SactoDoug

I am making plans to build a recumbent. It will be a road going bent using 700c x 23mm road wheels. Those road wheels will not absorb very many bumps. My goal is to have a fast bike that is relatively comfortable.

I have never ridden on a recumbent before. I understand that on a recumbent, you can't use your legs to absorb shocks like you can on a diamond frame bike. I am concerned about possible back injury and general all around ride comfort.

The members of this forum already have bent bikes. I am asking for your experience and opinion. Here are my options so far:

A. Full mountain bike front and rear suspension.
B. Just front or rear mountain bike suspension.
C. A simple hinge with a rubber/urethane stop in the front or rear.
D. A seat suspension of either springs or rubber/urethane.
E. No suspension.

If you were building such a road bike, which option would you go with and why?

dcrowell

Although there are recumbents with suspension, there are more without. My Bacchetta Agio has no suspension, nor do I feel any need for it. It handles bumps better than my upright bikes. It does have wider tires 20x1.5 and 26x1.5.

What really makes it comfortable is the fact any pressure is spread out on your entire bottom instead of your sit bones. Without pressure on the hands, you won't hurt your hands/arms/elbows/shoulders like you can on an upright.

If you're wanting a fast bike I suggest forgoing the suspension. Most of the 'bents with it were not known for being fast. You'll still have fewer issues with bumps than on an upright.

Jay D

I agree with dcrowell, there is no need for suspension on a recumbent bike dedicated for road use only. A suspension system will only add more weight and soak up power that could be used for speed. I have a Bacchetta Giro with a cro-moly frame and I find that the tires, the flexing of the frame and the contoured seat are efficient for a nice comfortable ride.

SactoDoug

Thanks for the feedback. No suspension it is then. I'm going to go all out for speed.

SactoDoug

Looks like I'm going to have a front suspension after all. I just bought the donor bike. It has disk brakes on it, which is a nice upgrade. It also has a front shock. So if I want to use the front disk brake, then I have to use the fork with the shock or buy a new fork with a disk brake mount on it.

Since I am doing this on a budget, I will use the fork with the shock and see if I like it. If I don't then I'll change it out next year.

I am thinking about posting pictures as I build the bike. I'm not sure if I should do that in the frame builder's section or in the recumbent forum. I don't see many recumbents in the frame builder's forum so I'm afraid all of the recumbent riders will miss it if I post there.

BlazingPedals

I don't have suspension on any of my recumbents. For most road riding, it's wasted expense and weight. If I'm riding on rougher-than-average roads, I use fatter tires. In fact, I have one of my lowracers specifically set up that way.

Fish_man

Go for wide tyres and skip the complicated and expensive suspension. I run 26x1.5 and 20x1.75 and apart from the occasional bump which jolts me it's fine.

bobbycorno

+1 The suspension on my semi-low (Performer Agenda) consists of Schwalbe Kojaks (35mm) at 80 and 85psi. Plenty fast and handles everything short of expansion cracks and root heaves.

SP
Bend, OR

Fish_man

Worth bearing in mind that if you decide agaist the suspension in the future then the front of you bike will drop .. how much will depend on how much travel you have and how much "extra" length the forks have.

Not a problem per say ... just bear it in mind when designing

Cant you just weld/braze disk mount's onto a rigid fork? I presume your welding/brazing the frame anyway.

adamrice 

Not to derail, but…a recumbent with 700C wheels front and back sounds like it might be tricky to ride—and more to point, mount/dismount.

SactoDoug

You have a point there. I will see what I can do. I'll probably trace the fork with the disk mount on it, plasma cut a 3/16" piece of aluminum to size, then weld it to my rigid fork.

The thing that I am a bit concerned about is that a fork not made for a disk mount might vibrate or torque steer when I apply the brakes. Most of the braking is done at the front wheel where I will be doing the welding. Also, I am not sure if welding on to the thin metal of the front fork will compromise its strength or not. I will do my best to minimise the heat, but I can't eliminate it entirely. At least I am TIGing it instead of MIG. I wouldn't even try something so delicate with a MIG rig.

SactoDoug

I am not worried about mouting or dismounting it. According to my plans from Atomic Zombie, as long as I am 5'8" (which I am) I should be able to get on and off with no problems with my foot flat on the ground even with 700c wheels.

Fish_man

I don't know what fork you have but all the forks I have ever worked with are pretty substantial .. and I would imagine aluminium forks would be even thicker.

When I started modding my forks I viewed things like this .... I've welded the entire frame out of rusted scrapped metal ... so I should be able to trust my welding on the forks.

Now I'm not saying that you shouldn't use the suspension fork. Just that you might want to keep the rigid fork as an option during the design phase. Would be a silly to decide to go for the rigid fork at a later date only to discover that you cant.

Something else I've just thought about ,weight or rather balance ... My bent is actually quite hard to lift up steps etc because the dammed thing balances right at the handle bars ... so when I try to lift the front wheel ONLY, to get up a step I find myself lifting the whole bike (if that makes sense). having more weight at the front in the form of a suspension fork would make getting it up a step a complete nightmare.

Hope I'm not throwing spanner's in your work's here ... just trying to make your job easier by giving you the benefits of knowing the mistakes I made.

SactoDoug

I appreciate your input, Fish_man. I am still in the planning/aquisition phase. This type of input is exactly what I need.

If I screw up the fixed fork, then I can either try again with a cromolly fork or throw the fork with the suspension on the bike. The recumbent that I am working uses the full sized fork so I can easily change them out without having to shorten them or make other modifications other than the disc brake mount of course.

If all else fails, I saw a couple on ebay for $75-100. It won't break my bank.

FeetFirst

A 'bent on the road does not need suspension with 26" or 700C wheels. My bike weighs 30 pounds, I weigh 145 and I'm running on 32-559 tires at 65front-75rear psi, and my SWB Volae rides like a Cadillac even on crappy SF Bay Area roads. I've ridden a Bacchetta Ti-Aero for several weeks on 23-571 tires in the same area, and that thing would vibrate your fillings out with the tires pumped up to 120 psi. But let a bit of air out and the thing became better, though still not great. Wider tires can run less pressure, and that's the key.

Fish_man

if it help's I did a write up of how I made mine ... although its strictly for the making not the actual design .. and kinda aimed at doing it on the cheap. Its not the best in the world I did intend on re-doing it but never got round to it.

PM me your email and i will send it off if you think it will help.