Suitable Frame Choice
- Thread starter MikeWinVA
- Start date
Andrew 1973
Zen MBB Master
Doug will probably chime in
Doug will probably chime in as he has more experience than anyone I know about the Cruzbike conversion kit. As I recall, the step-through/u-frame you show doesn't make a suitable donor; I can't recall why exactly, but I know that seat mounting is a concern. If you're planning to fabricate your own seat, then maybe you could find a way to make it work.
I cringe at the idea of that Raleigh mixte frame being altered. It's a beautiful frame and should probably be built up as a proper city bike instead.
Doug will probably chime in as he has more experience than anyone I know about the Cruzbike conversion kit. As I recall, the step-through/u-frame you show doesn't make a suitable donor; I can't recall why exactly, but I know that seat mounting is a concern. If you're planning to fabricate your own seat, then maybe you could find a way to make it work.
I cringe at the idea of that Raleigh mixte frame being altered. It's a beautiful frame and should probably be built up as a proper city bike instead.
I just pulled a picture off
I just pulled a picture off Sheldon Brown's website. It wouldn't necessarily be a Raleigh. I like the Mixte frames from an engineering standpoint, they are torsionally very strong compared to a woman's normal bike frame.
The nice thing about using a conversion kit versus building one from 2 frames means if it doesn't work out, I can still use the frame again.
I just pulled a picture off Sheldon Brown's website. It wouldn't necessarily be a Raleigh. I like the Mixte frames from an engineering standpoint, they are torsionally very strong compared to a woman's normal bike frame.
The nice thing about using a conversion kit versus building one from 2 frames means if it doesn't work out, I can still use the frame again.
ak-tux
Zen MBB Master
The main concern about
The main concern about the the step-through/u-frame is the difficulty to find suitable point on the downtube to clamp the cruzbike seat pan. Then there is a possibility that the space in the U may be too cramped.
However that being said if one was willing to make some welding modifications then it can make an excellent cruzbike conversion with a low seat height. I built my homemade MBB using a suspended step-through/u-frame, but I was willing to make some welding on the downtube to create a place to mount the seat. Then I also (cold) bent the seat post backwards and addded some reinforcement to allow more reach.
The best type of frame for a reversible cruzbike conversion remains the Y frame with a low top tube.
The main concern about the the step-through/u-frame is the difficulty to find suitable point on the downtube to clamp the cruzbike seat pan. Then there is a possibility that the space in the U may be too cramped.
However that being said if one was willing to make some welding modifications then it can make an excellent cruzbike conversion with a low seat height. I built my homemade MBB using a suspended step-through/u-frame, but I was willing to make some welding on the downtube to create a place to mount the seat. Then I also (cold) bent the seat post backwards and addded some reinforcement to allow more reach.
The best type of frame for a reversible cruzbike conversion remains the Y frame with a low top tube.
Tarmac Terrorist
Active Member
Suitable Doner
This Giant Warp DS2 has a broken seat post, snapped off at the frame so it a matter of consversion of scrapping. Would there be an issue with the seat pan attaching to the retangular frame tube? Seat height will not be a problem I will mount the pan at the end of the frame tube near the suspension mount, then attach two aluminium uprights, with stays to suopport the seat back and rear rack. http://www.motorabilia.biz/Images/Giant%20Warp/Giant%20Warp%20DS2.html
This Giant Warp DS2 has a broken seat post, snapped off at the frame so it a matter of consversion of scrapping. Would there be an issue with the seat pan attaching to the retangular frame tube? Seat height will not be a problem I will mount the pan at the end of the frame tube near the suspension mount, then attach two aluminium uprights, with stays to suopport the seat back and rear rack. http://www.motorabilia.biz/Images/Giant%20Warp/Giant%20Warp%20DS2.html
Eric Winn
Zen MBB Master
Or salvage some of the bits
Or salvage some of the bits and create your own custom stub frame using carbon fiber (or fibergalss) over urethane foam:
See Dave Wolfe's build blog at http://www.roguelr.com/2012/06/02/drive-train-parts-and-making-grooves/
Dave is building a modified version of Robert Riley's XR2 LWB recumbent. See http://rqriley.com/xr2.htm
-Eric
Or salvage some of the bits and create your own custom stub frame using carbon fiber (or fibergalss) over urethane foam:
See Dave Wolfe's build blog at http://www.roguelr.com/2012/06/02/drive-train-parts-and-making-grooves/
Dave is building a modified version of Robert Riley's XR2 LWB recumbent. See http://rqriley.com/xr2.htm
-Eric
Charles.Plager
Recumbent Quant
Or salvage some of the bits
Or salvage some of the bits and create your own custom stub frame using carbon fiber
At some point in my life, hopefully much sooner than later, this is exactly what I want to do. A carbon copy (pun intended)of a Vendetta would be a really cool thing!
