You ever heard of ‘Q-factor’? No?! Neither had I!
I’ll start at the beginning; my mate just sent me an email linking these chainrings from U.S.E (remember the ultra light seatposts from the 80’s?)
According to U.S.E. power is everything! Road developed Cranksets with 130 PCD are superior in stiffness and weight to traditional track crank chain sets. Believe the hype!!
Felix English of Team Ireland (ironically!) has tried and tested the USE Chainrings and this is what he has to say
“The new USE Chainrings have made a great difference to the performance of my set up. The increased stiffness through the drive train is really noticeable in getting the power to the track and the chain line and efficiency are also greatly improved.”
Machined from solid 7075 Aluminium, the chainrings are now available in Black, Red, Blue and Gun Metal Grey, and retail at £109.99. Yes, you read that right!!
Now I know how many BCD’s (Bolt centre diameters) there are out there, each discipline seems to have several, I exaggerate, I know, but seriously, common double-chainwheel sets use 130 mm or 110 mm diameters. Modern triple chainwheel sets have two diameters, a large one for the two
outer chainrings, and a smaller diameter, with a separate set of bolts, for the grannyring. Full-size triples usually use 110 mm/74 mm, or 130 mm/74 mm for newer “road triples.” Campagnolo uses 135 mm/74 mm. Compact triples commonly use 94 mm/58 mm. (Data courtesy of Sheldon Brown)
So i did a bit of googling to see if i could find anything to substantiate the claims that a 130BCD has any real benefit over the Track’s choice of 144mmBCD, and that led me here. I couldn’t find any real evidence that supported U.S.E’s claims, but Vomitron’s post caught my eye;
“Track cranks are preferred to road cranks due to the availability of 1/8” “track” chainrings in 144mm BCD. Also, track cranks supposedly have a lower q-factor due not having to accommodate a double/triple. I’m not actually sure if this is true in practice, but it makes sense in theory.
If you realy want 1/8″, you can get your hands on a few 110mm BCD 1/8″ chainrings intended for BMX. I think 110mm BCD cranks are ideal for conversion because they also usually come in shorter lengths and single-speed specific (smaller q-factor?).”
Some interesting points on crank choice, specifically the BMX option, which i had never considered. But “Q-Factor”!? According to Wikipedia (so it must be true!) the Q Factor of a bicycle is the distance between the pedal attachment points on the crank arms, when measured parallel to the bottom bracket axle. It may also be referred to as the “tread” of the crankset. The term was coined by Grant Petersen during his time at Bridgestone Bicycles. Read the full explanation here.
So, like i say, you learn something new everyday!