pcunite

Overview:

• In need of a new carbon wheel set
• Will only install 32mm tires
• Continental Grand Prix 5000 or Gatorskin
• Highway pavement roads

Question:
Since I will only be using 32mm tires, should I go with a carbon rim that has a 25mm inner dimension (32 outer) over a rim that is 21mm inner (28 outer)? I'm comparing the Light Bicycle WR35 to the AR36. Something like the Zip 303, I imagine.

JohnJ80

From what I can tell, the best/optimal external width for a rim is 1.05x the tire width when inflated. Obviously that gets impractical as tires get really wide. But you’ll be better off with the wider internal rims for a 32mm tire. Hunt has a set of wheels that are very well priced that are specifically aimed at wider tires. So does Enve with their 3.4 AR wheels (only not so well priced...).

rubiksoval

This is like saying, I'll either be riding on asphalt or in mud.

Iride01 

Is staying within the tire manufacturers recommendation important to you or are you going for your own set of specs? Perhaps aesthetics and how the tire profile matches the aero shape of your rim?

If you are going for the tire manufacturers recommendation then Continental's general guide for sizing rims and tires says a 32 mm tire should go on a rim that is between 15 and 19 mm internal width. What is it for external is entirely your choice and whether or not you use rim brakes and what range they'll function in if you do have rim brakes.

https://www.continental-tires.com/bi...g-instructions

Open the "Can I mount 28mm wide tires on my road bike? " and there is a chart that includes 32 mm wide tires. Note that the C is for "clinchers"

There is also this .pdf by Continental for mounting their tires on carbon rims. The chart in it shows the same for 32 mm wide tires.

https://blobs.continental-tires.com/...ction-data.pdf

WhyFi

Keep in mind that some of the very wide road wheelsets/rims are hookless and tubeless tire only (though you can put a tube in them) and that Conti tires are not compatible with hookless rims.

Out of curiosity, why 32mm only? With wide rims, 28s are pretty voluminous and allow low pressure/supple ride. I'm on Zipp 303S and 28mm tires and I'm running -/+60psi at ~185 lbs. Did you want/need to go lower?

bampilot06

My superteam carbon wheels are 25 mm wide and I run 32 conti gp 5000 on them.

pcunite

Thank you. That helps me understand better. It is older information, but very useful. I'm leaning towards aesthetics, but wondered what was considered proper and correct for air signature. I'm not a racer, just a curious individual.


I will only buy hooked versions. As far as 32mm only. I can't say for certain, but it seems a nice starting place. Seems popular with some data[1] to back it up. I think I just perceive it to be more comfortable. So, I want to invest in it. About comfort again, do to the higher volume of air in a 32mm tire, the air pressure is lower. This should increases comfort and grip. If I ever went hookless, 32mm might also be best because the standard states that for tires with a max pressure of 80psi there must be a rim hook. 32mm should not ever require such high pressure.


That is the outer dimension. What is the internal? I think it is 17 or 19.



Additional information:


[1] Are wider tires faster?



[2] Wider tires need less pressure. The ETRTO max pressure for hookless rims is 73psi.