q-rings work great (except for shifting)

[jeebus]

I've about got everything dialed in on my silvio now. The three main things I changed were
1. cut some 2 inch bacchetta foam for a new seat bottom: fixed the pain in whatever nerve my sit bone was directly on top of
2. 3/4 inch pedal extenders: so I can pedal toe-out without hitting the chainstay
3. q-rings: fixed the knee pain I was having
I still get a little finger/wrist pain after ~50 miles, but it's not too bad.

And now that I've got q-rings I can safely call the silvio superior in climbing to my strada (which has rotor cranks). My pedal strokes are not nice circles, so that's presumably why the change makes a big difference for me. Subjectively the change from round to q-rings felt much faster especially on hills. And my speedometer average of 16.8 instead of 16.0 isn't as dramatic, but shows there was a difference.

The hill climbing at 15mph on the same hills I had dropped to 10mph last week really was dramatic though, and so was the elimination of knee pain.

The only problem now is shifting. I thought I would be clever and bought a 50/40/30 instead of the usual 53/40/30 so the diameter at the q-ring's largest size would match my round ring thus not making the derailler cage stretch any further than before.

In that regard my plan worked, it's the middle 40 that's the problem. If I try to shift into the large ring, the middle ring runs into the derailler.

I saw John posted in a different thread about a new boom for shorter riders. Is there any chance that could solve my problem, or is this something else? I'm afraid I probably have the opposite problem. I don't have a camera at the moment, but my bb is farther out than some thus making that front angle more acute thus putting the bottom of my derailler much closer to the chainring than the top. And it looks like as big as that middle chainring is, you can't shift the derailler past it unless that angle is just right.

- Mark

 

[jeebus]

Now that I've slept, I'm realizing that description of angles doesn't make any sense. Moving the bb in/out shouldn't change the angle the derailler makes with the ring. But I can't find any adjustment on the derailler itself that would fix the angle. Any ideas? Hopefully I'll be able to take a picture one of these days.

- Mark

 

[Mark B]

jeebus wrote: Now that I've slept, I'm realizing that description of angles doesn't make any sense. Moving the bb in/out shouldn't change the angle the derailler makes with the ring. But I can't find any adjustment on the derailler itself that would fix the angle. Any ideas? Hopefully I'll be able to take a picture one of these days.

- Mark

I was wondering how one would go about setting up a derailler for an out of round chainring. I guess you have to set the derailleur to clear the rings at their highest angle, so when the oblong part comes to face with the derailleur, there is sufficient clearance. I'm guessing you set the big ring clearance in this fashion, but it's of no help with the middle ring? The only other thing I can think of is you learn to live with it and time your shifts accordingly, but that seems like a backwoods approach. Have you consulted the documentation that comes with the q-rings for suggestions? I'd guess you have. It seemed like it was a little bit of an ordeal to get the rings timed with your "dead" spot, so maybe it's the same for setting up shifting? I'm low on suggestions, but all ears on this one.

Mark

 

[drshuf]

I'm intrigued by your Q-rings. I have trouble with the hills in my area and your jump from 10 to 15 mph up the hills is attractive. Have you worked out an answer to the shifting? I'm running a triple 52,42,30 currently with shimano front derailleur and deore rear derailleur.
What type of shifting problems are you experiencing.
Thanks
Reid

 

[jeebus]

I'm no closer to a solution yet, but I'm definitely going to stick it out and make something work. The silvio with q-rings is a keeper. My first few weeks with the silvio and round rings was good but not great. I had found it to be basically equivalent in every way to my strada (which has rotor cranks). Cruising speed felt the same, and disadvantage vs the DF's on uphills felt about the same. But with the q-rings the silvio is clearly superior. Tonight was our group's hill climbing ride and the silvio was just plain great. So the strada is going to go up for sale soon.

I did mess with the derailler more, and it's not possible to move it far enough away from the chainrings to clear the milddle 40, at least not with the derailler at the angle the silvio braze-on thingy puts it. It's not just a matter of clearing it temporarily either, ie shifting when the ring is in its narrower position. The inner side of the derailler gets hit by the middle ring every rotation. Currently the overlap is something like 6-7mm, so it's not like it's just tapping or scraping, on each revolution. It hits the derailler and grinds to a halt.

