Beginner maintenance q's - saddle slipping and pumps

I have a couple of questions and would love any help or advice.

I am a shiny new beginner on a Marin Stinson. It's only a month old, but I've noticed that whenever I put the saddle to the right height, it slips back down again slowly as I ride. When I bought the bike the LBS showed me how to adjust the height of the post that the saddle sits on, and that bit seems to work fine except the post doesn't stay up and it's quite annoying now that I'm confident enough to want the saddle higher up. The bike's due back in for its first service in a week or so so I can ask them to look at it then. Is there anything obvious that I'm doing wrong? There's just a clip that loosens things so the height can be adjusted, and that goes back in again afterwards.

Secondly, I have a pump question. I have a little mini-pump, my instructor mentionned that a different pump might be better. Could anyone tell me the difference between types of pumps and which to use when please?

Thank you.

It looks like your seatpost clamp is a quick-release, similar to the quick-releases on your wheel hubs? If so, you can tighten it the same way as you do the hub QRs - release the lever and turn it. It should be normal thread (righty-tighty, lefty-loosey). You may have to play with it a couple of times to get the right tension on it to where it's not so tight that you can't close the lever, but tight enough to hold.

As for pumps, do you have a true mini-pump, i.e., one small enough to fit in a jersey pocket, bore of a half inch or so? That kind is basically only good as a back-up to a CO2 inflater. You can inflate a tire fully with that kind of pump, but it will take a loooooooong time (and high-pressure skinny tires take a lot of strength, too). For general on-bike use, you want either a full-sized frame pump (big enough to inflate a tire reasonably quickly) or a CO2 system with a mini-pump as backup if you run out of cartridges.

A floor pump is MUCH quicker and easier to use than a handheld, plus many floor pumps incorporate tire gauges, which is why it's better to have a floor pump at home for topping your tires off.

Also, bicycle tires can have two different types of valves. Fat-tire hybrid bikes like yours usually have Schraeder valves, the same type that motor vehicle wheels use. Skinny road bike tires usually have skinny springless Presta valves. Make sure your pump is compatible with the valves on your tires (most, but not all, pumps will handle both; some pumps require you to reverse the head or flip a switch, and some claim to fit both without making any adjustment).

HTH ... and welcome!

Thank you so much! I went straight out to the garage and have tightened that lever two turns. I'll give it a go once I've put my daughter to bed, but I think that's done the trick. I'm really glad I asked now.

The pump's not tiny-tiny, probably about half-size? I'll see if I can attach a photo. A floor pump with gauge sounds like an excellent idea. Thank you again for your help, it feels great to fix it on my own :cool:

That's a tiny pump. Great for fixing a flat on the road, but I would suggest getting a floor pump to inflate your tires before you ride. I check mine before every ride, and end up topping them off every 2-3 rides. Get a floor pump with a pressure gauge.

I notice that you don't have a water bottle cage on your bike. It's important to bring water or sport drink with you when you ride. Have the shop put on a water bottle cage, or two, and throw in a couple of water bottles.

Thank you, Tulip. I'll do both of those things.

Thank you, I've read the link, that's very useful. My saddle is perfect now and stays exactly where I put it :D

I'm feeling quite proud of myself - I unhooked the front brake, took the wheel off, and checked that I could fit the bike in my car. Then I got it all back together again, but did need some help closing the cam lever.