Saturday, December 5, 2015

Addressing drivetrain issues


Addressing drivetrain issues
Over the past few weeks I have received questions on how I was able to install the Praxis 11-40 on the DF.  When I first installed the Praxis cassette, it was a straight switch from the stock 11-36 but since I had a few issues including the lateral adjustment spacer of the crank coming loose so I had to start from scratch. So here is how I re installed the crank and adjusted the drivetrain.

First lets remember that I have a front Rotor 3D crankset with 56-34 rings which is close to the maximum of the front derailleur and the 11-40 is at or very close to the maximum gear difference that the rear derailleur can handle so it is a bit tricky to adjust but it is possible.
 
Second thing to remember is that a velomobile has a suspension and when you adjust and test without being in the velomobile, shifting may not work properly.  The weight in the velomobile pushes the suspension and takes some of the slack of the chain so the chain does not rub and shifts. 

First I placed the crank approximately at the location where I used to have it.  I put the crank brackets and tighten the bolts.  After this, I reinstalled the front derailleur cable then reinstalled the chain.  I had problems because the chain got twisted in the chain tunnel and I had to re-thread the chain through the tunnel.  It took three tries to get it in the right place without being twisted.  I installed the quick link then I turned the crank to ensure it was turning freely.

With the chain installed, I start testing the shifting through all the gears using rollers.   It is important to look at the space between the top wheel of the rear derailleur and the cassette, it needs to be far enough from the biggest gear for the chain to pass.  The adjustment is done using the b-screw, a screw at the back of the derailleur.  If not adjusted properly, the derailleur will not be able to switch down from the largest cog.  In this case you need to  turn the screw clockwise to increase the gap.

You need to go on the road and try the shifting.  The most extreme combination should be tested (largest ring, largest cog and Smallest ring, smallest cog).  In the large/large combination, you should have enough chain to not overstress the derailleur.  If overstressed, you may need to add a couple of links to the chain, or move the crank back a few millimeters.  When not loaded the derailleur is fully extended and may get stuck on the shell so make sure you try this combination when you are inside the velomobile.  In the small/small combination, the derailleur arm will be completely folded but the chain may still be loose and rub at the bottom of the shell.  To address this you may have to remove a few links or move the crank forward a few millimeters.
X-0 Derailleur position in large/large

X-0 Derailleur position in small/small

It takes a bit of time to sort out, it was a few hours for me to do this then I went for a ride.  When I returned I was not pleased with shifting, the chain was rubbing in small/small so I moved my crank forward about 4-5mm.  I went for another test and the issue had been resolved.

As usual this week there are velomobile industry news items to report.

Cab-Bike

Cab-Bike in Poland has a new English website for http://cabbike.pl/   The site shows 3 different models.  Piotr Majcher is the principal of the organization cabbike/PIMA that was spun off from Wejkama to produce and sell the new version of the Cab-Bike adapted by Maciej Kaczmarek.

Cycle JV

The finished Mulsanne was unveiled this week.  The velomobile is carbon-fiber black.  The velomobile is equipped with a hatch under to access steering components.  Apparently the new prototype should be ready for rolling tests by Christmas.

Velomobiel

There were 11 deliveries in November, including 2 carbon Stradas, 6 carbon Quests, 1 Quest XS and 1 carbon Quest XS.

In November there were 8 new orders 1 Quest and 7 QuattroVelo, bringing the current backlog to 58 including 36 QuattroVelo.  The initial rate for the QuattroVelo is probably going to be one per week so I estimate that it would take 9 months to produce the 36 QuattroVelo when the production starts.

IntercityBike

Daniel has produced a prototype of a new hood for the Quest/Strada/Mango.  He is currently testing.


In November ICB delivered 13 velomobiles these deliveries are split 9 DF-XL and 4 regular DF.  During the same period, 6 new velomobiles were ordered; 4 DF and 2 DF-XL.  At the end of November there were 25 velomobiles on order.  At the current production rate ICB could clear the backlog in 2 months, as a result with production outpacing sales I expect that production level will drop slightly.

Daniel published a rendering of the DF-XL showing most mechanical components.  This is similar to the one produced for the Quest.

Picture

Velomobiel.ro

You will remember that velomobile.ro was formed shortly before the Velomobiel.nl split.  In the announcement, it was indicated that Allert, Theo, Ymte and Jan would remain partners in velomobile.ro. This week Ymte posted on the German Forum that Jan Wilnen has taken over and is now the sole owner of the Romanian manufacturing company.  Since it’s beginning, the company has increased it production significantly now manufacturing shells and components for many other European velomobile manufacturers.

Dutch Forum

It looks like there is a new Dutch recumbent forum.  It can be accessed here: www.ligfietsforum.net.  There was an automatic translation function using Google Translate.  The function is near the top on the left hand side. Above the list of Blogs.

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