Bike rack mounting question
 

I have a 2009 Motobecan with carbon seat stays and no eyelet for a rack (old ****ty photo below).
http://bikeforums.net/attachment.php...hmentid=257181

I am doing a little three day 250mi self supported ride next month (St. Paul to Ely, MN) and I need to plop a rack on this bad girl. I have a spare aluminum Planet Bike rack that I was looking at using. I did do some research on solutions and most have come up with using p clamps or buying a new rack and quick release mounting gear (I really, really don't want to spend an extra $150). So here's where I get a little queasy about using p clamps, I'm really not too sure about about putting 25lbs+ of weight on the carbon fiber seat stays in a spot they were not designed to transfer weight.

Are my fears unjust or is that weight going to be too much in a bad spot for the carbon fiber to handle or is there another way to mount this that circumvents putting the weight on my seat stay?

I should also note am a big rider, 6'2", 210-220lbs depending on the day.

You shouldn't use p-clips or clamps with carbon. You choices are:
Seatpost clamp rack
QR skewer-mounted rack
Carradice saddlebag.
You can get upper seatstay-eyelets incorportaed into a seatpost clamp.
You can also fit a bar bag and a frame bag.
You will have to travel ultralight but it is quite do-able, esp in summer.

That's what I thought. Crap, looks like I'm going to have to shell out for a new rack one way or the other as I have a set of Ortlieb Back Roller Classic panniers enroute that I am planning on using. I just ordered 90% of my gear on Monday so I'm not too sure on the gross weight just yet but I am going with a Warbonnet blackbird hammock and a Kelty 12' x 12' tarp in lieu of the tent so I should be saving some weight there.

I guess the next question becomes do I grab a seat post mounted rack or do I take that $30-50 and invest in a Tubus rack with a QR kit?

*edit*
Double crap, after some research, the Tubus racks uses seat stay clamps for frames that don't have rack mounts. Looks like I am investing in a seatpost rack, returning my Kelty tarp and using some extra funds to grab a Warbonnet tarp that is 1/3 the weight and a little smaller. Now to start looking at my options for seat post racks.

I think you need to a bit more research. The Tubus quick release kit fits over the quick rear wheel quick release. Tubus does sell seatstay clamps but, as other's have said those aren't appropriate for carbon. Here's a good source for all of the Tubus products for fit problems

The Qr kit would work fine but since this bike does not have any eyelets on the seat stay period I would need the upper mounting kit that mounts below the split of the seat stay which happens to be CF on this bike. With a little dremeling I do think I found a way to securely jerry rig a p clamp below the CF on to the aluminum at the bottom of the seat stay and still keep parts out of the drivetrain. If I can do that, then I can still use the Planet Bike rack I have lying around as it can attach to the seat post clamp and that would be awesome. Otherwise, I will probably go with a Topeak-RX-Beamrack. Looks like either way I have to swap back to my aluminum seat post off my single speed.

trailer?

As a solo rider the added weight of a Yak or a Nomad turned me off a bit. I really want to build a bamboo touring frame similar to a Boo but with a little different geometry, unfortunately that is not in the cards for this season.

The only way to do this is to use a rack like the Axiom Streamliner DLX (cheapest) or the Tubus Fly (more expensive but lighter). The attachment point for these racks are on the QR rear axle and the caliper brake bridge. You'll have to remove the rear caliper brake to install the single stay and then re-install it back. You may need a longer recess bolt, but I managed just fine with the one on my Trek 5000 carbon bike. The maximum I would tour with a carbon bike with these 2 racks would be 20lbs -- less would be best and can be done camping wise. With a Old Man Mountain rack which is the creme de la creme in this rack category, you can push it to 30lbs. I had the Streamliner DLX before, but now using the Old Man Mountain rack as it's more secure and is secured via the brake bridge as well. However, I fashioned one of the long seat stays to work on the bridge.

In regards to seat stays. According the Old Man Mountain, the full weight of the load is borne on the rear axle mount leaving the stays as stabilizer to prevent the rack from rotating from the axle axis forward during breaking or steep downhill descent or rotating backward during climbing. Using P-Clamps is fine, you must build up a stay bridge using black insulation tape so it doesn't gouge into the carbon material during these forward and backward motion. It's easy to build and any mechanic who has more than 20 to 30 years of experience will know how to do this. OMM recommends the same.

Big Carradice saddlebag + handlebar bag should get you through - Carradice bags will also allow you to lash tarp/hammock to the top so you can cram more crap inside them.

