Old man, new bike, massive hills, lesson learned

[m@Robertson]

Bikes like these that come from a closed, proprietary ecosystem generally have barriers to doing something like changing their gearing. Bosch systems for instance. Bosch-allowed changes have to one of a few approved factory chainrings with only a couple of sizes available. The system then has to have its firmware flashed by an approved dealer.

Gearing changes are a simple thing people take for granted, but when you buy a bike like this you may find out there are limits imposed that you never expected.

And a gearing change is likely going to mean he kisses goodbye his top speed. My hill-climber bikes do by necessity. I'm fine with that, but that doesn't mean someone else would be.

Its a perfectly fine ebike... for someone else. It can't do the job being asked of it, and its pretty easy to see why with the low power it provides. Its fine for the seashore or somewhere flat or with low rolling hills.

 

[BlackHand]

I'm with Mike, no reason this bike can't climb hills. And no reason to start with changes that would effect top speed. It's a bit of an oddball - clearly designed as a 2x (it has a braze-on for a front derailleur) but shipped as a 1x with a not very wide range cassette.

Microshift makes inexpensive wide range 9sp cassettes. The question is how far you can go before you would need to put a long cage derailleur on?

It's interesting that several people take the 500w peak as gospel. One would think Yamaha would have a rough reputation if their emtb couldn't hang with Bosch and Brose powered bikes.

I'm not an expert, but I do speak as someone who daily goes up 20% grades and regularly goes up a 28% grade on a similar (lower torque, higher listed peak power bike). Oh, and yes I've changed my Bosch chainring withOUT needing a dealer to plug the bike in. Yes, you could trigger an error if you were changing a bike from say a time trial setup to a mtb setup. Reasonable changes can be made by the end user with no problem.

**Edited to change with to without in the 3rd to last sentence.**

 

[EMGX]

Yamaha lists the rear derailleur as long cage Shimano M3100 SGS with max cog size 36t. Usually you can go up 4t from the listed max cog size without problems. I've done it with Shimano 105 as well as SRAM X9 and X4 rear derailleurs without need for a derailleur extender. Maybe give a 11-40 cassette a try (no loss of top end) and decide if you want or need a smaller chainring. I changed the front chainrings as well as the rear cassette on my Shimano 105 2x11 BH Rebel gravel bike with Yamaha PW-SE for better hill climbing without any problems at all. If you want to go with a even larger max cog cassette you can use a derailleur extender (sometimes comes free with a new large cog cassette) but that can affect shifting some and/or rear wheel removal. The PW-SE provides excellent power and the ST has similar specs, except for auto setting and higher top speed limit, so it should do just as well.

 

[m@Robertson]

Looking at it again, that does look like a big chainring to expect to be able to climb hills with. The specs say its only a Samox 44T which should be 104 BCD. If the bike will tolerate it, a 40T and a few less chain links could be a good start. Rear cluster is a steel HG400 11-36 9s which is excellent for durability, if a bit dated.

A $20 WolfTooth Road Link and some elbow grease adjusting things could extend the rear derailleur enough to accept a $40 Microshift hardened steel cassette that is 11-46T. Leave the 44T on in front. Next step if thats a bridge too far is pull out the Shimano derailleur thats rated only for 36T, and shifter, and replace with Microshift Advent. Derailleur, cassette and shifter tally up to around $100 for everything so that would do it cheap and reliable. Or go 10s and do an Advent X for a few dollars more. 11-48T rear steel cluster. I run that on my daily driver cargo bike and its bulletproof.

But now we're getting into DIY, which is fine for some of us but not to a lot of folks that don't want to mess with or think so hard on it. Everything I was saying before assumes a closed proprietary system and an owner that doesn't want to get deep into the weeds on this... Typically the kind of customer that buys these local-dealer bikes is looking to write a check and just have the thing work.

 

[Mike TowpathTraveler]

Yamaha's Wabash gravel bike features an 11 speed rear cluster, (Shimano CS-M7000
11-42t). Same motor set up as yours, OP. Worth it to see if the components on Wabash are a direct fit (minus the shifter as it's made for the randennour handlebar). But that is a question to ask of your trusted local bike shop.

Post #21: I don't come to this site for silly, snarky arguments. Just giving alternatives for the OP to consider. I seriously doubt that the world's oldest Ebike maker (Yamaha) is going out of business. If they were, what's the point in offering up a 5 year warranty on these ebikes currently for sale? Could be clearing inventory for many reasons, including a new lineup for the coming year.

The older Haibike e-mountain bikes powered by the PW motor featured a 2 sprocket front chain ring, like my Full FatSix does. Then came along the Pizza Pie sized rear cassettes and the need for a dual front chain ring went the way of the dinosaurs......

Old school Full FatSix, Yamaha PW front chain ring, with a 44t outer ring for sea level riding and an inner granny gear for hill/mountain climbing. The advent of the bigger rear cassettes along with a more moderate sized single front chain ring eliminated the twin front chain rings.......

