Michael Hanslip Coaching

If you want to go faster, you have to pedal harder

July 2025
Writing | August 2025 | June 2025

Swapping spokes

26/07/25 22:51 Filed in: Gear
Four years ago I bought a new single speed bike - the Spot Rocker SS - from the company that is accredited with getting Gates into the bike business with their belt drive (for reference, see all the hype for this year's World Cup DH racing with 4 teams gunning for the big prize to be the first to win one with a belt). Spot designed the Rocker to be both SS and gear friendly. There are adjustable length dropouts for the frame to allow belt tension adjustment (much tidier than a creaking eccentric bottom bracket). The drive side dropout bolts to the seat and chain stays separately, making room for the belt to be installed into the rear triangle.
When I ordered the bike the stock wheel option was a Stan's wheel with a relatively skinny rim (25 mm from memory) in either aluminium or carbon rim options. Spot put ENVE wheels on their bigger travel bikes, and I opted to upgrade to an ENVE M630 to get carbon rims and wide rims in the same wheel (as the name implies, 30 mm wide). ENVE doesn't drill their spoke holes, makes all their rims in Utah, hand builds each wheel - all the little details that should make these wheels the envy of the industry. And the price was good.
 
And they've been basically good wheels. The CushCore has the tell-tale marks of firm impacts where the foam is damaged between the rock and the rim sidewall - the best way to break a carbon rim (or ding an alloy one). No marks on the rim at all. My biggest complaint would be that the ENVE stickers are a little delicate and missing in places where rocks have impacted the rim wall on the trail. Biggest complaint aside from my actual complaint - which is that the rear wheel regularly breaks spokes. And always the same mode: non-drive side spoke, where it enters the nipple, when I'm pushing on the pedals to complete a technical move. Each breakage requires removing the tyre and foam insert and the rim tape to access the hidden spoke nipples. I've always had to buy a new nipple as well as the spoke because there is a piece of spoke in the nipple rattling around inside the rim cavity - you can fish them out with a little effort once the rim tape is off, but getting the spoke out of the nipple is usually impossible. I hate taping rims for tubeless. I've tried many methods and different brands of rim tape and still find I'm hit-or-miss with getting a good seal on the rim floor.
With the most recent spoke breakage I decided to rebuild the rear wheel and see if I can avoid the breakage problem permanently. After some looking at what's available, I chose Pillar Wing spokes. The Wing is about the same mass as the Sapim CX-Ray spoke that was in the wheels already, but with a lower cost and a higher strength rating. They have a slightly oversized elbow to reduce movement in the hub flange, and a non-traditional wing shape to the bladed section to improve the aerodynamics (not a consideration at all on a MTB wheel). I'm hoping that a new set of spokes, carefully stress relieved, will not break. But in the rebuilding I noticed that the spokes are not as tight as I'd like them to be (tighter = longer life right up until they start snapping or the rim tacos) and there are only 28 of them (all my other carbon MTB rims have 32 spokes). Either or both of these might contribute to the breakage. I carefully preserved the ENVE spoke tension because I don't want to pull the rim apart.
 
Only miles on the wheel will tell me if I fixed it. Here's hoping.

Crazy YouTubers?

20/07/25 22:35 Filed in: Gear
Recently I watched most (not all) of a video by some engineer who has a channel on YouTube about how things work. This one attracted my attention - and probably slipped into my feed - because it was about bicycle wheels. I've seen so much rubbish about bike wheels, and this was more rubbish. I was really disappointed that an engineer, who should know better, was out there repeating nonsense theories about how wheels "work" as fact.
A spoked bicycle wheel is more like a pneumatic tyre (including the one mounted on the wheel) than it is like a spoked wagon wheel (the kind with big wooden spokes). Why? Because there is tension - lots of tension if built properly - in the bicycle wheel and the air pressure puts tension in the fabric threads of the pneumatic tyre. The tension allows the wheel to stand on the downward spokes (or threads in the tyre) rather than the popular notion of hanging from the top spokes (which is what this engineer put forth). Pre-tensioned structures do not behave like un-tensioned ones, or often, as intuition suggests.
If you really want to understand the system, go rear Jobst Brandt's book "The Bicycle Wheel" where he explains it all in detail, with measurements.
 
