 12, 2025 by JohanDiv

[Reinhardt56]

I've bought a Gravel bike. Now I'm wondering what do you guys the quickest, Gravel with 45's on or my Scott RC with 2.4's. Last your I've just missed the 4h00 mark, but want to get a sub 4. Thos downhills are bit ruff, and a MTB will be quicker, but the straights, the gravel? Funny I couldn.t really remember how many flat gravel pieces there were??

I know I know its overthinking and its a fun race, but still want to get the best time....

[Super Sywurm]

13 minutes ago, Reinhardt56 said:

I've bought a Gravel bike. Now I'm wondering what do you guys the quickest, Gravel with 45's on or my Scott RC with 2.4's. Last your I've just missed the 4h00 mark, but want to get a sub 4. Thos downhills are bit ruff, and a MTB will be quicker, but the straights, the gravel? Funny I couldn.t really remember how many flat gravel pieces there were??

I know I know its overthinking and its a fun race, but still want to get the best time....

What I would do in your situation:  If I already did it on the mtb, it's time for the gravel bike.

[sias]

15 hours ago, Reinhardt56 said:

I've bought a Gravel bike. Now I'm wondering what do you guys the quickest, Gravel with 45's on or my Scott RC with 2.4's. Last your I've just missed the 4h00 mark, but want to get a sub 4. Thos downhills are bit ruff, and a MTB will be quicker, but the straights, the gravel? Funny I couldn.t really remember how many flat gravel pieces there were??

I know I know its overthinking and its a fun race, but still want to get the best time....

I did a 3H51 with a Vipa with 2.2 tyres. This year it's a SuperCal with 2.4 Rekon Race front and 2.25 rear. And a few extra cm around the middle. 

I'd take the RC and just give it stick!

NS - Has anyone got their race number e-mails yet?

 

ALLOCATION OF RACE NUMBER AND SEEDING

ALLOCATION OF RACE NUMBER AND SEEDING

 

Seeding will be done in the first ten days of September 2025 and riders will be sent their race numbers via email by 15 September. Seeding will be done by Cape Town Cycle Tour Trust, based on past results.

Edited September 16, 2025 by sias

[HdB]

30 minutes ago, sias said:

 

NS - Has anyone got their race number e-mails yet?

 

ALLOCATION OF RACE NUMBER AND SEEDING

ALLOCATION OF RACE NUMBER AND SEEDING

 

Seeding will be done in the first ten days of September 2025 and riders will be sent their race numbers via email by 15 September. Seeding will be done by Cape Town Cycle Tour Trust, based on past results.

On the book of faces, their post mentions the emails will be sent from 8am

[Reinhardt56]

Why the Scott Spark RC 900 is Faster for K2C

• Terrain Match: K2C's early climbs (~1,560m total gain) reward efficient pedaling, but the technical descents (rutted, rocky, loose gravel) and variable surfaces (dirt roads, singletrack-like sections) expose rigid gravel bikes like the Revolt. The Spark's 120mm full suspension with TwinLoc (lockout for climbs, traction mode for loose terrain) provides better absorption and control, maintaining speed where the Revolt would bounce and slow (e.g., 10-20% time savings on the ~50km of descent). Reviews praise the Spark as a "winningest XC bike" with "aggressive race geometry" that excels on courses like K2C, where Nino Schurter-style efficiency shines. The Revolt is lauded as a "versatile gravel shredder" for smoother events but lacks suspension for K2C's "gnarlier terrain."
• Climbing and Efficiency: Both are climbers, but the Spark's integrated shock and lockout system make it "positively fast uphill" with minimal bob, rivaling the Revolt's rigid efficiency while adding rear compliance for the 10% Prince Alfred's Pass. Its 1x drivetrain and wide cassette offer easier low gears for steep pitches. The Revolt's GRX 2x is precise for gravel but feels less planted on rocky ascents without suspension. In XC race tests, the Spark "rockets to the top" and handles "progressive geometry" for K2C's demands.
• Descent and Control: This is where the Spark dominates—its slacker head angle (67.5°) and MTB tires provide stability on fast, technical drops, reducing fatigue over 96km. The Revolt's rigid setup and gravel geometry work for fire roads but can feel "twitchy" or harsh on ruts/rocks, leading to slower lines and more energy loss. K2C participants often recommend full-sus MTBs like the Spark for the "enough chops for the ride back down" without enduro excess.
• Expert Recommendations and Precedents: For 2025 K2C, MTBs like the Spark RC series are favored in the open category for their race pedigree (e.g., World Cup wins), while gravel bikes like the Revolt win in the dedicated gravel class but trail overall times by minutes on technical routes. Reviews highlight the Spark as an "XC speedster" for events with climbs and descents, and no direct comparisons favor the Revolt over it for MTB-gravel hybrids like K2C. The Revolt tops "best gravel bike" lists for 2025 but is positioned for "gravel racing" on less aggressive terrain.

Why Not the Giant Revolt?

The Revolt is a top-tier gravel bike—light, compliant via D-Fuse tech, and adjustable (flip chip for 53mm tires)—but it's optimized for faster, smoother gravel (e.g., Unbound-style events), not K2C's MTB-level roughness. Without suspension, it transmits more vibrations on rocks/ruts, potentially costing time and comfort. It's ideal if you're in the gravel category or prioritize weight, but for overall speed, it underperforms vs. full-sus options like the Spark.

Final Advice

Opt for the Scott Spark RC 900 (or SL variant for lighter weight) for the fastest K2C time—equip it with 2.25" semi-knobby tires (e.g., Maxxis Rekon), lockout-focused setup, and a dropper post if allowed. It's a proven XC racer that matches the route's demands. If you're gravel-focused or want lighter weight for climbs, the Revolt is still competitive in its category. Test ride both if possible, and check post-race results (after Sept 21) for validations. If you meant a different Spark model or have rider specifics (e.g., weight, skill), provide details for tweaks!

 

  Ekt vir Grok gevra, en die ou ken sy stuff!!

[PappaWatTrap]

Grok seems to be aligned with some of the comments I've heard from friends. 

A friend of mine has done it on a duel suspension and a gravel bike, without a doubt the duel suspension wins. You might see a marginal gain on the flat sections but the overall discomfort on the gravel bike might not be worth the marginal gain. The first climb and downhill section is really rocky. 

I've had a few moments in the race where I would pass my buddies up the hills on my hardtail for them just to fly past me down the other side.