July 23, 2013

The Fork

The bike build has been taking a back seat to many other projects over the past year.  I have managed to get some work done on the bike, however it is not yet complete as I would have liked when I began posting a year ago.

As far as components go I had Martin from Hoopdriver Bicycles Lace up a set of 36 spoked PBP rims to Crand Cru hubs.  The wheels are visually stunning, and although not as light as a modern day race wheel, they are far more reliable given that this bike is intended to be a gravel road randonneur.  I would not feel as comfortable riding a great distance on rough roads with only 18 spokes between me and the gravel.

The gravel (and mud) will be kept at bay with VO hammered aluminum fenders.  Stopping power will be administered via Grand Cru long reach brakes.  I am impressed with the reported power of these callipers as well the available clearance for larger tires and fenders.  Power to the wheels will be turned over by the VO 50.4 BCD crankset with the added torque of a 172.5mm arm.  The gearing is closer to that of a compact drivetrain with shifting managed by a Microshift 10 speed double.  If a larger set of rings will be needed the 50.4 BCD allows me the flexibility to substitute larger TA rings or VO rings.  I am assuming a complact drivetrain will adapt to the gravel just nicely.  Chances are I won't be out for large group rides on this machine.

The cockpit controls utilize the Microshift dual control levers mounted to a Soma alloy bar.  So far I have brazed the front end of the bike.  I started by brazing the steerer tube to the fork crown followed by adding eyelets to the fork ends.  I took extra care to mitre the fork blades to have just enough clearance at the same time taking care to ensure the fork ended up in correct alignment.  The brazing went well thanks to a simple fork-down style bicycle holder (intended to be mounted in pickup truck beds) I picked up at MEC for $25!  This served as a make shift fork jig to ensure the dropouts were held in place during brazing of the ends and the crown.  I was happy with the shorelines this time around.  There is a small amount of sanding and filing to do around the shorelines on the fork, a job I will put off until the rest of the bike is done.

Here are a few pics of the progress thus far:

More to come... in the next week.

June 23, 2012

Bar and stem

Once the brazing was done I started the finish sanding on the stainless steel lugged stem for the new build.  I have several minor blobs of silver to clean up at the shorelines.  Things did not go as smoothly as I would have liked.  This was my first attempt at brazing in a number of years, with the exception of brazing some copper plumbing pipe.  I was able to get enough heat into the lugs and tubing with a MAP torch as well as a propane torch.  I used the system 48 flux for the stainless lugs and tubing as recommended but found it much more challenging to get the silver to flow.  I didn't find it as hard to get things flowing with non stainless.

The shore lines were not as clean as I was hoping for, but on the positive side I was able to keep my alignment of the bar lug perpendicular to the steerer tube lug.  I mitred the tubing for an overall stem length of 105mm centre to centre.  The mitres were cut using the templates I had made earlier by hand.  I was careful to be as detailed as possible.  This step helped keep the two lugs from drifting from the desired alignment.  I tweaked the the lugs to sit snugly on the teardrop tubing with a few delicate taps of a ball peen hammer on the vice surface.  Once I was sure I had the correct angles I pulled the lugs off and applied a very liberal amount of flux (too much I think).

I will need to stock up on a few extra Oxygen cylinders for the MAP system as I ran out before finishing the bar lug.  I hope I don't have this problem with the steerer tube joint as it is going to take a considerable amount more heat the penetrate the thick walls of the steerer tube and fork crown.  I was able to finish up using the propane torch.  One thing I found different with brazing silver was you need to actually melt the silver in the flame as opposed to letting it melt on the hot metal as with copper tubing and lead-less solder.  I almost felt as if I didn't have enough heat in the tubes, however, if I kept the torch in one spot for too long I quickly saw the metal start to glow past a dull red.

Overall I think its an okay job for the first attempt at the torch.  If at some point in the future I want to replace the stem I can whip up another one as the kits are readily accessible.  I would consider the possibility of practicing fillet brazing on a stem for a future project before committing to a full fillet brazed frame.  In doing so I could use one of the two lugs supplied in the kit and fillet braze on the other end.  But for now it's on with the rest of the build.

On another note my headset I ordered last month arrived at Hoopdriver this week.  I took the opportunity to take advantage of the hot summer weather and rode down to the store to pick it up.  I can now do the layout of the frame and fork as I was not sure what the lower stack height of the  headset was.  The internet is a great thing but not all product information is available.  All that was listed in the on-line specs was the overall build height not the upper and lower stack heights.  12 mm was not what I had assumed for the lower stack height.

