Silvio ST "sport touring" concept

[Nanda Holz]

Over the years, I've seen customer and people on the boards and blogs do some loaded touring with their Cruzbikes. Even had one customer trade back his Silvio towards a more touring capable platform that had more capacity beyond the recommended 25lbs rear rack and carbon stay loading. I kept thinking it might make sense to make a rear frame that would be properly suited to loaded touring, or local errand running, and below are some concepts to consider.

All feedback is welcome eh!

Here is the first design attempt for your reference, which more closely followed the Silvio's main frame geometry:

Here is the latest design I came up with:

Made some mod's to the first design and added another cross-bar just about the lower stay for a secondary pannier mounting option that could be useful. Also added a cross tube for mounting adjustable seat struts, and hope to allow Mesh and Hoagie RANS, Euromesh, or Hardshell seats to be mounted, using a RANS 1.5" Radloc. A stock Cruzbike seat can be mounted using the conversion kit seat bracket with some Quest style upper seat angle adjustable stays. The main tubes are now parallel to the ground.

Here is another mock-up, nothing sexy, just purposeful around the Cruzbike Sofrider geometry, with Ortlieb side panniers and Arkel Tailrider.

A way to adapt the rear swing-arm would be worth consider for those that want a rear shock, beyond a 700x40 or 26x2" w/fender and disc brake.

 

[John Tolhurst]

Try to reduce the tube count,

Try to reduce the tube count, you will save weight and cost. Why not create a structure to bolt to the seat and seat pan?

 

[Andrew 1973]

Interesting Concept

By the looks of it, I wouldn't call it a sport-touring bike, but as a fully-loaded touring or cargo bike, it might be of interest to some. The design looks solid and is reminiscent of an Xtracycle. Similarly to Xtracycle's modular concept, you could create an attachment that would increase cargo capacity without having to redesign an entire bike. With that thought in mind, I think I would prefer to see the concept based on the Sofrider or Quest platform instead.

Thanks for posting. I love seeing how you innovators think!

 

[Nanda Holz]

Thanks Andrew.  John and I

Thanks Andrew. John and I were emailing a bit, and he got me thinking of Xtra Cycle:

Studying the differences between the Quest/Sofrider/Silvio, the headtubes are all relatively in the same location, just the seat is higher on the Quest/Sofrider requiring the tall stem to meet the bars. The Silvio seat is snugged lower in the frame, and can have the bars a bit lower, and lower overall rider CG on a cargo bike would be a good thing I believe. Might try the Xtra bars inserted backwars as John also suggested which would give more clearance near the seat and riders elbows, or just extend the back 2-3" more.

 

[Andrew 1973]

WOW

So after emails between you and John, you were able to come up with this design that quickly? I'm inpressed. I admit, I like the looks of your other frames too, particularly the trussed detail in your second model, but this is simpler and more elegant. The fact that it looks like it can work with the Xtracycle modular system is interesting...anyone else thinking a potential business partnership could arise under the right circumstances? ;-)

 

[Andrew 1973]

Impressed...

Not I n pressed. I can spell, I just can't type.

 

[kidneyboy]

Wow.... LOTS of welding

Wow.... LOTS of welding and Lots of tubes (expensive build?). Would the seat need to further forward to keep even weight distribution?

 

[charlesw]

I would love to see a cargo

I would love to see a cargo bike cruzbike.

I currently ride a RANS HammerTruck (courtesy of Mr. Holz) for my around-town-car-replacement. It's a truly awesome machine. But I find myself wishing for a cruzbike version so that I could double-up on the cruzbike training whilst running errands everyday (I actually use the cargo carrying capability _everyday_).

 

[Nanda Holz]

misc. ramblings

Thanks for the comments!!!

