So, I own a Cube Reaction TM 2018 with 27,5'' wheels and I would love to use 29'' wheels to upgrade my bike.

But I can't find any information, if 29'' wheels would fit in the frame or the fork. I often read, that 29 inch wheels also fit in 27,5+ sized bikes.
But...before I invest money just to try it, I wanted to ask, if someone has more information than me. Thanks in advance! enter image description here

1 Answer 1


There are two problems with such operation: clearance and geometry. For the clearance, simply measuring if there's enough space is sufficient, but it's not worth it as geometry is actually the problem. Geometry has an impact on how your bike handles, and it's not recommended to go too far off spec.

The underlying between idea behind fitting 29" wheels in bikes with 27.5"+ wheels is that the outer diameter is the similar enough: the taller tires compensating for the smaller rim), and so geometry is not impacted so much. Such bikes are usually also sold as such, and have a geometry that designed takes these two configurations into consideration.

With a regular 27.5" bike, as the one pictured in the question, it's different. The difference in diameter between a 27.5" rim and a 29" one is 38mm (looking at the bead diameter, which is not the rim outer diameter, but to compute the difference, it's OK). I don't really know the relation between the height of a tire and its width, but it's likely that if you want to that, you'll have to install cyclocross tires (33mm) on your 29" rim - which is technically possible because 29ers have the same rim diameter as road/gravel/cyclocross tires. But it won't be a good idea.


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