I have determined I have just enough clearance for Velo Orange 35 mm hammered fenders with the Grand Cru long reach brakes.  There will be enough for a 10 mm gap between the tire and the fender.  An interesting note, the Continental Gatorskin 28 mm tires are not actually 28 mm in width on the PBP rims, they are just under.  I will have more clearance between the tire and the bottom lip of the fender.  Even more room for a piece of gravel to clear without binding between the rim and the tire.  I am eagerly awaiting the completion of this build so I can venture out in search of southern Ontario's strada bianca.

May 04, 2012

Tricky Stem Mitres

I started some of the prep work for the mitres on my custom stem for the new bike today.  Typically one would use a program such as Tube Notcher to obtain a computer generated template for the tube to be mitred when cutting the tubes by hand with a hack saw and file.  This program (and several like it) allow you to input the outer diametres of both tubes, wall thicknesses and angle at which the two tubes meet.  The program calculates the mitre lines from the input and provides a printable pattern with which you can trace onto the tubes or wrap around as a paper guide.  I especially like some of the programs which provide templates for seat stay mtires and cross braces.  This is a quick and easy way to map out your work before you make the first cut.  Then there is the more complicated method of constructing a template by hand using a ruler, tape measure, angle finder and a good eye.

I decided that I would start work on the stem ahead of the frame and fork.  I would rather make an error on the stem as I develop my brazing technique than botch a fork or worse, the frame.  It would be easy enough to start by brazing the fork crown to the steerer tube and call it 'step one'.  Seeing as I have a bit of an excess length of stem tubing I thought I would start there for two reasons: one, if I were to make a mistake I could undo the braze and start over with the left over length of tube, and two, if I really screwed things up I would only be out the materials for the stem and I could still proceed with the frame and fork while I re-ordered parts.

The catch here is that I am not able to use tube mitre to create a template.  These programs are great so long as you are working with round tubing.  The stem kit I am using for this build is only available with a tear-drop shaped stem tube and matching lugs.  I would have rather been able to use a tested method for my first mitre, but alas it is not to be for this stem.  My one concern is being able to keep everything in phase since I will have less room for error with the tear-drop shaped tube.  The tear-dropped tube has a minor imperfection at the weld site along the length of the tube.  I am hoping this will not lead to a visible gap at the join with the lugs.

I used as much accuracy as I could in creating a paper template which fit both snugly over the tubing and as well inside the lug cavity.  If all goes well it will help me produce a clean mitre.  I was planning on using silver to braze the stem together, but I am now considering using brass, as I have plenty of brass rod an flux, more so than silver.  I will save the silver for the frame and fork lugs save for the steerer tube which I will braze using brass.

Transferring the template to the tube so that the lugs will end up in phase will, I expect be a little tricky.  If all goes well I will mitre the tubes to fit securely in the lugs with gapping at a minimum.  I will fabricate a crude jig to help keep things in alignment as I bring the joints up to temperature with the torch.  For now I will start by mitering one tube end and inspect for any extra gapping that could lead to a loss in alignment.  This stem will be brazed at a length of 105 mm centre to centre.  There is more than enough tube left over if I end up being too far off the mark to start again.

Tomorrow I will cut the mitres and clean up the lugs to get rid of the finish left behind by the investment casting process.  I am hoping to polish the lugs to a high sheen.  I have given some thought as to whether or not I will have some of the lugs on the bike chromed.  I will have to inquire as to how much it will cost as I have absolutely no Idea at this point.

 Once things are set up in alignment I will light the torch and braze my first joints.  Then it will be on to the fork crown, blades and dropouts.  Fingers crossed.

April 26, 2012

A rough sketch on Bike Cad

I have been spending the past few days measuring and comparing notes on my bikes, primarily a comparison of my my current road bike and those of the measurements that I have calculated for my first custom road bike.  It turns out that my Specialized Sirrus road bike (from the early 90's) is relatively close, in terms of angles and measurements, to the bike I intend on brazing.  This reinforced my belief that the Specialized does indeed fit me quite well for a stock production bicycle.  I did change a few items on the bike such as a longer 100 mm quill stem, 42 cm ergo bars with a 90 cm reach and Selle Italia Storica saddle.  All of which seemed to dial in the comfort level dramatically.

The Specialized Sirrus has a 54 cm seat tube, 55.5 cm top tube and 42.5 cm chain stays lengths. The 72 degree seat angle and 73 degree head tube angle are not that aggressive, however the bicycle responds very well to my input.  I especially appreciate how this bicycle feels while cornering.  The chain stays are of medium length with an average bottom bracket drop of 7 cm.

