Bottom Bracket Holder Adjustment | Bülk Velomobile Maintenance


Bottom Bracket Holder Adjustment | Bülk Velomobile Maintenance

Article made after the text from video. Enjoy!






Hi I'm Jan from and we are shooting here a maintenance video, so have fun.


In the today video I want to discuss the following topic, so you received your new Bülk from the dealer or you received your Bülk delivered at home in the shipping box because you live in America or you bought a secondhand Bülk and you need to adjust still the length of the pedals, if you received it at home or you bought it secondhand you have to do it yourself, if you buy it by a dealer it happened often, at least to me, that like, I put the seat where I think it's nice, I put the pedals, everything is perfectly adjusted and after 100 kilometer I think like hmm, I would like to have the seat a little bit more down and a little bit more laying, which influences the length of the pedals, so today I want to show you how to do it and how not to do it.


So it's practical to take this lid off, the hood or the combi lid off and this one off. These are really easy, these are with velcro, there's a little arrow here which shows you where's the top. Here you can take down the brake cable and here you can... So now you have much better space to work on it.


So here we have the bottom bracket holder and here we have four screws, this one we untighten/loosen, but before you untighten it's always good to have a reference point, so if you move to the front you put it, the reference point, on the back, if you move towards to the rear, you put the reference point here, in order you can measure the distance from the original position to the position you want to go. So you take an imbus (hex key) and you untighten/loosen the four screws. So this is the original position and I push it like eight millimeter to the front because that's what I need, maybe in your case you need more or less and I tighten it a little bit with my hands, I put the other clamp back on.


To tighten these screws it would be nice if you have something similar to this, because if you over tighten the screws you will squeeze the carbon fiber and you will break the frame, if you don't tighten it enough, then it can move still during driving which is also not funny. So I have here a... I think it's called Torque Wrench (Newton Meter), I put it on seven and a half Newton. So it's tighten...


The next step, it's important to verify if the chain is long enough, so I have it in the front on the biggest chain ring and on the rear on the biggest chain ring and I go to check now to see the derailleur how it looks like.


So what I can see is that there is still possibility for tension, but if you see the derailleur standing fully to the front on maximum tension, that's not good because you know that it's over-tensioned and it can damage the derailleur. In this case I can still take a little bit out of my chain because I would like to see if I put it on my smallest chain ring, you can see that there is already too little tension on it, on the derailleur, so I definitely want to make the chain a bit shorter, I will take out two of these and I do that by searching in the front.


I will search for the missing link that can be sometimes a bit of... can take a little time before you find it but it's just turning the wheel and wait until the missing link is coming by and yes I found it.


So I've found here the missing link, what I do is take off the chain from the front blade in order I have a bit of more space, there's a special tool for it but I don't have it here at home and I assume that many people don't have it at home neither, so I show it how you can do it with tools you can find at home, it's a little bit more difficult than with the special tool but it works as well like this.


So I established that I can take out two of these, maybe even a bit more, but I will start with only two of them and... so I took that out, now I put everything back in.


So we have two tips here, when you take out the missing link, make sure you're outside the bike because I dropped it inside the bike, it felt underneath the front idler and I couldn't find it in the beginning, luckily my cameraman had a magnet with him and with the magnet on a little stick we could take it out, and the second tip is... make sure that the return chain is not twisted. You can verify that like this... take the return chain, turn it as maximum until you feel like a resistance, turn it one, two, three, so by the third it's already very much ... so I go one back and I know that I have... so now I know this one is... so if you have in totally three turns, you go of course to the middle turn and then you know the chain is not twisted.


So if you can see the return chain is going straight in on the front and it comes straight out of the front you know it's straight, if for example on the front side the chain goes in like this and on the rear goes a little bit out like this, you know it's twisted, so you have to do it again.


So that's all about adjusting the bottom bracket holder and adjusting the chain, I showed you only how to shorten it, the chain, if you need to extend it, you need to buy a 12-Speed chain with a missing link and add it with a double... so missing link there and a little missing link there. From 10-Speed you cannot adjust... you cannot extend any more chain with this ... because it's not really reliable anymore after the 10-Speed, in my case I have 12-Speed, you can do it but it's not recommended.


I hope you enjoyed the videos about maintenance, if you still have some ideas, please let them in the comments, but before you put/post the comments, have a look to the other videos maybe we uploaded your question already, don't forget to subscribe and have fun, see you next time.

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