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Wednesday, March 30, 2011

EighthInch Splined Tubular Chromoly Cranks Tested - Off Road Fixed Gear

As seen on the Fixed Gear Gallery - http://www.fixedgeargallery.com/reviews/eighthinchcranks/index.htm


Reviewed by:  Bill Blandford (Elkridge, MD)



  • Age:  39

  • Height: 6'4"

  • Weight: 175


Products tested:



Riding fixed gear bicycles off road definitely takes it's toll on cranksets.  Relentless bashing and pedal striking on rocks, roots, and logs has led to my replacing broken cranks over and over again:  1996 XTR stripped out the V1 Octalink bottom bracket/crank arm interface, 2000 XT swaged spider separated from the drive side crank arm, 2 pairs of FSA V-Drive Single Speed Cranks met their end with broken spindles where the splines meet the pinch bolts on the left crank arm (moreover, the FSA's external bearings needed replaced every 6 months).

Until recently, the most trustworthy cranks I'd experienced for off road fixed riding were 1990s square taper bottom bracket cranks by Shimano and RaceFace.  I'd often wondered  whether BMX tubular chromoly cranks would be suitable for fixed gear mountain biking.  The advent of the BMX Euro bottom bracket made splined BMX cranks compatible with 68/73mm English bottom bracket shells found on mountain and road frames.  The planets aligned and I procured a set of EigthInch Splined Cranks to put to the test.

EighthInch's target market for these cranks seems to be the fixed gear trick and polo riders, so it makes sense that these cranks would stand up to off road abuse admirably.  The bike I decided to utilize for this experiment is a Vassago Fisticuff monster crosser.  I'd been running with a 1X8 geared setup for a year and wanted to fix her up.  EighthInch splined cranks are available in 160, 165, and 170mm lengths.  I chose the longest crank arm available, 170mm, and mated it with the 35 tooth spiderless chainring, the smallest EigthInch splined chainring available.   A pair of bash guards that bolt directly to the chainring and an EigthInch's own splined crank installation/removal tool finished out the order.

If I'd had my druthers, I would have preferred a 175mm crank, but I rationalized that using shorter crankarms on the Fisticuff was a good idea because it's a cross bike after all.  I'd also have preferred a few fewer teeth on the chainring for log clearance, but settled for the smallest available knowing that with a big rear cog I could still get the desired gear ratio.

Unboxing:

The parts shipped fast!  I finalized the order on a Thursday afternoon and received my parts on Saturday morning.  Packaging was smart and everything arrived shiny and without scratches or blemishes.  

The splined chainring came out first and shouted, "BEEFY!"  I'm used to 3/32" rings so the 1/8" aluminum one piece plate looked surprising fat and strong.  The pressed in steel spline insert  is in there tight.  I couldn't budge it with my fingers.

Next, the bolt on bash guards felt solid and begged to be mounted to the ring.
 
The installation tool (that I'd wondered if I'd really need) seemed overbuilt, as I tested its weight in my palm.
 
Then from underneath the last of the bubble wrap, the boxed crankset emerged.
 
The box was well constructed to keep all parts from jostling around.

The raw/silver color with EightInch shield logo stood right out.  The crank arms are well polished and look clear coated to me.  
Bearings spin smooth and free.  Cups are pretty and have deep threads.  Bearing/spindle interface is deep too!  Is that two sealed bearings pressed on top of each other into each cup?

Grease included...nice touch!  

Spindle is a brick, just as expected.

Installation:

Before fixing, the Fisticuff sported a WTB/Deore Disc wheel, LX rear derailleur, SRAM 850 11-32 cassette, KMC 8 speed chain, Avid BB7 Road brake, UN-52 bottom bracket, NGear JumpStop chain keepr, and a 1990 Deore XT 175mm crankset with Race Face bash ring and 34T Salsa ring.


I expected the new crank to be much heavier but...

the EightInch tipped the scale only 100g over than the old setup.  1150g total with BB, chainring, and both bash guards.

Installation was intuitive, which is a good thing considering that no instructions were included.  I'd never installed a splined BMX crank before, but who ever reads instructions anyway?  Right?  I started making some educated guesses based on the parts I had.  I measured the distance from cup flange to cup flange while pressing the aluminum sleeve between and I came up with exactly 68mm.  I figured that the two included 2.5mm washers were for to be used in 73mm bottom bracket shells and could be left aside when installing on my 68mm Fisticuff shell.

The cups threaded in easily with a 36mm headset wrench.


The EightInch splined crank installation tool proved invaluable.  I couldn't believe how much weight I had to put on the 1/2" drive racket to ease the arms onto the splines.  Even with copious amounts of grease, maximum effort was needed to install.  This step was worrisome, particularly for a newbie to splined cranks without any instruction manual.  The installation tool, however, was worth its weight and got the job done cleanly.  Without the special tool I'd have been hammering the arms on (with wooden scraps turning to splinters) and cussing up a storm as I ruined the finish on my new crank arms.  

Don't those bash guards look f$%ing cool?

