Friday, April 24, 2015

Velo Orange 50.4 BCD Cranks Mk II

While looking for lower gearing I was searching for a crank that would take smaller chainrings than my current 110 BCD compact double. Compact doubles usually take 34 teeth for the smallest ring. There are some mountain bike doubles available that go smaller, but they come stock with much smaller rings and I did not feel like replacing rings. The other option is to use a triple crank, but only use two of the spots, with the third left unused.

At the time, I only knew of Sugino, TA, Rene Herse, White Industries and Velo Orange cranks that would fulfill my criteria. Pricewise, the choice was clear: Velo Orange (VO) was at least $150 less than the others. Especially since when I was choosing them, I had access to them at wholesale prices. That access was unavailable when it came time to purchase because the company I work for is disorganized and incompetent, so I ended up paying retail. Afterwards, I also found the IRD Defiant Wide Compact cranks which are similar in price and features to the VO cranks. They use the more commonly available 94 BCD rings, instead of the less common VO/TA chainrings. See the bottom of the post for more comparisons.

Upon installation (greasing the bottom bracket spindle) it quickly became clear that one of the chainring bolt spacers was missing. The bolt that it was supposed to be on was still tightened, causing the inner ring to dive too close to the outer ring for one portion of the rotation. In this state, it was unusable as the chain would get jammed against the big ring.

The spacer in question, missing from another position on the crank.
My temporary solution: 4 small spacers to replace one large one.
I contacted the seller and they contacted VO and got me a replacement spacer and chainring bolt. The extra chainring bolt may come in handy since these aren't the same size as standard chainring bolts.

Standard chainring bolt on left, 50.4 BCD bolt on right
They also include very nice aluminum bolt covers (on right in photo below). Unfortunately, one of the crank bolts had a built in flange that was slightly off-center. With the tight fit of the cover over the bolt, I decided not to install it and risk damaging the extractor threads, I also decided not to go through the trouble of filing off the offending part of the crank bolt. I had an extra bolt cover from some very old cranks (on left in photo), but decided not to use it since I only had one. In any case, I didn't see any reason to put a cover over the bolt, it would just require one more tool for removal.

Cranks, minus crank bolt cover.
The recommended bottom bracket length is 118mm to give a chainline of 43.5, the standard for road doubles. I decided to go with a 115mm bottom bracket to keep the q-factor low (143mm w/ 115mm BB). The inside of the arms are 120mm apart at the ends, you can use that info to measure your chainstays to see if you need a longer bottom bracket for clearance reasons. I also figured since I wanted to use the entire cassette with the large 46 tooth ring (42 to 92 gear inches), putting the large ring a little closer to the frame would minimize the chain angle when using the large cogs on the cassette.

With a 115mm bottom bracket the measured chainline is 42.5mm (measured at the midpoint between the two rings) and rear cassette has a chainline of 42mm on a 130mm hub. When using the small 30 tooth ring, the chain starts to catch on the ramps and pins of the large ring when using the smallest cogs on the cassette. This can lead to severe chain suck and a broken derailer, so I need make sure I don't use those combinations. I may make a little indent on my barend shifter so I know when to stop downshifting in the small ring. This is a problem that is possible on other compact doubles, though it is a non-issue with an unramped large ring like I was using previously.

The gear range is what I was looking for, and it that respect, it gets the job done. My gear range is 27-93 gear inches using a 13-30 cassette, enough for everything I'm using it for, unless I start doing camping trips with it. The chart below (created using a wheel size 4 mm smaller than mine, so not perfect) shows the useable gears, good range in the big ring with a two gear overlap in the small ring.

The smallest chainrings available are 26 teeth. The 50.4 BCD designation is misleading, since the small ring mounts to the large ring, not to the crank arm spider. The small chainrings use a 6 bolt 80mm BCD pattern. To compare, the Rene Herse cranks use a larger BCD spider (70mm) but can mount smaller rings (24 teeth) because both rings are mounting to the same crank arm spider.

I rode it for a while until finally replacing the missing spacer. There was some lateral oscillation on the big and small rings. After a little internet research (thanks Sheldon and Jan) I took the rings off to check the spider. The video below shows that two of the spider arms are closer to the frame than the others. They disturb the zip tie I attached to the frame as reference. They are about .5-.75mm out of alignment, which is magnified at the chainring.  It may take a few viewings to see the arms in question.

I was able to straighten the offending arms with a 12" adjustable wrench. I don't recommend doing this unless you have a very good feel for the elasticity of metal. You need to be able to feel juuuust when it starts to deform, not an easy task when you're using a 12" lever. After doing this, there was one arm still slightly out of alignment (perhaps .1-.25mm), but it was so difficult to adjust the zip tie to get it to hit only one arm I decided to leave them alone.

After reinstalling the chainrings, they were much better, within 1mm at the edge of the chainring.

Here's a table comparing the Velo Orange and IRD cranksets

Velo Orange Grand Cru 50.4IRD Defiant Wide Compact
Stock Chainrings
50.4 outer/80 inner94
Smallest ring
Bottom Bracket
uses non-standard chainring bolts


Ἀντισθένης said...

I have the Sugino OX801D, not that I'd buy it at US/Canadian prices: got it in Japan. The quality it outstanding. Not sure the VOs sound as well engineered.

jefe said...

It's true it is not as well engineered. But at the same time, I don't require something that well engineered. I was using a SRAM Apex compact crank before and ditched it because I wanted something smaller than a 34T. I'm using a friction front shifter so don't really need ramped rings. I prefer square taper bottom brackets. I ride my company's bikes at work every weekday year around, external bearing bottom brackets last about a fourth as long as square taper in my experience.

This is why, if I was going to spend $400+ I would get the Rene Herse cranks. They focused on longevity and versatility (things I care about), not on shifting or stiffness (things I don't).

After posting the review on a randonneuring forum, someone mentioned their experience was the chainrings wear quickly and suggest replacing worn ones with TA rings available from europe for about the same as VO rings.

Other people also had concerns that the cranks were not clear anodized as this could lead to corrosion related fractures. After contacting the VO, they were informed that they recently started clear anodizing their cranks to address this issue.