biopace rings
- Thread starter e-rider
- Start date
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snailracer
Über Member
Front mechs rub and shift poorly even with round chainrings.
In the case of VCN riders, mostly because they follow trends. AFAIK only one has done the testing to see if they are quantifiably beneficial to him.
MartinC
Über Member
- Location
- Cheltenham
OK. How do you ensure the mech cage outer plate is 1-2mm above the chainring when the diameter of the chainring varies?
MartinC
Über Member
- Location
- Cheltenham
Alembicbassman
Confused.com
Maybe I should rephrase:
I have no problems shifting rings using my non-indexed downtube shifter.
OP
OP
e-rider
Banned member
- Location
- South West
byegad
Legendary Member
- Location
- NE England
The thing is Egg rings and Biopace rings are both oval and set at approximately 90 degrees to each other. They can't both be right and I suspect neither is. The placebo effect over rides both.
snailracer
Über Member
Good for you, but most aren't, especially bikes with short chainstays. If it was possible to avoid rubbing on every bike, the trim function would not be included.
OP
OP
e-rider
Banned member
- Location
- South West
without trim mine would rub; but I have trim so it doesn't - I'm not sure what your point is? Any decent front mech set correctly will not rub if used correctly.
snailracer
Über Member
Some folks (me included) would not consider a front mech that requires trimming to be "fine".
MartinC
Über Member
- Location
- Cheltenham
A front mech that never needed trimming whatever frame geometry and other components it ran with would probably let you down in some other area like speed of change. Life's a compromise.
snailracer
Über Member
I am sure there are solid technical reasons why front mechs rub, however I still find it irritating and unsatisfactory. Knowing why a flaw exists does not eliminate it as a flaw.
It seems Shimano agrees, as their electronic Di2 front mech is designed with auto-trimming to eliminate this very issue. Obviously Di2 is a compromised concept, if you consider cost and reliability important.
MartinC
Über Member
- Location
- Cheltenham
The flaw is that the laws of geometry apply - hard to eliminate.
You might see (Di2) Auto trimming as a solution but as you say this brings other problems. Personally, trimming a front mech just isn't a problem, any more than having to change gear is. Every 'solution' seems to bring more problems. Short stays and wide cassettes are the solutions to other problems!
snailracer
Über Member
Solutions spawn problems, however I would be happy to solve a bigger problem if it resulted in a smaller problem.The flaw is that the laws of geometry apply - hard to eliminate.
You might see (Di2) Auto trimming as a solution but as you say this brings other problems. Personally, trimming a front mech just isn't a problem, any more than having to change gear is. Every 'solution' seems to bring more problems. Short stays and wide cassettes are the solutions to other problems!
There is a hill on my commute that strains my dodgy knees. I would like to remove it, however the resultant nuclear fallout would be more bothersome than having gears on my bike, even if they do rub.
