DT 240 vs shimano dura ace 9000 hubs
 

what the difference? which would be best for mountain climbing? Need a rear hub, not sure on spoke count, 28h? thinking about using 23mm wide HED belgium tubular?

DTs are lighter by 18g, the freehub is serviceable (instead of replaceable), I think engagement is a bit faster, potentially the Dura Ace has slightly less bearing drag when well adjusted, the cup & cone bearings are easy to overhaul for perfect performance, but the races can be permanently damaged if neglected, whereas the cartridge bearings in the DT are pressed in and out as units. They're both very nice hubs and I'd be happy to use either. The Dura Ace has a quieter freehub.

+1

Eventually you'll wear the DA race. With fresh bearings you'll always be able to rebuild the DT 240 or sell it on eBay.

You can easily swap in "race day" low drag bearings as needed with sealed bearings. Most mechanics just order mid-grade but there have always been ceramic and special use low friction bearings available for things like going for the hour Record, time trial, etc. Fewer seals, lighter oil, much less endurance and darn fast in communication n sizes.

One privateer racer trick is to remove the dust seals, and clean out the factory grease and relube a sealed bearing with heavy weight oil not grease. Sealed bearings are disposable and you can sacrifice bearing life for short term speed. Races self contained in the unit.

Not so with the DAs.

what the opinions on straight pull pokes? no j hook

Why do you not want j-bends? This is a serious question that you should be asking yourself.

BTW, Shimano does not sell bare hubs in straight-pull configuration--you have to buy a complete wheel to get them.

Straight pull spokes are generally a little less likely to break due to fatigue because they don't fail at the bend. They're more expensive and difficult to source, and can sometimes be very slightly annoying to build with because you absolutely need to hold the spoke to prevent it to spin--although this is generally a good practice anyways. They lock you into a lacing pattern, although that pattern usually is sensible. That said, the advantages are pretty slight, and again, cost and availability. I think they largely exist because they eliminate some production variability (less chance for spoke windup, little or no need to correct spoke line).

The DA hub has titanium splines so that cassettes don't dig in.

I have a road bike with DA wheels, and a mountain bike with 240 hubs. Both are excellent. DA hubs are cup/cone but use an allen wrench to adjust the preload, making them very easier to adjust.

DA hubs are basically quiet. DT can sound like angry bees. It's a personal choice.

"Eventually" can be a very long time. i have a 7700 DA rear hub with 58,000 miles and the races, cones and freehub body are all original. I just overhauled it today (after 7000 miles since its last service) and the internals are still in perfect condition.

You'll meet cyclists in the Pro peloton riding on old pedals that are heavy because they like them. You'll hear stories of cyclists that rode a Mavic Zap group (sealed bearings) or a Sachs ARIS indexing group (sealed bearings) throughout their whole career, but you'll never ever hear a story of a competitive cyclist putting 50k on the same races, cup/cones.

There is a reason for that. Just because you feel like you can still adjust them to spin like butter doesn't mean they actually do. There are some remarkably long wearing cup/cones that have been thoroughly heat treated. However, the bearings Spin in the real world and in the races. There is significant wear there, whether you can perceive it or not.

Cup/cone hubs don't get faster every season with use. They just don't.

^^ huh?:wtf:

+1 I also don't know what that was all about.

I have the 240s, and several generation of Dura-Ace hubs going back to the very dawn of Dura-Ace.

First question is why you would go with wide tubular rims? For climbing wheels, you should absolutely go with tubulars due to the insurmountable weight advantages vs. clinchers. However, the reason for wide clincher rim fad is to allow for wider tires. The reason for wider tires is to allow for more air volume so as to help prevent pinch flats. But since tubulars do not suffer from pinch flats, fat/wide tubular tires and rims are unnecessary. I regularly ride 22mm tubulars at 80psi over long stretches of gravel with no problems. You cannot do this with clinchers. Hence another major advantage for tubulars.

Back to hubs: the 240s may be slightly lighter. And freehub servicing is easier on the 240s - it takes literally 5 minutes, and requires no tools. However, if you use the wrong (too thick) freehub lube/grease, you run the risk of chipping and destroying the ratchet rings - as I did last year. Use the vendor recommended grease!

Flipside: since the 240 hubs are not as well sealed as Dura-Ace, you have to service the 240s more often.

As far as the design and implementation of the hubs, I would always go with Dura-Ace. Superior cup and cone bearing technology, so more adjustability, and easier to source replacement parts. As with all cartridge-bearing hubs, you are supposed to be able to replace the cartridges in theory, but this is often frustrated by the difficulty (or impossibility) of removing the bearings, or finding replacements, or the cost of a shop doing the work for you. Again, even mid-range Shimano hubs are very well sealed, and very resistant to water and dirt intrusion.

I think someone just came out of a 30 year coma, or was incarcerated with nothing to read but cycling magazines from the 70s and 80s. Looking forward to seeing what pearls are offered next!