Shimano freehub

[LegendRider]

I have two pair of Shimano Dura Ace tubeless specific wheels (7850-SL and 7850-C24-TL). Although I love both, they exhibit the same annoying characteristic that drives me crazy. Occasionally, when when I give it some power, the freehub slips and makes an clunking noise. I had the 7850-SL freehub replaced under warranty not too long ago and it is back to making the same noise. The other set - which I bought used - makes the noise even more frequently.

Here's a thread on Weight Weenies describing the problem:
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=72347&hilit=shimano+freehub

What are the options? Can I use a DT or Chris King freehub on these otherwise great wheels?

[Louis]

Since there is nothing tubeless-related at the hub wouldn't they be standard DA hubs? If so, is this a typical problem with DA hubs? (I've only used Ultegra, which has been fine.) If it is a typical problem one would think that we would have heard of it before.

Good Luck

[LegendRider]

Since there is nothing tubeless-related at the hub wouldn't they be standard DA hubs? If so, is this a typical problem with DA hubs? (I've only used Ultegra, which has been fine.) If it is a typical problem one would think that we would have heard of it before.

Good Luck


They are not 7800 or 7900 hubs, though the freehub may be the same. The hubs are widely used in their pre-built wheels. As the WW thread indicates, this problem is apparently not uncommon.

Strange bikes noises annoy me and I'm willing to spend some money to silence it.

[kramnnim]

Wow, I have the same problem...didn't know it was so widespread. Good to know.

Might be able to swap the freehub body from another Shimano hub...not DT or CK, though, as they are completely different.

[PSC]

I have the same problem with my wheels, 7850 hubs on OP rims. With over 15k miles on the wheels, I am not too concerned.

[FixedNotBroken]

Solution to your problem=Campy


I have two pair of Shimano Dura Ace tubeless specific wheels (7850-SL and 7850-C24-TL). Although I love both, they exhibit the same annoying characteristic that drives me crazy. Occasionally, when when I give it some power, the freehub slips and makes an clunking noise. I had the 7850-SL freehub replaced under warranty not too long ago and it is back to making the same noise. The other set - which I bought used - makes the noise even more frequently.

Here's a thread on Weight Weenies describing the problem:
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=72347&hilit=shimano+freehub

What are the options? Can I use a DT or Chris King freehub on these otherwise great wheels?

[oldpotatoe]

I have two pair of Shimano Dura Ace tubeless specific wheels (7850-SL and 7850-C24-TL). Although I love both, they exhibit the same annoying characteristic that drives me crazy. Occasionally, when when I give it some power, the freehub slips and makes an clunking noise. I had the 7850-SL freehub replaced under warranty not too long ago and it is back to making the same noise. The other set - which I bought used - makes the noise even more frequently.

Here's a thread on Weight Weenies describing the problem:
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=72347&hilit=shimano+freehub

What are the options? Can I use a DT or Chris King freehub on these otherwise great wheels?


Cannot use any other freehub on those hubs, not even another shimano model. DA hubs changed quickly from 7800 to 7810 then 7850, now 7900. I think it's great that shimano recognized problems with their new design, not attached to the freehub body, in 7800 and 7810 and 7850 was much better but this problem is finally solved in 7900.

I recommend taking the freehub out, cleaning the pawls well and use a light oil in there. What's happening is one of the pawls is getting stuck down.

[PaulE]

On the Shimano freehubs aren't the pawls somewhere inside the freehub body? It's been a while since I had one off and the Shimano tech doc's don't show any detail on the freehub itself. If you can't get to the actual pawls, you can also try the Morningstar Freehub Buddy to flush out the freehub body, either on the hub or off the hub, and then repack the freehub with Morningstar Freehub Soup. You'll also need to buy a Morningstar removable dust shield for your Shimano Freehub if you go this route.

[oldpotatoe]

On the Shimano freehubs aren't the pawls somewhere inside the freehub body? It's been a while since I had one off and the Shimano tech doc's don't show any detail on the freehub itself. If you can't get to the actual pawls, you can also try the Morningstar Freehub Buddy to flush out the freehub body, either on the hub or off the hub, and then repack the freehub with Morningstar Freehub Soup. You'll also need to buy a Morningstar removable dust shield for your Shimano Freehub if you go this route.

On 7800/7810 the hubs are very similar to Campagnolo hubs with 3 exposed pawls.

[kramnnim]

What about 7850? Shimano's "exploded view" PDF makes it look like Shimano's usual design...

Edit: Here's a picture of the freehub body... http://www.treefortbikes.com/product/333222354040/595/Shimano-Dura-Ace-7850-10-speed,.html

Okay, I guess it doesn't look the same.

Edit #2: Okay, Sheldon confirms that the 7850 freehub body design is not like 7800/7810. Boo. So what's the best way to lubricate the pawls hidden deep within the FH body? is lubrication the problem, considering new wheels exhibit the annoying "clunk"? Maybe the grease used is too thick?

[oldpotatoe]

What about 7850? Shimano's "exploded view" PDF makes it look like Shimano's usual design...

Edit: Here's a picture of the freehub body... http://www.treefortbikes.com/product/333222354040/595/Shimano-Dura-Ace-7850-10-speed,.html

Okay, I guess it doesn't look the same.

Edit #2: Okay, Sheldon confirms that the 7850 freehub body design is not like 7800/7810. Boo. So what's the best way to lubricate the pawls hidden deep within the FH body? is lubrication the problem, considering new wheels exhibit the annoying "clunk"? Maybe the grease used is too thick?

Take freehub body off, take off wee seal on the back, flush well with WD-40(a solvent), let dry, oil, like Mobil One.

[kramnnim]

Thanks!

Now to find a 14mm allen wrench...