Mountain Bike Reviews Forum banner
Cancel
Create thread New Forums

Small bike with longer stem, or medium bike with shorter stem?

Jump to Latest
1 - 20 of 35 Posts
B

Bikechop8

· Registered
Joined
·
21 Posts
Discussion starter · #1 ·
I have seen a bike that I am between two sizes on. I have tried both and I can use both without problem, but to be 100% correct on the small bike I would have to put a stem 1-2 centimeters longer, and on the medium bike I would have to put a stem 1-2 centimeters shorter.

What option would you choose?
 
#2 ·
Depends on what type of riding the bike is for and what type of bike it is. Enduro I tend to prefer a bigger longer bike. Trail/fun bike? Smaller so I can toss it around easier. XC bike? Usually have longer seat tubes and I have short legs so I try to balance out my desire for a longer bike with is the dropper going to have to be really short to be usable? 435mm+ seat tube and I'll need a dropper shorter than in the 130-140mm range. Gravel bikes? again depends on the seat tube as more exposed seat tube can be more comfortable but then the smaller one might have toe overlap. but I also like larger triablges to fit more bags and water bottles. So the answer is it depends.
 
#5 ·
Most biikes are now designed around 30 to 50mm stems. I guess as long as you don't need to go beyond those specs...you should be ok. Thing about sizing up is that if the bike is too long...you're stuck. There aren't many stem manufacturers that go shorter than 30mm. I see a lot of bikes with their saddles slammed all the way forward, already with a super short stem. If you're on the small and need to run a 60+ mm stem with the saddle slammed all the way back...then it might be too short.
 
Discussion starter · #6 ·
Thanks for the answers. Although sometimes I take complicated mountain trails, let's say that 80% of the time I go on asphalt or "green roads" as they are called in my country. They are mostly not too difficult mountain routes that can be done with the family, although some can be quite long. I also planned to do the Camino de Santiago one day, which is many kilometers and a comfortable bike is preferable.
 
#7 ·
I would factor in wheelbase as the decision maker not longer vs shorter stem. If you want a more playful bike go shorter wheelbase. If you want more stability at speed go longer.

Another benefit of smaller frame longer stem would be a lighter frame but ultimately I would be focusing on which wheelbase you would prefer.
 
#10 · (Edited)
Big difference between +/-1 or 2cm on the stem. For me having to go +/- 1cm is an acceptable compromise, 2cm means the frame is too small/big. I went from 40mm to 45mm because I wanted more weight on the front and it made a noticeable difference. So 2cm is huge.

As stated above, take wheelbase in consideration. If you want to dive deeper, consider front/rear centre ratio as well. Some frames get longer chainstays for the larger sizes, others have a fixed length across the range. This can mean some sizes are not as balanced as others.
 
#12 ·
justwan naride said:
Big difference between +/-1 or 2cm on the stem. For me having to go +/- 1cm is an acceptable compomise, 2cm means the frame is too small/big. I went from 40mm to 45mm because I wanted more weight on the front and it made a noticeable difference. So 2cm is huge.
Click to expand...
2cm wasn't necessarily an excessive change to mtb stem length a couple decades ago. but now that mtbs are longer to start with and tend to come with pretty short stems, I agree that 1cm is an acceptable adjustment without undo effects on other aspects of fit or handling.

If you're talking 2cm, you're pretty much looking at a different size, anyway.

Pick the size you need to make the least adjustment to. If a particular brand doesn't offer any sizes that give you that, then look at a different brand that does (and meets your other criteria).
 
#14 ·
Many riders are in between sizes. I could have gone S or M, I went M but I wonder if S with 50mm stem would have been better? In the end my feet and hands are in the same place so it really comes down to wheelbase. I can live with either so I dont' over think it. Because I'm running double 27" with short stays the longer size M wheelbase is likely the best. I would be fine with even more bias towards play with a shorter wheelbase as well. If I had double 29 or MX I would go shorter wheelbase to liven things up. That's my personal preference so take it for what it's worth.
 
#15 ·
Back in the old days/ old style geo, I would 100% size up, but now that modern geo bikes have become so long, I think I would opt for a smaller frame with a 10mm longer stem. < This is for typical trail/xc riding, not enduro/steep riding.

If you need more than +/-10mm stem to get comfortable, you probably bought the wrong size, or have some atypical body proportions.
 
#16 ·
d365 said:
Back in the old days/ old style geo, I would 100% size up, but now that modern geo bikes have become so long, I think I would opt for a smaller frame with a 10mm longer stem. < This is for typical trail/xc riding, not enduro/steep riding.

If you need more than +/-10mm stem to get comfortable, you probably bought the wrong size, or have some atypical body proportions.
Click to expand...
Totally, though I would consider up to 20mm Just in the stem and another 5mm or more in the bar geo/stack. Just back sweep alone can be 5mm then there's stack to further dial in the distance between hands and feet. People get hung up on a frame's actual reach number but all I care about is the distance between my hands and feet. Between stem length, back sweep, and stack most of us can put our hands and feet in the same spots on two sizes. Given how stretched bikes are I would typically go down a size. My current frame has pretty conservative numbers (revel rail 27) so size M made sense.
 
Discussion starter · #17 ·
Thanks for the opinions, I will take them into account.

I'm not going to use the bike in overly technical areas and I plan to do routes of many kilometers, so maybe the medium size would be better than the small?
 
#18 ·
For long distance weight matters. Smaller frame cuts weight. Longer wheelbase is really about stability at speed. It's not really doing much for you when talking about covering distance.

The main reason bikes today are so much heavier than they used to be is because everything is supersized. Frames, rims/hubs/tires, cassettes, derailleurs, shocks.... Only thing that's smaller thus lighter is cranks though many still run 170 for some odd reason even though bikes have been low riders for 10 years now.

Many metric sized shocks on trail bikes are as big as shocks used to be on 180mm FR bikes back in the day. Making everything bigger adds up. The biggest component is the frame. Reducing its size is the best way to cut weight without reducing durability. If it was me looking for a bike to cover miles I would go with the longer stem and shorter frame. That said, I wouldn't over prioritize frame weight. Fit is the most important but if S or M ends up being 6 of half a dozen for you I would go smaller all day long.
 
Discussion starter · #19 ·
Ok thanks for the opinion. I'll put on the two sizes again and see what sensations I have. I think I was comfortable in both.

Another reason why I preferred a medium frame is also for aesthetic reasons. I have the seat at a height of about 68cm from the bottom bracket axle, and with sizes S having a seat tube length of about 38-40cm, I would have to expose the seatpost by about 22-23cm (not counting the saddle itself) and not I like how so much of the seat post is exposed.
I also find that very small frames don't look as good with 29" wheels.
 
1 - 20 of 35 Posts
About this Discussion
34 Replies
17 Participants
Last post:
slimat99
Mountain Bike Reviews Forum
posts
16M
members
534K
Since
1990
A forum community dedicated to Mountain Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, trails, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General Discussion Downhill - Freeride California - Norcal Shocks and Suspension Passion