Quest on AIR
installed air shock on Quest, smooth noise free ride. Good Bye BOB
I put an air shock on the Quest hopping to eliminate any noise, and the original spring shock seemed to bottom out occasionally. I didn't expect the 20% increase in performance. Went on a 50+ mile ride today with some good climbs, the air shock stiffened the frame and I could climb 10-12% grades with two clicks left on shifter and not struggle. I can now start uphill with very little problem. My fatigue level is half what it was using the mechanical spring shock. Anyone that wants better performance from their Quest while keeping the comfort level should invest in an air shock before clip-in pedals. New name for Quest is Pocket Rocket.
Not quite sure why that is the case, but I am interested.
What make and model of air shock did you use on your Quest?
I think that it might be a Kind Shock A5-RE
Is that correct? Which length? I'm keen to give it a try on my Quest. Where can I get one?
Mr. Tolhurst, you may remember my question, quite a while ago,
about experimenting with my Sofriders' rear suspension by turning it into a hard-tail.
I took your advice and replaced the stock sprung shock with a length of hardwood dowel.
The stock comfort disappeared, of course, but I did notice that the bike
was moving more efficiently... almost as much improvement as Jphipps notes.
My takeaway from the experiment was to reinstall the stock shock and crank up the spring preload to the
point where the spring barely sags under my weight.
Sharp road shocks are still absorbed by the rear suspension, but the bike has most
of the performance gain it showed when it was a hard-tail.
Why does the shock absorb power?
I guess it's during upper-body involvement, when the arms and/or shoulders
are putting power into the bike.
See this for yourself:
with your bike held upright in either a stand or a trainer, lay back into
Now, with your full weight supported by both the seat back and the seat proper,
push against the handlebar.
Push, push-pull or just pull.
You'll see that you're either compressing the rear spring (pushing on the handlebar)
or you're relieveing the load of the rear spring (pulling on the handlebar).
The spring in the rear suspension may be soaking up some propulsive effort
from the upper body.
The bad news, is that watts may be dissipating in the suspension, rather than being
used for forward propulsion.
The good news is that it's not a problem, just cruising along, pedaling with your legs only.
Comfort is good, in the long run.
A combined spring and shock absorber always absorbs energy whenever it moves. Although the spring returns all energy which it sites during compression, the shock absorber does not. If it didn't work that way, going over a bump would result in you continuing to bounce afterwards. The point of the absorber is to absorb unwanted energy (the vertical movement). That energy is supplied by the slowing up a you hit the bump and only the spring part is pearly returned (minus pivot frictionand the energy dissipation of the shock absorber) If the payload is cranked up high enough that the small irregularities of the road don't lead to any movement of the spring (instead the whole bike and payload moves up and over the bump.), the energy loss will be less, but so will the comfort (and perhaps wheel life if the bumps are hard andfrequent enough!)
Went on another ride today with same results, better performance of Quest.
The shock is Kind Shock A5-RE 125mm length with 20mm of travel.
Finding someone to sell you the shock is the hard part. I ordered direct from China, shipped via USPS ( $5 US for shipping). the name of the vendor is AliExpress on the net at http://www.aliexpress.com/store/product/KS-Rear-Shocks-for-Downhill-Bike-Mountain-Bicycle-Rear-Shock-125mm
?Maybe CRUZBIKE could order a load of these and make them available as and upgrade for current Quest owners.
Thanks for the information, jphipps.
I'll contact the UK distributor for Kind Shock, to see if they can help me out.
I guess that Cruzbike might be able help supply the air shock as the OEM fitted shock is also from Kind Shock.
Maybe JT can get hold of an A5-RE to evaluate?
Went for another ride today and started noticing more differences using an air shock. The stability of the bicycle is better, especially going down hill, on rough pavement and attempting to make a turn. To test this I found a low traffic road, down hill, that has rumble strips. Going over rumble strips at 20 mph was somewhat exiting in the past, now the Quest is more behaved and stable. I am running 150 psi in the shock which is the maximum recommended pressure. The comfort level is better, even though the shock only moves 1-2 mm.
I've ordered a Kind Shock A5-RE from AliExpress.