I plan on building my first frame with similar characteristics.  The lug set from Long-Shen has a 73.3 degree seat angle and a 73 degree head angle.  I will stick with a standard 7 cm bottom bracket drop.  The measurements I have calculated for this bike will have a 54 cm seat tube and a 54.75 cm top tube.  The stem will be brazed at a length of 105 mm.  This is close to the measurements of the Specialized, however it will differ slightly in the length of the top tube.  Currently I am deciding between a 43 or 43.5 cm chain stay length spaced at 130 cm for a 10 speed cassette.   I am basing these calculations on the 700 c X 28's that I will be running on the new wheels and the current clearances of 23 cm tires and planet bike fenders on the Specialized.  I will need to accommodate for clearances of the 37 mm fenders while still leaving room for brake pad adjustment using Grand Cru long reach caliper brakes.

I have heard fantastic reviews of these brakes and look forward to comparing the stopping power with what I am currently using.  This bike will have a bit of a Velo Orange/Grand Cru theme as I also plan on using the Grand Cru 50.4 bcd crankset as well.  I  still have yet to decide on a saddle, seat post, handlebars and tires for this bicycle.  I have, however decided to opt for a less expensive 1" threadless headset made by Tange.  A Chris King 'nothreadset' is still the best in my books but I can't seem to justify the added price.  Martin from Hoopdriver Bicycles has placed an order for one which should be arriving within a few weeks.

I have also ordered a set of Velo Orange PBP rims laced to Grand Cru hubs from Hoopdriver.  My skills are severely lacking in the wheel building department.  Not wanting to mess around with a brand new set of rims and hubs I am having Martin build up the wheels.  Some things are best left to the experts.  I chose to go with 36 instead of 32 holes so these wheels should be bomb proof!  I'll save wheel building practice for my next build project.  For now I will practice by adjusting my poorly built machine made mountain bike wheel sets on my truing stand at home.

I drew up a quick sketch of the bike using Bike Cad on-line.  Since I do not have the headset, wheels and brake calipers in my hands yet I have not actually done any real calculations of fork length and trail given that the fork crown will have a 7 degree offset and straight blades.  There appears to be a slight possibility of toe overlap in the Bike Cad drawing, however the settings did not let me change the fork angle on the basic web application.  Since I have yet to calculate my 'actual' fork offset and trail measurement with my set up I have relied on the Bike Cad being close enough at this point.  In the event of toe overlap I might extend the top tube by a few millimetres to compensate.

Bike Cad sketch

There is something nice about being able to see a visual layout of the bike before it is actually constructed.   This is more or less how I pictured the bike in my head, although the finer details are not represented in this drawing.  

Before getting too far ahead of myself I will be sitting down at the dining room table to sketch out a 1:1 scale drawing of this build.  Having got a good idea of the overall measurements for the front triangle I will most likely start by braze the stem first before I cut and mitre the tubes for the frame and fork.  Fingers crossed, I hope to be lighting the torch in the next few weeks.  Once the basement floor is painted I can finish setting up my workshop to actually function as a work area rather than a pile of boxes and bikes hanging from the rafters.  Sadly this seems to be the one task causing me the most amount of anguish.

April 19, 2012

Dual Control Experiment

In a previous post I explored the idea of equipping the new build with Retroshift adapters and brake lever mounted thumb shifters.  The idea seems like a reliable way to achieve shifting from the hoods at a reasonable cost, not to mention the benefits of serviceability with this system. I am still curious about this setup however I  have decided to go with conventional Dual Control levers for this build.

Over at the lazy randonneur's blog, Vic has acquired a set of Retroshift equipped levers and intends to review them on his new 26" long haul trucker build.  I am in eager anticipation of his feed back as he is a reviewer who tells it like it is.  Although his long haul trucker build will not be his go to long distance bike, he is sure to be putting in some decent miles on it in the near future.  I am interested to see what these levers will be like for a randonneur as opposed to their intended cross rider market.

In my research for parts and components for my build I came across a drive train system that immediately caught my attention.  I decided early on that a ten speed double set-up is what would suit the intended purposes of this bike nicely.  Since I am building this bike from scratch and will not be transferring any components over from my other bikes, this gave me a certain freedom to pick and choose so far as my budget and my sense of aesthetics allowed.

In my attempt to keep within a reasonable budget I came across a review of microShift's Dual Control levers and derailleurs.  I had never heard of microShift before but was impressed with their line up of drive train components.  What blew me away was the price!  As far as I have read from the reviews there seems to be no lack in performance in shifting, nor any complaints or issues regarding durability.

MicroShift is an engineering company based in Taiwan and has been in production of Dual Control levers and components since 1999.  Although Sram, as a drive train component manufacturer also arrived on the scene about this time (Grip shift 1988, Sram derailleurs 1997), Sram's success with acquisitions and marketing has allowed for a greater share of the north american market.  While Shimano, Campag, and Sram have been battling for market share, microShift has come in under the radar with an attractive line up of components which might cause others to sit up and take notice.