Unfortunately I wan't to put my trunk to use in future trips this summer/fall as it is insulated and carries food well and judging by the width in the pictures and the descriptions of the two, the Fly is out and probably the Axiom as well. I have plenty of time to figure this out, I start ramping (how is this word not in Google's spellcheck...) up my training the first week of July and do a test 160 mile two day trip on the 15th.

I get to play with them tomorrow morning as I have some work to do on the single before I ride it into work. Going P clamp shopping later today to see if this dremel solution might work.

*edit*
Axiom claims the Streamliner DX can carry 110lbs? That sounds like recipe for disaster.

You can use a seat collar rack mount since your bike has a removable seat collar. They look like this

https://encrypted-tbn0.google.com/im...iZ75cZiYGrHzSH

Or you could mount the rack using a single stay behind the brake somewhat like this

http://i144.photobucket.com/albums/r...e/DSCN0577.jpg

It is a very sturdy rack and I like mine a lot. As a bit of a weight weenie, I actually wish they made one about half as heavy duty. 110 pounds on any rack sound like a bad idea to me though.

Change , the frame's seat post clamp to one with the threaded mounts added,
seen above... for top mount of a rack that supports it self by the QR slewer.

Because of how far down my brake is mounted in relation to where the rack will be I don't think it will work there, but a seat collar sure will and I get to keep my CF seat post a major plus since I will be on 23s. The real disabler for any of the Tubus racks for me right now is the price tag. I really can't afford that this season as I went a little over budget for gear already.

How wide is the rack? I can't seem to find a definitive answer on line. I have an old Transit DX trunk with a space blanket liner that I really want to be able to use for cold food storage. I am packing a 8" carbon steel frying pan so I can have the luxury of having eggs every morning and extended meal options in the afternoon and evening. It does have a soft flexible bottom that can give a little bit, but that rack looks mighty narrow.

My thoughts exactly.

Why wouldn't you think your trunk bag won't fit on the Axiom? I managed to fit an Arkel Tail Rider 8L trunk bag with a pair of Ortlieb Classics on this no problem. The Tail Rider can act as a cooler for food stuff. You can also buy a portable cooler bag from REI that functions somewhat the same to keep yogurt, eggs etc cool so you can stuff in inside your panniers. You can also use bungee cords to secure your trunk bag to the rack if your attachment straps aren't long enough to form secure loops.

110lbs is static weight. You can take that with a grain of salt. What's important is the true dynamic load because what's important is not the downward weight, but rather the side to side movement of weight that can wreck the rack stays and these minimalist racks are way more flexible than say the more expensive Old Man Mountain racks. My older generation OMM Sherpa has a dynamic load rating of around 30lbs. I hear reports people breaking or bending the arc stays of the Streamliner as the load approaches 20lbs. I already bent the bottom arc stays on the Streamliner even with a 15lbs load on an overnight trip! That's why I took it off.

My advise to you is this. Get the rack, and load it with your load and then commute with it. Don't train unloaded. It's not helpful because the load characteristics between a bare bike and a bike with a rack and a load are different. If you want to carry pots and pans, make great hot breakfast with eggs etc, perhaps a Burley Travoy trailer can be your answer. It's foldable and you can tow up to a 60lbs load. No compromise here.

Hope this helps.

Good luck.

I found a link that said it is 9 cm wide (3.54 inches). That sounds about right, but I will check when I get home if I remember.

That was not my impression, at least for the Streamliner DLX. Granted that impression is based solely on yanking on the rack, but despite the light weight, it seems to be one of the stiffer racks I have handled. It is definitely stiffer than my Blackburn EX-1. The Streamliner Road DLX seems like it might be a bit more noodly because of the lower mounting hardware, but I have not seen that rack in person.

To be clear I am not advocating putting 110 pounds on it.

Both the Streamliner DLX and Road DLX are similar in construction, being the DLX has a 3.54" top base for trunk bag versus the narrower road which I think is close to half that.
I have the DLX model; its right in front of me on my bike at this moment. The stiffness of the rack is measured in how much side to side motion it can resist and the weakness of the streamliner series is those thin plates that hold the rack in place on the skewer. 110 lbs is static weight pushing down. Not doubting that it can not sustain that load, but most of the time, it is the dynamic side loading stress that breaks the rack stays and welding. My older OMM has a dynamic side loading of 30lbs (this is more realistic), but the plates and attachment points are way way thicker than the Streamliner. I suspect the Streamliner only has a side load capacity of 10 to 15lbs and judging from reviews of people overloading it with 20lbs and my own experience bending the stays to the side which you can because there's nothing stopping it from moving side to side as opposed to OMM racks, the stays can break through repeated bending from left to right like a paperclip with enough twisting. This is true if you have panniers loaded on its sides. If you have a 20lbs load strapped on top, then this will be different. I had since moved my DLX to my folding bike as the much lower center gravity, light, extra vertical stiffness for the price and my ability to carry front panniers means I never exceed the 10lbs on the rear.

