Trek Fuel EX Sizing Help

[snuboy360]

I’m on the verge of purchasing a 19 Trek Fuel EX 8, but I’m having trouble trying to decide between the 18.5 and 19.5. Below are my deminsons

 

Height: 5 feet 11” 180 CM

Inseam: 33

Apex: +1.5 wing span 6 feet 1/2

 

I’ve read through a few posts mentioning sizing and honestly I’m not sure which one I should get. Based on the trek website and the new sizing chart on the fuel ex 8 page being 180 cm I fall a littte outside of the 18.5 (170-179cm / 5’ 6.9” - 5’10.5”) and more so on the backend of the 19.5 (177-188 / 5’9.7” - 6’2.0”). I’ve test ridden both sizes several times and while the bike shop sides more so with the 19.5 based on my size, the 19.5 feels a tab big. Granted the 18.5 is really only 1/2 inch shorter than 19.5 based on the ETT measurement. This is my first MTB as I’m used to riding a road bike (56cm Trek Domane) so I’m not sure if the bike should feel big.

 

On the 19.5 I’m not overly stretched out and I still have a some bend in my arms, but it just feels like it might be a smig too big. On the 18.5 The bike feels just about right, not too small but not too big. My arms have a good bend and I don’t feel like I’m leaning as much as on the 19.5, but while it might feel better I have some concerns going with a smaller 18.5 over the 19.5.

 

since I’m more so used to Road biking and not used to MTB I’m concerned that a smaller bike will have trouble descending or even climbing. I don’t want to go OTB and understand that bigger bike helps put my weight back better. Also on bigger bike I understand I have more room out of the saddle climbing. But on the 18.5 I feel like I have a little better control and feel like I can wip the bike around a little more easily.

 

One bike shop says that the big feeling is normal and that I should be on the 19.5, while another shop tells me the if I’m between sizes I should go smaller as I’ll have more control over the bike. I’m sure on the DH the 19.5 would probably be great and out of the saddle I might have a little more room to climb. On the 18.5 I feel like I have a little more control and want to wip the bike around a little more.

 

My wife and I did demo the 19.5 on some local trails and it felt ok, but since the shop doesn’t have the 18.5 to rent, I’ve only been able to test ride the 18.5 around the parking lot and over some curbs and drainage ditches, so I’m not sure how it going to handle on the actual trail and going DH.

 

At this point I’m not sure which way I should go since I fall just outside the 18.5 on the trek sizing chart. I do understand that I can always move the saddle up or back and buy a bigger or smaller stem. Just hoping some of you might have some advice and expirence. thanks in advance.

[ChrisF]

"feel" is a strange thing ... rather dangerously so ....

 

15 months back I bought a TREK Fuel EX5 - after a test ride.  It "felt" absolutely perfect !  

 

BUT, I was off the bike for many years before that and my seating position was very rigid and upright .....  The more miles I added, the more my seating position improved.  Earlier this year I started getting some strange locallised pains in my upper legs.  Turns out the bike is one size too SMALL.  Even maxing out the various settings my knees are too far forward over the pedals ....

 

The EX5 is up for sale and I bought a larger bike a few days back.

 

 

 

Can the shop do a PROPER "bike-fit" for you ?  If not, instead of a test ride, take the larger frame to a proper specialist for a bike-fit.  Not just for the "fit", but to also check further adjustability.

 

Does that bike have a saddle post with a set-back clamp ?  If so it may be possible to move the saddle forward, if needed.

 

A different stem to the handlebar is another way to adjust it to your dimensions and fit ....

 

 

 

All this said, it is a bummer when ones dimensions are on the cusp of two sizes .... This time I am on the cusp of the M or L in the Scott series .... The L gives me that bit of adjustability, so we went this route ..... 

 

 

 

wishing you all the best, and hope you get that "perfect fit"

[ChrisF]

You dont say where you live .... If you are in the Western Cape I can truly recommend you visit IRMA for a bikefit.082 802 2183.  She works on Meerendal.

[PhilipV]

I am on the edge between L and XL on the chart for Giant bikes, and going with the XL was the right decision (used to have a L.)

