GENETIC TIBIA TRACK CRANKS & CHAIN RING
(42 tooth 165mm, as tested) £99.98
The Genetic Tibia Track cranks are a nicely executed mid-point option for track, and indeed road biased fixed gear/single speed, or hub geared builds. Rigidity, standards of finish are on par with more expensive track cranks I’ve used, in the long term. On the flip side, they might be a touch too pretty for a workhorse. Especially one that spends several hours a day, tethered to street furniture.
Pros: Affordable, nicely made and finished, sensible choice of arm lengths, 144BCD.
Cons: Too pretty for a more traditional hack/commuter.
The Tibia are a five-arm model, available in a choice of polished, or black anodised finishes, and three different lengths-165mm, 170 and 175mm. Catering for most tastes, and leg lengths. Designed for JIS (Japanese Industry Standard) rather than ISO bottom bracket tapers, if mated to the latter, they’ll throw chainline slightly out, so you’ll need a compatible bottom bracket (or the Halo Fixed-G Track Hub ).
The arms are made from “warm” forged 6061 T6 aluminium alloy. The reverse is sandblasted, rather than shot-peened. This is for cosmetic purposes. Polished components generally age better than their painted, or coloured counterparts. Nonetheless, standards of finish here are high, even behind the spider.
144BCD (Bolt Circle Diameter) means there’s plenty of choice, rings-wise, too. TA, Campagnolo and others will fit. Assuming of course, you didn’t fancy the Tibia rings.
These were an obvious choice, and Ison-Distribution generously sent me a colour-co-ordinated, 42tooth version. Red, or gold, and 47 teeth, are the alternatives. Genetic also offer a lightweight Karyotype JIS option, if the Plain Jane Cartridge types are too heavy, dare I say ordinary, for your tastes.
In some respects, my Holdsworth TT build might’ve been a more obvious candidate. However, my fixed gear winter/trainer racks up considerably more miles - in all weathers. It has a 110mm Shimano UN55 cartridge bottom bracket, which remains in rude health. Besides, I wanted to keep the build as constant as possible, to make fair comparisons between these, and the System EX.
165mm arms sound an odd choice, given my 33.5 inch inseam and the bike’s lofty 11.5 inch bottom bracket height. Fourteen years back, the stock build had 175mm cranks, which still offered a reasonable amount of ground clearance.
I’d then gone to System EX Track Crankset, with 170mm arms, which has been in place for several seasons. These had formed an unexpectedly firm bond with the UN55’s tapers, requiring a liberal helping of penetrant spray and claiming my twenty-nine year old extractor tool!
JIS & ISO Explained
JIS (Japanese Industry Standard) and European ISO square taper bottom brackets appear identical. However, the ISO are slightly longer, tapering down to a smaller end than their JIS counterparts. Both will be of identical length e.g. 107mm JIS =107 ISO, 110 ISO=110 JIS. The chainline will also be identical.
However, mating an ISO chainset to a JIS bottom bracket will decrease your bottom bracket with by 4mm. So, in this instance you would need to use a 103mm (rather than 107mm) axle. Fitting a JIS chainset to an ISO bottom bracket, will increase the width by 4mm. Therefore, you’d want a 110mm (rather than 107) axle to correct chainline.
Since we’re here, taper matching used to be a big deal. However, I’m assured all contemporary chainsets (regardless whether ISO or JIS) will marry just fine. You’ll just need to correct the chainline.
Exorcism complete, the Genetic Tibia slid straight home.
There is an argument that shorter arms reduce joint stress. Knees and hips, specifically. Got to be a good thing. 42 ring, 15 sprocket translates as a joint friendly, road practical 76.1 inches.
Shorter cranks tend to induce a higher cadence, something that was quite apparent during the formative rides. Any change of contact point/components feels different. Compared with the more traditional System EX, the Tibia’s arms felt noticeably stiffer, much closer to the Stronglight Track 2000, fitted to my Holdsworth, giving the bike a racier, more responsive persona.
This was particularly apparent, when accelerating away from the lights, or climbing out of the saddle. I run a 110mm axle, on this build, wider than a supposedly Q-factor optimal 107mm. Given the bike’s persona, I’ve always felt more comfortable with a little extra-leeway between arms and chainstays.
In practical terms, I’ve not noticed any difference, no doubt helped by the Halo fixed-G’s adjustability and therefore perfect chainline. Several weeks and 500 miles later, I’ve cruised along the flat at a higher than typical tempo and felt a deeper connection with the bike on longer, 50-mile outings.
Given the machine’s bottom bracket height, this combo encouraged more spirited cornering. Aside from the obvious S bends and roundabouts, it gave better scope for tackling forest trails (although a 63inch gear is a much better option, if you’re thinking singlespeed cross/gravel).
The 7075, 42 tooth Tibia rings are nicely executed. Exchanging it for the Stronglight 2000 confirmed my suspicions that lateral stiffness was good, rather than great.
Something I attribute to the Stronglight’s deeper section. Hardly a deal breaker, since 144 BCD is a very popular pattern and well catered for. 80 kilos plus, I’d buy the Genetic Tibia cranks and slot another ring straight home.
Polished components always age more gracefully than their painted, or anodised counterparts. However, Genetic’s standard of finish has always impressed me and the Tibia are no exception. No sign of swirling, or similar light abrasion, along the arms, in 500 miles.
These have also been struck by rogue stones and similar detritus, with not so much as a scratch. The polished option is welcomed and would be my first choice for four seasons service.
Talking of which, the electroplated OEM ring bolts succumbed to some superficial taint, after a week’s wet riding, along coastal roads. Mildly annoying but easily arrested with a drop of wet lube, or Green Oil Eco Spray Lube.
Decent quality square taper cranks remain more prevalent within fixed/track circles. £59.99 for the cranks and £39.99 for the rings (nigh on £100) is somewhere around the midpoint. Stronglight’s venerable Track 2000 retails at £99.99 for the arms alone, so, the best part of £160 for a comparable setup. Deeper pockets? 130 BCD? Gran Compe might be worth a look .
The Genetic Tibia are a nicely executed mid-range crankset, for track, TT and pretty, fixed gear road bikes. There’s scope for hub gear projects too. I’ve really enjoyed testing them and they’ve brought some extra pizazz to my mile munching winter/trainer.
Some have suggested the choice of Tibia rings is a little narrow. I can see their point, but 144 BCD means you’re spoilt for choice. By no means whippy, I’d suggest powerfully built track/time trialists, plump for a beefier ring.
Genetic’s standard of finish seems very good across the board. (These chain tugs still look very good, a decade down the line).
However, for a commuter/hack, I’d be inclined towards something like System EX track crankset. Its less “bling” and cheaper. A complete bundle, (including bottom bracket, chain and bargain basement sprocket) will give change from £100.