Q Hybrid

boddhi

New Member
Questta or Questio an interesting hybrid for those of us that like to tinker. I found the larger seat tube of a mountain bike fits into the sliding tube of the Quest. From there the attaching head stem bracket was turned to the top. Then a simple U shape bracket went over the tube and bolts back onto the head stem bracket. A bolt under the tube holds it securely. I had to make a thin spacer to hold the handle bar. I kept the dual drive and disc brake setup. I found the bungy cord shock absorber a big help to get my balance and co-ordination sorted.
 

Rampa

Guru
Awesome!

Congratulations on your sweet mod there! I know several forum members have been thinking of doing this.

I'm going to have to start looking at a Quest.
 

low wong

Member
Hi boddhi,
My Quest has


Hi boddhi,
My Quest has smaller diameter sliding tube then yours, may be difference generation.
 

Rampa

Guru
I would try and use a fatter

I would try and use a fatter tube for the upper part, and have it slide over the existing lower (orange) tube. It'd be stiffer. The first thing I thought of using was the tiller from my Performer Agenda Midracer. It already has the handle bar clamp built into it, and it's lower end has a clamping slot to slide over the nub it mounts to.
 

billyk

Guru
further comments on stiffening the Quest

As someone who has put thought and experiment towards stiffening the Quest's energy-eating front end, I'm intrigued by boddhi's beautiful mod (see my post "Quest frame flex tested" in the Q forum, 23 Aug 2014, and earlier posts and photos).

I've gone in another direction:
Thinking that the main problem was flex in the tube from the handlebar stem to the BB, I got an extra-length slider tube to replace the standard one, that only went about 6 inches inside the boom (for my mid-sized leg length). The new slider is 20 inches long, and goes almost all the way down the boom. I thought this would add stiffness.

Imagine my surprise to find out that the inside of the boom widens just below the clamp, so the extra length did exactly nothing. In fact, it rattled inside the boom. The clamping action of the boom is only just at the clamp itself. This seems a strange design choice and not easy to manufacture. But they did.

Next try was to get a piece of slippery polyethylene plastic sheet, about 1/16th inch thick. I slid a length of that inside the lower (wider) part of the boom, and re-inserted the long slider. This was quite tight and not easy to get in!

The result is good, however. The new setup has about half the flex I measured previously (see earlier post mentioned above). The extra stiffness is very noticeable in hill-climbing. For ordinary acceleration, there is almost no movement between the handlebars and BB.

Boddhi could do a similar thing on his setup, which would probably improve it further.

A better solution would be to manufacture the boom so the narrower diameter of the clamp section extended all the way down the boom (while still keeping the large diameter outer tube). It would be a little heavier but I think much stiffer.
 

boddhi

New Member
Q Hybrid Stiff-ness

If I need to modify something it,s to make it easier for me to use.
Everything from Chainsaws to heavy machinery controls and I have always come up with a way.
Flex in the Quest 3 is not a problem.
I,m very happy with its performance, its my performance that needs to come up to its capabilities.
John Tolhurst has addressed this by coming up with the Silvio and Vendetta both incredible Bikes and progressively stiffer.
Which is why we have trouble choosing between them.
All Cruz bikes are meant for riding. The more K,s you do the more natural and pleasurable the experience becomes.
If you want more speed and get more competitive then option is there to upgrade.
My only Quest 3 Stiffening is a Kind 150ml air shock on the back. It supports my chunky 85 kilo body a lot better.

Cheers
 

richa

Active Member
interesting


Once again, nice research Billyk.

When you say "the extra stiffness is very noticeable in hill-climbing" I assume you mean it's easier to climb. This would be great! I like a lot of things about the Quest, but am disappointed in it's climbing ability, so an improvement on that would certainly be a welcome modification.

My only issue might be that sometimes my wife rides it and we use a fair amount of the adjustment (I have it around 10, she has it around 4 IIRC).

Did you get the extra length slider from cruzbike? And where would I get the plastic sheet?

Thanks in advance,

Rich


 

billyk

Guru
reply to richa

Hi Rich -

- I got the extended slider from the fine people at Cruzbike (support@cruzbike.com). Costs $50+ shipping, and is identical to the standard but is 5 inches longer. Numbered markings go to 17 inches instead of 12.

