To experts mechanics: FD Clamp or... on a Spesh Amira
Moderator: robbosmans
My friend bought a Specialized Amira for his daughter. She's 11 yrs old, racing U12 category.
She has to use a 42T front Chainring for best ratio at 42 X 16 ( 6.00 meters ).
But the FD is a braze-on on the Amira, and at the lowest, is more than 8-10 mm over the big chainring, and the gear changes are a mess. The chain always drops over the big ring.
Any other options that wouldn't penalize the 6 meters ratio ?
I though putting a home-made "squared" 34.9 mm (I think we'll need bigger than that) clamp to the squared seat-tube below the braze-on till next year (she'll be U14 and then can use a 46T front chainring)...
What else ...?
Louis
She has to use a 42T front Chainring for best ratio at 42 X 16 ( 6.00 meters ).
But the FD is a braze-on on the Amira, and at the lowest, is more than 8-10 mm over the big chainring, and the gear changes are a mess. The chain always drops over the big ring.
Any other options that wouldn't penalize the 6 meters ratio ?
I though putting a home-made "squared" 34.9 mm (I think we'll need bigger than that) clamp to the squared seat-tube below the braze-on till next year (she'll be U14 and then can use a 46T front chainring)...
What else ...?
Louis
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Sadly, that's probably not low enough. I have a Rival derailleur on the same bike as a 46t chainring, and it's about 4mm. It's functional, but not particularly smooth. I guess it's better than nothing at all though, so that's a reasonable fallback for OP.
Yes, that's one of the "least worst" options for now. Using a 46T front chainring, but I'm shure that'll penalise her with the ratio, as 46-17 will probably be over 6.00 m (illegal) , but 46-18 will have her lose ground every pedal stroke...
I had an Excel file somewhere, but can't find it. probably 45T X 17 would bring her close to max 6.00 m .
Louis
I had an Excel file somewhere, but can't find it. probably 45T X 17 would bring her close to max 6.00 m .
Louis
Hmm maybe possible to create a bracket the shape of the braze on mount with a hole for the derailleur bolt where you need it.then you can bolt the bracket to the braze on..
Now I know the u12 category is super competitive and serious business but how many more races does she have to be disadvantaged until next season?
Now I know the u12 category is super competitive and serious business but how many more races does she have to be disadvantaged until next season?
Good idea crohnsy. Brobably easy to to do as well
I know. But at the same time, when you're at your second and last season under a category, you want to perform at your best. Still 5 races to go, maybe 6...
Next year, she'll get the 46 X 16 ratio, the shifting "problem" will be resolved, but she'll be 1st year U14...struggling against the "big girls" again...
Louis
I know. But at the same time, when you're at your second and last season under a category, you want to perform at your best. Still 5 races to go, maybe 6...
Next year, she'll get the 46 X 16 ratio, the shifting "problem" will be resolved, but she'll be 1st year U14...struggling against the "big girls" again...
Louis
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Rotor makes some shims that moves the derailleur back 6mm, and also a shim that is tapered 6mm/4mm (top-bottom). That should move the derailleur enough to make it shift ok.
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