It's hard to be sure just holding the derailler loose in my hand, but I think it's capable of clearing the 40 ring if angled differently. If a 37 or 38 middle q-ring existed I might try that, but there doesn't appear to be such a thing. So I think I'm stuck with no ability to use the 50 ring for now. I don't know yet whether the "correct" solution would involve the derailler moving father out or having its angle changed, and I don't know how much jerry rigging I can do to accomplish either of those things.

I hope to take pictures this weekend.

 

[JonB]

will this work with a internal gear hub? then you dont need to change, and i suppose you could use the derailure gear changer arm in static mode to keep the chain tensioned.

 

[John Tolhurst]

JonB wrote: will this work with a internal gear hub? then you dont need to change, and i suppose you could use the derailure gear changer arm in static mode to keep the chain tensioned.

I like your thinking, Jon.

 

[John Tolhurst]

Riddle me this oh learned friends.

If you take a q-ring, and cut it in half right through the centre, you would always have half teeth on one half and the rest on the other. So no matter what point it is in its rotation, half the teeth have chain on and half don't (assuming here the return chain line is parallel to the drive chain line). Therefore, you could set it up without a sprung tensioning roller.

On the other hand, and I'd like this validated jeebus if you have noticed it, setting the bike stationary and cranking backwards, you will notice a slight fore-aft movement of the rear deraileur in sync with the crank rotations.

Can anyone of our thoughtful riders and readers shed a little light in my direction?

 

[drshuf]

Mark,
When you installed the rings did you use the instructions they have for recumbent bikes? It seems that it is very different than the diamond frame bikes.
Are you saying that you can get the chain on your middle ring but that it rubs all the time? So are you just riding on the inner 30t ring?
Or are you saying that you can get the chain on the 40 but not from the 40 to the 52?
What if you just went to a 2 ring system, would the gain in the low gears make it worth it?

Is it possible to bypass the braze on front derailleur and put on the type that has a band around the post? I have had some time adjusting the angle of my fd (shimano 105) with respect to the angle the back part of the derailleur makes with the chainring. Seems like the brazeon mounting needs more adjustability so that you can move the tail of the deraileur up higher as well as more versatility in side to side adjustment. Seems like once you lock down the screws, it "self centers" with very limited adjustability.

Finally, could you just add the inner 3rd ring as a q-ring and leave the rest round rings and still get the climbing advantage?

Thanks, I'm really looking for a way to enhance the climbing abiliity of this bike as I live on the top of a big hill and every ride I take ends up coming back up the hill!
Reid

 

[jeebus]

Jonb/John: I suspect an internal hub would work pretty nicely, but $1500 for a 15 speed rohloff is quite a bit of money. As far as tension, I suspect (but don't know) that you could get by without a chain tensioner in a setup like that. I think John's comment about half the teeth always being on the chain is right, with the caveat he noted about the angle. And since the angle changes by a few degrees every stroke there is a very slight change in chain tension every pedal stroke. You can see the derailler tensioner thingy moving back and forth maybe as much as 1-2mm each stroke.

Drshuf: I did follow the recumbent-specific instructions from a .pdf that the rotor company had online. I had to read the instructions very slowly and keep track of their terminology, but ultimately I think they documented it pretty well, and I'm very pleased with the result. Also the nature of my derailler problem is that I am able to use both the 30 and 40 rings, but can't shift into the 50 (I got a 50 instead of the usual 53).

I agree the derailler could use more adjustability. I made a couple attempts at sticking a thin piece of rubber in to change the angle, but that didn't go real well.

I do think you could just use an inner 30 and leave the other two round, but if you're like me you'll want the middle ring to be a q-ring too. It made a big difference for me.

- Mark

 

[JonB]

jeebus wrote: Jonb/John: I suspect an internal hub would work pretty nicely, but $1500 for a 15 speed rohloff is quite a bit of money.

Yes it is pretty expensive. I think i found a used for just about $500. I might buy that. Else i was thinking of a nuvinci.

 

[drshuf]

Are you thinking that the 53 would have been better than the 50? Have you tried mounting the derailleur on the front position of the braze on lugs, or if you are on the front, perhaps the rear one would work. Could you possibly take pictures of how the derailleur is binding and post them?
Thanks
Reid

 

[Mark B]

drshuf wrote: Are you thinking that the 53 would have been better than the 50? Have you tried mounting the derailleur on the front position of the braze on lugs, or if you are on the front, perhaps the rear one would work. Could you possibly take pictures of how the derailleur is binding and post them?
Thanks
Reid

That's a great point, Reid. I wonder if he has the braze on widgit bolted to the right set of holes? That would make a huge difference.

