Complex sentence: However this increases the risk of the rim' bottoming out on the ground, although this is little a problem as tubulars cannot pinchflat thus the only concern is damage to the rim.
Split into simpler sentences: However this increases the risk of the rim' bottoming out on the ground. On the other hand, with a tubular set up, this not a problem as they cannot pinchflat thus the only concern is damage to the rim.