I have a DA 7850 straight pull rear hub from a broken c50 wheel. The hub is fine and I would like to use it again. Some questions:
1. Is the hub is compatible with standard (DT or Sapim for example) straight pull spokes? I think it is but I'm not 100% sure.
2. How do I calculate the correct spoke length? Any pointers on how to do this? I read the post from ergott to 'reverse engineer' this by checking the old spokes and old rim ERD. (viewtopic.php?f=3&t=89693#p774717) Is this the best way?
3. What (cheap?) rim would be strong enough to accommodate a 70 kg rider on a 20 spoke rear wheel?
An option I found is this: http://www.cnc-bike.de/product_info.php ... ts_id=9694
The seller told me that is it suitable for a 70kg rider and that it isn't a H Son Plus SL42 (I thought it might be)
Thanks!
Reusing DA 7850 straight pull hub
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These aren't standard spokes that you could simply replace with a DT or Sapim. You will have to rebuild with Shimano rims/spokes seeing as the nipples thread into that rim, instead of the traditional style where the nipples thread into the spoke.
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@Zen Cyclery - Nope, you're probably thinking 7800/1 or the 7850 C24's (except for the full carbon tubular).
@athos - 7850 C50 use normal spokes so there are no issue reusing the hub with another rim. The 'blade' dimensions are the same as CX-Ray (pretty sure I remember reading somewhere they were even made by Sapim). ergott's method for finding the spoke length sounds good provided you've still got the original rim
The original spoke length is 278mm according to Shimano tech docs.
Are you trying to find a replacement rim to match the height/appearance of the Shimano front, or will anything do provided it's strong enough for you?
@athos - 7850 C50 use normal spokes so there are no issue reusing the hub with another rim. The 'blade' dimensions are the same as CX-Ray (pretty sure I remember reading somewhere they were even made by Sapim). ergott's method for finding the spoke length sounds good provided you've still got the original rim
The original spoke length is 278mm according to Shimano tech docs.Are you trying to find a replacement rim to match the height/appearance of the Shimano front, or will anything do provided it's strong enough for you?
I think jooo is right, this is the more traditional style wheel. Difference I think is that the thread and nipples are larger as compared to standards.
It doesn't really matter what it looks like, just a rim that is strong enough and isn't very expensive. I may also redo the front wheel. (16 spoke)jooo wrote:Are you trying to find a replacement rim to match the height/appearance of the Shimano front, or will anything do provided it's strong enough for you?
