will a bagman damage my saddle/bike?

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melon
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will a bagman damage my saddle/bike?

Postby melon » 18 Jan 2011, 8:44pm

my bike is an aluminum race style frame with alu post and a Fizik Arione Saddle on top of it. all the parts are race orientated, i dont have eyelets for a rack.


i want to fit a bagman, and it says it has a weight limit of 10kg. this is fine, but will a bike not designed to take weight not find this a little difficult? is it likely to bent my saddle rails, or seat post cluster?


do i need to choose another saddle (im not using a brooks)? will my post and frame handle being loaded?

rualexander
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Re: will a bagman damage my saddle/bike?

Postby rualexander » 18 Jan 2011, 8:52pm

Your saddle rails and seatpost are designed to carry your weight so a few extra kg will not make any difference to them.

thirdcrank
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Re: will a bagman damage my saddle/bike?

Postby thirdcrank » 18 Jan 2011, 8:53pm

Consider your own body weight on the saddle, then imagine the difference a saddlebag makes.

As far as handling goes, I've posted before about a lesson I learned on my very first tour with a full saddlebag. (In addition to quickly learning not to take so much unnecessary stuff on tour. :roll: ) When you are off the bike, a heavy saddlebag shifts the centre of gravity much further back. This means that when you are getting on, the front of the bike can unexpectedly rear up. I ended up at the bottom of a very deep, steeply-sided ditch - luckily completely dry. Easy to prevent if you know it's likely to happen, just don't pull the bars, but a lot better to learn this easy way. :D

melon
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Re: will a bagman damage my saddle/bike?

Postby melon » 18 Jan 2011, 9:06pm

obviously its designed to take my weight, but the saddle rails arnt designed to hold that weight levered off a quite an angle. id imagine the human load would mostly go straign down through the contact point and seat post/tube.

thirdcrank
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Re: will a bagman damage my saddle/bike?

Postby thirdcrank » 18 Jan 2011, 9:16pm

I simply don't know if the rails of your saddle are OK, but they are intended to be clamped on the bike so it's hard to see how a much smaller weight would be a problem. As a comparison, the once widely-used Karrimor Uplift supports the whole caboodle on just two small tongues of metal which slot into the bagloops on a B17 or similar. I've carried some quite big weights like that, without problem. Perhaps somebody will come along soon who really knows.

In the emantime, I'd be inclined to say 'Don't risk it.' That's not because I think anything will go wrong, but it's impossible IME to enjoy a bike ride if you are constantly worried that something is going to break.

Malaconotus
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Re: will a bagman damage my saddle/bike?

Postby Malaconotus » 18 Jan 2011, 9:31pm

thirdcrank wrote:Consider your own body weight on the saddle, then imagine the difference a saddlebag makes.

As far as handling goes, I've posted before about a lesson I learned on my very first tour with a full saddlebag. (In addition to quickly learning not to take so much unnecessary stuff on tour. :roll: ) When you are off the bike, a heavy saddlebag shifts the centre of gravity much further back. This means that when you are getting on, the front of the bike can unexpectedly rear up. I ended up at the bottom of a very deep, steeply-sided ditch - luckily completely dry. Easy to prevent if you know it's likely to happen, just don't pull the bars, but a lot better to learn this easy way. :D


My brother and I swapped bikes when out for a ride so he could see how my converted MTB handled and I could try out his new ultra-light road bike. I had a full camper longflap mounted high up the seatpost weighing perhaps 12kg total. He pulled a wheelie and came straight off the back.

Melon, if you have doubts about the saddle rails and you have a fist of seatpost showing, why not look at the SQR uplift instead (http://www.carradice.co.uk/products/other/sqrclamp) My own seatpost is fully extended, (10cm minimum in and 25cm exposed) and I have carried more than the max recommended 10kg in my longflap addition to my own 125kg. My 27.0 seatpost remains intact, albeit that my Kona XC frame is possibly stronger than yours.

Graham
Last edited by Malaconotus on 19 Jan 2011, 2:10pm, edited 1 time in total.

sjl
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Re: will a bagman damage my saddle/bike?

