need a few opinions

nam

hi,
i have just bought a marin nail trail.due to the fact that i am a short arse i had to go for the smallest frame (15") which looks more like a bmx!!
anyway i love the bike but im trying to find the best riding position.
when i went out with a mate he reckons i am very upright and on the upstroke my knees were very clost to my arms so to spread myself out a bit i have moved the seat up and back and fitted a 110mm stem as opposed to a 90mm and also lowered it a bit.this feels ok as does the original stem.
im just wondering now whether im tinkering for the sake of it and whether altering the geo of the bike is pointless.maybe its just an upright bike or i have to live with it cause im vertically challenged??
any advice/opinions welcome,cheers

maximus69

you need to set the seat height so that your legs are at all but full stretch on the peddles at their lowest point. i would say that is the most important thing to get right then alter things around that.

a longer stem will slow the steering down a bit but wouldnt ruin the ride.

its like my mate said they cant build bikes to suit everyone so a bit of tinkering is probably the way to go.

i prefer to be a bit more upright. if i`m a bit more head down i find my back hurts a bit

dave_hill

For a start, have you got your saddle at the right height?

Sit on the saddle and put one pedal at the very bottom of it's stroke. Now put your heel on that pedal. If your knee is significantly bent, your saddle is too low. Your leg should be dead straight but without your knee being locked. Like this -



With the ball of your foot on th epedal in the same position, your knee should be slightly bent. Like this -



Having your saddle too low makes it difficult to pedal properly and efficiently, and can play havoc with your knees and lower back.

Fitting a longer stem will help to stretch the cockpit out but will put a lot more of your weight over the front end. This can make the steering more twitchy and descending can get "interesting" as it it will be harder for you to slide your weight backwards.

Looking at the geometry, the 15" Nail Trail has a 21.1" top tube which is quite short - are you sure you've got the right size with a 15" frame? You don't say how much of a short-arse you are! If it isn't a personal question, what's your inside leg measurement? It should be roughly 12" to 14" more than the frame size.

If you're stil having problems, take it back to the shop where you bought it and get them to set it up properly for you (which in all fairness they should have done for you before you toddled off with it).

nam

yeah thinking about it i may raise the stem to the original height and go with that.at least i can always go back to the old setup....its annoying tho cause i really got the bug again for cycling and i wanna get it right as it wasnt a cheap bike.
i got it thru a bike scheme but they only run it with wheelies in wales and im in devon so couldnt road test it! tried to find similar locally so went off those dimensions and the marin size guide??

nam

im a 29" inside leg ish.5ft 4 " tall.i was going off the 4" between my undercarriage and the top tube for the frame size.they only do 15, 17 19 or 21.17 was too big.

nam

im a 29" inside leg ish.5ft 4 " tall.i was going off the 4" between my undercarriage and the top tube for the frame size.they only do 15, 17 19 or 21.17 was too big.

maximus69

Fitting a longer stem will help to stretch the cockpit out but will put a lot more of your weight over the front end. This can make the steering more twitchy

ah was i giving rubbish advice again!! :roll:

either way wont make a massive difference.

its a pain being short, i know all about it!!

im sure you will set it up right in the end