Hybrid Gearing

448

Sachs Orbit 2 speed hybrid hub with 6 speed cassette

I became interested in hybrid gearing after acquiring my 1973 Jack Taylor Tourist, about 9 years ago.  The bike features a single front chainring, 6 speed cassette and a 2 speed Sachs Orbit internal hub.  That gives it 12 gears overall, with a good range for the kind of riding I do, as the internal hub’s lower gear is about a 33% reduction, which is quite significant. For awhile, I didn’t think much about this interesting arrangement, and instead just enjoyed riding the bike, and being able to do a substantial downshift while sitting still at a stop light.

2015-02-14-005

Sachs Orbit 2 speed hybrid hub with 6 speed cassette.

There are a number of ways to accomplish hybrid gearing.  You can forgo a front derailleur, and use an internal two or three speed hub to take the place of multiple chainrings.  You can also use multiple chainrings with an internal hub, and forgo the cassette/freewheel.  Or, you can be like Sheldon Brown and do both, achieving a 63 speed bicycle – his beloved “O.T.B.”  which used a 3 speed SA hub, a seven speed cassette, and 3 chainrings.  Doing the math:  3 x 7 x 3 = 63.  So with modern technology, let’s calculate the possibilities:  a 14 speed Rohloff hub, paired with an 11 speed cassette, with a triple chainring = 462 gears!  Probably that set up would be a mechanic’s nightmare, so if you really want this many gears, I suggest you purchase a continuously variable NuVinci hub – but be prepared to deal with quite a bit more than a couple of pounds of extra weight.

2017-02-07-009-copy

Sachs Orbit hub – NOS early 90’s with two optional cassettes

There is really only one source on the internet for information about the Sachs Orbit 2 speed hybrid hub, and that of course is the Sheldon Brown site, with additional information and clarifications by bike guru John Allen.  One of the things I worried about with this hub on my Jack Taylor was being able to find replacement parts, given that the hub was so rare.  Fortunately, a while back I found a NOS Sachs Orbit hub, pictured above, which I could use as a replacement in case something went wrong.

2015-11-06-005

1973 Jack Taylor Tourist Sachs Orbit hybrid hub

Meanwhile, the original hub is working just fine, and needed only occasional lubrication with automotive oil.  I had sent the hub out for a rebuild nine years ago, and it is working perfectly, still.

2017-02-07-017-copy

Info on the box of the replacement hub seems to indicate this is a 1992 hub

2017-02-07-004-copy

Very pretty hub logo engraved into the hub shell

2017-02-07-007-copy

Be careful with these spindles!

2017-02-07-010-copy 2017-02-07-001-copy

The replacement hub I purchased is quite lovely, and has two different cassette options – for 5 or 6 speeds. The cassette cogs and spacers slip onto the freehub with tabs to line up the rings, except for the final smaller cogs, which screw onto the freehub.  As one pedals, these smaller cogs with screw-on threads will get tighter and tighter.

Because this replacement hub is so nice, I have been thinking about using it to build into an interesting wheel set for a road/commuter bike, rather than keeping it in reserve for spare parts. One of the convenient features of this hub is that it can be operated by pretty much any front derailleur shifter, as there are only two positions on the hub.  And, if something goes wrong with the hub on the Jack Taylor, maybe I will rethink hybrid gearing altogether.

2015-02-13-025

1973 Jack Taylor Tourist

The bike’s rear wheel was an alteration from its original 1973 build, and whether or not this rear wheel was built by the Taylor brothers is unknown.  However, I have noted that British bikes built in the 60’s through the 80’s sometimes featured hybrid gearing.  This was especially true for the boutique manufacturers of that era.  Sachs internal hub gears are considered on par with Sturmey Archer, and I will say that is true, based on my experience with riding this Jack Taylor. The hub has been totally reliable.

2017-02-07-003-copyorbit_expl

This early 90’s Sachs Orbit 2 speed hybrid hub has 36 holes, so it could work with a number of possible rims.  It needs a bit of lubrication to bring it back to full glory, and if I end up needing to rebuild it, John Allen and Sheldon Brown will come the rescue.

1950 Raleigh Sports Tourist – 45 lbs of Riding Pleasure

2016-07-29 007

I recently cycled home from work on my 1950 Raleigh Sports Tourist.  The bike had been sitting at my office for a while.  One of the reasons I haven’t ridden it with greater frequency is that the full chain guard (“gearcase” for those who speak British) and the drive side crank arm contact each other with an annoying noise with each pedal stroke.  Previously, I had tried to solve this problem by mashing various parts of the gearcase with my hands to see if I could force it into a different position that would provide clearance for the crank arm.

