Frame size - do the same rules apply for EMTB...Size up or size down?

[FlyingKiwi]

The pros and cons of sizing up or sizing down your Emtb

If your close to the manufactures size change point (in between sizes) on these latest 2020 geo emtb's is your preference to size up or size down? Do the normal pedal bike parameters/ compromises apply to these weighty and generally longer bikes or is there a definite preference? With longer WB, CS and heavier bikes do you sacrifice some reach and TT length to try keep more agility with going smaller?

What is the experienced ebikers opinion on this?

If ive missed a thread elsewhere on this topic my apologies...just point me there. Thanks.

 

[Gary]

shorter Emtbs are MASSIVELY more agile than long ones

FACT!

5'11" and ride a small ESommet VR with 435mm reach (right around what most size large Enduro bike would have been 4 years back)
Have ridden loads of longer L and XL Emtbs in the last year or so... Every one was a complete pig agility wise in comparison

 

[HORSPWR]

The pros and cons of sizing up or sizing down your Emtb

If your close to the manufactures size change point (in between sizes) on these latest 2020 geo emtb's is your preference to size up or size down? Do the normal pedal bike parameters/ compromises apply to these weighty and generally longer bikes or is there a definite preference? With longer WB, CS and heavier bikes do you sacrifice some reach and TT length to try keep more agility with going smaller?

What is the experienced ebikers opinion on this?

If ive missed a thread elsewhere on this topic my apologies...just point me there. Thanks.

I base it on the geometry specs of the new bike and compare that to the geometry specs of my current ride that I'm happy with and go from there.

 

[Pdoz]

I honestly feel sorry for the manufacturers. All the keyboard experts and magazine scribes look at a geometry spec sheets and ignore the fact that emtb's are not normal mtb's . Deviate from the latest trend at your peril.....

Example 1 - giant reign e , OMG , the chainstay is a few mm too long...all the journos are busy hitting that long chainstay autotext to fill up some magazine space without considering that maybe...just maybe..giant has thought about what is required for extreme emtb climbing ability?

Example 2 - once I got over the horror of having bought a "short " medium full e pro I spent 12 months reading everywhere how amazing long low mtb's are and how my world would be a better place if I submitted to the will of the masses. Hmm...a not so quiet voice on here kept talking about how compact is cool...and I do sort of enjoy my flicky little bike. EVERY longer lower faster wheel barrow I've ridden feels boring by comparison. But surely I should have bought a larger longer bike?

Try for yourself, ideally allow enough time to get over the " this feels different" factor. Better still, try riding with someone else and think about where and why you're faster / slower then decide what is right for you.

 

[MattyB]

The pros and cons of sizing up or sizing down your Emtb

If your close to the manufactures size change point (in between sizes) on these latest 2020 geo emtb's is your preference to size up or size down? Do the normal pedal bike parameters/ compromises apply to these weighty and generally longer bikes or is there a definite preference? With longer WB, CS and heavier bikes do you sacrifice some reach and TT length to try keep more agility with going smaller?

My short answer... I personally think any benefits you get from sizing up on an ebike are less pronounced than on a clockwork/acoustic, and the disadvantages (i.e. restricted range of movement making it harder to raise the front wheel) probably greater on a heavy EMTB. Unless you are a taller, heavier rider with an aggressive riding style think carefully before sizing up.

Long answer...

I honestly feel sorry for the manufacturers. All the keyboard experts and magazine scribes look at a geometry spec sheets and ignore the fact that emtb's are not normal mtb's . Deviate from the latest trend at your peril.....

Yeah, I think you have a point there - in all honesty there is no "correct" geometry for all, it depends on your preferred riding type, terrain and skill level. Longer and slacker could be good or bad depending on what you are coming from and what you want out of your new ride.

If you have a spare hour this podcast on mountain bike geo is worth a listen...

BikeRadar Tech Talk Podcast Ep 3: Mountain bike geometry

Yes, there is a fair bit of on trend geometrista buzzword bingo and repetition, but in between they make some good points about the different factors and how they interact. In particular the section where they talk about the extreme long and slack geos restricting range of movement and the ability to manouvre the bike vertically rings true to me as a medium height, relatively light rider with low-intermediate level skills. If I went to a very long ebike I suspect I would be unable to lift the front wheel over trail obstacles when I needed to.

