February 22, 2017 Login  

My next crazy project
Last Post 02/21/2017 06:06 PM by 79 pmooney. 7 Replies.
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02/02/2017 01:59 PM
First: the challenge.  Cycle Oregon announced its route last week.  The 30th.  Every 5 years, the course is a big one.  Crater Lake is often featured.  5 years ago, we climbed to the Crater Lake rim fomr the south, then the option to go around.  I looked at the course when it was announced, signed up, then started thinking that the fix gear TiCycles had just delivered could do it!  Huge grade changes but each day, except Crater Lake, was basically one or two very long climbs withthe descending late.  Makes for not many stop ans flip wheels ans only one cog change per day.  Crater Lake I could go around with just a 23 and a 12.  For 23 miles, there are no flat stretches.

This year's course is to Crater Lake again, from the north.  Very similar course profiles.  Jessica, the ti fix gear, would be perfect EXCEPT - there are three days with 15 mile grave options.  A couple of long climbs and a very real multi-thousand foot descent.  No way I'm doing those on 25c tires and a 54" (42-23) low just doesn't cut it.  I'll be 64 years old for crying out loud.

Then my brain dis what it loves to do.  It found a way to ride the course fixed AND stretch the ratios.  Ride the Mooney.  It can handle 35c ties easily.  Put them on for the three gravel days.  Ride 27c Opens the rest.  Bike has horizontal drops which I spec'd 39 years ago so it COULD be ridden fixed.  Now's its chance.

I have heard of using two chainrings and chainlines to get two very different gears on the same chain and with short dropouts.  (Mine is the classic and in the 70s very common Campy, not the long version.)  But two gears?  What two gears does a 60 yo pick to go up 8% gravel, down 10 miles of 5% plus and 20 miles of flat?  Fixed.

What about using a "dingle", two cogs fused together and screwed on like a single, on one side and a little descender on the other.  Three chainrings.  Googled the cogs.  Surly makes them but they are 3/32" and Surly recommends a 9-speed chain.  9-speed?  No thanks.  I want 1/8" track sprinter strength and reliability.  This body has seen its share of crashes, including a few from gear failures.  I want stuff that is stamped, approved and certified by the Department of Redundancy Department.  1/8" drive all the way.

So, how to make an 1/8" dingle".  And that 1/8" triple crankset.  Can I get the chainlines to work?  And what cogs and rings would I need and is it possible?

Last question first.  Actually not hard.  Yes, very possible.  45-32-38 or 36 allows me to go 45-13 (93"), 42-16 (71"), 38-20 (51" or 36-22 ((44") with room to push all the cogs one tooth in either direction.  So I could set up a 17-21 dingle and put the 12 on the other side. 

The dingle.  I spent hours at my desk, cogs in hand, wheel at my side with calipers and my AUTOCad open.  I saw that the large cog could be put on backwards, ie the outside, flat surface seated against the hub.  Cog sits right up on the spokes, but does seat properly.  Should work fine.  Chain is well clear.  The smaller cog would have to be machined out as it needs ot fit over the threaded base of the large cog, now extending outboard.  I drew up a bolted version with a machined spacer between and showed it to Dave Levy.  He didn't like it but thought that the cogs could be brazed together with a steel spacer, that probably a low temperature silver solder could be found that would keep the cogs below their heat treat temp.  (There's a reason I go to Dave when I am dealing with metals!)  That would make for a very clean assembly and plenty of room for the cog wrench.  (Bolted and nutted with nuts I would trust to 4 times a chainring bolt's load would mean that I would also need a FW style remover tool and a big wrench, not
my 16 ox aluminum chain whip that works so well.)

I'm not there yet on the crankset, but my thinking is that an older Sugino 130 BCD double with its nice straight low Q arms would be perfect.  Phil Wood BB so I can dial in the chainline to be as far inboard as possible.  Good thing is that I don't actually need clearance.  Bike is due for re-paint, so any damage I go this year doesn't matter.  And 531 is hardly going to care about some aluminum teeth.  I measured a crank spider bolt hole yesterday.  10mm.  I should be able to find a 10mm shoulder bolt. Pan head or flat head (would need a touch of machining to the inside rings if I go that approach - I'll have to see about chainstay clearance)  and the nut to the ouside.  Not pretty but should be bulletproof, even with a TA erector set style assembly of the bolt going through inner chainring, spacer, middle, spider and outer.

I think I can get chainlined below 6 mm off and if I can get the rings far enough in, maybe less than 3mm.  The high gear will be the worst.  I'll probably buy some aluminum round barstock, drill it down the center for the axle, then just cut spacers as required for the hub on the table saw.

Another plus of this crazy venture - Pete needs attention.  (Pete, my Peter Mooney.  "Pete' and "Peter" is just coincidence.  I had never known a "Pete" despite having brother,uncle and framebuilder named Peter.  All to my knowledge did not like to be called Pete.  The bike is "Pete" simple because I was riding one day, year three, and just realized out of th e blue, the bike's name was Pete.  It didn't come from me.  (Funny, I had a discussion yesterday about cats.  Was told that we do not name cats.  We call them names until we find one that works for the cat and it responds.  When I have named bikes, I always end up forgetting what I named it.  Pete stuck.  It will be formalized on the next paint job.) 

So this crazy venture is in real part about falling in live with that old bike again.  It has suffered from being a true all-arounder.  It isn't great at anything.  Anything except being the one bike I could ride anywhere I was going to live 12 months of the year anytime I needed to ride to stay sane over the years after my head injury.  For that it was superb and for that I will be forever grateful.  And now?  How many bikes out there can ride very hilly gravel roads fixed in style?  And I could even go crazier and throw panniers on it and tour in that mode!  It carries load very well.  (Jessica is my pre-derailleur TDF - but post paved roads - racer.  Pete is my 19th century tourer.)

