Its deep-section, black-finished chainring makes this Lasco track chainset look similar to a Sugino Messenger, which is three times the price.
Like the Sugino, the Lasco has forged aluminium arms and is designed to fit a 103mm width JIS-type bottom bracket.
JIS is the Japanese square-taper standard used by Shimano and most Sugino chainsets. The alternative is ISO (Campagnolo, Miche, TA) and it’s incompatible, sort of.
An ISO crank will sit about 4.5mm further out on a JIS spindle, while a JIS crank will slide about 4.5mm further in on an ISO spindle. If you can get the chainline right, you can still mix and match.
This talk of tapers is moot because the tapers on these Lasco cranks were off. The cranks should have fitted perfectly on our 103mm JIS bottom bracket, but in fact the right-hand crank sat about 2mm proud and the left about 4mm proud, much like an ISO crank would be.
As we still managed to get a decent chainline, the only real problem with this was having the pedals about 6mm further apart – a wider Q-factor. Fixed-wheel time-triallists will be bothered by this, though commuters probably won’t.
While the careless taper tolerances mark the Lasco as a budget chainset, it’s otherwise decent. It looks the part and there was no detectable crank flex.
The bolt circle diameter is 130mm. It’s available with 165mm crank arms for 1/8in chains, in 44 or 48-tooth models, or 170mm for 3/32in chains in a 48T model. The 165mm/48T set we tested weighed 716g.