Spirit upgrade from 16 to 20 inch front wheel?

[bobcolover]

I have a 3 year old Spirit [HP velotechnic] semi recumbent which has a 16 inch front wheel and 20 inch rear; they have now produced model with 20 inch front; does anyone have any experience/views on whether it is worth buying the new 20/20 model [in which case i would have a 16/20 to sell]

HPV said that the geometry etc had altered so that it would not be possible to retrofit a 20 inch front wheel to my current bike.

many thanks
bob

 

[Alf]

I guess their problem is that they can't be seen to be recommending something they have not tried and tested because of their liability if it caused problems. That means they are always likely to give negative answers to questions like this.

That said, you are going to raise the front end of the bike by something of the order of 4 inches relative to the back end and that is going to affect your riding position and maybe your steering. If you think it's worth the risk and that these changes won't be too bad, your next problem will be finding a suitable fork. They are not easy to get hold of but if you ask one of the recumbent retailers they might suggest a source.

Alf

 

[Alf]

Sorry, I didn't read Bob's post properly. I have never ridden a Spirit but I suppose the question is about whether there is a problem with the 16" front wheel version that would be improved with a 20" wheel. I suppose it means you would only have to carry one size of inner tube with you.

Alf

 

[PaulM]

I had a 16/20 Spirit. The front wheel is actually a 305, so about 2" smaller than the Brompton 16" wheels. I haven't tried the new Spirit but the BB/Seat relative heights are very different to the point where it is now more extreme than the Giro say. I'm not really sure why anyone would choose the new Spirit over the Grasshopper for example.

 

[bobcolover]

i chose the spirit over the grasshopper because of price and visibility; i commute every day in london and feel the spirit gives me a higher viewpoint and can be seen easier in london traffic; also i carry panniers and the spirit evenly balances those; also on occasions i have to take the spirit on the train and negotiate stairs ; its well balanced and i can manage that. I just feel that there is virtually no freewheeling with such a small front wheel. We did 300km along the loire this year and i felt i had cycled every inch; i also ride unladen on the longer rides eg the london-brighton ride; and not much freewheeling even there. I just think that HPV realised this as i have ridden the 20/20 a short time and was impressed with the way it just seemed to roll/ freewheel easier; i think you lose a lot of forward movement/energy in the little movements the 16 inch wheel makes as it doesnt have the greater centrifugal force/ gyroscopic effect of a larger 20 inch wheel ; its really whether that 4 inches/ 2 inches increase in radius, is worth buying the new bike for . i do about 3500 miles a year on the spirit, so it would be worth it if its a more efficient bike to ride. bob

 

[Alf]

That's a very interesting comment on the effect of small wheels, Bob. Certainly the freewheeling on my Grasshopper (406 - 20"" wheels) seems pretty 'free' to me though the rolling resistance of bigger wheels is supposed to be less, so, the bigger your wheels, the easier they roll, I suppose. If you were wondering how much of a financial hit it would involve to change to the 20-20 version, it might be an idea to speak to a dealer to enquire what they would give you in part ex. I know D-tek do part exchange so a quick phone call there might be useful.

Alf

 

[eric]

Hi Bob,

I live in Belgium and own a 3 year old spirit myself. I also consider to convert it to a 20 inch front wheel. Have you already done some experiments with a 20 inch front fork?
I think by removing the front suspension, about 2 inch may be saved, which might compensate the bigger fork so that the original head angle is preserved.
We still have to investigate that this doesn't yield too much heel-strike in extreme steering manoeuvres...

Eric

 

[bobcolover]

20/20

Hi
I have just acquired a kingcycle and have spoken to kevin at dtek who seesm to know about these things; i havent changed the 16 inch front wheel on my spirit to a 20 inch wheel, but having had time to ride the kingcycle quite a lot i think that the issue is that the 20 inch wheel at the back is too small for the spirit to go really fast. the frame is heavy as well and i have just come round to the idea that the spirit is ideal for comfortable transporting of a body and plenty of stuff in bags, but at no great speed; i am therefore not too sure that changing the size of a front wheel will make a lot of difference;
so it may be that the kingcycles big back wheel at 24 inches is the thing that really makes a difference both in terms of providing roll along speed and centrifugal force so that the bike can coast, whereas i have found that the spirit never really coasts along for any distance
hope this helps
bob

 

[ufkacbln]

This is a problem with the small wheeled bikes... smaller lower profile machines, but low gearing and easy to spin out.

My Hurricane was one of the first imported into the UK and I found that the gearing was low and I was slower.

So with a bit of bodging I have a 42 gear setup... A Sachs 3x7 on the rear and 52 /64 chainrings on the front - this gave me the speed I wanted without the need to change the wheels.

I do love evolution though...... when I first started the main racing machines were small front, big rear wheel King cycles and Ross Speeds, but these then lost out to the small wheel Hurricanes and the likes, and now we have the advent of the "high racers" with big wheels front and rear.

However there is a drawback.... you still need to be able to place both feet on the ground when you stop to be safe. Small front wheels allowed this and 16" wheels made this even lower...... most people could ride a recumbent. However the big wheel high racers are not possible for some riders.

 

[eric]

Bob, I don't have the feeling that my Spirit is that slow, sometimes I even join a group of amateur cyclists and I don't have too much trouble to follow them, coasting included. Obviously, due to the smaller wheels, the tire pressure is very important. Since the spirit has an excellent suspension, I can affort to put my tires on 5 bar (about 72 psi) or even more, and that makes a huge difference.
I also removed the lower chain tube and replaced it with a small low friction chain wheel mounted on the joint of the back wheel fork (actually, on the spirit there is originally already some provision to do that).
I think that speed is much more influenced by the seat angle, but that is something I don't want to compromise.
I really need the higher seat position in heavy traffic...

The reason that I would like to have a 20 inch is to be able to use spike tires in wintertime, and smoother (and therefore faster) riding on bad roads.

Eric

 

[bobcolover]

20 inch front wheel

i will try the tyre pressure increase and see what happens; i dont know about spike tyres; i live in the south of the uk and i have never seen such tyres over here
bob

 

[eric]

If you still have the original balloon tyres, then the maximum pressure is specified here: http://www.schwalbe.co.uk/c2-1076-schwalbe-tires-big-apple.html
For the 16 inch the max pressure is higher than 20 inch tyre...
eric