I have a big TT coming up. It’s an out and back course with some sharp climbs at 9%. It’s 15km with 240vm. I’m not a strong climber and love low cadence but on the flip side I can descend like a stone. I’ve been testing the course on rouvy. My tacx smart bike is set up with a virtual gear ratio of 53-36 x 11-32. I’m climbing the hills in the 53x28 and spinning out on the down hills in the 53x10 combination.
My real bike is ultegra 11 speed 52-36 x 11-36. I’ve don’t the maths putting a 59 tooth chain ring on the front would equal the range of the virtual bike. Rotor sells a 58-44 chain ring kit for just over au$200.
Here is the question what will be the fastest upgrade option?
A: upgrade to the bigger rings
B: rent a disc rear wheel. Just under $200. The bike currently has a 60 or 80mm deep rear wheel (I can’t remember)
C: getting some conti TT tires, upgrading from GP5000 S TR. about $230 for the pair.
Thanks for your input
Add a new chain into the cost of the chain rings. Plus you have to adjust the front derailleur for the bigger chain, and hope that the derailleur mount allows the derailleur to high enough. And this setup only will help with chain alignment and going faster downhill, assuming you are spinning out on your 52/36. Just doesn’t seem like the best option.
I’ll let others opine on the savings of the disc vs 60/80 rear wheel, but they’re probably close. Then it come down to practical matters. Does the course tend to get cross winds? Avoid the disc. Is the tarmac buttery smooth? Or is it pretty rough? That would impact my decision on whether or not to do with TT tires. But in the end, tires are a wear item so that $200 has to be spent at some point. If you can reuse the existing tires on another bike, the TT tire upgrade makes the most sense financially.
Have you been able to test the real-world course? I’m wondering if spinning out on descents on Rouvy is something that would happen in real life. If not, that would point toward tires. Also, can you adjust the virtual gear combo for Rouvy to test the delta between the gains of pedaling on a descent with a larger chainring versus spinning? That would give you some idea of what the benefit of the bigger ring is. As Jeff mentioned, you’ll also need that new chain.
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No I haven’t been able to ride it in real life its’s an 8 hour drive away. But I am wishing for bigger gears on local TT course with less steep hills.
Looking on Google street view the road surface looked good in 2021 when the images were taken. And a section has gone from gravel to tarmac in the last 2 years.
The course looks very sheltered with tree windbreaks or forest most of the way. I’m a big dude so cross winds do worry me to much.
I might try matching the gear ratios in my next training session and see what the difference is.