mobilemail

About two weeks ago I was hanging out at Books-A-Million with my wife, slurping coffee and checking out the October ’11 issue of Bicycle Times magazine. I came across an article on pg 65 describing the FSA Metropolis Patterson Bike Transmission, and as I read it I realized it would be perfect for my trike.
I have a TerraTrike Path 8 that I purchased used. I love the trike, but the wide range of the Sturmey-Archer XRF-8W 8-speed IGH wasn’t quite low enough to get me up some of the local hills, and still have enough top end for normal use. I had remedied the problem by installing a 24/42 double crank with a front derailleur and twist shifter, and an old rear derailleur on back to wrap the extra chain. Actually I tried a chain idler on back first, but found the derailleur was able to tune the chainline more precisely.
This setup worked well enough. I even rode a 55-mile loop on it that included hills I would have only attacked with a granny ring on my wedgie bike. But it had the disadvantages of still requiring front and rear derailleurs even though I was using an IGH. And the rear dropout wasn’t made to accept an idler or derailleur, so I had to kluge together an external derailleur hanger arrangement that would not interfere with my IGH’s dropout washers. And the front shifting was a bit stiff.
The article I was reading described the Patterson crank as a two-speed with 1:1 and 1:6 gear ratios, producing an effective 28/45 crankset. Wow, I thought, that is almost exactly what I’ve been using! As I read on, I learned that the Patterson crank installed like a conventional bottom bracket, no frame chamfering or modifications were needed, differing from the popular Schlumpf Drive. And the best part is that the price was only $299 MSRP, hundreds less than the Schlumpf. How could I lose? Okay, there were a couple of disadvantages. First, there were no options to change the chainring size, so I would have to like the gearing. This was no problem, the gearing was almost exactly what I had. Second, I had to order a couple of tools I didn’t have for the installation, and that would add $30-40 to the cost. Okay, I’m a guy, when was ordering another tool ever really a problem?
I was totally stoked by the time I went home, but I knew I should do more research. It turns out I couldn’t find anyone who had used one of these yet except for a mountain biker on the pattersonbike.com website. Obviously that seemed like it would be less than objective. And I also learned that I could order the crank from bikesonline.com for $237 with free shipping ($267 with the necessary tools included). I also checked out the excellent installation video at pattersonbike.com and decided this was worth pursuing. The printed installation instructions that I also downloaded included a strong recommendation not to use the crank with a front shifter with “click stops” – basically, one that is not infinitely adjustable between its end stops, as I read it. I figured the grip shifter would work, but I decided I would look for something better. I ordered the crank.
The goodies came a few days later, and I began the installation. I was concerned that the chainstay stop might not reach in far enough to rest correctly against the TerraTrike’s frame tube, but I devised a plan before I ordered the drive. If needed, I planned to remove the stop and put an aluminum spacer behind it, with holes drilled through it to pass the two screws. Of course longer screws would be necessary too. I think the screws and aluminum bar stock could be obtained easily at a hardware store. As it turned out, the stop protruded enough that this was a non-issue.
The second issue of concern was the direction of cable travel. I took care of this by purchasing a clamp-on cable stop made by origin8. Since the cable actuation had to come from above, I simply dressed the housing to loop up from the boom, then face down in parallel with the derailleur riser. This worked out quite well. Since there were no pre-existing cable stops for the FD, nor an OEM FD cable, I had lots of latitude for creativity. The cable stops are available for different diameter tubing. Here is an example on Amazon https://www.amazon.com/Origin8-Clamp-.../dp/B003BC7MZK
The third issue was the front shifter. I found the Shimano A050 shifters designed to be mounted on road bars on each side of the stem. These shifers only cost about $20 for the set (shipping included), and met my needs beautifully. If you already have bar ends, this is a non-issue for you. https://www.amazon.com/Shimano-Handle.../dp/B001L5Y1GC
Since I installed the crank I have had it out on one 30-mile ride, with more “testing time” over the next few days that should include more hills and dales. So far I have experienced no issues or concerns with the drive, and have been quite pleased with the result overall. You can check out pictures of the TerraTrike Path 8x2 (before and after installation of the Patterson crank) at https://skydrive.live.com/?cid=c5295...1337&sc=photos

mobilemail

I guess I should add that I am not sponsored or affiliated with FSA, TerraTrike, bikesonline, Patterson...or really any professional in the bike industry.

Bobsk8

I have seen this same exact post followed by the disclaimer on 4 different forums.