Cheers,
Charles
Or salvage some of the bits and create your own custom stub frame using carbon fiber
At some point in my life, hopefully much sooner than later, this is exactly what I want to do. A carbon copy (pun intended
)of a Vendetta would be a really cool thing! Cheers,
Charles
Tarmac Terrorist
Active Member
I'd vote for scrapping - the
I'd vote for scrapping - the seat post is still needed for a conversion (to stabilise the seat back).
No, not having the seat post means I can get the seat lower and further back. I will make brackets to support the seat back.
I'd vote for scrapping - the seat post is still needed for a conversion (to stabilise the seat back).
No, not having the seat post means I can get the seat lower and further back. I will make brackets to support the seat back.
Charles.Plager
Recumbent Quant
I'd vote for scrapping - the
I'd vote for scrapping - the seat post is still needed for a conversion (to stabilise the seat back).
No, not having the seat post means I can get the seat lower and further back. I will make brackets to support the seat back.
I'd recommend against this for two reasons:
1) The frame has now failed once. I'd be worried that this might cause the frame to fail again.
2) It's going to be hard to mount the seat against the main body of the frame. You don't want to mount the seat against the rear swingarm because your working against the suspension in this case.
If you want a low seat angle, I'd recommend trying what Jake is: a bent steel seat post.
Cheers,
Charles
I'd vote for scrapping - the seat post is still needed for a conversion (to stabilise the seat back).
No, not having the seat post means I can get the seat lower and further back. I will make brackets to support the seat back.
I'd recommend against this for two reasons:
1) The frame has now failed once. I'd be worried that this might cause the frame to fail again.
2) It's going to be hard to mount the seat against the main body of the frame. You don't want to mount the seat against the rear swingarm because your working against the suspension in this case.
If you want a low seat angle, I'd recommend trying what Jake is: a bent steel seat post.
Cheers,
Charles
MrSteve
Zen MBB Master
Tarmac Terrorist-
My guess is that the frame of the Giant Warp DS2 is junk.
The hole left behind in the main frame tube is ragged and
will -if it hasn't already- propagate more cracks.
If I were you and was doggedly determined to make the Giant
frame (what's left of it) work, I'd fabricate new brackets to hold
the seat.
Just like you planned to do.
Only my brackets would extend from the steering head all the
way down past where the seat would mount -just about where the
ragged hole is, in the main frame tube- to the swingarm pivot.
Having done all that, I would not venture very far from my workshop
on that conversion... and I would not be going very fast on it.
My point is, I could build a sturdy, trustworthy frame out of cardboard,
from scratch, that would be more dependable than your Giant Warp DS2!
That's just my opinion... have fun and ride safe!
-Steve
My guess is that the frame of the Giant Warp DS2 is junk.
The hole left behind in the main frame tube is ragged and
will -if it hasn't already- propagate more cracks.
If I were you and was doggedly determined to make the Giant
frame (what's left of it) work, I'd fabricate new brackets to hold
the seat.
Just like you planned to do.
Only my brackets would extend from the steering head all the
way down past where the seat would mount -just about where the
ragged hole is, in the main frame tube- to the swingarm pivot.
Having done all that, I would not venture very far from my workshop
on that conversion... and I would not be going very fast on it.
My point is, I could build a sturdy, trustworthy frame out of cardboard,
from scratch, that would be more dependable than your Giant Warp DS2!
That's just my opinion... have fun and ride safe!
-Steve
Eric Winn
Zen MBB Master
David Wolfe carbon fiber plans built XR2
Dave Wolfe finished his XR2 build and has moved his website:
http://roguelsr.wordpress.com/
And posted his first ride video:
I purchased a set of these XR2 plans. One of these days I would like to combine some of this idea with a Cruzbike conversion kit...
-Eric
Dave Wolfe finished his XR2 build and has moved his website:
http://roguelsr.wordpress.com/
And posted his first ride video:
I purchased a set of these XR2 plans. One of these days I would like to combine some of this idea with a Cruzbike conversion kit...
-Eric
Charles.Plager
Recumbent Quant
Hi Eric,
Thanks for the
Hi Eric,
Thanks for the update. At some point, I'm going to just build my own carbon fiber Silvio (with at least rear suspension).
Cheers,
Charles
Thanks for the
Hi Eric,
Thanks for the update. At some point, I'm going to just build my own carbon fiber Silvio (with at least rear suspension).
Cheers,
Charles
