More Project Reports

The mechanical technical aspects of our pastime are, to some of you fascinating.  To others, what follows will be as dull as ditch-water and dry as stale toast.  If you are not one of those who find intriguing the "greasy bits," then please do feel free to skip today's offering.  Tune in tomorrow for fare that is less mechanistic and more lively.  Thank you ~ your most humble etc.

We mentioned recently that we would be doing more follow-up reporting on some of our equipment projects.  We also dropped a few hints about a newer “secret” project.  Today the curtain goes up, with mixed results.

The following bit is a touch technical.  If you want to skip that, feel free to drop on down to “Conclusions” and “Riding Impressions” at the bottom of each of these project reports.

PROJECT X: Modifying Shimano Groups for Super Low Road Gearing

Background:

It seems to us that Shimano have a definite opinion about gearing.  This has been a source of frustration with us for many years.  The wonderful folks at the redoubtable Japanese component maker have very strong feelings about how low a road gear-set should be.  For the longest time the lowest “authorized” Gearing was on a “road double” driveline, with a low gear combination of 39 X 27.  That yields a ratio of just under 1.5:1.  That’s okay if one is riding in the flats, or climbing the occasional hill.  It seems to work well for young racers.  But for those of us who have older knees, or weigh a bit more, or wish to climb much taller things on a regular basis, it’s just not adequate.

Eventually, Shimano (grudgingly, it seemed) introduced road “triples.”  (A lot of us were already adapting mountain triples for use on our road bikes.)  That was a little better.  Now we had a low combination of 30 X 27, yielding a bit over a 1.11:1 final.  Better, but many of us wanted more.  And besides, triples are heavier, more complicated, and less reliable.

During the 9-Speed Era it was possible to do some interesting things.  At that time, components from both road and mountain groups could be mixed and work well together.  This led to some interesting possibilities.  For instance, a road double of the 53-39 type could be paired up with a 34-11 cassette and a mountain rear derailler.  That gave a huge high gear of 4.82:1, and a low of 1.5:1.  That’s a very adequate high.  The low leaves a bit to be desired.

The road triple, combined with the same rear treatment, resulted in 27 possible combinations from a low of 0.88:1 up to a high of 4.73:1.  That’s some serious range!

All that ended with the advent of the 10-Speed Groups.  Mountain gearing was restricted to 9-Speed, and the 10-Speed road groups were completely incompatible.  The advent of the compact cranks helped some, but not enough.  For those of us desiring truly low “digger” climbing gears, or the gearing for hauling heavy loads up hills, the road groups were out of the question.

That Brings us to NOW:

Thanks to some stiff competition from another component maker, Shimano has recently introduced 10-speed mountain groups!  Ah ha!  We thought that it just might be possible to again combine the mountain stuff with the road and yield wonderful results.  Alas, this turns out not to be the case.

Shimano has deliberately engineered the crucial mountain rear derailler to be completely incompatible with the road shifters.  The “pull ratios” needed to activate the deraillers are quite different.  That means road levers just will not operate the new 10-speed mountain deraillers.  There may yet be a way around this, and research is on going, but as of this writing the two are incompatible.

We wouldn’t want to give the impression that Shimano are prosecuting some vendetta against us.  There are sound engineering reasons for the incompatibility.  But the fact remains, the road shifters just do not work with the mountain deraillers, and the road groups do not allow the sub 1:1 low ranges we desire.

Conclusion:
As of this writing, it is just not possible to combine Shimano’s 10-Speed road and mountain equipment to yield super low gearing and usable highs from the same driveline.  This project is on going, and we’ll post more news and results as we have them.

~~//~~

PROJECT SRAM APEX “WiFli”:  Super Wide Road Gearing

Possibly some of you will remember references we made to testing the SRAM Apex component group.  Apex is SRAM’s entry level road group.  For our money it performs right up there with Shimano’s vaunted 105 level of components.  But wait there’s more!