 

[Gary]

Example 1 - giant reign e , OMG , the chainstay is a few mm too long...all the journos are busy hitting that long chainstay autotext to fill up some magazine space without considering that maybe...just maybe..giant has thought about what is required for extreme emtb climbing ability?

Hmmm...
Except. They haven't (2020 Reign, aye?)

470mm stays actually are too long for a 27.5" wheeled Enduro bike.
it's also far too heavy and the BB is a bit high.

I agree with you about many Journos not even being decent enough riders to know why that's the case though despite tieing themselves in knots with current jargon and fashionable cliches.
The ratio of cluelessness/lack of riding ability over clued up great riders is still way higher among Emtb buyers than journos ough.

Giant probably stuck such long chainstays on it because their choice of motor and Maestro suspension dictated stupid fucking plus tyres (E rated obvz) wouldn't fit in the available space otherwise.

 

[Niklas]

I think eBikes needs to be smaller then a regular MTB, first I got a L Levo (since all my Stumpjumpers where L) and had to switch it for a M after 3 weeks and it feels so much better?

 

[33red]

Never look at suggested whatever. It is about a somewhat average human probably not you. Before you invest real money you should know what works for you. Just as a small guidance sit on a bike, close your eyes. Put your hands on the handles. You can ride blinfolded on your bike what ever is written on it. Is it too long? too short? A manufacturer maybe wrong for you, no size fits you. Like i have a short torso, too long a top tube means look at other brand. I like a playfull bike so for me a small bike is super. Others look for stability. Some talk about riding on a bike versus riding in a bike.

 

[FlyingKiwi]

Never look at suggested whatever. It is about a somewhat average human probably not you. Before you invest real money you should know what works for you. Just as a small guidance sit on a bike, close your eyes. Put your hands on the handles. You can ride blinfolded on your bike what ever is written on it. Is it too long? too short? A manufacturer maybe wrong for you, no size fits you. Like i have a short torso, too long a top tube means look at other brand. I like a playfull bike so for me a small bike is super. Others look for stability. Some talk about riding on a bike versus riding in a bike.

Thanks for posting...Yes, understand the pros, cons of non-e bike fit and geo, and the benefits to test riding. Like most I have my size/geo preferences, the thead is a question about wheather the extra weight & CS length of ebikes is changing the riders preference specifically for the E....which some posters feel it does in order to keep desired ride attributes. Sitting on a ebike (or mtb) and pedaling it around the carpark i'd suspect would tell you jack s%#t about how it would ride on the trail (apart from how it manuals and wheelies). Proof is in riding the trail but I don't have access to test sizes back to back for myself, main thread was seeking out those that had ebike experiece with this....do you prefer the similar size/geo for both your mtb and emtb? Reading posts here it sounds like the experienced ebikers with this real world size testing have a preference to size down?

 

[33red]

Thanks for posting...Yes, understand the pros, cons of non-e bike fit and geo, and the benefits to test riding. Like most I have my size/geo preferences, the thead is a question about wheather the extra weight & CS length of ebikes is changing the riders preference specifically for the E....which some posters feel it does in order to keep desired ride attributes. Sitting on a ebike (or mtb) and pedaling it around the carpark i'd suspect would tell you jack s%#t about how it would ride on the trail (apart from how it manuals and wheelies). Proof is in riding the trail but I don't have access to test sizes back to back for myself, main thread was seeking out those that had ebike experiece with this....do you prefer the similar size/geo for both your mtb and emtb? Reading posts here it sounds like the experienced ebikers with this real world size testing have a preference to size down?

Ebikes are more complicated. In an ideal world i want the motor/system with my priorities reliable and great range. Than a frame that fits my body. Than suspension for my riding, transmission, geo so i made a compromise and you will probably too. My chainstay is longer than my ideal but let say i was lucky i found a bike about 90% of my ideal. I would say some riders want to play with the challenges others want the bike that turns all stuff flat. They go fast, feel like experts. The long suspensions are not for every one. A bike designed to be playfull is for some riders. Just sitting will tell you a lot about sizing. Some stuff is expensive to modify, some stuff is impossible. Try finding a bike that is close to your ideal. I like a low top tube. It is also about what you like. It is probably easier to adjust if it is too small so i would say a bit too small is no big deal.

 

[Pdoz]

The ratio of cluelessness/lack of riding ability over clued up great riders is still way higher among Emtb buyers than journos ough.

