trimtanks

I just bought a new e-bike with a Shimano steps E8000 engine. I know the motor cuts out at 25km/h, but it feels like I don't have the necessary gears to push the bike much past 32km/h using muscle power. When I approach that speed on a flat surface it feels like my cadence is just too high and it becomes really difficult to go faster. Like my legs are just spinning with little resistance. The front chainring is a 38T and the cassette is a 11-36 (9-speed). This is really disappointing. Have anyone else experienced something like this? Is there something I can do or try? I've noticed that Bosch generally have really small front chainrings. Is it even possible to use brute force to push those bikes much past their engine cut-off speed?

2old

Bosch isn't good for comparison since they have a Schlumpf (sp?) drive which "magnifies" the front chainring. AIR, when I tested a 2016 Haibike with a 20 mph cutoff, I had difficulty going faster than about 23 mph.

slomoshun

Check if the E6000 44t chainring will fit the E8000.

trimtanks

So, I went to my LBS and tried a bike with a Shimano E6000 motor and a 44t chainring fitted. It mostly alleviates the problem of low speed while muscle powered. Mostly. I could at least get up to 40km/h in a slight downhill and not be completely spun out.

Also, the sales guy at my LBS claimed that it was well known that e-bikes, especially mountain e-bikes, had this problem with a low top speed for muscle power. But I've been researching e-bikes for almost two months now before I finally bought one and I've never heard this mentioned.

As far as I can tell however, the e6000 chainring is not compatible with the e8000 motor. That is a major bummer. Anything besides returning my bike I should look into?

CliffordK

Do you have a photo of your bike's drivetrain?

It appears as if the chainring is bolted on with 4 bolt spider. That should mean that the chainrings are replaceable, and you should be able to source larger rings if you have the actual specs (or can measure it).

Does your bike use a cable guide? Is there any adjustment?

If you can return your bike, perhaps take a day or two to look at alternatives, and it may be the best option.

trimtanks

This is the bike:
hxxp://whitebikes.no/sykler/xc-e-pro-275-steps-8000-18/

Would this part be compatible?
hxxps://www.bike24.com/p2275531.html

It says it is for 10/11-speed cassettes

sorry for the weird links. I don't have url privileges yet.

CliffordK

That will probably work, as long as your cable guide will clear the ring.

CliffordK

Changing the sprocket size could also affect your speedometer, and speed regulator which could be an issue in certain locales.

trimtanks

This may be a stupid question but, what is a cable guide?

How could this affect the speedometer though? It measures speed with a magnet at the rear wheel. I'm not messing with that in any way.

CliffordK

Sorry, I meant chain guide. Circled below. It will need to be raised maybe 1/2 inches, depending on your new chainring.

Guide.jpg

Ok, so a magnet sensor on the wheel is good. Is that part of the speed governor system?

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BTW: You may be limited to 5 posts a day. Use your last post wisely.

2old

Probably it's part of the speed governor system because a few years ago individuals would move the magnet and sensor to the crank (which moves more slowly than the wheel) and achieve much higher top speeds. Manufacturers have placed controls in the system to prevent that now. Looks like the guide is a pretty tight fit. It may need to be removed and a narrow-wide chainring used to prevent the chain from coming off.

trimtanks

I don't have the part circled in red, so there is an infinite amount of clearance at that spot. BUT, the chain stays have practically zero clearance with the existing chain ring, thus making it impossible to upgrade to a larger one. Huge bummer. I guess this e-MTB is not built for speed. So I ended up returning it. Now I'm eying the Canondale Synapse NEO 3 2019. It might be what I'm looking for.

trailangel

Should have bought a Haibike Sduro with Yamaha motor and 44/32 front plates.

trimtanks

ThermionicScott 

I think it's your legs. Your 38/11 gearing with 27.5" wheels is the same top gear (95") as my touring bike, and that's plenty for speeds over 32 km/h.