650B Rims weight

[jambee]

I was looking at 650B rims and realised that their weight is very similar to their 700c models.

Example: WTB KOM i25 weights 438 grams in the 650B variant and 465 grams in the 700C model.

Velocity Aileron for both sizes is around 460 grams.

It seems odd to me since 650B rims should be smaller and hence require less material. I dug further and found that DT Swiss for example has the XR 331 which weights only 340 grams.

Does anyone know why there are such minor differences in weights in the above examples? Is there a risk in riding these super light DT swiss and the likes?

[sandyrs]

I know this is highly oversimplified but the 650b wheel size (584) is 6% or so smaller than 700c (622). That's about the same as the weight difference between the WTB rim sizes. I wouldn't expect a 650b wheel with the same profile to be more than a few dozen grams lighter than its 700c counterpart.

The super light weight of some rims is due to differences in rim profile, not just wheel size.

[PacNW2Ford]

According to the Velocity site, the Aileron weights are:
650b = 445g
700c = 460g
Not quite 6%, but samples can vary as the extrusion dies wear.

[oldpotatoe]

I was looking at 650B rims and realised that their weight is very similar to their 700c models.

Example: WTB KOM i25 weights 438 grams in the 650B variant and 465 grams in the 700C model.

Velocity Aileron for both sizes is around 460 grams.

It seems odd to me since 650B rims should be smaller and hence require less material. I dug further and found that DT Swiss for example has the XR 331 which weights only 340 grams.

Does anyone know why there are such minor differences in weights in the above examples? Is there a risk in riding these super light DT swiss and the likes?

The weight ? answered but light rim? No such thing as a free lunch and 340 grams for this disc specific rim is light. Use enough and proper spokes, not be tough on stuff and ride thinking light thoughts and these 'may' be ok. But, add 100 grams or so to a rim(6 ounces for a wheelSET) and gain reliability without really any downside.