Giant probably stuck such long chainstays on it because their choice of motor and Maestro suspension dictated stupid fucking plus tyres (E rated obvz) wouldn't fit in the available space otherwise.

Guilty re clueless wannabee

Re the reign having 470 chainstay - nb my old full e has 463 - both have the same motor / maestro / 2.6 tyres - presumably it has something to do with the longer travel / where in the arc of travel the chainstay measurement is made. That's a really good example of how stupid it is to get our knickers knotted over a few mm on a chart - when systems like the maestro are moving through an ark they get different " chainstay measurements " ( mine drops from 463 at full extension to 455 when I'm on the bike...ohhhh....suddenly playful in magaspeak ?)

 

[33red]

Guilty re clueless wannabee

Re the reign having 470 chainstay - nb my old full e has 463 - both have the same motor / maestro / 2.6 tyres - presumably it has something to do with the longer travel / where in the arc of travel the chainstay measurement is made. That's a really good example of how stupid it is to get our knickers knotted over a few mm on a chart - when systems like the maestro are moving through an ark they get different " chainstay measurements " ( mine drops from 463 at full extension to 455 when I'm on the bike...ohhhh....suddenly playful in magaspeak ?)

It is about the feel when we ride.
I tested for 2 hrs a shorter chainstay. I knew nothing about #s on some sheet. I noticed the difference. It is also about the weight. You can enjoy it. To others it feels like a school bus. Long suspension are not for everyone.

 

[ninjichor]

Problem with long chainstays is that they need to be balanced by long front centers, else the front wheel weight bias is higher than others would expect from a normal enduro mtb.

The front weight bias must be compensated for with technique. To hit a drop at low speed with a long chainstay bike, having a manual/wheelie skill practiced is critical. Without such skill and timing, you need to ride off the drop at high speed to keep the front wheel from diving down pre-maturely. This deters riders from taking features that have rough entries, even though they might do it on a normal enduro MTB.

Look at the pictures of promos of the Giant Reign E+, and the extreme shots typically show the rider with arms fully extended with their hips way back. That's what I mean by compensating for front weight bias. If the chainstays were shorter, such a position may be actually detrimental, due to too little weight up front, and causing the bike to understeer and washout. Riders who are used to getting far back will find it familiar/appealing, while other riders who have ridden a wide variety of bikes, such as those journos autofilling text about long CS, find that from all the various bikes they've ridden, they rather have the ride experience of something with shorter CS, rather than spend the time to adapt. They've been spoiled by knowledge of better and easier, while others can buy in ignorance of all that, only opening up when they actually can afford the opportunity to ride better.

Take a look at fail videos and see how many crashes involve the front wheel coming down first undesirably and sending the rider over the bar. Some of the blame is due to the bike having excessive weight bias up front.

Take two weight scales, put one under each wheel, get on the bike and stand up straight in the pedaling position. Record the weight measurements. Add them up, and then find out how much of a % each wheel is of that total. I think the sweet spot is 60% weight on the rear, and 40% up front. I consider 55:45 and 50:50 to be excessive weight up front.

I think the choice of smaller size bike is a reaction to this need of getting weight back. A shorter wheelbase is more sensitive to rider input. It feels like your input is making a difference to control the heavy front, but this is a fallacy/paradox. I feel like an ebike should be dialed from the start. An XL Decoy, Commencal or Vitus, or L Pivot Shuttle, Canyon Spectral-On, Lapierre eZesty, or RM Altitude Powerplay should feel better than the smaller sizes. I only recommend downsizing if you're XL and must pick from what I listed in L.

I don't have anything against long chainstays. I just know that a bike should have a front end length to proportionally match. If you can't make a CS shorter, then make the front longer. I'd happily ride that 455mm CS bike if it had a 1310mm wheelbase and its seat angle were steepened to hit my preferred ETT on such a long bike (and seat tube isn't so tall, prefer it 390mm would be nice for my 30" inseam). 469.5mm CS with 1223mm WB? That's a hard pass...

 

[Gary]

I'd wager most guys with a 30" inseam would struggle to manual a 50lb bike+ FS Enduro Emtb with a 1310mm wheelbase and 470mm stays.
Overly long, super heavy bikes aren't so great for that sort of rider.