- With this mod, adjusting it will be a problem, for two reasons:
1) it's very tight (has to be tight to do the job) so adjusting it would be a pain. I got the slipperiest plastic I could find, so it does slide, but not easily.
2) The new slider extends almost all the way down the boom, so you wouldn't be able to shorten the length very much. For my legs, the last visible number is 6.75 inches; at that setting there is only about another 1-2 inches before it hits bottom.

- I got the plastic sheet from our local Tap Plastics shop, which has many kinds of retail plastic. I make a lot of things out of plastic so it's a piece I had sitting around. This is gray polyethylene sheet, 1/16 inch. It's quite flexible and naturally somewhat rounded, so I just cut to length, beveled the top edge so the slider would push it out of the way, and slid it down the boom. I think I paid about $5 for a much larger sheet than I needed for this.

But this is really the beta version. 1/16 inch is too think if it goes around the whole way, so this just goes on one side. That's not ideal, although it does the job. I think this really needs about 1/32 inch all the way around, but it's hard to imagine how one would get that down the boom and still have the slider able to be inserted into it. I think it would take making a (wood?) insert in the slider that made it pointy: then it would push the plastic out to the sides evenly as it went down. Experiment required! Will post results when I get a chance to try this.

One problem is that I can't think of how to measure the inner diameter of the wide boom tube through the narrower opening at the top! That's necessary to do this right. Anyone got an idea of how to do this? How do you (accurately!) measure something thick through a thinner tube?

It's hard to quantify how much difference it makes climbing, but it definitely feels more rigid, so less energy is being lost. I did a few miles of riding with my test setup (earlier post), and get about half the deflection measured before, but the setup is not super-accurate for small deflections so I'm hesitant to say more than "about half". But now it's cold and raining and I need the fairing, so had to remove the test bar. The fairing - attached to the handlebar ends and the BB - is a sensitive if non-quantitative indicator of flex, and it flexes noticeably much less in hill-climbing.

BK
 

billyk

Guru
but what it the wall thickness?

Hi Rampa - I don't know the wall thickness of the large boom tube. It's welded to the BB at one end, and partly filled by the narrower clamp tube at the other. I'm tempted to say that the clamp tube just fits into the boom, so the o.d. of the clamp is the i.d of the boom, but when you look down there it's pretty clear that there was some welding and such that might not be so simple. Looks like a few hours of fun experimenting ... when I get a few free hours. BK
 

Wannabe

Well-Known Member
Does the soft rider suffer

Does the soft rider suffer from lack of stiffness like the quest. In other words, does it allow one to climb a bit better than the Quest?
 

super slim

Zen MBB Master
The Softrider V1.0 and Quest

The Softrider V1.0 and Quest V1.0 both have the same size booms at 31.9 OD 2.15 wall BB tube, and 27.2 OD and 2.00 mm wall handle bar tube, so both are flexible (Average 35,000 mm^4 polar Moment of Inertia), and about 50% of the stiffness of the Silvio V1.0 with 35.6OD 2.30mm wall BB tube, and 30.6mm OD 2.00mm wall handlebar tube. ( Average ?60,000 mm^4 polar Moment of Inertia).

The Softrider V1.0 vertical steerer tube is a lot stiffer as 34.14 OD 1.83 wall, 53,300 mm^4, compared to the Quest V1.0 28.9mm OD 1.83mm wall, 28,600 mm^4.

I do not know the dimensions of other versions of Quests and Sofriders, so later versions of Quest could be stiffer, as the Silvio has increased its boom size with each version.
 

ratz

Wielder of the Rubber Mallet
Ver 2 & 3

slim, I haven't measured the boom to the degree you have. But I do jump on all three versions and ride them depending on who grabs which bike. The flex on all three feels to the rider to be the same. I have also moved boom parts between the v1 and v2 without issues. The other thing to consider is the front suspension. Riding really hard up hill a fair amount of power is lost to the shock. The boom angle depicted here would reduce that as an added side effect.
 

boddhi

New Member
Your Quest-ta mod is coming along so I,ll post another pic of the U bracket.
I had a 25ml x 2.5ml flat piece of aluminum on hand so that,s what I used.
I have the Quest 3 so there is a difference in the steering tube diameters from the early versions.
The bolt in between the boom and the attachment bracket gives easy adjustment and
when tightened stiffens the whole front triangle.
This has been working very well for about 12 months of casual riding
Snapshot_20150310_1.JPG
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