Yes Andrew, SketchUp is a fast and nimble CAD tool, and after years of using more advanced design software programs in my past life, SketchUp is sooo refreshing and intuitive to use. Granted whipping up these concepts still takes a couple hours, and they are not dimensionally accurate and are traced off grainy web images of the Silvio scaled up using the longest dimension, the wheelbase spec. I've asked John for a PDF of the Silvio CAD (a side DXF) would be ever better, and happy to sign a NDA etc. if needed. With regards to any partnerships, I already have a partner...Cruzbike...as a dealer . My goal is to inspire the ridership and get a little fire going under John's busy rear end (which is hard to do from so many miles away .

Guess internally I am trying to marry my past mechanical design engineering experience with my fledging bike business, and help manufacturers realize holes in their product offerings (with the drive and focus being towards responsible cycling...as in more transport and less sport, park the car, save the planet kind of stuff). It's easier to work with an established company and influence them in a positive direction...leading by example.

Part of the reason I went and brought on Nazca from Holland into my offerings, frankly was because I was tired of outfitting RANS bents and crank forwards, and Cruzbikes into commuters and tourers. Nazca "gets it" and includes fenders, rear racks (55lb rated), and a rear LED integrated with the rack, and offers underseat panniers, Alfines, Rohloff's, SON's and on an on everything a purposeful rider could dream of outfitting their bike with. The EU bike Co's are refreshing to do business with because they treat cycling as transport first and foremost, a life style choice exercised daily, not just sport, recreation or weekend rides for various causes. I also brought on Toxy from Germany for the same reasons and have been chatting with the owner designer about a mod that would convert their ZR low racer into a delta trike... read more here http://www.bentrideronline.com/messageboard/showthread.php?t=87693

 

[Charles.Plager]

Hi,
Following up on Andrew's

Hi,

Following up on Andrew's comment, another option is to just convert an xtra-cycle into a Cruzbike. Here the link to the discussion on this forum, too.

It of course depends on many factors: cost, how close final product is to what is wanted, etc, but by offering the final product, you might be scratching an itch that the market has.

Cheers,
Charles

 

[Nanda Holz]

FreeRidical

Thanks for link Charles, I had seen some Xtar Cruz pix in a couple web searches and it was good to read through the comments and responses. He touched off on the same issues and upgrades I was thinking about, with the to-and-fro dog tail wagging action that would likely be amplified with a heavier load (other the plastic bottles). A disc brakes, and e-assist would a be tested in the prototyping phase, as would frame separation under the seat in front of the vertical support tube, thus the reason for parallel tubes. This would be done with a simple sleeve system, with pairs of pinch bolts on either side and a free floating inner joint tubes (which could also be welded to one half), and finally a perpendicular cross bolt with a ny-lock nuts to keep it from unintentionally separating. This would allow a few these, break down for travel for would wide cycling touring and smaller frame kit shipping, and the ability to make a new front half for other Cruzbike model head tube geometries, as well as other back ends if some revelation occurs for a simpler of more advanced design.

 

[Nanda Holz]

Here is the Xtra-Cruz frame

Here is the Xtra-Cruz frame concept overlaid on the Sofrider, just had to line up the headset.

Here is the Silvio and Sofrider image layers turned on over the Xtra-Crubike frame concept.

I am actually thinking that for the best cargo setup, a dual 20" (406mm!!!) could be the best option with an overall lower center of gravity, and gearing...after reading up Sam's design.

Read this and watch the interview by designer Sam Whittingham:
http://momentummag.com/articles/cargo-bike-review-xtracycle-edgerunner-electric/

http://www.xtracycle.com/blog/edgerunner-series-part-2/

 

[Nanda Holz]

Xtra Cruzbike concept 4

Frame separation's added with internal sleeve tube added, and 36V battery shown below main frame.

1.5" top tube, 1.25" lower tube

50" wheelbase to clear Xtracycle with seating system

 

[Nanda Holz]

XTRA CRUZBIKE CONCEPT 5

This latest design fully accommodates a stock Xtra Cycle Free Radical, instead of building a frame that uses their standards...so just a plug and play design which will likely be the simplest to build as well

Using the complete Xtra Cycle saves a lot of time, as all the specifics with regards to geometry, hardware, and clearances for their accessories is already sorted out instead of created a specialized frame around their avialable design standards. The only trick is the 135mm spacing if you are using a front wheel in the back of this cargo conversion. I've founds a few Surly and Salsa 135mm front hub with disc brakes that could be laced up and would be very strong with the wider triangulation of the spokes vs. a 100mm traditonal hub, so perfect for load duty.

