Hello, I bought a Trek Allant+8S a few weeks ago and like it a lot. I've had one issue with it, though, when riding at top speed in turbo. The crank becomes hard to turn and the speedometer jumps wildly from 35kph - 45kph. This doesn't cause the generation of any error codes in the app and the local bike shop techs didn't detect a problem in test riding it when I brought it in. I've petaled the bike at or above 45kph without power assist and this doesn't happen. Does anyone know what's going on? I asked the bike shop to open a ticket with Trek/Bosch in hopes there's a documented explanation. Thanks!
Trek Allant+8S crank resistance in turbo at top speed
- Thread starter Wakasacho
- Start date
biker1234
New Member
- Region
- USA
I'm having the same issue Wakasacho. Im thinking (hoping?) it might be caused by dirty speedometer sensors. Did you figure it out?
BTW, retinedNH, you have "no doubt" that the speed drops from 45 to 35 instantly because we reach top speed? Can you imagine how dangerous that would be!? Jesus.
BTW, retinedNH, you have "no doubt" that the speed drops from 45 to 35 instantly because we reach top speed? Can you imagine how dangerous that would be!? Jesus.
fooferdoggie
Well-Known Member
actually power cuts out at a max of 27.5 mph but it starts dropping at 26 and often boschs are a mph faster than actual.
Did I say "instantly"? Pay attention, and don't put words in people's mouth. fooferdoggie gave you a more nuanced (look it up if you don't know what nuanced means) explanation of "cuts out".
Guess you should have gone with a Bafang equipped bike with no restrictions?
biker1234
New Member
- Region
- USA
Thanks for the input but again, the issue isn't that there is a speed limit on the assist, we're fully aware of that. The problem is that when we get close to that limit, the speedometer becomes erratic, like 7-10 kph up and down a few times each second. IE at 40kph, the speedometer will show 40, 48, 37, 43, 40 within a single second. If going at constant say 44kph, the computer will withdraw support every few seconds because it thinks we're going too fast. It's extremely annoying since the support is randomly withdrawn / brought back without any changes in effort. Issue seems to be with the speedometer...
Alaskan
Well-Known Member
If you post this question on the Bosch sub forum you will likely get some knowledgeable help from the Bosch team. This was the wrong sub forum on which to ask for help on this issue. The Bosch North America team is very active and helpful over there.
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Easy Motion Bosch City Wave Review | ElectricBikeReview.com
Price: $3999.00 | Model Year: 2015 | One of the only deep step-thru electric bikes powered by Bosch that's available in the US for 2015
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MartsEbike
Well-Known Member
- Region
- United Kingdom
- City
- Dunstable
I'd check the speedo magnet/sensor. I think on these bikes it might on the brake rotor? It might be loose.. I don't have one of these bikes so guessing a bit!
biker1234
New Member
- Region
- USA
OK thanks will do!If you post this question on the Bosch sub forum you will likely get some knowledgeable help from the Bosch team. This was the wrong sub forum on which to ask for help on this issue. The Bosch North America team is very active and helpful over there.
Easy Motion Bosch City Wave Review | ElectricBikeReview.com
Price: $3999.00 | Model Year: 2015 | One of the only deep step-thru electric bikes powered by Bosch that's available in the US for 2015
biker1234
New Member
- Region
- USA
Not helpful....
fooferdoggie
Well-Known Member
ok that sounds like something loose. well maybe but tis weird I only happens at that speed unless there is a lot of vibration.
Alaskan
Well-Known Member
@Wakasacho It sounds like something that should generate and error code that would be picked up by connecting the bike to Bosch diagnostic software at a certified Bosch bike shop (which includes most if not all Trek shops as most Trek ebikes incorporate Bosch electricals.
I would take the bike in to the shop where it was purchased just a few weeks ago and let them figure it out and make it right. They should be happy to do so without charging you.
fooferdoggie
Well-Known Member
I got some of those issues when my nyon was not making good connections. but with the smartphone hub it wouldn't or be the same.
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