I recommend the 19.5 for you.

[DieselnDust]

I’m on the verge of purchasing a 19 Trek Fuel EX 8, but I’m having trouble trying to decide between the 18.5 and 19.5. Below are my deminsons

Height: 5 feet 11” 180 CM

Inseam: 33

Apex: +1.5 wing span 6 feet 1/2

I’ve read through a few posts mentioning sizing and honestly I’m not sure which one I should get. Based on the trek website and the new sizing chart on the fuel ex 8 page being 180 cm I fall a littte outside of the 18.5 (170-179cm / 5’ 6.9” - 5’10.5”) and more so on the backend of the 19.5 (177-188 / 5’9.7” - 6’2.0”). I’ve test ridden both sizes several times and while the bike shop sides more so with the 19.5 based on my size, the 19.5 feels a tab big. Granted the 18.5 is really only 1/2 inch shorter than 19.5 based on the ETT measurement. This is my first MTB as I’m used to riding a road bike (56cm Trek Domane) so I’m not sure if the bike should feel big.

On the 19.5 I’m not overly stretched out and I still have a some bend in my arms, but it just feels like it might be a smig too big. On the 18.5 The bike feels just about right, not too small but not too big. My arms have a good bend and I don’t feel like I’m leaning as much as on the 19.5, but while it might feel better I have some concerns going with a smaller 18.5 over the 19.5.

since I’m more so used to Road biking and not used to MTB I’m concerned that a smaller bike will have trouble descending or even climbing. I don’t want to go OTB and understand that bigger bike helps put my weight back better. Also on bigger bike I understand I have more room out of the saddle climbing. But on the 18.5 I feel like I have a little better control and feel like I can wip the bike around a little more easily.

One bike shop says that the big feeling is normal and that I should be on the 19.5, while another shop tells me the if I’m between sizes I should go smaller as I’ll have more control over the bike. I’m sure on the DH the 19.5 would probably be great and out of the saddle I might have a little more room to climb. On the 18.5 I feel like I have a little more control and want to wip the bike around a little more.

My wife and I did demo the 19.5 on some local trails and it felt ok, but since the shop doesn’t have the 18.5 to rent, I’ve only been able to test ride the 18.5 around the parking lot and over some curbs and drainage ditches, so I’m not sure how it going to handle on the actual trail and going DH.

At this point I’m not sure which way I should go since I fall just outside the 18.5 on the trek sizing chart. I do understand that I can always move the saddle up or back and buy a bigger or smaller stem. Just hoping some of you might have some advice and expirence. thanks in advance.

 

You hav summed up your dilemma nicely.

Do you buy the 18.5 for a more nimble bike or the

19.5 for more stability.

 

For a first MTB my choice would alway be the more nimble bike.

But the Fuel EX is a trail bike so you want stability to help you build confidence.

Trek sizing come up a little bit small per size so I d say go for the 19.5

[thebob]

Trek don't bring the Fuel EX in to SA in 18.5. Your choice is 17.5 or 19.5

[DieselnDust]

Trek don't bring the Fuel EX in to SA in 18.5. Your choice is 17.5 or 19.5

That was true. They did start brining in the 18.5 with their last shipment of 2019 colour way bikes

[splat]

According to the Trek sizing, you should be on a 19.5"

 

Looking at the Geometry Table, there is very little between the 18.5 & 19.5" frames (which is probably why they didn't bring both in on previous years)

 

Longer seat tube, but with lower standover (?) on the 19.5"

Wheelbase is 1.5cm longer

Reach is is also 1.5cm longer (longer top tube), but stack is the same

 

Is the stem length on each frame size the same?

That can obviously be swapped out.

 

I would go for the longer top tube and shorter stem option...

But that is me.

[Iwan Kemp]

You hav summed up your dilemma nicely.

Do you buy the 18.5 for a more nimble bike or the

19.5 for more stability.

 

For a first MTB my choice would alway be the more nimble bike.

But the Fuel EX is a trail bike so you want stability to help you build confidence.