I have a 33" inseam and I know I struggled like hell to raise the front of an XL mondraker RR (with exactly the wheelbase/chainstay lengths you mentioned) to the balance point to manual it on the flat.
At 26kg it was incredibly heavy too though. (which definitely made it even harder)

 

[ninjichor]

Like I said before, it's a fallacy/paradox to think you want a shorter wheelbase in order to make the bike easier to manhandle (easier to lift the front). To make the wheelbase shorter on an ebike like the Reign E+ it likely has to give up front end length, since they can only make the rear so short.

It's counter-intuitive to want to make the front longer, which makes it harder to lift the front. But the reality is that the weight, from you standing on the pedals, is shifted from the front to the rear wheel, if you lengthen the front of the bike. Guess what other geo figure change shifts the weight from the front to rear? Shortening the CS does.

I'm sure you've seen riders go off of ladder drops, with hardly any technique, without the front of the bike nose diving. That's due to their bike geo not being front heavy. I'm sure you've seen fail videos where someone tries to ride off a bench or picnic table with hardly any speed, pop a wheelie, but the wheel drops before the rear wheel clears and they fall face first. That's due to their bike geo being too front-heavy, such as having chainstays being too long, *or* front end too short in length. It's a problem that has plagued short travel 29ers since their inception, and why people are now opening up to 29er enduro bikes, since they're getting super long to account for the long CS.

It's absolutely critical to nail this weight balance on long wheelbase bikes, since they are much less sensitive to rider input. With ebikes designed as they are now, with extra long CS, they mimic the geo of beach cruisers, intended for riders to spin in the saddle to enjoy the scenery, rather than to hit any bonus features with confidence.

 

[Gary]

There's no need to repeat yourself. I get what you are saying. you clearly don't get what I'm saying.

The Mondraker I mentioned "nailed" the balance to EXACTLY the numbers/ratio you were asking for.

3 of us rode it.
all Expert/Elite DH/Enduro riders/racers (me ex)
ALL 3 of us within in Mondraker's recommended height range for the XL (although personally I'd never ride a bike that long)
ALL found the same difficulty in raising the front.

Fact is. Super long heavy bikes are much harder to raise the front. This makes them far less playful.

I agree it's critical to get the chainstay/front centre ratio right on long bikes. But it's a personal preference down to rider style rather than the other way round.
A bike should not dictate how the rider rides it. The rider should.

These aren't race bikes. They're expensive toys for folk who want to use less effort to mountain bike.

I don't want a bike that I have to PILOT. I want a bike I can RIDE

I'd honestly love to see a guy with a 30" inseam ie. YOU (what height would that make you? 5'9"? less? ). try to manual that XL Mondy in the street.

 

[MarkH]

On all previous (acoustic) bikes I've been at the top of size small (I'm 5'5'') - I've been mtb'ing since 85 and owned over a dozen bikes.

Tested a medium 2018 Levo (that's the only demo size that was available) and the bike felt like an ocean liner, super stable but not agile at all. Took a punt that the Levo small would be better as it was closer (but still longer reach and wheelbase than all but my downhill bikes) and sure enough the small was much better; far more agile and lighter riding.
2 years on, and looked to replace the Levo; recommendations on sizing had moved on and I was 2 inches into the medium sizing for a YT Decoy, and well outside the 'small' range - but again took a punt and ordered a 'small' despite the recommendations, as I checked out the geo when they were released and noted that, despite the recommendations, the small Decoy was actually slightly longer than my small 18 Levo, and the medium obviously longer still. Demo'd a medium Decoy at Gisburn and it felt good, certainly more agile than I remembered the medium Levo had been 2 years previously, and was considering I'd made a mistake ordering a small Decoy. A couple of weeks later was able to demo a small Decoy at PDS and sure enough the small was even better and I was able to chuck it around like the Levo.

Maintained my order and very happy with the small Decoy now its arrived, despite being outside the size range. IMO Ebikes acquire stability due to the weight, particularly if the design ensures a low centre of gravity, and you don't need to size up to gain this as you might with a traditional bike.

Just my opinion of course and depends on you riding style and what you're looking for in handling traits. If you're more of a cruiser or XC orientated then the above might not be relevant to you at all.

 

[miPbiP]

I'm a medium. I bought a medium Levo. Best fitting bike I ever had.

In one of Rob's videos he says he'd like if his Levo was a bit more on-trend with longer reach. But he's an XL Please Spesh don't do this on the medium/small sizes, it's balance and compactness is partly why it handles well. Enduro folks can still get a Kenevo for long and slack!

