Picture of Bicycle roller trainer
I recently got back into biking, but need an outlet during the Chicago winters.  I don't like stand trainers, but then found out about roller trainers.  They are several hundred dollars to buy, and so I thought I'd look into building one.  There is another instructable that covers this, and I used some of those ideas, but had a different approach for making the rollers.  I built this to be functional rather than pretty, and the whole thing cost about $50.  Here's the other instructable:  http://www.instructables.com/id/DIY-Bike-Rollers/
I used 2" pipe rather than 3" pipe because that's what it looked like the professional models use.  I don't know if 3" would be easier to ride.  I've only given it a few tests, but it all seems to work.  I will say that riding this thing is not like riding a bike in that it takes a lot more coordination and balance!  I think that's a good thing, but it will take some practice to be able to use it like they do in the online videos.  I do like the way it feels more than the stand trainer -- more realistic and requires some real concentration.

I've added a video of it in action.  You can see that it takes balance and concentration -- i've only done it a few times but am getting better quickly.  Ignore the grunting in the background, that wasn't me, someone was doing P90X.
qwertykeyPADpc10 months ago

i'm Afraid the PVC pipes will crack. will it crack on usage?.. it seems to be fragile.

Sharanga1 year ago
I'm hoping to build one of these soon. Thanks for the info.

I do have one question: is there any principle regarding the spacing between the two rear rollers (the rollers supporting the back wheel)? What would be the ideal spacing between the the two rear rollers?

Regarding roller size, I believe the larger the roller diameter, the easier it would be to ride. That is, 3 inches would indeed be easier than 2 inches; 12 inches would be even easier, and so forth (assuming that the friction at the bearings does not increase along with size increase). Of course, at some point it will just start looking silly and be too unwieldy.

The principle is exactly the same as for the gears on your bike. Your large bicycle tyre is trying to rotate those rollers. The larger the roller diameter, the easier it is going to be.

I believe large diameter rollers would have other advantages too: since they will spin slower, they will be less noisy at high speeds. You just have to make sure they are strong enough to take the bicycle weight. You could also use larger bearings for better performance.

Perhaps the manufacturers use smaller diameter rollers considering that you can compensate by using a lower gear setting on your bicycle, and having smaller rollers means smaller package size and a little more ease in carrying the whole thing around.
I've used commercial rollers before. The front roller should be positioned just enough ahead of the axle center to stabilize the bike, but not enough to make it tend to rock the rear wheel off the middle roller (and of course usually the back roller when the bike rolls back). 1/2" should do it. If it is directly under the front axle, you may find the bike to "buck" or rock. You can make the strap from a trash-can lid strap (round silicone band) or make your own from old inner tubes. (they eventually decay, but if you have a supply of thrown away tubes, You'll get months out of each band. Just sew like you did for the fabric strap.) Larger roller spin more easily. (Smaller rollers create more rolling resistance as the tire deflects over them. This is why the "pro" models have smaller drums, for resistance training as well as spin training)
Aron3133 years ago
Im amazed that the friction wouldnt stop the rollers.
sanjaysy3 years ago

Can you please tell me the relation between the,
distance between bicycle tires & the distance between rollers

Thanks & Regards,
dhouggy (author)  sanjaysy3 years ago
My bike tires were 38.5 inches from hub to hub. The back rollers are 11" apart. The front roller is 41" from the back tire hub (so just in front of the front tire hub). That puts the front roller 46.5" (41 + 11/2) in front of the back roller and 35.5" (41 - 11/2) in front of the middle roller).
Thank You, Thank you very much.
criggie3 years ago
Nice - could you please add a shot video of it in use?