squirtdad

Odd question, has anyone noticed increased stiffness or ride/handing differences when adding a rear rack, especially one where there are eyelets on the drops outs and on the seat stays for attachment? reason i ask is I am in early stages of contemplating a custom and thinking pros/cons of various options

thanks

rumrunn6

no

rseeker

That's my exact scenario (rear rack, seat stay and dropout eyelet mounting) coming up if UPS delivers on time today. Looking forward to finding out.

noobinsf 

If the geometry is favorable to a rear load and stability, then no difference, even with the added weight. Specific examples are that I had a rear rack on my old Puch Bergmeister, which had a long wheelbase and generous fork curve, and it was very stable with a rear load. The same is true for my Motobecane Grand Record. I also had a rack on a Felt SR91 flat bar road bike with a pretty steep fork rake and tight geometry, and with every bump, it seemed like the front wheel wanted to flop and fold under me.

Without any load, there was no perceptible difference between rack and rackless.

Dfrost 

I’m a big fan of versatile bikes, especially since the stable has to be kept small.

A Tubus Fly SS rack lives on my Marinoni SLX Sports Tourer (43.5cm chainstays, 103cm wheelbase) mostly full-time, usually with this bag. The 6-7.5 liter bag is attached to the seatpost, but it’s weight is supported by the rack. I’ve also ridden it sans rack, or with a smaller bag, but also with a full single pannier when I used it for long work commutes. The only difference in all those configurations is the influence of additional weight going up the many hills around here. Descents and flat roads are unaffected. When I once used two large and full panniers, the handling was less confident, but I’m sure that was just the relatively extreme weight shift off the front, which was notably on less secure (i.e., skinnier) tires.

It’s worth noting that the rack is quite stiff laterally with its triangulated design of strong but light tubes, and the single forward link, a solid rod to rack mount on the seat stay, doesn’t have to do much.

52telecaster

Just a lightweight rack, id say no. However i have removed front and rear racks and fenders and had an eye opening exp. What amounted to possibly 4 lbs turned a nice bike into a wonderful bike. That said, all my bikes have fenders and at least 1 rack.

gearbasher

I have a trunk bag on one of my bikes (Guerciotti TSX). It mounts just on the seat post. I use this bike for my long hauls away from home. So, it's loaded with a bunch of tools and it's heavy. Yes, I do feel a handling difference. I say it feels a little loose. Nothing drastic though.

dedhed

I know if you bungee a couple Weber gas grill cast iron grates on top with one side pannier full of commuter stuff it affects your handling.

In general I don't really notice any affect normally.

nlerner

As others have said, the rack alone won’t have any discernible effect, but load it up and you willlikely notice a change in handling characteristics. I do know that gugie has said a front rack with stays to the dropout eyelets will stiffen up a front end, usually beyond what one would want.

verktyg 

Off the topic... the ubiquitous old Swiss made Pletcher "rat trap" rear racks used to shake side to side with any kind of load on them which could severely affect the bike's handling causing a front end shimmy.



The clamps that attached to the seat stays was one source of the problem, the other was the was flimsy design of the struts. But for $5 bucks what did you expect?

We used to use plastic covered wiring harness clamps to attach the rack to the seat stay on all of the ones that we installed. It reduced a lot of the shimmy plus those clamps were less like to come loose like the Pletcher strap clamps always did.

There was a US made Pletcher knock off rack that didn't have the rat trap spring device. They had more robust struts and gussets cast into the rack where they attached. The racks were powder coated red. I had one that I used one for heavy touring and there wasn't much shimmy induced wheel wobble on high speed descents.

By 1975-76 Blackburn and Eclipse racks hit the market. They solved the shimmy problems.

verktyg

SurferRosa

Absolutely.

I always have my Blackburn rack on my Moto Grand Record for grocery getting. But in the summer, I remove the rack a few weeks and get the bike out on longer rides. It's a stable bike anyway, with heavier rear stays than my others, but I can definitely tell a difference without the rack. The bike feels livelier and lighter. It feels more like one of my full 531 bikes. I look forward to removing it each summer. It reminds me of its first purchase years ago. It feels new again. Fast.

Wildwood 

What's this thing? A rear rack...

79pmooney

I never noticed a rear rack making any difference at all but weight on it making a huge difference for this guy who loves to climb and accelerate from lights out of the saddle and throw the bike side to side in "the dance". With weight back there at the end of a lever the length of almost the entire bike and my hands trying ot fight it with a lever only 16" long,it gets old fast. I do that climbing without the dance, holding the bike steady.

My love is LowRider (or equivalent) racks up front with low panniers on them. There I can do the full dance with a lot of weight. Easy on the hands and I can do a full side-to-side rock.

xroadcharlie

That's a good question. It never occurred to me that my rear rack would effect the ride. I ride a comfort bike at speeds that handling isn't likely to be effected, so there's no problem there. But I must say when I ride MUP's and sidewalks with small curbs the rear of the bike REALLY slams. I stand for some of the small curbs at driveways.

