Bike too big or just fine ? Need Advise

Buguy

Hi I accidentally refer to wrong bike fit and purchase online a 20" Frame Mountain bike (XC hardtail)! While the bike is about 20" (51 cm) Frame , I'm about 176 cm (5' 9" tall and go 79.X cm (31") inseams .

My arm quite lengthy so i don't have problem to reach to handlebar and no need to adjust my saddle . just nice clearance about 0.xx-1 CM from my crotch to the top tube .. it might hit my crotch (and might ruin my future!) so I will need to very cautious when ride off road

Considering all the cost .. I feel that it will be nice if just keep it and do at road and slightly hard terrain .. but it is safe if I go to XC, rough terrain ? what are the risk ? and any suggestion on how to make it safer and just fit to me ?

Picture :

https://ibb.co/z4C9rWb

mugensi

I'm 181cm and have a 21" (XL) Cube hardtail 29er. I have about the same clearance on the top bar as you and this was a slight concern when buying the bike however as I bought it second hand (albeit unused and in new condition) I didn't have the choice to try or buy the smaller size. Anyway I decided to go for it as it was an absolute bargain and I couldn't be happier. In reality you will never straddle the bar with both feet on the ground, if you are getting off the bike then you put one leg down and lean the bike to that side so the bar will not be any where near the crown jewels. In the event of a crash or spill the same thing happens, you go down on one side and so the bar height isn't going to really be a consideration. I've had mine 2 years and put approx. 2k kms on it over the last two winters (really only use it in winter when I cant get out on the road) and have had a few hairy moments where I've had to get a foot down quickly but never had any issue with the bar height. I fitted a shorter 60mm stem on mine to reduce the reach and the bike is perfect for me now, totally comfortable on it and love how it rides/handles. The larger size is not an issue.

steve_sordy

We all have different body proportions. I'm 6'1" and I nominally ride a Large size, which is a 19" frame. But one bike of the size does not suit me, while another one will. One will be too long, another too short, one too tall, one not tall enough. You can do some thing to fix the length by moving the saddle forward or backwards, changing the stem length etc, but these both have impacts upon other things that you may not like. For example moving the saddle from its perfect place for you may cause knee pain. Changing the stem length may cause back pain unless other compensating things are done.

Overall, a 20" framed bike may be just too big for you and despite making the best of it you may never get comfortable for long rides.

Early on in my biking career, I bought a 17" when I should have bought a 19" (LBS advice failure). I did all sorts to that bike, longer seat tube, fork steerer extension etc, but the bike was too short fir me and it caused back pain. I had to get rid of it.

Read this on how to get the perfect fit on your mtb:
https://www.bikeradar.com/advice/fitnes ... -bike-fit/