 

[Grueso]

[...] And who would pay $1000.00 for a 500 watt battery? My 1000 watt is $350.00. [...]

Watt hours?

 

[Stefan Mikes]

And who would pay $1000.00 for a 500 watt-hour battery?

One who would not like to have their place burnt to the ground?

 

[Chargeride]

I find the pw se on my fat6 perfectly fine for climbing, Ive climbed hills way steeper than anything that is ever tarmaced.
It doesnt feel like it needs a lower gear, in fact it surprises me by pulling a higher gear than I thought.

 

[Grueso]

Yamaha's Wabash gravel bike features an 11 speed rear cluster, (Shimano CS-M7000
11-42t). Same motor set up as yours, OP. Worth it to see if the components on Wabash are a direct fit (minus the shifter as it's made for the randennour handlebar). But that is a question to ask of your trusted local bike shop.

Post #21: I don't come to this site for silly, snarky arguments. Just giving alternatives for the OP to consider. I seriously doubt that the world's oldest Ebike maker (Yamaha) is going out of business. If they were, what's the point in offering up a 5 year warranty on these ebikes currently for sale? Could be clearing inventory for many reasons, including a new lineup for the coming year.

The older Haibike e-mountain bikes powered by the PW motor featured a 2 sprocket front chain ring, like my Full FatSix does. Then came along the Pizza Pie sized rear cassettes and the need for a dual front chain ring went the way of the dinosaurs......

View attachment 182564
Old school Full FatSix, Yamaha PW front chain ring, with a 44t outer ring for sea level riding and an inner granny gear for hill/mountain climbing. The advent of the bigger rear cassettes along with a more moderate sized single front chain ring eliminated the twin front chain rings.......

I'm also optimistic that the 44T front/11T-42T rear single chainring combination on the Wabash RT will work for me. Compared to my current 50T/34T front/11T-34T rear dual chainring on the Canyon Roadlite 6 I will lose 15% at the high end, which is ok, since I almost never use the 50/11 combination, and 5% at the low end, which should be fine since there is help from the motor. I'm actually thinking I will like the 1x11 setup better, since the gear changes will be more seamless. Is the GRX 600 derailer/cassette combination sturdier than the 105?
Another question: What is the Q factor on the 2024 Wabash RT with the PW-ST motor? I can't find that info anywhere. (I've seen 168mm quoted for a bike with a 'PW-X' motor, but the pedal crank shape might be different.) Yamaha, in their 2025 model announcement, state that the new Wabash RT with the PW-S2 motor will have a 22mm shorter axle, and thus a smaller Q factor, but maddeningly they don't give a number!

 

[snipechief]

I'm in California visiting family and I'm loving these flat roads where I can get over 30 miles on a charge. Big difference from my home AO of E.TN and nothing but hills and only getting 18 miles per charge on a 14 ah battery on pas lvl III.
Hills make a huge difference. Glad I have at least a 750 watt hub motor.
I also use the walk mode to pull.my 42 gal rv waste tote to the dump station which is only 50 yds away, but its very heavy to pull over the gravel road by hand. The Ebike is very useful for RV'ing.

 

[Catalyzt]

Let's see..... sell a perfectly fine ebike at a loss and buy something with "more power".

or

Invest 150 to 200 bucks on an mtb-style geared derailleur drive train & with that Yamaha motor and battery, know that you're gonna get 10's of thousands more of trouble free miles on that bike.

I'll take choice number 2 and with those couple thousands you want him to spend on an ebike with "more power", he can splurge right now on one of those Yamaha Moro ebikes that are deeply discounted, along with a spare 500wh battery that costs a thousand bucks, for free. 2, uber high quality drive ebikes in his stable for one of those bikes with "more power". One for the road more at sea level. The other to take on those hills.

And to boot, 80nm of torque on those Moro's compared to the 70nm on his CrossCore.

Of course, choice number 2 is what I'd do. Your solution is something else altogether. No right or wrong going either direction. But I'm here to tell you that 70nm is good enough to climb most hills within reason. Better, lower gearing allows better climbing ability.

Absolutely-- and maybe a smaller chain ring, IF a swap is even possible. With 42T or more in back (and hey, smaller at the chainring if possible-- it's probably not) you can probably grind away all day at 5 MPH on well over 15% grades, and even with a lot less power than that.

This will not be plug and play, probably! I'd have an LBS do the job. But will make a huge difference. Even with an underpowered bike (one of mine is 40nm) that's geared right, if I can get halfway up or more, then it's just a training issue, if my health is okay. However, with 70+ nm even on a 42 pound bike where the crank is a little too big and and the low gear a little too small, I'll bonk way sooner on the steep stuff.

 

[Kayakguy]

It has never occurred to me that there are paved roads that an ebike can't get up. What % grades are these hills exactly? There are hills not too far away from me that road signs indicate are 17% and I can climb those on my road bikes (no motor) so I would guess with how powerful some ebikes are that I should be able to climb 30% grades with a motor, but that is of course just a guess.

If an ebike can't climb a vertical wall, why bother?