I have since ordered a set of microShift Dual Control Levers, braze-on front derailleur, and 10 speed rear derailleur form Bike Nashbar in the US.  These parts came out to be well under the price of a comparable Shimano product.

microShift Dual Control Levers (10 speed double)        SB-R102B        $139.99 USD
microShift braze-on front derailleur                                   FD-R72-F         $ 29.99  USD
microShift 10 speed rear derailleur                                     RD-R56S          $ 39.99  USD

I plan to write a follow up review of the microShift drive train once I have finished the build and put some solid miles of wear on the components.

We are fortunate to live in an age where the modern bicycle derailleur has more or less been perfected with reliable and accurate shifting available to all models of (properly adjusted) components.  Shifting has never been better, and although companies will try and make you believe that electronic shifting will be the new standard it is still too early to tell if the market will accept the added price and complexities of these new digital systems.  Mavic, Suntour and Sachs tried early in the 1990's to convince the market that electronic shifting would be the next big thing, but failed to produce a reliable system.

January 29, 2012

The Tubes and Lugs have arrived!

I had a knock on the door Friday morning and was greeted by the FedEx man with a long slender cardboard package for me.  My tubes and lugs had arrived from the UK.  Many thanks to Peter from Ceeway for processing the order so quickly.  I had confirmed my order on Monday morning and the package arrived Friday morning the same week.  I have since opened up the package and inspected the tubes and lugs that I ordered.  All seems well, everything is there and in good condition.  Herer is what I ordered from Ceeway:

STAINLESS STEM LUG 'A' STANDARD                                    

STAINLESS STEM LUG 'B' STANDARD                                    
LC302R FORK CROWN. FLEUR DE LYS                                 
LT302R FLEUR DE LYS TOP HEAD LUG                                 
LD302R FLEUR DE LYS BOTTOM HEAD LUG                          
LS302R FLEUR DE LYS SEAT LUG                                       
LB302R CAST FLEUR DE LYS SHELL BSC                              
LR302R CAST FLEUR DE LYS REAR ENDS                             
LE302R CAST FLEUR DE LYS FRONT END                              
189 CONICAL BRAKE BRIDGE - 80MM                                     
244 CONCAVE C/STAY BRIDGE. 26MM                                    
ST-01 PUMP PEG                                                                   
362 DIAMOND FOR SEAT STAY BR.                                         
286B CAST FRONT MECH BOSS. LONG SLOT                         
477 BOTTLE BOSS                                                                  
581 BRAZE ON MUDGUARD EYE                                            
142 TERMINAL INNER GUIDE                                               
453 STOP. LARGE                                                                  
313C OVERBRACKET GUIDE SET                                            
367 INTERNAL WIRE RE-INFORCEMENT                                 
SL NIOBIUM TOP TUBE 25.4                                                    
SL NIOBIUM DOWN TUBE SL2I12                                             
SL NIOBIUM SEAT TUBE SL2I13                                              
SL CHAIN STAY SL0I14OV                                                       
SL SEAT STAY 14MM SL0415                                                   
SL0I18600 SL HEAD TUBE 600MM                                           
NIVACROM STEERER 25.4MM X 320 NO THREAD                    
SL FORK BLADES. SL0I16V1                                                   
SIF BRONZE 2 1.6MM 150 G

The raw lugs are beautiful as they are.  I can't wait to see what they will look like when I put a little elbow grease on them and polish them up.  I had a thought when I inspected the tubes.  I have more than enough length with the steerer tube and head tube for for an additional frame.  I suspect this will lead me to temptation.  There is a good possibility that I will have to put the extra length to good use as I hate to waste anything.

I will be setting up my work shop in the basement and building some simple jigs for the fork and frame in the coming months.  I will also layout all the tubes and mitres as I decide on the final measurements for the frame.  I am planning to build this frame with a classic geometry.  I don't think I will set it up as a 'Crit' bike, more like a race bike for longer distances.  I will allow enough clearance for fenders as I plan on using this bike on unpaved as well as paved roads.  I have yet to figure out if I will need to go with long reach brakes or If regular dual pivot brakes will work.  I have ruled out installing bosses for Mafac styled center-pull brakes as this would add a level of complexity to my first frame that I am not yet comfortable with.  I have, however not ruled out fabricating my own custom rack similar to the one Mike Barry has built for his 'Mountain Bike'.

I will be taking my time with this build as I am currently taking a full course load at school.  For the next few months my priorities will be on finishing up the semester and setting up the shop.  I don't anticipate I will get around to brazing until early summer.  Until then I will try and post a few tidbits of my thoughts and plans for this frame and other bike related ideas I have.