Alternative facts are not a real thing. I can tell you that airplanes fly due to magic and the Earth is flat - I could even believe these things - but that doesn't make either true. People shouldn't put educational content online that is wrong. I'll leave quantum physics to Brian Cox, and explaining spoke tension to Jobst.

Le roi (de rayons) est mort, vive le roi?

06/07/25 14:49 Filed in: Gear
For a good number of years now the ultimate spoke used in the ultimate wheel builds is the Sapim CX-Ray. The DT Swiss Aerolite is approximately the same spoke, and it seems like DT started making these to offer a DT alternative to the Sapim option. These spokes are expensive - but the price is probably worth it to achieve one of the lightest spokes you can get and also one of the strongest spokes you can buy - the extensive working of the steel wire to achieve the blade shape makes them really strong (and they use the best steel, but I don't actually know how this is any different from the steel in more mundane spokes; perhaps it is all down to the manipulations).
 
Back in 2011 I bought some carbon wheels for my hardtail that were built with Pillar bladed spokes. These spokes actually look a lot like the CX-Ray, but don't seem to have the "pedigree" that the Sapim spokes have (Pillar is Taiwanese, but lots of great bike components come out of Taiwan - compared to DT Swiss which is obviously Swiss and Sapim which is Belgian). Enter Pillar's new Wing spoke. These bladed spokes not only use the same Sandvik steel wire as the other two brands, but they have a new shape that makes them allegedly more aero, slightly more stiff and the breaking load is almost double that for the CX-Ray according to what I found online.
 
My ENVE wheels were built using CX-Ray spokes (28 per wheel) on Industry Nine Hydra hubs. If I was going to pick the weak spot in this trio of parts, I'd have picked the rear axle in the Hydra hub. But, as the bike is my single speed, it seems that not having a low gear nor having a gear right at the inside of the freehub body (where the bending load on the axle would be highest) and despite being heavier than your average cyclist - I've not experienced any axle issues to date. I have, however, broken at least 3 Sapim spokes to date.
 
The broken spokes are always in the same place - the non-drive side "pushing" spoke when I push on the pedal to deal with a technical terrain feature. This unloading of the spoke breaks it off at the start of the threads. I really hate this because it means disassembling the tubeless tyre system, removing the rim tape and coaxing the nipple out of the rim cavity. The section of spoke left in the nipple precludes getting the spoke out of the nipple - hence needing another nipple. The spokes are expensive (around $11 each), the nipples are expensive (ENVE nipples are $5 each), and I hate the down time on the bike. I think all replacement spokes in my wheel are actually Aerolites because no one seems to have the CX-Ray in my needed length in singles (they sell them in packs of 8 or more).
 
I've decided to rebuild the non-drive side of the wheel with Wing spokes. I ordered 14 spokes, 14 new nipples and a nipple tool so I can carefully re-do the off side when the parts arrive. I'll be taking the long road of replacing each spoke one at a time so as not to de-tension the wheel as a whole. Which will leave me with 13 spare spokes and nipples - I'm counting on not ever requiring them. The Wing spokes have a slightly thicker elbow section because this is where spokes break most often. That hasn't been the case for me - all have snapped off where they enter the nipple right at the start of the thread. But a stronger spoke with a thicker elbow - maybe it will deal with loads better overall? Fingers crossed.
 
I will also do an extensive destressing of the spokes after building as this is the most critical element of the wheelbuild for longevity. I have done this each time I replaced a spoke, so either 28 spokes is insufficient for my rear wheel or the CX-Ray is insufficient for my mass or the damage was done in the first few months of use prior to the initial spoke breakage.
 
Incidentally, these wheels came on a new bike. The bike brand told me to deal with ENVE. ENVE told me to deal with their importer in Australia. The importer told me they weren't interested because they didn't sell me the wheels. Great run-around there. Amusingly (not really!) the importer insisted I could purchase single CX-Ray spokes from my preferred bike shop, but the bike shop said the spoke importer's order desk offered them only large packets of the spokes. More run-around.
 
Back to my entry title - if the CX-Ray is no longer the king of spokes, is the new Wing the new King?

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