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Tern BYB P8, first experiences (gear cage length?)

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Tern BYB P8, first experiences (gear cage length?)

Old 01-12-23, 10:49 PM
  #26  
Winfried
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Originally Posted by olegosna
​​​​​​Thanks for that input, helps a lot. Also to the others in regards of alternatives for more gears.
… or you could replace the whole thing with a Nexus/Alfine gear hub. A much better option for a folder with smaller wheels, IMHO.

The eight-speed version provides a wider range (307% vs. Tern's 291%), allows shifting at a stop, and does away with broken cages.
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Old 01-14-23, 01:43 AM
  #27  
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Originally Posted by Winfried
… or you could replace the whole thing with a Nexus/Alfine gear hub. A much better option for a folder with smaller wheels, IMHO.
Honestly, I think that is a good option for my purpose. Before I purchased a BYB I wanted to buy the Link with a Nexus. But currently I do not want to change more than necessary and test the bike in the summer. Maybe I will do bigger changes then.
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Old 01-14-23, 08:48 PM
  #28  
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Originally Posted by Winfried
… or you could replace the whole thing with a Nexus/Alfine gear hub. A much better option for a folder with smaller wheels, IMHO.

The eight-speed version provides a wider range (307% vs. Tern's 291%), allows shifting at a stop, and does away with broken cages.
Don't they require 135 mm spacing?
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Old 01-15-23, 07:22 PM
  #29  
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The Alfine is 135mm while the Nexus 8 is 132,5mm
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Old 01-17-23, 06:28 PM
  #30  
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Originally Posted by Winfried
… or you could replace the whole thing with a Nexus/Alfine gear hub. A much better option for a folder with smaller wheels, IMHO.
IMO, geared hubs make more sense for small-wheeled bikes for the reasons you list. One thing to consider before attempting a simple substitution is that geared hubs work best with horizontal dropouts, which allow for easy chain tension adjustment. Bike frames designed for derailleur-based drivetrains generally have more vertical dropouts. To adjust chain tension might require the use of "half links" or a chain tensioner. In the latter case, there's more drivetrain hanging down potentially in harm's way.
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Old 01-18-23, 03:55 AM
  #31  
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Good call

Shimano's CT-S500 tensioner is quite compact, but there might be some even smaller.
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Old 02-11-23, 02:17 AM
  #32  
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Final setting so far

Hi,
thanks again for all the advice. As mentioned I had to change sth. anyway, as shifting performance was bad and my mechanic was not able to synchronize the shifter.
I bought a simple Altus RD-M310 not because of the price, but because I could not find any other model fitting the other components and being shorter than the current derailleur.
Unfortunately my mechanic had no time anymore (or did not want to), so I tried it. Unfortunately I had to change the cable and the cable tunnel, as the original setup was too short (annoying). Now it seems all to work and yes the old derailleur seemed to be bent.
As expected there is some downside. The new Altus needs more space in lateral direction. I can avoid collision with the front wheel after folding, when switching the gear to the bigger cogs. That's fine to me as I am getting slower anyway before getting off the bike and folding it. The distance of the lower pulley to the road is significantly increased, which make me feel safer in the city. Shifting performance is totally alright.
Thanks again and if you have further questions, feel free to ask.
(unfortunately I have not enough posts to send a picture )
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Old 02-11-23, 01:25 PM
  #33  
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Originally Posted by sweeks
Bike frames designed for derailleur-based drivetrains generally have more vertical dropouts. To adjust chain tension might require the use of "half links" or a chain tensioner. In the latter case, there's more drivetrain hanging down potentially in harm's way.
BikeFriday tikit, vertical dropouts, Shimano Alfine 11, Surly Singleator with the push-up spring.

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Old 02-11-23, 06:13 PM
  #34  
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Originally Posted by tcs
BikeFriday tikit, vertical dropouts, Shimano Alfine 11, Surly Singleator with the push-up spring.
Nice and tidy!
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Old 02-13-23, 03:55 AM
  #35  
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Originally Posted by olegosna
Hi,
As expected there is some downside. The new Altus needs more space in lateral direction. I can avoid collision with the front wheel after folding, when switching the gear to the bigger cogs. That's fine to me as I am getting slower anyway before getting off the bike and folding it.
Fit one of these guards:
https://bankruptbikeparts.co.uk/prod...gn=sag_organic

I have them on kids bikes because they keep bending/breaking derailleurs and hangers...
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