SRAM has, quite deliberately, taken pains to integrate  their products and to actually promote cross-group compatibility.  That means that absolutely anything in any of their road groups will work with the stuff in another road group.  Apex, Rival, Force, and even the top of the line Red group are completely cross-compatible.  Now that’s cool!  (But wait!  There’s still more!)

All of SRAM’s 10-Speed road equipment is completely compatible with their 10-Speed mountain groups.  (Say what?)  Yes, SRAM’s 10-Speed road shifters will operate their 10-Speed mountain deraillers, across any of their 10-Speed cassettes!  Yowza!

We evolved a pretty good setup.  There was a bit of trial and error to match things up so that they would produce exactly the desired result.  Here’s the current state.

Brakes:  SRAM Apex

Shifter/Brake Levers: SRAM Apex

Front Derailler:  SRAM Rival

Rear Derailler: SRAM X7

Crankset:  SRAM Apex Compact 50-34

Cassette:  SRAM PG 1030    11-36

Chain:  SRAM PC 1071

Changes from a complete Apex Group:

First off, we substituted the Rival front derailler for the Apex unit.  This was done to achieve a bit smoother, lower effort front shifting.

We choose the PG 1030 cassette in order to avail ourselves of the widest possible gear range, with the lowest possible low gear.

The Apex WiFli rear derailler was capable of handling the huge low gear, but only just barely.  On some bikes, with shorter stays, or somewhat more aggressive hanger positioning, there are problems with this setup.  The WiFli unit is an SG, or medium long cage derailler.  We found that rear shifting improved dramatically when we substituted the X7 SGS, long cage unit in.

Riding Impressions and Conclusions

Six month riding impressions:

We’ve used the basic Apex set for about two months, and then made the above-mentioned modifications.  Over the entire six month period we have had very little to complain about.  The initial setup of the SRAM driveline is very precise and procedural.  It should be noted that there is a bit more post-installation adjustment required than with Shimano equipment.  However, once this initial dial-in process is complete (usually in a couple of weeks to about a month and a half, depending on volume of use) the equipment performs flawlessly.

The adaptation part is simply getting used to using one lever to operate both up and down shifts.  For users who are new to road bikes this is a non-issue.  For those with experience and habits formed by Shimano or Campy, the adaptation usually takes about a week.  After that it’s as natural as walking. 

NOTE:  We routinely switch between bikes equipped with Campy, Shimano, or SRAM systems, as well as singlespeeds or fixies.  There’s always a moment or two of confusion, and then the brain just goes,  “OH!  Right!” and no further thought is needed or given.  That said, it did require about a week to become fully comfortable with the DoubleTap controls.

Additional note:

The SRAM equipment does work in a very different fashion.  Riders who are accustomed to Shimano or Campagnolo will find that there is a bit of adaptation necessary in switching to SRAM’s Double Tap ™ system.  There is also a bit of different technique required.

Some folks may find that the addition of SRAM’s Chain Spotter ™ is well worth the additional cost of approximately $35.  And for anyone who is operating this equipment on a carbon fiber frame, I’d say this is a must have!

It should be noted; one particular bit of technique is required for good riding.  When upshifting from the small chainring to the large, it is best to make one’s recovery downshift at the rear first, and then effect the upshift while spinning the “unloaded” chainring.

Conclusion:  The SRAM setup (especially with their WiFli™ options) may be for you IF…

·     You are frustrated with a driveline that does not give you a low enough low.

·     If you are a “spinner” and like lower ranges for climbing.

·     If you do a lot of mountain work.

·     If you want to build up a “mountain specific” bike.

·     If you just have some older knees and want to save them a little longer, and you just don’t care how long it takes to get to the top, as long as you are not walking before you get there.

·     If you are building up a utility bike, a commuter, or a tourist, and want to avoid the complexity of a triple while still developing the widest possible gear ranges.

The stuff works, and it works well.  Once dialed and adapted to, it is precise and reliable.  It contains possibilities for amazing performance.