ganchan

I've noticed that there are no positive reviews of any seatpost-mounted racks anywhere in cyberspace, as far as I can tell. Are they just an inherently sucky product, or is there actually such a thing as a reasonably stable, sturdy seatpost-mounted rack out there somewhere?

10 Wheels

Topeaks worked great for me for over 4 years

https://i256.photobucket.com/albums/h...r/IMG_3074.jpg

MichaelW

A generally sucky design that is heavier and less effective than the cheapest of bolt-on racks (see the max load figures). If you have no eyelets, it is one solution. Others inc Carradice saddlebags and Old Man Mountain racks. I see people equipped with rack eyelets, fitting seatpost-clamp racks out of ignorance (rather than quick on-off convenience)

My local bike paramedics use an MTB with no rack eyelets. They fix an OMM with fugly clamps and quick-release skewer. They carry a seriously big load, every day. It works but its not pretty.

fietsbob

Bikes that have no other option , they work, just not too much weight, and such..

What Bike do You need to equip? dual Suspension? very small frames no Rear Eyelet?

TiBikeGuy

If your seatpost is smooth surface, the clamp can rotate unless it is tighen really tight. You can't really hang your panniers as the center of gravity is too high up. Suitable only for light loads even though some has a sticker that it can carry up to 15 kgs.

Also don't try to mount these on a carbon seatpost.

ganchan

Well, I can take a rear rack -- sort of. I had one all lined up to purchase for my Giant Simple Seven cruiser, but discovered today that (a) its weight capacity is hardly any better than a seatpost rack and (b) even the pricier rear racks that can hold a hefty amount will require me to also buy special extension arms for proper installation. It was turning into a bit of hassle and costing more than I'd wanted, so I hoped against hope that there was a cheaper, easier alternative that didn't totally blow. Guess not.

chaadster

I use a Xootr Crossrack and love it.

Usually it carries their Crossrack Bag pannier, but I sometimes use a smaller pannier for it.

I move it between my utility bike and my folding bike.

It's awesome, and way cooler than a typical rack. Although it only carries one pannier, it's versatile, out of the airstream, easy to move from bike to bike, and easy to remove if you want to ride "clean".

i highly reccomend it.

no1mad 

Seat post mounted racks tend to have limited weight limits, best served for rack trunks. Rack trunks tend to be smaller volume, unless you get one with fold out panniers- but then you need side rails for the rack so that the bags don't flop around into the wheel, which decreases the amount of cargo weight you can carry...

Take a look at the Xootr CrossRack. Weight limit of 25#s and you can pretty much any standard single pannier or soft shell basket you'd like. Do take careful measurement before ordering, if it's something of interest.

ka0use

mostly you're right. i have a delta that would not tighten enough and i was afraid of really torquing on the steel bolts (rack is Al). i got some jb weld from a hardware store, mixed it up, smeared it between the post and faces of the rack, and in 9.5 years the rack has never moved. it takes 24 hours to cure. i also put red loctite on the bolt threads. the rack is rated to 25 pounds and it does ride high.

i love it.

chaadster

Regarding the Xootr, this is a good point. You'll need a fair amount of space between the saddle and wheel to make it work, because if it's up too high over the seat, swinging a leg over to mount and dismount *could* be difficult. It was designed for 20" folding bikes, but works on my 700c utility bike just as well as it does on my Dahon. Here are a couple of pics to help you visualize the spatial dimensions you need to consider:

Here's the Xootr on my utility bike:





and on my folder, with the bag stuffed to show its dimensions:

MichaelW

The Giant Simple, Seven is properly equipped with rack eyelets so you can fit any standard bolt-on rack. You dont need any special extension arms, the std adjustable stays reach to the upper eyelets.
The load/weight ratio of bolt-on racks is much higher than clamp-on racks. If your suggested bolt-on rack had a low max-load, it must have been quite puny.
Look for a rack with 3 legs, non adjustable (but correct length), fully triangulated, like a Blackburn EX.
If you have fenders, use an open frame top not a top plate.

Modern rack designers add lots of designy features, of no real use, that can interfere with good quality , locking, pannier-mounts. Locking mounts need free sections of single rod, NOT twin welded rod.

fietsbob

Perhaps you need to seek out a Better rack , if Heavy Carrying capacity is a Goal,
like Tubus, material : Chromo Steel Tube .