 

[ninjichor]

These aren't race bikes. They're expensive toys for folk who want to use less effort to mountain bike.

I don't want a bike that I have to PILOT. I want a bike I can RIDE

This is seemingly where the misunderstanding lies.

I choose bikes based on the geo matching my terrain. I see a long WB bike as one made for proportionally higher speed. You seemingly see speed as racing. I see the motor as something that raises the bike's min speed, rather than max, due to cut-off and gearing.

How do you even choose among ebikes? By motor, the "feel" from a demo? If chucking the bike around is your main preference, sounds like the more rational plan is to avoid long CS and get a RM Altitude Powerplay, Canyon Spectral:ON, Fezzari Wire Peak, Lapierre eZesty, Pivot Shuttle, or something else with sub-440 CS so you don't have to compromise on weight balance.

I don't see a need to manual. I never properly practiced. I got fenders for water/muck, and don't even need to make much effort to keep the front end up for drops, since the weight balance is good on my bike. I mainly use J-hops and weight shifts. I can bunnyhop emtbs, but I admit I can bunnyhop much higher on a shorter wheelbase bike.

I have a second bike for "riding" (chucking around), and use my long bike for speed. My area is speedy, since it allows me to see the turns and and other features from a long way due to a lack of trees obstructing view. I don't race, I like to flow--I just think there's something special about a riding experience that doesn't suffer from constant braking (and re-acceleration). That flying/piloting feel is something I can't get enough of. Maybe this is also part of the misunderstanding, as I advocate picking bikes based on wheelbase matching terrain and riding style.

 

[33red]

The thing is many people buy a bike, keep it 15 years, use it less than 15 times per year.
Many of us are in the +1 club. Manufacturers are aware so instead of making good versatile bikes many are specialized bikes so many bikes are not good allaround. I like my new Ebike but there is room for an other.
I like to climb, i like flowy sections, i like technical section, i like variety.
No i am not fat, no i am not trying to use less effort, so different riders are happy on different bikes. A bike on a pedal recharge mode is what i love. No down time or as little as possible.

 

[Gary]

From what I've just read I get the feeling I'm probably a lot faster and more skilled rider than you @ninjichor

 

[ninjichor]

@Gary I got no teeth in that game. I'm all for utility, not arrogance. I like a bike designed to get me from point A to point B, with as little effort and risk as possible. In other words, safe, easy, capable vehicle, rather than a toy.

 

[Gary]

not arrogance

So why on earth are you running around the Internet telling us there's an exact ratio of wheelbase to chainstay length as if its going to be the same preference for everyone?

 

[miPbiP]

aw guys, not here, take it to peoplewholiketoarguetrackworld pls.

 

[CjP]

Let em go, I don’t watch much Tv so I need the drama!

Never knew about this weight biased stuff but I just weighed my Kenevo and it’s 59.8/40.2
I think the bike is absolutely perfectly balanced for me.
I can’t manual to save my life but that’s just me cause I’m shit at it. I am learning to pop wheelies though.

Keep up the babble guys I love to learn!

 

[Gary]

weighing the bike on two scales is a waste of time.
For many reasons.
But mainly as there's no optimum front to rear weight bias/ratio
Riders have a preferred weight bias too.

I'm a rear wheel baised rider. Yet another reason for me preferring shorter bikes. and if I wasn't a smooth rider I'd need even more rear weight added to my bikes (in the form of stronger rims/tyres)

I don't even feel this is an argument. Just a geeky discussion with a bit of a lack of knowledge/openmindedness on the part of one contributor. Happy to help anyone open their minds a little and maybe learn something. As am I just as happy to learn myself.

 

[CjP]

Oh I ‘need more input!’

It’s good to be open minded, it’s how we improve ourselves.
I’ve learnt heaps from all the keyboard mechanics on here, I choose what I feel to be relevant to me and try it out.
Heaps of fun!

 

[Gary]

I'm a F/T mech dude.
#PreKeyboardz

Have been on and off for 30yrs

 

[33red]

I agree with Gary. I like a high handlebar. I can lean forward when i want but i will not use a position that is popular just like i like a narrow bar and do not care what others think about it. I try to avoid braking my bike and myself and slowly improve.

 

[Gary]

That's not agreeing with me.

it's not disagreeing with me either.

WIN WIN ?