Saturday, June 20, 2015

Not very bike related

Well, it's not a bike, but many of you who know me know I'm also car guy.  I'm thinking about putting my baby of 17 years up for adoption:


It's a 1992 Sunburst yellow miata which I've owned since 1998.  The list of upgrades is pretty long as it's been my project for 17 years.  The condition is phenomenal, particularily for a 23 year old car.  All paint is original and in excellent condition other than the lower front air dam which has some rock chips.

114,000 miles which for a 23 year old car is mighty low.  Compression on all 4 cylinders is right at OEM spec (I'm happy to measure it for serious buyers).

It has a Jackson Racing M45 supercharger with Big Boost Kit and a slightly turned down nose pulley on the blower providing about 9psi of boost.  The Supercharger system is very well sorted out, meaning this is my summer daily driver and requires no special attention.  The only quirk is on cold start-up occasionally there is a small throttle waver until you start driving.  I can provide video of it for serious buyers, but it's truly a non-issue just want buyers to be aware.

Timing control is done by a Bipes ACU unit, additional fueling is provided by rising rate fuel pressure regulator with JR BBK black box controller, high flow fuel rail and larger 254cc injectors and of course a higher pressure fuel pump (part of the JR kit).  Also has an O2 clamp.

Here's a more complete list of upgrades:

JR m45 supercharger kit
JR BBK kit
Bipes ACU
High flow fuel rail and injectors
Roadster sport stainless exhaust with OBX header
DDM works air intake heat shield
Innovate Motorsports LC-1 wideband Oxygen sensor and controller/guage
Flyin' Miata stage 1 clutch (best feeling high clamp force clutch out there!)
ACT lightened flywheel
Autometer boost guage (and LC-1 guage) mounted in custom stainless surround in dash
KYB GR-2 shocks, new this year
969 Racing 6UL 15" wheels with Toyo Proxies and Mcgard spline drive lug nuts.  Mounted, balanced by Goodwin Racing.  Very good tread left, best tires I've ever had on the car!
Hard Dog Duece roll bar
Robbins sunfast canvas top with glass window (new in 2013)
Voodoo shift knob
IL Motorsports center console (best cupholder and center console available!)
Leather shift and brake boots
Chrome shift boot and vent trim rings

It's a blast to drive and is daily driver reliable.  It's never been raced or driven on a track, I just like a fun road car.  Performance-wise, if you wanted to get faster the next logical steps would be intercooling or water injection and then a stand-alone ECU,

Condition is great.  The car has been waxed more times than it's been driven in the rain.  Never seen snow, it's garaged every winter.  If you're serious, let me know and I'm happy to share more details.

I'm thinking around $8000 seems fair based on the condition and upgrades.

Thanks

Bob















Thursday, April 09, 2015

fat review

I've been meaning to write a summary post of my first winter of fat-biking for a while.  Now that spring is pretty much here, I'm finally getting around to it.  This winter was pretty terrible as far as MN/WI snowfall went.  Usually I spend the winter xc skiing but there just wasn't snow so I opted for fat biking.  I have to say it was the best move I could have made.



People who know me know I've been pretty skeptical about fat bikes in general. Every one I had ridden felt like a big, slow, clunky bike with a horse riding-esq pedal position.  My goal with building this bike was to overcome all those.

I feel the biggest single problem with most fat bikes is simply the ridiculously wide BB which positions the riders feet too far apart for efficient pedaling.  I knew from the start I wanted this to feel racier for hard-packed trails (ie White-tail ridge). It's not meant for all day trekking through deep powder,

For those reasons I limited the tire size to a 4" tire on a 80mm rim, that's plenty big enough for hooking up on anything other than deep unpacked stuff.  I also knew I would be fine with a single front chainring.  1x set-up's have gotten so good now I just couldn't see a need for a front derailleur.  With those constraints I did some detail design work and researched cranks.

Most modern MTB cranks flare the arms out much wider than needed for reasonable frame designs, normally I hate that feature as it makes the Q factor unnecessarily wide, but for this application it's an advantage.  All that extra flare leaves room to move the single chainring further outboard and still allow the chain to clear the crankarm.  With some custom machining I was able to move the single ring about 1cm further outboard than stock.  That combined with a 170mm rear axle spacing and some very heavily shaped chainstays I was able to cram it all in there:

Standard 73mm BB shell with Sram X1 cranks, 4" tire on a 80mm rim, full 10 speed cassette, and the chain clears the tire in all gears.  There is about 6mm of tire clearance to each chainstay and 4mm to each crank arm.  In a nutshell, it's very tight but it works!


The geometry is also more mtb-like.  A little faster front end handling, lower bb drop.  Between the lower drop and narrow q factor it feels pretty much exactly like you're riding a 29'er just with a lot more float and traction!  It's not just me, everyone that has ridden it says they're shocked how much it feels like a "normal" mtb.  

The trade-offs are the tire width limit, but for packed trails it works great.  If you like to wear loose pants, they may rub the rear tire since your pedals are closer to the tire, but with tights it's not an issue.  Lower drop would make your feet drag in deep snow in the powder, but as I said it's a packed trail bike.  I think for it's purpose, this design cannot be beat!  It's completely changed my notions about fat-bikes.

Just my humble opinion : )

bbbb

Thursday, February 05, 2015

small and fat

This is somewhat of an anomaly for me, but I finished up 2 bikes this week.  One is rather small and one is rather fat:

This one is a women's lugged loaded tourer.  Lugs are custom carved with the new owner's Thistle design.  Lots of sweeping curves makes for a pretty nice looking frame.  The couplers in curved tubes were difficult but came out very nice.





Then there's this fat guy:


 Lots of curvy tube goodness on this frame.  The paint is icy white with some winter theme touches.

This is the magical part.  This fat bike doesn't have the typical 100mm super-wide BB and cranks.  It has a 73mm bb shell and uses a standard Sram X1 crank, but I did some custom work on the crank to move the ring outboard.  With a single front ring and the appropriate engineering, this bike fits a 4" tire and has a q-factor of 168mm!



Thursday, January 22, 2015

Museum opening night event

Goldstein museum opening night party is tomorrow.  It's open to the public, you should go:

https://www.facebook.com/events/782101631852490/