Left pedal installation went smoothly and there was no doubt that the threads had engaged properly by hand before needing to grab the wrench.  The right pedal threads, however, were bad.  The threads were rounded over and there was no way to get the threading even started.  Luckily I have a set of 9/16" pedal thread chaser taps on hand.  I inserted the tap from the inside of the crank arm and tapped her clean through to the outside.  There's such a feeling of satisfaction when you can feel a tap cleaning up boogered threads.  Voila!  I sighed relief as the right pedal slid into the repaired crank arm like butter.

Next came the challenge of chainline.  Typically I run the disc hub with bolt on fixed cog setup for off road fixed gear cycling (51mm chainline, the default for most MTB cranks, works perfectly for these disc hub fixed cogs).  I was preprared to bolt a 19T VeloCog on the disc hub and get rolling.  The EighthInch splined chainring, however, measured up to a 45mm chainline on the digital calipers.  45mm chainline is good for 110mm BMX hubs and 120mm fixed gear lock ring hubs, but lousy for 135mm MTB anb 130mm road hubs.  Luckily I had a Salsa Delgado rim laced to a 120mm Nashbar flipflop hub lying around.  Luckier still, I scrounged up two 5mm spacers and respaced the axle to 130mm, which the long Nashbar axle supports outta the box!  Vassago Fisticuff rear dropout spacing is 132.5mm so you can run MTB 135mm or Road 130mm easily.  By the way, EighthInch does offer a 48 spline 130BCD Splined Chainring Apdapter spider for $49.50 too.  It looks like you could mount it backwards and put a 130BCD chainring on the wrong side and get ~55mm chainline.

A 19T Surly 1/8" cog and a KMC Kool Chain finished up the build.  I tensioned the chain nice, screwed the rear brake calipers in on each other to keep pads from falling out, and called it a night.  The Fisticuff is now a Fixicuff:-)

Ride:

The first test ride was a family fun ride.  I pulled my four year old on the Alley Cat on some soft core MTB trails at the county park.  Things felt tight and smooth!

After packing the kids and the Alley Cat back into the minivan, I donned my daughter's helmet and rode home via some harder core trails, all the while kicking up mud on my street clothes.  A local favorite trail called Renegade/Nacho Mama's was definitely in order.  This trail twists like small intestines and is littered with 5 inch logs, 8 inch logs, and a few 12-20 inch logs. This is the trail that broke all the old cranks, I'm certain.  

I was quickly impressed by the stiffness that the EighthInch splined cranks offer.  What's funny is that I've never really ever been able to feel crank stiffness differences before.  The 1996 hype said that XTR Hollowtech was stiffer and I couldn't feel the difference, then the 2006 hype said that external bearings and 2 piece cranks with 30mm spindles were stiffer and I still couldn't feel the difference.  But with the EighthInch tubular chromoly cranks, I can definitely feel the increased stiffness! This stiffness makes thumping into logs feel a bit easier too.

Pedal strike when riding fixed in inevitable about 1/3 of the time when riding over logs.  With an aluminum crank the arm end sticks out a bit further than the pedal and often hits the log before the pedal.  This can cause the back end to twist a couple of degrees left or right.  The EighthInch tubular chromoly cranks seem to handle strike better.  The smaller rounder end of the chromoly arm lets the pedal make first contact with the log.  The wider stance, Q Factor, that the tubulars offer may also contribute to their nimbleness while log bashing.

The bash guards perform as expected and look cool.  But when I switch back over to gears for cyclocross season, I'm sure these guards won't keep the chain from slipping off the outside as well as a traditional bash ring.

The 170mm arm length means a tighter and more comfortable spinning radius for those spin-like-a-mad-bastard downhills and gives 0.5cm higher log clearance than I'm used to when approaching obstacles straight on.  But on the other hand, the much wider Q factor on the tubular cranks increases pedal strikelihood while leaning in corners.  

Since the virgin test ride, a few more mods were needed to make everything right.  A 20 tooth cog in the rear has replaced the 19.  A cyclocross tire with 35X20 matches up better with my preferred fat tire 26" fixie 32X18 ratio.  With this gearing, 47.5 gear inches, I'm now able to clean all the usual burst climbs and rock gardens that I'm used to cleaning on the MTB fixie. I also swapped the front brake over to the right hand lever (something I do with all my fixies) and pulled the dead-weight-rear-brake completely off the bike.  This conversion from 1X8 to fixie shaved 1.8 pounds overall!

I think she looks better dirty, but here she is hosed off.





With around 110 off road miles on the new cranks to date I'm super happy with them and expect them to be durable under relentless abuse.  I'm hoping that the width of those bearings will translate into longer life too, but wonder how easy it will be to find replacement bearings/cups when the time comes.

Bottom Line:

I love them for off road fixing!  They aren't terribly expensive.  They are strong, stiff, and not much heavier than aluminum cranks.  They look great, and work perfectly with hubs that have close to a 45mm chainline.  If they came in 175mm length and I could find a 4 bolt 104BCD spider that would give 51mm chainline, I'd definitely throw a set on my Surly 1X1 too.  



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