Arkel CDN company adds a brace down from the saddle rail to their seat post rack.
as seen on their website.. never in hand.
see:
https://www.arkel-od.com/us/all-categ...neur-rack.html

Nightshade

While not a "sucky" product seat post mounted racks are a really bad engineering design when their purpose is considered.

When ever a cantilever design is used sudden failure soon follows.

ganchan

I've found a local bike shop that claims to sell the Blackburn EX, so I'll check it out today. Also found the Bontrager Back Rack at another shop, which looks pretty good.

E.W.G.M.B

i have a topeak one and its ok for some light items on smooth surface but on trails it start to move around.

badmother

I do not use them instead of a "proper" rack. I have one now on my roadbike just so I can carry a jacket and one or two items from the shop.

I use one on a folder for the same reason. I carry the lugage mainly in the front on forlders, only a trunk bag in the back. If I want to carry more I use a trailer. I do not like to hang anything heavy from the seatpost of a folder.

chaadster

Speaking of folding bikes, Dahon make a seatpot rack called the Portage PostRack, which uses the Klickfix attachment design, which is pretty nifty.

canklecat

Bumping rather than starting new thread since this one is close enough...

I'm looking for a rack that uses the seat post for a supplemental support, like the West Biking universal rack, but without the quick release. I figure a rack that clamps onto the seatpost might deter theft of the saddle on my Globe Carmel 01 (no suspension seatpost), which has a somewhat unnecessary QR seat post. Seems like bolting a rear rack onto the seat post would do nicely to support the rear rack and to deter theft. The Carmel has standard rear rack mounts so a seat post clamp isn't absolutely necessary, but it might be stronger due to the extreme angle of the Carmel frame.

fietsbob

1 you can replace the QR seat post clamp with one that requires a wrench, & 2 , by having a bracing strut that will take some of the strain off the seat post.

your frame size as small as the one in the picture?


why not a proper bike rack? , a bike shop will even put it on for you.

Drew Eckhardt 

I gave up after trying 4 or 5 and not finding one which had both a clamp which cleared my thighs and side-frames strong enough to keep panniers out of my spokes.

P-clamps with hose-clamps to positively locate them let me use a regular rack without eyelets or a skewer mount.

canklecat

After looking at a Topeak seat post clamp rear rack, also with QR, I think I'll go with a conventional rear rack and just take the saddle with me into the store.

The Globe Carmel is an oddball. The bike seems big and bulky to me, but that's mostly because I've never had an aluminum frame bike before. But the frame design seems reminiscent of a BMX bike, only a big larger.


Yup, I'll probably do that. They have a good selection of Topeak and Bontrager racks, and the prices are within a dollar or two of Amazon.

fietsbob

why ?do you have a lot of saddle theft in your town, even if there is a more difficult to use, bolt, on the frame , gripping the seat post?

canklecat

A lot of theft, period. It's not quite swarms of locusts, but not much better. Bad enough that my original plan to was get a folding bike to toss into the shopping cart to take into the grocery store.

Lots of ex-cons, druggies and folks with mental illnesses in this area. Records show these are non-violent offenders, but there's a lot of petty theft. Anything that might fetch a dime at a flea market is likely to vanish.

When I rode a motorcycle anything not bolted or glued on might be stolen. I once locked my spare helmet to the motorcycle helmet lock. When I returned after work the helmet was gone. Some fool had cut through the web strap, making the helmet useless to anyone - it wasn't a good enough helmet to be worth repairing the sliced web strap. But he had a helmet. Hopefully he lined it with aluminum foil to keep out the voices and mind control rays.

ka0use

am on my second delta post porter.
a) not possible to clamp it tight enough to the seat post, so i used epoxy. it works.
b) my main trouble is getting the seat post tight enough so it doesn't pivot.
c) weight limit is 20 pounds and i've gone way over that. i recently bought a used kids' trailer for anticipated heavy loads, skipping the rack.

Rick@OCRR

I've used the Delta with good result on my commute bike for four years now; just used the four Allen bolts, i.e. no JB Weld or Epoxy.

But now I want one for my bike with a large dia. seat post (31.8?) and all the racks I see are for 27.2 . . . but will keep looking!

Rick / OCRR