I think my bike is too big, do I get a shorter stem or a smaller bike frame?

I’m new to cycling so don’t know anything about bikes.

My stats for reference:

Height: 179 cm

Inseam: 83ish cm

Ape Length (middle finger to middle finger): 177ish cm

I bought the Boardman Hub 8.6 (Hybrid) Bike. Their sizing guide is the following:

                          |     Small      |     Medium   |
Recommended Height        |  170 - 179 cm  |  177 - 183 cm|
Recommended Inside Leg    |  74 - 82 cm    |  78 - 85 cm  |

Bike link: https ://www.boardmanbikes.com/ie_en/products/2365-hyb-8.6-silver-2021.html#size

I bought size medium as my inseam fit into the medium category. However my arms seem too short for the bike. I have pushed forward the saddle as much as is allowed according to the measurement on it, but it did not make much difference. I feel my shoulders are a bit too forward for me to reach the handlebars. I can reach the handlebars and cycle, it’s just that it feels a bit too far forward.

What I noticed is that the stem is quite long (I think) on the bike. It is 100cm, so I think I have two options:

Option 1: Just get a shorter stem

Option 2: Get the smaller bike frame

The shorter stem is an easier job as the smaller bike frame is out of stock for another month. However, I am not sure what the consequences are when getting shorter stems? Is there a limit to how short the stem should be? does it make controlling the bike harder?

Note this is for a hybrid bike, I prefer to ride more upright than flat like a road cyclist

Looking for any advice!

Are you using this bike for Zwift or outside or both as the advice will differ dependant on your intended usage.

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90% of time will be on zwift

I will occasionally take it outside to cycle on a greenway or something.

If it’s a large proportion outside then do not go with a shorter stem. Bike handling will become twitchy with minor movements being accentuated.

The fact you’ve already pushed your seat forward and still struggling implies the bike is too small.

You can make a smaller bike bigger but you can’t make a bigger bike smaller. I’m in between sizes with my chosen bike. Bought the smaller then extended it using a longer stem which has a lesser effect on handling than a very short one.

If you’ll never ride outside then it’s not an issue putting on a short stem for Zwift and then you don’t have to take your bike back and wait for the smaller one to come into stock.

If you’ll only ride 10% outside then I’d risk shortening the stem, especially if you only do slower trail type rides.

Personally I’d get the smaller bike as your riding habits may change over time.

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Stuart have very good advice.

Only thing I would add is a stem is very cheap you can get a very short one and test it. Some bike shops will even lend you one.


Would a stem decrease from 100mm to 60/70mm make a big difference in bike control?

Ah, I might ask a bike shop close by then and give it a test.

However, seeing as I am new to cycling, I’m not entirely sure what I would even be looking for when cycling the bike.

Massively recreates the stem. In my opinion it would make your bike really unstable.

No way would i ride with anything that short on a road or hybrid bike.

If you need to lose 3/4cm to get comfortable then the bike is definitely too big for you.

Whereabouts are you? There may be forum members nearby that can help you with a bike fit.


I’m in South Ireland.

Yeah I definitely need 3/4 cm, maybe even 5cm reduction in the sum to get it to be more comfortable. However, I only bought the bike recently so am still in the return window.

If reducing the stem that much makes it unstable, then I’ll just get the smaller version of the bike.

100% the right decision.

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I have a 80cm stem on my road bike. It handle ok. Yes it is very sensitive but I am so used to it that it’s normal to me.

I have a funny built with long legs so my saddle is almost at max height.

Edit: stem is 80mm

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I was in a similar situation.
It’s always best to have the correct frame size but there is a lot you can do to make a frame fit you better.
I would absolutely use a shorter stem.
I’m down to an 80 mm stem.
A lot of people feel this makes bikes twitchy but I have not noticed an issue going from 100 to 90 then 80.
You should make sure your handle bars are not too wide.
A narrower handle bar pulls everything closer too.

You can buy inexpensive 80 and 90 mm stems to see how you like the fit.
If your concerned about weight, then you can purchase an expensive light weight one but if it is just for Zwift, wt wont matter.
Actually, the weight wont be significant either way.

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The trouble is that the OP had already pushed the saddle forwards so that’s likely to be in an unnatural position.

Then they are still needing to gain up to another 5cm.

So whilst you might say an 80cm stem is fine the OP effectively is talking about going down to a 60 or even 50cm. That really is way too short.

They have the option of returning the bike for a shorter frame which is without doubt the way forward.

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Saddle fore and aft position is nothing to do with reach but the position you are sat over the pedals. moving it forwards to compensate for a small frame will likely lead to knee problems.

as a rough rule put your foot on the pedal and put the crank in the 3 o’clock position the front of your knee cap should be directly above the pedal axel. this sets the saddle position.

Stem adjustments should then be made for reach.

again as a very rough rule for road bikes, when sat on the saddle and with hands on the hoods look down and the handle bars should be in line with the front wheel axel. Not too sure if this is true for hybrids (i suspect not)

as others have said, small frame with a larger stem will be better than a large bike with a smaller stem.

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Hybrid/MTBs aren’t really my thing but my understanding is that stem length isn’t as big an issue due to flat handlebars being much wider. If you look at some there is basically no extension from the steerer at all

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You can get a somewhat shorter stem and help mitigate the reach issue by going for one with a different angle as well. Just googled the Boardman Hub 8.6, looks like it comes stock with a 7 degree stem. You could go with a bigger angle on that and keep much of the length–will bring the bars up towards you more, but will keep the lever arm longer for better steering. That bike’s front end is also pretty slack–I wouldn’t worry about handling if you went with a 70 or 80mm, more of an angle. At least give it a test ride, the shop should let you do that before you leave with it.

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FWIW, inseam is the more determinate measurement of bike size. Ensure you’ve measured correctly - standing in socks against a wall, back flat, hardcover booked jammed up into your crotch and mark the spine of the book against the wall. Then measure from that mark to the floor for your actual, “bicycle-relevant” inseam.

The geometries listed for that bike seem… odd. It’s almost like their small and medium are more like medium and large in bigger brands like Trek. I question their sizing chart - it seems to suggest you’d want the medium but you’re running into reach issues.

The site “BikeInsights” is a great tool for comparing geometries. Here’s one comparing the Boardman HYB with the Trek FX: Compare: 2021 Boardman Bikes HYB 8.9 SM vs 2022 Trek Bikes FX 2 Disc M - Bike Insights,

…sure enough, the Boardman in a “small” is very similar to the Trek FX in “medium.” (Boardman in medium similar to the Trek in large)

It might be worth talking to a local bike fitter to ensure the saddle height and setback are optimal. (dial in the saddle and foot position before making cockpit changes) They’re also going to be able to tell you if you’re outside the comfortable adjustment range for the size of bike and need the small. If you want to give that a go on your own, you can start with this BikeFitTuesday video: How To Set your Bicycle Saddle Height - YouTube

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where exactly is the pedal axle on the bike?

This is interesting. I can’t really find much info online about it though. There seem to be very little posts on hybrid bikes online, that I can find anyway.

That bike’s front end is also pretty slack
What do you mean by slack? Is that a good thing or a bad thing lol?

You could go with a bigger angle on that
Would that not just raise my hand position, and make it feel less comfortable?