trainer help

[jeebus]

I just ordered the 1up trainer online:
http://www.1upusa.com/bike_trainer.html
and I'm thinking that may have been a mistake. [[ Update: I was able to make it fit, see later posts, and like the trainer very much now. ]] At its widest position it just barely has over 170mm between the cups. From my measurements, the silvio's front skewers are 170mm from inside-edge to inside-edge, and since one of them is recessed, the distance from outside-frame-edge to outside-frame-edge is more like 175mm (correct my measurements if I'm off by a few). Anyway I was also in the process of jerry-rigging a skewer using M5 0.8 threaded rod and a couple skewer caps:
http://www.1upusa.com/quicknuts.html

But if I continue with that as described it has no hope of actually working because those nuts are 23mm each bringing my bike+skewers width to 216mm, and I only get to deduct 9-10mm for how far each skewer recesses into the trainer's cups, which still leaves the cups probably more than 196mm apart.

Thus far I've been able to get a max of 179mm between the two cups of the trainer. I might be able to get another 1-2mm by doing things that would keep me from being able to return it. But if I used relatively thin skewer bolts of some form that recess all but a couple mm into the trainer's cup, the 179mm might be enough. So I haven't given up yet, but need help on how to construct my skewer.

If I just use a washer and a small bolt it would be thin enough and protect the silvio frame from the trainer cups clamping in on it, but the lack of a rounded skewer cap would probably keep the trainer's cups from holding the skewer in a firmly centered position (does that matter?). Any ideas appreciated.

Mark

 

[John Tolhurst]

Jeebus,
The work around is to replace the skewer with a threaded rod 5/16 and a pair of nuts. Not perfect but this small adapatation should fit you into any road bike trainer.

 

[jeebus]

Thanks for the fast response, I'm in the process of fiddling more but have stopped for the night because I doubt my neighbors would appreciate the noise my dremmel makes cutting through the threaded rod.

First here's what my rod + washer + bolt looks like and a decent shot of the trainer's cup that will be clamping in on the bike (the bike is sitting on the floor upside-down in case the parts look oriented wrong).

It sounds like your recommendation is something like below, where I let the trainer's cup clamp directly against the bike

If that's stable I have no complaint, but the part I don't understand is whether the trainer requires a rounded skewer cap it can clamp onto for stability. With the rounded skewer cap, the rounded trainer cup not only pushes inward on the bike, but also would resist any up/down/side-to-side movement of the skewer cap. With the regular nut and washer in place of the skewer cap it seems like the skewer could move around inside the trainer cup. I gues the most likely outcome is gravity would have the threaded rod resting at the bottom of the trainer cup which ought to be more-or-less stable.

Still, I'd like confirmation from the experts that I've got the idea right and that it should be stable.

The alternative I was considering was to stick a few more spacers and another washer on the outside like so, where that outermost washer fits fairly nicely into the trainer cup, at which point the trainer cups would be clamping their pressure into the outermost washer on each side and wouldn't quite be directly touching the frame anymore. Would this be better, worse, or about the same as the second picture above where we let the trainer cups clamp against the bike?

Mark

 

[John Tolhurst]

Mark,
we go to the threaded rod set up to remove the bulk of the QR and allow the spread of the assembly to be spanned by the trainer. If when you study your particular trainer you can provide a good fit to it using another nut and washer and still fit the trainer, it would seem a sensible approach.

 

[jeebus]

Good news: the threaded rod solution does work with the 1up trainer. I still don't know if the rounded skewer caps are technically required for stability, but I went with the solution in my last photo above and it feels quite stable.

So here's a mini-review of it. The 1up trainer appears to be very well made, and I like that there's no fluid to leak. I get great exercise pedaling in the 16-20mph range and put 50 miles on it this afternoon. Having the front wheel mounted in the trainer definitely interferes with the overall dynamic of riding a cruzbike; it's still good exercise and rides well, but it's pretty far removed from the riding experience on the road. That said, the overall resistance and feel of the trainer was quite good, and seemed consistant to me. I couldn't draw a graph of resistance vs speed, but it's easy to find a speed for whatever power-output you want to have.

Also it never got too hot at least during my initial tryout. I have no basis of comparison vs other trainers, but the noise seemed moderate to me. I did have to turn the tv up pretty loud to be able to understand what people were saying.

Mark

 

[Mark B]

Just make sure you put the bike into the trainer in the right direction relative to the drive wheel. Common mistake with FWD bikes. I know of at least one trainer that blew up because of this.

Mark

 

[WhiteSilvio]

Mark B wrote: Just make sure you put the bike into the trainer in the right direction relative to the drive wheel. Common mistake with FWD bikes. I know of at least one trainer that blew up because of this. [without mentioning any names....]
Mark

 

[John Tolhurst]

WhiteSilvio wrote:

Mark B wrote: Just make sure you put the bike into the trainer in the right direction relative to the drive wheel. Common mistake with FWD bikes. I know of at least one trainer that blew up because of this. [without mentioning any names....]
Mark

Okay, that'll be enough a that. It was me, okay?