Postby sjl » 18 Jan 2011, 9:38pm

I have used a bagman with a fizik saddle on my race bike for years with no problems - remember that sitting on the back of your saddle puts a MASSIVE leverage on the saddle rails and the post (i'm 85 kgs) and its designed not to break- another 10 kgs from a saddle bag is not going to make much difference.

tatanab
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Re: will a bagman damage my saddle/bike?

Postby tatanab » 19 Jan 2011, 7:31am

So the Bagman is limited to 10kg. Now think about what that represents. Can you get 10 kg in a saddlebag? Yes, if it is made of bricks or other purposely heavy items. For saddlebag touring I'd say that my load is about half of that, which includes tools and heavy old cape as well as clothing etc. I get to 10kg, maybe more, if I add my camping kit, but that requires more than just a saddlebag..

So I think you need not worry.

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beachcomber
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Re: will a bagman damage my saddle/bike?

Postby beachcomber » 19 Jan 2011, 10:05am

I have used a bagman on a Fizik Pave3 without problem. It's now on a Specialized saddle. I also have one with the Q/R mech fitted to a Brooks. I think they are a solid product. I would suggest that the bagman clamp should be fitted tight up against the saddle clamp. This would reduce the leverage on the seat rails.

melon
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Re: will a bagman damage my saddle/bike?

Postby melon » 19 Jan 2011, 11:37am

the saddle bag will probably hold close to 10kg as it will have my camping gear in it.

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beachcomber
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Re: will a bagman damage my saddle/bike?

Postby beachcomber » 19 Jan 2011, 1:27pm

If you are concerned about the weight, can you fit a bar bag? If you can manage with one bottle cage, you could put tools in a cage mounted container. Meaning less weight in your saddle bag.
I like a bar bag when audaxing. Somewhere to hold my route sheet/map, put all the things I need at controls or when off the bike,valuables etc. When touring,I keep my camera in there and other small items I need when on the road. It saves delving into my saddle bag or panniers.
Unless you are particularly heavy I guess the saddle rails on the Fizik will cope.
The only other altenative is swap saddles for a heavy duty one. That might be better for touring anyway.Only you can decide what suits you best.

snibgo
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Re: will a bagman damage my saddle/bike?

Postby snibgo » 19 Jan 2011, 3:09pm

10kg hanging off the rear of the saddle shouldn't cause the saddle any problem.

I can sit upright, on the very rear of my saddle, and bounce up and down without anything breaking. It's important that I can do this, as it simulates worst-case potholes.

thirdcrank
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Re: will a bagman damage my saddle/bike?

Postby thirdcrank » 19 Jan 2011, 4:40pm

melon

You seem to be working backwards, in that because the Bagman is apparently rated at 10 kilos (AKA approx 25 lbs or amost 2 stones in old money) which is quite some tonnage, you fear the saddle may not take it.

I'd suggest that unless you are already committed, the thing to do is decide what weight you want to carry (and then use the various ideas others have come up with on the forum to reduce that as much as poss.) Then explore the best way of carrying the stuff, bearing in mind that you have a bike that was not intended to carry much more than the rider and a couple of bottles.

I can't remember if anybody resolved the issue of whether a Carry Freedom trailer was suitable for hitching to an alloy bike. If it is, then I'd suggest with all the humbleness I can muster, that that may be the way to go. Apart from anything else, as I posted above, once you have a nagging doubt about something like this, you will never enjoy your cycling.

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andrew_s
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Re: will a bagman damage my saddle/bike?

Postby andrew_s » 19 Jan 2011, 5:57pm

I'd have thought that a Bagman and full Longflap wouldn't be any different to someone a stone and a half heavier as far as your bike and saddle are concerned.
Bike riders can get over 20st, and stuff is designed not to break when used by large people, so I'd have thought that any kit that doesn't specify a rider weight limit (some does) should be OK.

melon
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Re: will a bagman damage my saddle/bike?

Postby melon » 19 Jan 2011, 6:07pm

ive always used a rack on previous tours, my rear weight normally comes to about 7-8kg but i do have some lighter gear now which ill probably offset with more clothes. the bag itself must weight nearly 1kg. i normally strap stuff to my bars, but i now have a new STI bike, but thats another story...

the back basically contains my clothes and tent+mat+spare tarp. im always looking to minimise my gear and putting everything into one big bag seems like quite a nice idea. im not really sold on trailers.