A traditional lower bb shell is used with full length chainstays that can be straight instead of bent because there is only a small tube to get around (maybe with horizontal rear facing fixie dropouts for quick installation and disassembly). I think the simpliest upper seat solution is something like the RANS telescoping struts with tabs on the mini seats, which stays in front of the Xtra Cycle frame and their bags that wrap around the front face of the frame.

Both downtubes are not 1.5" diameter...keep it simple right.

 

[Nanda Holz]

Latest design


Here is a look at what be the "black box" piece to adapt the new rectangular XtraCycle Leap 26 (to be released around June)...to a Cruzbike Sofrider.

Now I just have to get my hands on a Leap 26 production prototype and or drawing

The front tube telescopes, which is makes it much easier to shorten up the wheelbase then the fixed tubes on the FreeRadical.

This setup would make the total wheelbase somewhere between 4-6.5" longer then the stock Sofrider

Here is a rider that toured recently on his DIY Cruzbike style bike with a full load...and I am hoping to clean up this rig with the Xtracycle bits and make it accessible to people that want to buy a touring setup off-the-shelf vs. DIY.
http://www.bentrideronline.com/messageboard/showthread.php?t=94170

With an even longer wheelbase design, a crank could be mounted in the lower pivot bb position for a impromptu tandem ...if the knee clearance is adequate. But I imagine a dedicated rigid frame would be best for a tandem application.

 

[gannet]

I'm thinkin' that the

I'm thinkin' that the Softrider option looks better. A simpler bolt off/on job. As the Silvio was always a lighter sporting bike, it would be compromising it too much.
BTW, you might have mentioned somewhere, but what software are you using to do the drawings? Could have a bit of fun with that. I recently downloded Sketchup ( good for woodworking) , but haven't had time to try it.

 

[wwp3gamer@gmail.com]

framework

Have you given any thought to square tubing? It's a lot stronger than round for the heavier loads that touring bikers have.

 

[rjs]

Quest

Would a xtracycle adaption for the softrider also work for the quest? I would be very interested if it did.

 

[Nanda Holz]

Cargo musings con't

Here is the latest on the Cruzbike Sofrider + Xtracycle concept.

Square tubing is a great suggestion and something worth looking at if there is any way-the-dog flexing when loaded.

Adapting the Xtracyle FreeRadical to a Quest would also be a fun project, but for a more limited market. The new Sofrider with it's rigid fork and overall stouter will be the model best suited for cargo duties. The other priority is making this system available to a wider range of riders, and the lower priced Sofrider helps in that respect. The rough target price for having a fully optioned modified FreeRadical on a Sofrider will be around $2k+/-.

$1,195 - Sofrider
$319 - FreeRadical Classic (base frame, deck, racks, bags)
$150 - Kickback kickstand
$150 - Modifications est.
$100 - 2nd rear wheel
$1,914 est. total

I also sourced a Surly 135mm front disc hub w/o all that space for a cassette (for the 4" wide tire phat bikes), so a true load worthy rear wheel can be built up with more spoke triangulation, if a standard cassette-less rear wheel has any issues.

My daughter is excited, because we'll finally be able to put a child seat...on a recumbent, and she will have an even better view looking over my shoulders instead of just at my love handles

 

[John Tolhurst]

"My daughter is excited,

"My daughter is excited, because we'll finally be able to put a child seat...on a recumbent"

Well, that is partly true, in that the kids love it. But you are many years behind being first. I've been doing that all along with both sofrider and quest. For sofrider I hand made a beam rack of sufficient strength, for Quest you need only puchase the heavy duty rack and mount the child seat on that.

My solution for the child seat trumps yours Nanda, because it costs less and ensures the child seat is on the suspended part of the bike.

For the cargo load solution - kudos! I like what you are putting together.