2016-07-29 008

As I was noisily making my way up Clinton Street, I came upon a rider on a Mercian.  We chatted for a while and I learned he was riding an early 80’s model that a friend had given him as a frame (nice gift!), which he then built up.  That’s only the 2nd Mercian I have spotted in Pdx, aside from my own.  Interestingly, because my Raleigh is geared so high, I ended up surging past him in my big (but lowest) 52 gear inch as we began to climb the steeper hills, and so we parted company.

When I arrived home, sans heart attack, I put the bike into the shop stand, determined to solve the gearcase/crank arm clearance problem.  The first thing I did was to mark the position of the axle in the dropout and the adjuster on the shifter cable.  This way, I could restore the wheel and cable back to their current position – something which took a while to perfect so that the hub shifts correctly.

2016-07-20 005 2016-07-20 006

One thing I’ve gotten questions about before is how to get the gearcase off the bike.  There are two pieces at the back of the gearcase which can be removed by unscrewing the bolts which attach them to the main part of the gearcase.  After that, there is a bracket which attaches the gearcase to the chainstay, plus a bolt which holds the front part of the gearcase, and attaches near the bottom bracket.  Once those are removed, then it’s a matter of re-positioning the gearcase and sliding the opening at the back through the narrowest part of the drop out.  The photos above show how this is done.

2016-07-20 001

Once I had the gearcase off, I took my mallet to it and tried straightening it out a bit.  Then, I tried various methods of altering the position of the gearcase once I re-mounted it to the frame, but nothing worked.

2016-07-29 010

Finally, I took my files and filed away a small section of the metal on the inside of the crank arm, to provide more clearance.  I didn’t want to take a lot of material off.  But with these solid steel crank arms, I probably have nothing to worry about.  Ultimately, I was successful in adjusting the gearcase cover to eliminate any contact with the crank arm.

2016-07-20 003 2016-07-20 004

Since I had the pedals off, I thought it might be time to overhaul them. Their last overhaul was 8 years ago.  Sure enough, the grease was pretty dirty.  Fortunately, the brilliant design of the cone and lock washer made the process incredibly quick and easy.  The tabs on the back of the cone make it simple to adjust the cone to perfection.  Once adjusted, the cone’s tabs lock into position with the grooves on the lock washer.  If your adjustment needs a tweak or two, just loosen the nut and move the cone one notch at a time.  If only all pedals were designed this way!

2016-07-29 019  2016-07-29 012 2016-07-29 011

I headed out on the bike today and thoroughly enjoyed not only the new, silent drive train, but the amazing ride quality of this bike.  The steel frame and steel wheels absorb road shock very well, so that even the upright riding position does not transmit pain waves to your spine.  With the inertia of the heavy steel wheels, the bike really rolls once it gets going.  In my high gear, I have even passed a carbon fiber bicycle or two, much to their riders’ surprise.  The components, the paint, and the attention to detail in every aspect of how this bike was manufactured puts modern quality control to shame.

The bike responds to pedal strokes and never feels mushy or bogged down.  The geometry is perfect for the type of bike it is, and it does not wobble at slow speeds and provides for fun descents and excellent cornering at high speeds.  In fact, the ride quality of this bike is a sharp contrast to another 45 lb. machine I recently rode – the SoBi bicycles which are part of Pdx’s new Biketown bike share program.  Those bikes are made with large diameter aluminum tubing, and also feature an upright riding position, although much more extreme than that of the Raleigh.  The stiff aluminum frames, bad geometry and questionable component quality provide for a really unpleasant riding experience.

2016-07-29 017

It would be fun to see a bike share program which used quality vintage bicycles and de-emphasized modern technology (which serves as a barrier to those who cannot afford the latest internet device) as a way to introduce new riders to urban commuting. There are so many quality vintage bicycles out there. Find one and ride it!

First ride on the 1972 Mercian

1972 Mercian

Test riding a newly built bicycle can be unnerving.  Will the bike be uncomfortable to ride?   Will the brakes fail while descending down a steep hill?  Will the shifters slip while climbing?   Will I drop the chain while crossing a busy intersection?   Well, now I can one more possibility to the list of dreaded catastrophes.  But first, let me share how I chose this 1972 Mercian frame’s components, which I recently acquired as a frame and fork with very compromised paint.

1972 Mercian

Here it is, after cleaning, reviving, and waxing the frame and building it up.  The tubes are double butted Reynolds 531, but the transfers were lost long ago.  Fortunately, there was no rust inside the bottom bracket shell or anywhere else on the frame.  And, the compromised paint on the top tube is not that visible from afar.

2015-02-14 001

I was surprised to find brass residue inside the bottom bracket shell, left over from brazing.  Normally I expect to see silver, as is typically used.  Since silver can be brazed at lower temperatures, there is less chance of overheating and weakening the main tubes.  That led me to research how these frames are built and I discovered the whole frame is heated, after tacking the lug points, in an open brick oven, with natural gas.  Apparently, this evenly heats the areas to be brazed, so the chance of overheating doesn’t exist, as when one directs a flame at the lug joints.  Each builder has their own preference as to brazing materials, some use brass and some silver.  The builder of this Mercian frame chose to use brass, at least for the bottom bracket shell.

