Klaus has now had Celeste the Strada Velomobile for about four months and cycled over 5,500km in her, including a 9-day 1,270km solo tour to the Baltic Sea last week.
Anyway, he’s the sort of chap who likes to do occasional modifications to his bikes and had purchased a couple of months ago a set of elastomers for Celeste’s suspension.
The usual suspension set-up for the Strada is a large spring underneath a piston-thingy (my terminology is not very good here), but some Strada owners had changed this for a system of elastomers to replace the springs which gave a harder ride but slightly better cornering handling. Or something. I’m not entirely sure of the purpose of the change but Klaus decided he wanted to Pimp his Velomobile a bit.
So on a rainy day when he had nothing else to do he decided to do the suspension ‘upgrade’ and asked if I wanted to help. I am always game for a bit of bike maintenance, especially as we are slowly reducing our incompetence level from High to Normal. The chance to practice on someone else’s velomobile, rather than my own, should not be passed up.
Changing the suspension spring for elastomer
I arrived at Klaus’s house after he had returned from his day sitting at a desk pretending to work in Mülheim-an-der-Ruhr. I was expecting to be working in the garage but no, as his wife was out he had introduced Celeste to their lounge…
And here are the parts we had to substitute for the spring – some purplish-coloured elastomers, some blue ones, some white washers and there was also some silicone grease in a syringe.
Stage 1 was to measure the height of Celeste with her current suspension, so we stuck a piece of sellotape to her side and measured how high she was off the ground to this point.
I then measured again with Klaus sitting in the velomobile – 1.5mm lower.
Klaus had laid some cardboard on the laminate floor and also a soft mattress onto which Celeste was then laid.
This suspension leg is what we have to get at and disassemble..
So the first job was to remove the bolts inside the cockpit which hold the suspension in place. Then remove the wheel. This was all very easy.
Here is a close-up of the drum brakes.
I had assumed he would remove the brake cable and the cable for the trip computer but he decided to leave these in place and just work on the suspension arm roughly in-situ.
We had to disconnect the metal plate under the suspension from the steering mechanism which just involved undoing three nuts-and-bolts.
Once that was done we were able to bring the suspension out of the bodywork.
After removing a washer, rubber cover and plastic sheath we were able to pull out the innards for a look. This is the top half of the system, and the left hand side is what pushes against the suspension spring.
And then the spring came out…
Here is the suspension devoid of its innards.
I had been very organised and laid out all the parts in order as we removed them – here is what we had to remove to get to the innards of the suspension.
And here are the new elastomers arranged as to how we would need them – the two blue would be at the bottom end.
Klaus had very sensibly drilled small holes all the way through the elastomers so he would be able to get them out of the suspension arm if necessary with a skewer or something.
He used some of the silicone grease and then slid them in in a long sausage. It was pretty easy, but much more challenging (and unphotographed due to dirty hands) was getting the arm back in and the screws to bite into the sheath that holds it all in place. It took us about 15 minutes to manage it, which involved also removing a couple of the washers that we had put in with the new elastomers.
Once we had just about managed to screw the suspension arm back into the socket, we then put the bike back together and measured again.
The second column is the first measurement after the new elastomers were put in. Unweighted it was sitting much higher, but when Klaus got in it returned to the previous weighted measurement (15.5cm in this case). When he got out again I re-measured and the unweighted reading was now lower (presumably the elastomers had had their first compression).
Emboldened by our relative success (it only took 45 minutes to do the left hand wheel) we decided to do the other side, which took us only 20 minutes. We are getting good at this stuff!
So Celeste was put completely back together (wheel covers included).
Klaus got in again to check she was level now both sides were done.
And at this point we noticed that the two sides behaved a little differently when you rocked the velomobile from side to side. One side settled back to the level, the other side stayed a bit high up until you put weight on it.
We thought this might just be that we needed to ‘run in’ the new elastomers so Klaus went out for a short ride. His conclusion – it was a good modification, giving stiffer suspension on cornering although cobbles were a bit more teeth-rattling (he had known this would be the case).
He had mentioned whilst we were working that there might be something we had to remove from the top of the suspension piston thingy but it didn’t seem necessary so we didn’t do anything. It was after the successful test ride that Klaus decided to look at the detailed instructions he had been sent… and discovered there is indeed something we should have removed. And this might account for the fact that Celeste didn’t settle back down under her own weight so well.
As it had been raining and Celeste was wet we decided not to bring her back into the house but to check this out the next day instead.
Here is a short video by Velomobiel.nl showing the difference between spring and elastomer (a different variety of elastomer than Klaus bought):
And here is the thread in the Velomobilforum.de which describes it all at great length – assuming you can understand German!
And here is Klaus’s explanation as to why he didn’t remove the part:
Das mit dem Reibdämpfer habe ich allerdings irgendwie verteilt. Ich dachte es wäre ein massives Elastomerteil, deswegen habe ich die Finger davon gelassen.
And a response from the chap who sells them:
ohne die Reibungsdämpfung wird der Negativfederweg erst schnell genug.
Ich ließ bei meinen alten Elastomeren diese ja drin und der Unterschied ist wirklich groß.
So Klaus decided to remove this small part the next day.
Klaus is the sort of person who really likes to complete a job when he’s started it so was clearly irritated that he’d left out this small task of removing a rubber collar thingie. One small part of the job needs four hands so I agreed to cycle over and give him a hand.
By the time I arrived (having not at first noticed his message to say he was on his way home from work) he had already disassembled one side and was already beginning to remove this mystery rubber collar.
Once that was off, it was just a case of putting the suspension arm back together.
And here is what was removed.
The whole job took about half an hour.
We then went out for a longer ride to test it out.
The first observation is that Celeste sits noticeably lower when looking at the front wheels. Previously there was quite an air gap at the top, now it’s a pretty tight space the whole way round (partly as Klaus is running relatively large tyres, Continental Perfect Moiree).
It initially seemed to me as if Celeste looked more jerky/bumpy, but Klaus reports the opposite – that the ride is better. He has particularly noticed that the handling is really secure – he seems to corner faster (which means I have to be careful not to try to follow him round corners too closely as Penelope is higher and more liable to roll) and has done some speed slalom tests which he says showed it is a great improvement. One minor downside will be a less comfortable ride over cobblestones but that could be improved by a change of tyres (he has bought some Shreddas and they are known to be better over rough surfaces, a fact to which I can attest).
The lowered suspension (which is effectively what he’s done) means he really has pimped his velomobile. Combined with the flashing light on the top, all he needs is a loud music system to play whilst riding along and he could fit in well amongst Essex Boy Racers in their souped-up Corsas!
Here’s a ‘before’ and ‘after’ photo to compare the difference in height when not in use.
Oh, and a final note. Klaus wrote a short report (in German) for the Velomobilforum. I include it here because of a rather amusing German word which is included. ‘Bewegungen’ are ‘movements’.
Heute habe ich es endlich fertig gebracht und konnte die Elastomere final einbauen. Das VM liegt jetzt ein wenig tiefer, das tur aber dem Komfort keinen Abbruch. Das Abrollen ist jetzt definitiv angenehmer und Schläge kommen nicht mehr hammerhart durch die Karosse. Großartige Wankbewegungen konnte ich keine feststellen und ich habe das Gefühl, dass sich die Kurvenlage verbessert hat. Wie bereits mehrfach berichtet…als ist so schön leise geworden. Die Lösung ist ein echter Gewinn.