Mark

 

[Mark B]

JonB,

I don't know if you've seen it, or not, but there is a 26" wheel with Nuvinci hub for sale on BROL. Some discussion about the hub, as well.

Mark

 

[JonB]

Mark B wrote: JonB,

I don't know if you've seen it, or not, but there is a 26" wheel with Nuvinci hub for sale on BROL. Some discussion about the hub, as well.

No, i havent seen that, thanks for the heads up.

 

[drshuf]

I installed an inner 30 and middle 40 q-ring this weekend. After 35 miles, I can't say that I've seen the level of improvement that was mentioned in the beginning of this post :-( I think that I am getting better acceleration from a start and the overall feel of the rings is good. Shifting between rings is a little rough compared to normal rings. I left my original 52 outer ring on and am doing fine shifting up into it.
I was really hoping for a boost in hill climbing, but so far, if there is any improvement, it is subtle.
Reid

 

[jeebus]

I had been meaning to get back to this thread. I started fiddling with the little black piece that attaches to the frame and holds the derailler, trying to pick the right angle to use irrespective of what the frame would allow, and where I ended up holding it was very very close to the original angle. So I put a couple pieces of tape on the derailler to modify the angle just a hair and tightened it down and the gears are currently all usable (although barely). The 30 ring has the chain touching the bottom of the cage every rotation, and the top gear involves over a dozen pedal strokes of kachunka-kuchunka-kuchunka before finally going onto the 50 ring. But in an emergency the gears are all usable now. Visually I think the angle could still be a little better, and I might try putting even more tape on.

Anyway the q-rings are still working wonderfully for me, and I'm sorry to hear they're not doing as much for drshuf. I guess you could experiment with the other settings 1 and 3 that the instructions had you mark. I never did that because I was so delighted with the first setting I just haven't touched it since. I must spin in the worst circles ever because it really was a night and day difference for me. I missed last weeks hill climbing ride, but now I look forward to powering up the hills and showing off how well the silvio climbs.

- Mark

 

[John Tolhurst]

How many degrees before LDS is the major axis of the q-ring on your set up? Can you count the holes (there are 35 in total), each hole is 360/35? = 10.286deg ... and you can get half hole increments by rotating the chainring 180 and moving half a hole to line the next one up.

Is it recommended at 45 degs?

http://www.rotorcranksusa.com/pdf/recumbentqrings.pdf

 

[Robert Stewart]

JonB wrote:

jeebus wrote: Jonb/John: I suspect an internal hub would work pretty nicely, but $1500 for a 15 speed rohloff is quite a bit of money.

Yes it is pretty expensive. I think i found a used for just about $500. I might buy that. Else i was thinking of a nuvinci.

I looked into the option of a Rohloff hub when I was selecting my Silvio build components back in January. Here is what the Rohloff people told me:

Quote: Thank you for your Em@il concerning our SPEEDHUB and the Silvio model
from Cruzbike.

I believe that the adaption of this bicycle to our gear system will
unfortunately not be possible. Racing bikes have a frame spacing of
130mm and because the Silvio also uses racing wheels, I am expecting
that this too has a 130mm frame spacing. Our SPEEDHUB requires a frame
spacing of 135mm (standard ATB / MTB width) and therefore will probably
not fit regardless of which type of torque support is to be chosen. It
is also not possible to bend the frame the minute amount of 5mm in order
to accomodate the hub because this puts too much strain upon the axle
and could in turn lead to shifting problems.

The website from Cruzbike.com unfortunately does not state the exact
frame spacing so I am only guessing but it doesn?t look hopeful. Get in
touch if it turns out to have the correct spacing and we can have
another look at the compatability, but the use of the SPEEDHUB (due to
the fact that the torqueis being supported by the frame) lies with
Cruzbike themselves so that your guarantee does not become affected.

Cheers,
Rob

 

[Mark B]

Good heads up there, Robert. That would have been an expensive "oops".

Mark

 

[JonB]

Mark B wrote: Good heads up there, Robert. That would have been an expensive "oops".

Yeah oops. Would a rohloff work on a freerider?