Thank you! My trunk is 5.5" wide. Looks like that still might work if my PB fix does not work.

Being a clydesdale, my wheels have very much cared about static weight in the past. The set I have now are pretty bullet proof. I do understand what you are saying about the stress put on the rack components and that makes sense.

I ride all the time on this bike and my single. The reason I start "training" the first of July is because I will be loaded then as at the latest all my gear will be in. I commute 16 miles round trip on a single speed Timeline 4-5 times a week. It is a tank. I would never dream of riding my Motobecane downtown, then locking it up in a parking garage. I'm paranoid enough with my single speed and a Bordo 6500.

As stated above, I'm not a fan of the trailer for solo runs because of the unnecessary added weight, the YAK and the Nomad are about 13-15lbs and the cheaper you go the more weight is added. My fry pan is 1.2lbs, it's my one real guilty pleasure in my pack along with my 3.9oz stove. Sure I could have gotten a thin and cheap pan but I don't very much like ingesting teflon and all the lightweight "non stick" pans are all covered in it, cheaply I might add. I'm not exactly a weight weenie but I'm not looking to haul the kitchen sink, I don't have a gross lb estimate because sometimes the manufacture's listed weight is off and I haven't tallied it all up yet :p I have plenty of space and head room for weight but that doesn't mean I'm going to fill it because I have it.

*edit*
On a side note I do wan't one of these for around town! http://bikeforums.net/attachment.php...hmentid=257280

I think you are mistaken on both counts.

Both are the narrow models the difference is in the mounting. The Streamliner DLX (the one I have) does not have the plates and does have two rods at the top rather than the single brace to the brake mount.

Streamliner indicates the narrow models, the wider ones are the Journey models.

I will verify the measurement for the Streamliner DLX when I get home. Can someone measure the Streamliner Road DLX and post the width just to be sure?

This trailer here is what I also have

http://www.cyclelicio.us/2010/burley-travoy/

Is not a nuisance and it's not heavy -- 9lbs. Don't forget that panniers do weight something. If you can do away with panniers, all the better ofcourse. My suggestion to train with a load is due to the load placement of the panniers on road bikes. In order to provide heel clearance on panniers, all these racks have a rear offset from the rear hub. So the load isn't exactly sitting right above the center axis of the rear hub which is what is ideal and what a normal dedicated touring bike will allow you to do. This changes the loading characteristics of a normal bike with an offset rack. With a light load say 10lbs; no problem. 20lbs then yes slightly. 30lbs and up and you will feel it. I use the Travoy trailer sometimes when it makes sense or if I want to carry even more luxury pass 30lbs. I rarely do this nowadays.:p

According to REI my panniers are 4lbs 3oz and my PB rack is 1lb 6oz. I could carry three more fry pans and just about break even in weight with the trailer :p

I do expect packing and pannier position to be a trial and error process, getting used to a loaded bike is practically what my training is. I know I can spin :D

I would very much appreciate this, that rack is looking very appealing as a solution to my dilemma. How many loaded miles do you have on yours?

I'm in Canada, so maybe there's the confusion and you brought up a good point and reminder. My Axiom Streamliner DLX is actually what you find I think in the states as the Streamliner Disc DLX but without 2 stays mount. Mine mounts on the brake bridge. It's exactly the same configuration as the Road DLX except, the top base is wider and it has pump pegs for a pump. The narrower Road DLX does not. The axle mounts are connected with the thin plates. A normal Streamliner DLX mounts on the rack braze-ons, not on the axle. So probably the Road DLX version will not be to the OP's liking with its narrow base, which was the sole reason why I went with the one I have now.

Sorry for the confusion OP; thanks Pete for bringing this up.

Jclaine,

To make matters simple and your camping life much more enjoyable, take a lot at this..

http://www.amazon.com/Axiom-Streamli...+pro+tour+inox

Similar to my Canadian version of the Streamliner DLX, but with reinforced plate gussets (lower part near the axle are thicker) and the load ratings are much better than mine!! This might be what you need. Not sure why my model is no longer listed. Perhaps this model had superceeded mine and looks like it shares some design commonality with my Old Man Mountain. Price pretty good for this pro quality rack.