Mine bolts to the drops outs and on the seat stays and I must say looks pretty darn strong. It wouldn't surprise me if it makes a noticeable difference in ride. I think I'm going to remove it one day to see if it helps. Perhaps I can mount it in such a way that that there is some give or a pivot of some sort without adversely effecting its stability for the light loads I carry.

Salamandrine 

I've never noticed a difference, but I guess I pretty much never ride bikes with empty racks either. I guess theoretically it might add some stiffness and resistance to lateral deflection. I'd guess it would be pretty small difference. It seems to me the down tube of the main frame is way more important. There's probably FEA of this somewhere. Anyhow, It wouldn't be that hard to jury rig a setup to test deflection with and without a rack, if you were super motivated.

With a loaded rear rack, it's absolutely different. You can't wag the bike back and forth at all, as noted above. Being that out of the saddle climbing is maybe the main beneficiary of a stiffer frame, it kind of renders any improvements moot...

AFA ride quality, IMHO it's the distortion of the main 'triangle' and deflection of the fork that is most responsible for vertical compliance. A rear rack wouldn't change that.

gugie 

Like Neal sez. There are designs for low rider racks that minimize the effect, snd racks that attach mid-fork and near the fork crown don’t affect fork stiffness. A steel fork with slender blades will give significantly on bumpy roads, especially washboard.

daoswald

I have a Tubus Cargo Evo rack on my Cannondale Quick CX hybrid, and a Tubus Fly Evo on my Cannondale Synapse endurance road bike. I don't believe there's any difference in handling, except a little added weight.

I've ridden both bikes with and without racks. I detect no difference in frame stiffness with the racks. The Cargo Evo adds one and a quarter pounds to the bike. The Fly Evo adds about three quarters of a pound to the bike. They're both very sturdy; the Cargo can handle officially up to 55 pounds, unofficially up to 88. The Fly can handle 44 pounds. Sure, with panniers attached or a trunk there will be a difference in handling. And if racing were my thing I'd remove the racks just so that my psychological state doesn't focus on how much the rack is contributing to me getting beaten.

It would be securing a rod between the seat stay mount points and the drop-outs. That would stiffen the ride a lot. But a rack has a lot of give in its geometry because the seat stay mount points and the drop-out mount points form approximately a right angle; there's a lot of flex available.

Tubus racks don't have a solid platform; they're just tubes. As such, I feel they would probably have less of a footprint when you're out in gusty conditions. When I used to ride with a rack that had a plate/platform, I noticed it more when in a cross-wind.

I think you will discover once you get used to how it looks, you're going to forget it's there.

rumrunn6

they do add wind drag especially with a trunk. not enough to discourage me. but I remember seeing a wind tunnel analysis video showing various designs I think the best design was one that is just attached to the seat post and angles upward hiding from the slipstream behind the rider’s back

ramzilla

No ride difference unloaded. Ride changes incrementally with load. If it's just a couple towels or a jacket then no big deal. If you put a twelve pack of beer on one side & a watermelon on the other side then oh boy! It can be a pretty dramatic impact.

RiddleOfSteel

Those four-ish extra pounds imbue a good bike with a sense of grace while in motion. But take them out and the bike becomes something really special. Unencumbered, it is it's truest self.

That was a bit, uh, effusive, but the thrust remains. Now you know why it's so hard for me to saddle a bike, even a touring bike, with such things. It's great the way it is!

Fenders, plus a front and rear rack on my former '90 Cannondale ST400 made for a fantastic ride. It just glided along!

Dylansbob 

On a super flexy frame, yes.

I have a titanium track bike I've had for ~15yrs. When I was closer to 200lbs, standing for hills would cause the rear end to shimmy all over the place. I installed a seatpost collar with integrated rack mounts and p-clamps for the legs to install a rear rack. It made a palatable difference.

Miele Man

I was quite surprised that this item didn't noticeable affet the handling of my bicycle.


Yes, there was a brand new 50 pints dehumidifier in that box.

Cheers

Lascauxcaveman 

Wow, I'm having a hard time imagining you at 200 lbs! I guess you'd lost at least 40 by the time I'd met you. But maybe because I've always been around 200 lbs or a little more, I'm used to a little flexing on all my steel bikes, at least. I've never noticed a rack to reduce that. But once I've got a rack on back, I tend to load it up and that leads to a little tail shake when I'm mashing. So for that reason, a rear rack increases flex for me

ExPatTyke

I'm using the car as little as possible at the moment due to being on furlough, so I bought a cheap rack, bag, and panniers for my AO-8.

Unloaded I can't tell the difference to be honest - it's not the lightest bike to start with. Add 40 pounds of shopping and you do notice it, especially going uphill. The steering is fine though, and no problems braking.

bear_a_bug 

You may notice some amount of "tail wagging the dog" effect (even on a triangulated rear rack) if you bungee a 50 lb window air conditioner to your rack and haul it a few miles down the road.
I did some crazy **** before I had car.