Sorry, I came in late, so some of this may have been covered
- over a 10 mile race you are highly unlikely to see any tangible difference in speed/time over the wheels you currently have. There is a good possibility you could be slower due to handling, as was previously mentioned
Here are some things to consider that may not have been mentioned (all of these assume your position is optimum)
- Drive train friction- this can be a very big factor, especially for a smaller, less total wattage rider. The difference between a dirty chain and a clean chain with a good Lube can be 15 watts or more. That can easily be 10% or more of available power. Main sure your drive chain is super clean, than pick up one of the many 5 watt or less lubricants as noted by Friction Facts, or more recently ceramic speed. This will save you money, increase your drive train component life AND make you faster :-) My Lube of choice is Lilly Lube for its ultra low friction properties, ease of application and low cost. The overwhelming choice of ST nerds is wax.
- tires and tubes- your choice here, for a wheel set, and gain you or lose you another 15 watts +/-. Without any doubt the best tube choice is latex, they are actually easy to install if you know how to do it correctly- pm if you want details, and a nightmare to install if you don’t know what you are doing. For tires go to
http://www.bicyclerollingresistance.com and pick the flavor you like!
Those are by far the 2 biggest performance considerations. In regard to wheels, with little or no wind, or dead head or tail wind, wheels make very little difference. The more wind and bigger the wind angle the more you benefit from race wheels, assuming you know how to handle the bike with them on.
One last big issue with renting wheels is your brake pads. You will likely be getting carbon rims, and if you do not have the correct brake pads, which you probably don’t, it can be dangerous. I saw a guy crash out from top 10 late in an Ironman because his rims overheated due to wrong brake pads on rented wheels. Don’t do that!
Clean your chain, get good race tires and latex tubes, and have fun!