After taking measurements and determining the rear spacing, I was inspired to set up the drive train using Suntour components combined with a Stronglight crankset and Huret shifters.

Suntour adjustable BB

Suntour adjustable BB with sealed cartridge bearings.

109

2015-02-27 029

Suntour SL High Normal front derailleur.

2015-02-27 028

Suntour Perfect 14-32 5 speed freewheel.

2015-02-27 027

Suntour Vx rear derailleur.

Vintage Huret Shifter

Huret drilled downtube shifters

The rear Vx derailleur works perfectly and provides very smooth shifting.  The front SL is a “high normal” front derailleur, and it was extremely easy to set up.  I chose it because its cable stops were what I needed, given the type of stops used on the frame.  The Suntour cartridge bearing bottom bracket is about as smooth and free of friction as they come, and it has lock rings on both sides which allow for a perfect chain line adjustment.  It would be nice if all BB’s were built this way.  The 14-32 Suntour Perfect freewheel is … perfect!  The low gear is a 33, but I found that I never actually needed it, even climbing the steep hills of Mt. Tabor Park.1972 Mercian

I still haven’t determined what model Mercian this is.  The lugs are fancy, and resemble the lugs used for the Olympique model of this era.  The fender eyelets and the 44 cm chainstays suggest the bike was meant to be an all-rounder – good for sport riding as well as light touring and randonneuring.  Mercian cycles are well regarded, so there are plenty of photos and websites available on the web.  One particularly fetching Mercian can be seen here.1972 Mercian

It has been a while since I have ridden on 700c wheels shod on a classic road bike. I was reminded how much fun it is to blast up the hills and to be inspired to sprint past other riders on their newer carbon fiber machines.  This bike is fast!  The downside to 700c wheels on such a small frame, however, brought me back to reality.  With headtube and seattube angles of 72 degrees, and fork rake at about 50 mm, this bike has tons of wheel flop and trail.  More than I like, and I noticed that right away when I rode into downtown Portland across the Hawthorne Bridge on a windy day – the front end was blown around due to the high trail.  And, at slow speeds the bike is not as stable as I would prefer.  However, at higher speeds and while descending, this bike performed well.

Mafac racersMafac racers

After spending way too much time trying to get a set of GB vintage centerpull brakes to work (due to the small amount of space at the seat stays), I finally switched over to a set of Mafac Racers, and was done with my brake set up in no time.  Really, no better engineered centerpull brakes can be found.  I had to clean and sand the rims, and install Kool Stop orange pads on the front set to eliminate brake squeal.

2015-02-27 0172015-02-27 034

 

GB Stem

Mercian headbadge

For the rest of the build, I used a Maillard/Weinmann wheelset from 1988 which was in great shape, and mounted Continental Gatorskins to the rims – great tires for 700c machines.  I had a GB stem and rando bars on hand, and decided to use some green cable housing to bring out the colors in the Mercian headbadge.

1972 Merican in Mt. Tabor Park

Now to the mishaps of its test ride.  First, I took the bike up to Mt. Tabor Park, prior to taping the bars, to see how the bike performed and determine if any changes were needed in the set up.  All good.  The bike fit me perfectly, and I really enjoyed the first ride.  Then,  I commuted to work on this bike, across the Hawthorne Bridge and into downtown Portland.  No problem, had fun, passed other cyclists, felt like a champ.  Then, it came time to venture back through downtown Portland.  There is an area of 4th Avenue that seems jinxed.  On this particular stretch I have experienced a tire blow out on my Jack Taylor, a rear flat on my Guerciotti, and too many near death experiences involving car drivers changing lanes into me or pulling out in front of me.  Today, something new happened.  As I was descending down 4th toward the Hawthorne Bridge ramp, I switched over to the far left lane to avoid traffic.  Then I encountered some kind of strange road surface anomaly that set up quite a bit of vibration on the front end.  As I was struggling to hold on to the brake hoods, the water bottle, which I had mounted to the handlebars, flew out and began a cannon-like descent down the street, fortunately not hitting any cars or pedestrians.  I quickly pulled over, spotted the water bottle, chased it down and polo-like was able to stop its progress, pick it up, and proceed on my way, quite daunted.

2015-02-27 007

And that’s when I remembered the bad ol’ days of putting 100 psi or more into my narrow road tires.  I had inflated these tires to 100 rear and 80 front.  As soon as this mishap with the water bottle occurred, I pulled over and lowered the pressures.  After that, I rode home in quite a bit more comfort.  And with a smile on my face.