My Raleigh Competition could do this except it has one huge barrier - a low BB.  It's a pedal scraper.  Wonderful a lot of the time, but scary as a fix gear and it will never do that.  The Mooney has a 10 3/4" BB height with small tires.  Very suitable for 175s fixed.  Barely lower than Jessica and more than my winter fix gear.

This also gives me a physical challenge.  I need that.  (And maybe, just maybe, get me into shape to ride a climb with Suzy Jones, my sister mountain goat.  We did a magic 15 miles of climbing together out of Ashland 5 years ago when we were both completely spent, day 4 of consecutive huge days of climbing.  Saw her for the first time since last Sept but wasn't remotely fit enough to stay with her.)

This could be fun!

Now off to rebuild my Sachs 7-speed.  New chain skips on almost all the cogs.  Picked up three used 8-speed yesterday.  In the future, Pete is going 130 so they may see use and I am betting I have some usable cogs in the meantime.  And I just bought and rebuilt some Power shifters just like I set it up with originally.  What great shifters!  What great shifting.  So I am off.  I'll report back as the 3X3 takes place.



02/02/2017 07:49 PM
Wow, Ben you are an inspiration!


02/03/2017 03:19 PM
Beast! ...but but a beast without a camera or the wherewithal to post pics of all the cook stuff you do.

Would sure like to see photos of all the bikes and modified cogs you have!


02/03/2017 03:59 PM
No modified cogs yet. But I do have my 12-speed fix gear cluster, 12-23 straight. (All those cogs hung on a loop of bailing wire.) That cluster has now done 4 COs (but I don't think I have used all the cogs. I don't think the 15 has been ridden at CO and perhaps not either the 20 or 21.

This won't be my first time at drive train innovations. I rode Mt Washington in a previous millenium on a TA 28t single. I cut an old outer ring down to just the spider, then bolted the 28 directly to it on the inside. Perfect chainline to my middle cog. 13-21 5-speed FW wasn't far from perfect once the hill started. And the opening 1/4 mile of 28-13 - great warm-up though the two guys who started with me were out of sight when I hit the hill!



02/05/2017 03:02 PM
I'll bet they were back in sight pretty quickly!


02/13/2017 11:28 AM
Yes!!! We need pics!!!!!!!!!!!!


02/13/2017 11:44 PM
Of course, there is something else I have to get in order to make this crazy idea to work. My body. The past year plus has been less riding than I have done in the past 15. I am quite aware that setting priorities doesn't cut it. I have to carry out those priorities!

Got off the plane from a California trip (family service) past 11 Saturday to a forecast of three beautiful days. Got out yesterday for 38 miles fixed, 53F and light wind. 42-18. Today was the same except more wind, straight flags much if the time. Rode 52 miles, half on the 17, rest on the 18. Tonight? Whipped! Tomorrow ~ 30 miles. Wednesday (and I suspect the next 5 days) rain and a day or two on the trainer.

Since I am not working, I am going to try to ride three days in a row when we get windows of good weather. Should help at CO where I will be riding seven.

I keep thinking about what I need to do to get the Mooney (Pete) into true fixed gear climbing condition. On is the handlebar setup. Currently fairly narrow traditional road bars and levers with cantis. Cantis are fine. ('80s OEM Shimano calipers, really good!) But those handlebars and levers will get really old climbing fixed. I want pista or Cinelli 65 style bars with the sloped "shoulders" that offer such a wonderful seated power climbing position, huge levers and 43-44 width bars. (39s are best fit to my skinny shoulders but 44s offer easier climbing and more secure high RPM descents. (ANd more wind resistance. Most people think less wind resistance is better, but, believe me, more is better downhill when you are riding fixed, by a lot!! ) In the past on Jessica J I have used two "cockpits, a road setup with SunTour Superbe brakes and pista bars, huge hooded V-brake levers and dual pivot brakes. This year I want to keep it simple, so one cockpit. Plus this year there is one (1) day without a 2000'+ climb. The next easiest day only climbs 2500' but descends 7000.

So how to get V-brake hoods to work with the cantis? (The Tektro V-brake levers are much bigger than any regular lever.) I could go V-brake lever and a reversed travel agent but that doesn't sound simple and bulletproof. An idea I have had is to get the V-brake hoods. (This is Tektro - won't break the bank if I have to buy the whole lever.) Make a base, perhaps carved out of wood, that will extend a regular lever to V-brake length and make some longer metal straps to go around the bars. Put the big hoods over the extended lever.

I think I will try the V-brake levers as is with the cantis first. I don't mind losing a little braking power as you really don't want to lock things up on hard slows at speed riding fixed. (The Superbes and regular levers are a fair amount more power than I like going downhill.)

This is going to be fun! Pete gets to stretch out a little, do some things other bikes don't get to do.



02/21/2017 06:06 PM
A lesson: go check your stock! Bought (2) chainrings, 47 and 39 All-City 130 BCD. Went to mount them on my old Sugino arms from my winter/rain/city fix gear. (Retired because a good portion of the cross section at the balls of my feet is worn off by thick socks and winter road grit.) Surprise! I've been riding 110s all this time. Went on line and there are lots of 110 1/8" chainrings. Most are cheap and boast of being 6061 T-6 like that is something special. (6061 T-6 - a good aluminum in high salt water environments and very corrosion resistant, moderately strong, hardened to decent hardness. As a bicycle chainring? Not crap but nothing special at all.)

I wish the BMX crowd was still into 1/8" and 110 BCD. The Haro ring I bought a long time ago was a seriously good ring and lasted me years. Kinda gaudy but I will live with that.

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