However, the downside of this setup is noticeably more drag compared to a normal chain drive bike. Although the geometry is quite close to a proper road bike, with drop bars as well, it just feels slower than my road bike. The internal hub is heavier and a bit draggy, while the belt drive is not as efficient at transmitting power as a metal chain. It is probably a very fast commuting bike, but not as good as a proper road bike.
For my all-weather commuting bike, the most important feature is to be maintenance free. My understanding is that a chain will rust if left uncleaned and unlubricated after riding in the rain. The rear derailleur will also collect lots of dirt from riding in the rain. That was why I believed in using internal hub and belt drive.
However, I recently heard that the KMC EPT chain is virtually rust-proof, with some first-hand accounts to confirm this. If the chain does not rust, it also means maintenance free, except for some lubrication once in a while. If I am using a Di2 rear derailleur, there is no shifting cable to rust or get contaminated, so it should also be maintenance free. As for the cassette, higher end ones are also quite rust resistant, as I have not come across an Ultegra cassette that rusts.
With this new knowledge, I realized that it should be possible to build a chain drive, rain proof, road bike, by changing the internal hub + belt drive to a conventional cassette + chain + rear derailleur. This would make it ride more like a proper road bike, with good power transfer in the drivetrain. Basically what I wanted is a road bike with mudguards and weather resistant components.
The wonderful thing about the Fabike C3 frameset is the versatility. By changing the rear dropouts, the frame can accommodate a normal 12 mm E-thru axle and rear derailleur hanger. The cleverly designed rear dropout can accommodate internal hubs (135 mm OLD), when the non-turn washers are installed. When the non-turn washers are removed (3.5 mm thickness each), the frame OLD becomes 142 mm, which is the standard for road E-thru.
I emailed Fabio of Fabike, whom I bought the Fabike frameset from 2 years ago. He was very nice to send the rear dropout conversion kit over at no cost, although I have to pay for shipping.
Rear dropout on the left. I also requested for the front derailleur mount, in case I want to mount a front derailleur in the future.
The rear dropout is threaded for the E-thru axle to screw into.
The dropout is not fixed to the frame, but merely clamped onto the frame with the E-thru axle.
Prior to receiving the rear dropout, I also measured/estimated the E-thru axle length required. This differs from frame to frame, depending on dropout width and dropout design.
After measurement, I found that the thru axle length needed is about 169 mm. The thread is a standard M12 x 1.5 mm. That said, the Cervelo Aspero has a rear thru axle with a M12 x 1.75 mm thread. DT Swiss makes many E-thru axles and I really like the adjustable lever.
DT Swiss rear thru axle, with a removable and adjustable lever.
The thru axle comes with a nut, but it does not match the frame in this case.
The lever is removable for saving a bit of weight, while the lever angle is also adjustable.
Here is how it looks, with the thru axle screwed into the rear dropout.
Rear thru axle weighs 63 grams
Rear dropout weighs 15 grams.
Previous dropout setup has two non-turn washers and two adapters, which weigh 18 grams in total.
In summary, changing the dropout design saves 3 grams (18 - 15 grams). The versatility of the dropout is really good to have, as I am not aware of any other frame that can convert between thru axle and nutted axle type.
Since I will be changing to chain drive, I will need a new chain ring as well. Previously I was using the Gates front sprocket with a Dura-Ace 7900 5 arm crankset, but I am not able to use this any more. This is because I got this Wolf Tooth narrow wide chain ring from a friend, and it requires a 4 arm Shimano crankset.
I have been using the Wolf Tooth narrow wide chain rings on many of my front single bikes, such as the folding bikes and the mini velos. It is my first choice for a front single chain ring, although it is quite pricey as well.
Based on my usage and experience, a 38T chain ring will give me the biggest sweet spot for gear range. Coupled with a 11 speed 11-32T cassette, the gear ratios are as shown below. Note that I am now using 27 inches as the wheel size for a 700C bike.
Although the ratio may seem low, it is ideal for my commuting, as there are no steep upslopes or downslopes. Most of the time, I will be cruising along at around 28 km/h in gear 8.
Gear range is from 32 to 93 gear inches, with a 38T chain ring and 11-32T cassette on a 700C wheel.
This 38T Wolf Tooth chain ring weighs 65 grams. Pretty lightweight as it is quite small.
4 chain ring bolts weigh just 8 grams.
Chain ring bolt length of 8.5 mm from Litepro is just nice, to attach the Wolf Tooth chain ring to a Shimano road crank arm.
Why not get more colours? Let's make this crankset look more unique.
4 different colours, which are coincidentally the Google colours.
I installed this chainring on the 4 arm Ultegra R8000 crankset, which is the same as what I installed on the Dahon MuSP.
Right side crankarm plus chain ring and bolts weigh just 396 grams.
Left crankarm plus bolt weighs just 194 grams.
The crankset weight is thus just 590 grams, which is a nice low weight. This is the first part of the conversion, where I showed the new dropout and the new 38T chain ring.
No comments:
Post a Comment
Every comment is moderated before publishing due to spam bots. If you don't see your comment yet, it is likely that it is currently being reviewed. Thank you for your patience!