AlexZ

So....Are you saying "mobilemail"is a spammer?

mobilemail

It was certainly not my intention to spam. I was kind of excited about my results with the Patterson. Since I could not find any information myself when I was looking around, I thought I would publish my results. And since I know that not everyone follows every possible forum, (although many of us obviously do), I posted the information in multiple places.
FWIW, other forums generated a lot of interest and comments. Not so much here. That's fine, I've met my goal in just letting people know.

And I'm still not affiliated with anyone that would provide gain in my publishing this information...just trying to be a contributor to the community.

mobilemail

Or...am I taking this too seriously???

Cyclebum

Great article mobilemail. What difference does it make how many sub forums you post it on?

As a trike newby, I missed the nuances, but understood the big picture of your mod. Was especially interested in the close up pictures of your TerraTrike, a bike I may end up owning. Specifically looking at the 26" Rambler for its higher profile. Ain't crazy 'bout the twist shifters, but.....

mobilemail

Generally speaking, I think twist shifters feel cheap, although I have had some that have continued to work reliably for thousands of miles. The only bar end available for the Sturmey 8 speed IGH (that I know of, anyhow), is made by JTek, and it's $80 for a rear shifter only. I can't quite bring myself to write the check. If the OEM shifter would just die, I could probably justify it.

VegasTriker

I have Schlumpf Mountain Drive on my third-hand 2001 Greenspeed GTO. Just replacing the 65 tooth chainring alone costs half of what this transmission does so I can see that it might appeal to some trike owners. However, there is a serious limitation on the upper end of the gear range with a large chainring equivalent of 42 teeth and a 20 inch drive wheel common to most tadpole trikes. You can do the calculation on any of the online gear calculators. I found a 90 gear inch top gear on my first trike (not the GS GTO) to be very limiting after I had ridden the trike for a few months. It has a 20 inch drive wheel, standard 3 X 9 gearing, and a 52 tooth largest chainring. I would often "run out of gears" on even a modest downhill. Fast is fun, and I couldn't be fast enough with the 90 inch top.

The other question is how long will this transmission last? None of us will know until someone has ridden it many miles. I have 22,000+ miles on my Schlumpf drive and in all those miles, I have had only one repair. I broke a ring gear inside the unit at around 13,000 miles. I was able to repair it myself at a cost of around $45 by buying the part and installing it myself. When I took it apart, I was amazed at its simplicity but also at its beautiful workmanship. The Schlumpf drives have gotten to be obscenely expensive these days mainly due to the fall in the value of the US$ as compared to the Euro.

mobilemail

Your points are important ones. As for the gearing, that fact that this is being paired with an IGH is important. The Sturmey 8 IGH starts out at 1:1 as its lowest gear and steps up from there. It has a double-size step from first to second and 7th to 8th, resulting in a hi/7th gear of 90GI, and a hi/8th gear of 117GI. For a very strong rider, the rear cog on the Sturmey can be changed down a few teeth (they make a 22 or 23 tooth available). But those high gears are plenty for me! I will concede the double size step at the top of my range is not my favorite design nuance of the Sturmey.
As for the longevity, you are right that it is basically untested. In making my decision to take the plunge, I was swayed by the facts that a.) it has a respected company behind it, so they must feel like it has merit, and b.) it's actually about the same price as other decent, but not top-shelf, cranksets.
So I'm one of the guinea pigs. Of course I'm not an especially strong rider, I don't ride a lot of miles, and I don't ride in rain or snow, and my bike is always stored indoors in an environmentally controlled area...but other than that I'll use the heck out of it!!!

cabledawg

Hey mobilemail, I enjoyed the write-up on this modification. The Mrs and I are looking at getting a Rover8 with the tandem addition next spring and this would be benificial should we need the extra gearing options. We're mostly low speed as we use our bikes for grocery runs and leisure rides, but with us moving to DC, we'll be riding more often just to get around town. So thanks again!

mobilemail

You may want to check with Patterson as to its ability to hold up on a tandem. Tandems tend to stress chains and drivetrain components a fair bit more than single bikes do, and I would hate to see you disappointed...especially if you were disappointed several miles from home on the side of the road. If you are strictly tandeming on flat ground and bike paths, it's probably not as much of an issue. But check first anyway.

cabledawg

Didnt think about that. I'll have to check with them before I buy one, but we're still months away from gettingour Terra and who knows, we may like it with the 8 spd IGH.