Originally Posted by
violini
"Always good to find Pentaxians around."
I plan to have a frame custom built using titanium. I have the following requirements: 1. the bike would be used for multi-modal transport, therefore, it should be as light as possible (preferably 8Kg or less). 2. The frame should be able to accommodate 700x28C tires with C-brakes as well as 26" tires with disk brakes. 3. The bike in folded configuration should be able to fit in a small car trunk and be carried into MRT and high speed trains.
The movable joint between down tube and BB shell exists long before Changebike. Their invention is the notched joint between the top tube and the seat tube. I do not need that. I would cut the seat tube and install two cramps, using seat post as the connecting tube.
Actually I am tempted do custom a Titanium bike with the Ritchey Breakaway system.
Based on what I can gather :
1. Ti bike is not that light if going for a roadbike like frame design (7.8kg-8.8kg ) thereabouts seems common and often the lighter ones use caliper brakes.
2. A caliper brake and disc brake mount option adds weight (alternatively, opt for V-brake on the rear for tire clearance and the front is easy to settle with either a disc ot caliper fork. ); Personally, I'd just go for disc brakes for multi-purpose and a pure caliper brake bike for lightest possible weight (and probably just road riding).
3. Yes, ChangeBike's innovation is the notched joint and sometimes, I feel that adds a bit too much weight.
4. The Ritchey breakaway system is claimed to add only 0.1kg so any other folding system will be a bit more.
My Bike Friday Pocket Rocket Super Pro weights 8.5kg (all in except saddle bag and bottles) .
It gives any roadie a run for their money unless they can sustain 52/13T for more than 20min on an individal effort or try to out gear me on a downslope with the 52/12; 52/12
Basically, the road bike rider has to use the higher gearing to his/her advantage.
I know there are lighter builds out there using carbon fork and seat post.
So perhaps the bike that matches a road bike (up to a point) is already out there (for me)
All said, hope you go ahead with your project and let us know how it pans out.
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