Alfine 8spd internal hub
I have a bike that I've been developing. The 28er. It is meant to be the fictional 'one bike'. A bike that can be used on road, off road, commute, full dirt. It will never exist as everyone should know, but a real bike geek will always dream of attainment.
- 1 The rise of the Alfine
- 2 Parts and Cost
- 3 The good
- 4 The bad
- 5 Weight
- 6 Gear Reduction
- 7 Chainring & Sprocket Choice
- 8 Cable and Housing
- 9 Servicing and Special Tools
- 10 Technical Dopcumentation
- 11 STI Shifting
- 12 Braze ons
- 13 Trimming the nuts
- 14 Images
- 15 The Rohloff Speed Hub
- 16 The Sram iMotion 9
The rise of the Alfine
Alfine is Shimano's high end cruiser parts group. 2009 brings this group to the USA. Along with it a nice internal 8spd disc hub.
Parts and Cost
- Alfine SGS501 32h Disc brake 8-spd Internal hub Black, QBP# HU7887, $275.00 (MSRP)
- Alfine SL-S500 8spd Shift lever Black, QBP# LD5705, $50.00 (MSRP)
- Alfine SG-S501 small parts kit, QBP# HU7889, $15.00 (MSRP)
- Nexus 16 tooth cog, black, QBP# FW7016
The hub itself is fantastic. It works impressively well. shifting under power, while coasting, while pedaling with only minor blips. I'm hoping figuring out the cable finesse will eliminate all of those.
Almost everything about the shifter sucks. You can't remove the display, it's low normal, it doesn't have 2 way triggers, the look is just gross. Most noticable is that you are only able to shift one gear at a time. Skipping a few sometimes would make a big difference.
A drop bar hydro STI lever would rule, I'd also like to know if other 8spd STI levers will work with the system.
The hub is heavy. It's weigh in the rear is odd since I am not used to this.
I will be doing more testing to see about seals and offroad performance.
The Alfine system added 3.5 lbs to the single speed bike weight. While a bit much for pure perfomance, it is in range for someone looking for a bombproof clean drivetrain with good performance.
- Gear Ratio Total Difference 3.07
- Gear Ratio 1 0.527
- Gear Ratio 2 0.644
- Gear Ratio 3 0.748
- Gear Ratio 4 0.851
- Gear Ratio 5 1.0
- Gear Ratio 6 1.223
- Gear Ratio 7 1.419
- Gear Ratio 8 1.615
Below is a comparison of these reductions to other common reductions used in cassette design. The Alfine gears were multiplied by a factor of 21 to get them to start at an equivilant of 11. I also include a 6 spd cassette that I built where I learned that spacing on cassette gears should not be even. This is because fine adjustment is needed in higher gears and gross adjustment is used in lower gears.
Chainring & Sprocket Choice
I did my first ride as a commute to work. Golden Gate Bridge to Daly City. A perfect sample of San Francisco riding.
I had 32/16 primary gearing with the absolute worst tires for this test, 700x45c knobbies.
The gearing range was near perfect. For street use, I suspect that 34/16 will be really nice with 700x38 slicks, possibly taller.
I will test the 32/16 offroad this weekend.
Cable and Housing
I noticed that the stock cable housing was totally dry out of the box. I lubed the cable with Shimano Special Grease for SP41. That should help from the get go. I also used a sealed end with a grommet at the hub end. I do this on all my cable runs. Makes a huge difference in the life of the housing.
http://img1.qbp.com/6SPsvm45/prodl/LU8403.jpg Shimano SIS SP41 Grease, 50g, Y04180000
http://img1.qbp.com/6SPsvm45/prodl/CA1067.jpg Shimano 4mm sealed end caps, Y6AM98080
Servicing and Special Tools
TL-AF10 opens the hub for servicing the shifting.
SG-S501 8-Speed Internal Hub Gear
SL-S500 Shift Lever
Will a sora 8spd shifter work? What about a down tube shifter. I hope to get a down tube shifter to work by modifying an existing part.
The Alfine cable needs to be pulled 5.38mm per index for the hub to shift correctly.
I will probably need to modify a straight Shift Mate with a 1.9x magnification to get things working properly.
All Shimano shifting systems use a shift ratio of 1:1.7 except for pre-1997 Dura-ace which uses 1:1.9. New DA10 will surely have a new ratio.
Shimano Shifting Gearing Cable Pull Cassette Pitch Shift Ratio 6 3.24mm 5.50 1.7 7 2.94mm 5.00 1.7 8 2.82mm 4.80 1.7 9 2.56mm 4.35 1.7 10 2.32mm 3.95 1.7 New DA10 ?.?mm ?.?? ?.?
Down Tube Shifter
Shimano SL-R400 8spd
Shimano SL-1056-8 105 8spd
The cable end holder arm can be eliminated if the correct braze on is positioned in reference to the hub. Basically, the cable needs to run to the hub offset 15mm from the locknut/dropout interface.
Trimming the nuts
I found that I was able to cut 0.225" from the nuts to clean up their appearance.
The Rohloff Speed Hub
- Gear #1: 0.279
- Gear #2: 0.316
- Gear #3: 0.360
- Gear #4: 0.409
- Gear #5: 0.464
- Gear #6: 0.528
- Gear #7: 0.600
- Gear #8: 0.682
- Gear #9: 0.774
- Gear #10: 0.881
- Gear #11: 1.000
- Gear #12: 1.135
- Gear #13: 1.292
- Gear #14: 1.467
The Sram iMotion 9
Overall 340 % 1st gear 0,542 2nd gear 0,621 3rd gear 0,727 4th gear 0,853 5th gear 1,000 6th gear 1,172 7th gear 1,375 8th gear 1,611 9th gear 1,844