Trek sizing come up a little bit small per size so I d say go for the 19.5

 

 

What is nimble and what is stable? Is MORE stable stable or is it simply MORE stable?

 

That "criteria" was maybe true way back when when sizing of MTB's belonged to their road bike roots, but things have changed quite a bit.

 

Stable is important when you are BOLTING down a mountain at break neck speed. Nimble is important when you break berm tops and leave a dust rooster in your wake carving down the mountain (at break neck speeds).

 

For most trail and SA type riding fit is more relevant and important than going a size down for nimbleness and a size up for stability. 

 

Edit: not having a go at you. Just putting this out there. 

[DieselnDust]

What is nimble and what is stable? Is MORE stable stable or is it simply MORE stable?

 

That "criteria" was maybe true way back when when sizing of MTB's belonged to their road bike roots, but things have changed quite a bit.

 

Stable is important when you are BOLTING down a mountain at break neck speed. Nimble is important when you break berm tops and leave a dust rooster in your wake carving down the mountain (at break neck speeds).

 

For most trail and SA type riding fit is more relevant and important than going a size down for nimbleness and a size up for stability. 

 

Edit: not having a go at you. Just putting this out there.

 

I hear you. Hard to quantify without a test ride but the OP has done that and arrived at that juncture on his own.

When between sizes that is the choice you face. For the bike in question it's safe to assume the smaller bike is the more nimble while the bigger bike is the more stable

Relative to what? Well we don't know so play with the cards in hand.

 

It's also safe to assume that the Op will take some time to get up to break neck speeds on the descents since he has indicated that he's new to the game

[dirtypot]

I'm the same size as you and generally sit squarely in the middle between bike sizes.  On some bike the smaller frame fits nicely and on others the larger frame is better.  I can fit onto either and make it work with adjustments / stem but most of the time the one frame will just feel better.  if you've tested them and one feels nicer then go for that one. 

[Christofison]

I'm the same size as you OP and I ride a 19.5 Fuel EX 8 (2018). The extra reach on the descents is important, and with the seat slammed forward it puts you in a lekker position for the climbs.

[TrekBikesSA]

Hi Snuboy

 

Thanks for the inquiry;

 

We as Trek SA are only bringing in the Fuel EX 8 in either 17.5 or 19.5 sizes, given your height and the relevant info posted above from the sizing chart found on our website, I would put you solidly on the 19.5 bike even if the 18.5 was available. The 17.5 would be too cramped in the top tube length/reach for you. 

 

 

That was true. They did start brining in the 18.5 with their last shipment of 2019 colour way bikes

I think you may be thinking of the Top Fuel range - we are offering this range in 18.5 sizing but not the Fuel EX range.

[DieselnDust]

Hi Snuboy

 

Thanks for the inquiry;

 

We as Trek SA are only bringing in the Fuel EX 8 in either 17.5 or 19.5 sizes, given your height and the relevant info posted above from the sizing chart found on our website, I would put you solidly on the 19.5 bike even if the 18.5 was available. The 17.5 would be too cramped in the top tube length/reach for you. 

 

 

I think you may be thinking of the Top Fuel range - we are offering this range in 18.5 sizing but not the Fuel EX range.

 

 

Thanks for clearing that up. LBS said the 18.5 in FUEL EX would also be available for 2019.

Out of interest, why does TREK SA not bring in the full size curve? The 18.5 would be my preference over the 17.5 for my height

[Stevief]

I have a 2018 Fuel ex 9.8 and im 5 ft 8 .  Im on a 17.5 and it is perfect.  SO i think if you feel happier on the 18.5 i would go for it.   

[Skinnyone]

Thanks for clearing that up. LBS said the 18.5 in FUEL EX would also be available for 2019.

Out of interest, why does TREK SA not bring in the full size curve? The 18.5 would be my preference over the 17.5 for my height

I'm sure Trek can answer better, having been involved in the industry for a number of years, I have seen it a few times where there is "demand" for a size so the importer then brings in the minimum order quantity (let's say that is 15 bikes) and all of a sudden that "demand" disappears and the importer is left with a model/ size that they have to discount at the end of the season.