I've been experimenting lately with adjustable crank shorteners on my
recumbent, trying to find a shorter crank length that suits me and my
one wonky knee. I've settled on a length of 125mm and now want to buy
a new chainset that I can have re-drilled and threaded by Highpath
Engineering.
I'm having difficulty finding a suitable chainset and am wondering if
anyone has a suggestion for cranks that will be up to this kind of
modification.
I'm currently using a 39/53 double. With shortened cranks and the 406
wheels on my Taifun this works well as a high gear ratio (11t
sprocket), so the new chainset will need to be a road model in order
to retain this kind of top end. However, the set up doesn't provide a
low enough gear for me to be comfortable on some ascents and I'd like
to move to a triple chainset. I think a 30/42/52 "racing triple" would
work very well, but I can't find one that looks strong enough in the
arms at the required 125mm length to support the new pedal position.
Highpath have said they need a minimum width of 25mm at the point of
the new thread. I'd just about settled on a Campag Centaur, but the
width is borderline - it's just 25mm but the arm is beveled so it's
thinner than that on the front face. Of course, this is for use on a
recumbent, so the pedals wont ever be stood upon and honked uphill as
on an upright bike. Perhaps it would be okay, but buying the chainset
and then having it rethreaded isn't cheap, and I'd rather not have to
start over again in 6 months time because it's cracked due to lack of
material.
Shimano cranks are out because most of their range nowadays is hollow
and so unsuitable for re-drilling. I think the Tiagra is still solid,
but it's rather clunky and comes with low quality rings and I was
hoping to find something a bit nicer as this is my favourite bike.
Anyone have suggestions on something that might be suitable? Comments
or advice much appreciated.
"Bob"
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