The UK distributor for Kind Shock only brings in their suspension seatposts.
I'll post my impressions of the air shock once I have it fitted onto my Q3.0 559.
interesting question as to why this air shock works while the mechanical spring seems to give a less efficient ride? I think this is because the this air shock is simple, you set the air pressure to match your weight and what size "bump" you want the shock to absorb. The rest of the time the air shock gives the Quest the features of a "hard tail" mountain bike. Which means the Quest will accelerate much faster, climb better and the rider will experience less fatigue. For my 150lbs and a bump size that equals the drop off my drive way at home, I use 130 psi. This pressure, for my weight, will some times result in activation of the shock going over rumble strips at 25 mph and the rest of the time I'm in " hard tail mode". I could never adjust the mechanical spring enough to give the same results.
The air shock arrived here in the UK today from China. It looks good. I'll get it fitted to my Q3.0 559 sometime over the Xmas/New Year break.
I've got my fingers crossed for a fine day so I can take the bike for a test ride.
Would it fit a Sofrider?
?Or putting it another way, which size/specs to use this shock on a Sofrider?
Might be worth you starting a new thread about air shocks on the Sofrider part of the forum? Maybe John Tolhurst or Doug Burton will see that and answer?
Looking at pictures of the Sofrider, it would appear that you would need a longer air shock than the one for the Quest IMHO.
Have you had a chance to try the new shock yet?
No. Not yet. Will post something when I've done a proper test ride over twenty miles or so. Only had two brief test rides around a car park in the dark. LOL. :)
On my Softrider V1.0 I fitted a Manitou Radium R air shock with 165 mm extended length and 38 mm stroke with 175 psi air pressure for my small 110 kg weight.
It stopped all massive rebounds when hitting potholes at speed!!!
It improved the handling by a Massive amount
Hi Super Slim
I'm pleased that your air shock is working so well.
Its still pretty cold here in the UK, so I've yet to give my own air shock a proper try.
I'm hopeful that we'll get a warmer day soon.
I see the A5-RR1 on ebay but not the A5-RE. the only difference seems to be that the RR1 has a "air top out chamber and valve"
Does anyone here know what difference that will make?
BTW I tried to stiffen up the existing spring shock but only seemed to succeed in winding it up and down.
turning it doesnt seem to make much difference. How do I stiffen it up?
The A5-RE is a single chamber so the ride may not be adjusted to your exact preference. The A5-RR1 has a negative air chamber plus the main chamber. I have used both and can say that the A5-RR1 will give you a nicer ride. I also changed the length of the shock about 30 mm. to 150 mm. and the resulting ride is more tuned to my style of riding. With the longer shock I feel a little elevated, but not to high.
The power loss of the rear shock is because the front wheel has to pull you forward, but there's a little give from the back wheel lagging, with each surge of power. (More consistent stroke should minimize this, and the E-ring is probably part of that.) Keep in mind, this is an order of deformity on the order of low pressure fatty tires flattening to cause more Rolling Resistance. How much depends on how much play you have in the suspension (It's basically centered between the wheels) so your adjustment to right about the load in the seat (Rider weight) is a good place to start before dialing out the remaining energy from surging. Also, gear down and spin, as always while climbing, and acellerating. (A bright guy by the name of Einstein said that Gravity, and Acceleration are indistinguishable, so Inerta is like a hill that slowly flattens out as you gain Momentum.) I'll probably experiment with adjustability in my rear shock when I get my Q3. Right now I have little more than Theory, and a good understanding of the Engineering.
I started having some back pain after installing my new A5-RR1 150mm shock, the quest seemed harder to ride on starts and uphill. So I did some research online and discovered that the elliptical bump is "retarded" 90 degrees for upright bikes vs recumbent bikes. Since my Quest is now slightly higher and the push angle has changed, I "retarded " my elliptical ring one hole. Problem solved, what a comfortable ride and easier to climb and start. Thank you John for including that adjustment in the elliptical chain ring. Of course other things changed when the seat height went up, the kick-stand no longer worked, actually it never worked very well unless the front wheel was supported. I made a new kick stand as can be seen in the picture.