Stephen’s Personal Blog

The new rear wheel and cluster arrived today. I swapped it out in a couple of hours with a minor change to the cluster. The old cluster was an 11-32 SRAM PG-950. The new cluster is an 11-34 SRAM PG-980. Instead of an 11-34 cluster of 11-13-..-34, I replaced the 13 with the 12 of the old cluster. The two smaller cogs cluster the gearing on both ends (high and low) and spread it out in the middle. The new 34 is for mountain climbing. The new low gear is now 19 instead of 20 gear inches. The gearing is a bit customized and requires some attention.

The wheels now match; both Mavic Open Pros on Ultegra hubs. The rear is a 36 spoke for the extra weight and the front is a standard 32 spoke. Both handbuilt from Bikeman. Very nice.

Today, I ordered a few things for the bike instead of training. It was cold and threatened rain all day. Even after truing the original back wheel seems out of whack slightly. It was wobbly and I had that fixed, but it’s still not right. The ride feels fine, but it looks weird when looking at it spin. Like a little jitter up and down, not quite perfectly circular. Normally, I would just write this off, but the wheel I bought from Bikeman last year to replace the one I ran over is rock solid after over 1000 miles. So, I ordered another one like that with 36 spokes instead of 32 (normal). It’s an Ultegra hub on Mavic Open Pro silver rims.

While I’m fiddling with the back wheel, which I hate, I decided to replace the cluster. It bugs me that I have the very cheapest cluster and chain. These are rather important parts, constantly in motion, and without which the bike doesn’t go anywhere. The replacement is a SRAM PG-980 11-34 and the chain, a PC-991 Cross Step. You replace chains about when you replace derailleurs, clusters, etc. or over a certain mileage. The current setup is a SRAM PG-950 11-32 with a PC-951 chain. The new setup is 200+ grams lighter and changes the gearing again. The top gear is up a bit. The bottom gear drops even lower, because of the 34T gear. 11-34 is as wide as it gets. And the 24/38/50 up front is nearly as wide.

The training rides, especially the 44 miles yesterday have been great with the new gearing. I spend most of the time in the middle ring. The big ring does come in to play on downhill, especially with a tailwind. The gear is easy to remember. The middle and big chainrings make the rear gears 2 clicks apart. So, shifting from middle to big also shifts the rear down 2 to find a similar gear.

To look at it another way, I have a small chainring with 6 or 7 unique gears. Then the middle gives me 9 with 7 overlapping the big ring, which gives me 2 more high gears. It feels like I have 18 distinct gears, but I want the overlap between the middle and big ring, because that’s were most of the work is and it makes things predictable. Though sometimes I think about a 52, 53, or 54 tooth big ring.