converting carrera kraken..back wheel came off :-|

[Stu33]

Hi,
So I`ve been converting a carrera kraken using a conversion kit from http://www.electricbikeconversions.co.uk (rear wheel kit), it seemed to be working ok when i tested it, but then I accidently put too much power on the throttle and the front wheel went up in the air like a wheely and it seems the back wheel came out of the sockets on the frame....the jubilee clip covering the torque plate broke and so did one of the disc brake pads. I`m a bit worried about it happening again, the sockets on the frame of the kraken for the wheel aren`t that deep.....any tips on stopping this happening again?

regards,

Stuart

 

[Nealh]

Usually drop outs need to be filed deeper as hub motor axles
are 3 - 5 mm larger, in your case probably about 3 or 4 mm deeper. A dremmel is quite a good tool to use with the right attachments fitted other wise you will have to do it with hand files, the important bit is not to square off the bottom of the drop out holes but round them to suit the axle.

 

[Stu33]

thanks for that Nealth , do you know of any youtube videos that can guide me to do that please? I`ve put it all back together now, think i did a better job !

Stu

 

[Deleted member 4366]

You need torque arms on each side. Anchor the one on the brake side to the caliper mount like this:

 

[Stu33]

thanks d8veh, the place I bought it from did`nt say put a torque plate on both sides, I`ll get it sorted though.

Stu

 

[anotherkiwi]

... it seemed to be working ok when i tested it, but then I accidently put too much power on the throttle and the front wheel went up in the air like a wheely

Stuart...

Throttles are dangerous!

Not like a wheelie, that WAS a wheelie

 

[Stu33]

kiwi? most ebikes have throttles, what you on about?!

 

[chris_n]

Mine certainly doesn't

 

[Wisper Bikes]

To achieve a wheely simply by twisting a throttle probably indicates the motor power is well above the legal limit.

This also demonstrates the reason we pulled out of the kit market and dropped DaaHub. The frame and bike that's chosen to fit the kit may not be suitable. Ebikes are designed to take the extra power and weight the battery and motor adds. Some push bikes are simply not up to it.

Be careful.

All the best, David

 

[Alan Quay]

To achieve a wheely simply by twisting a throttle probably indicates the motor power is well above the legal limit.

This also demonstrates the reason we pulled out of the kit market and dropped DaaHub. The frame and bike that's chosen to fit the kit may not be suitable. Ebikes are designed to take the extra power and weight the battery and motor adds. Some push bikes are simply not up to it.

Be careful.

All the best, David

A Kraken will be up to the job, but the motor needs to fitted correctly. I always file the dropouts deeper with a round file. Takes about 10 mins on an ally frame.



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[snowboarder]

it shouldn't happen if kit is fitted properly, Guess its always best to start peddling before you engage the motor as well

 

[Deleted member 4366]

To achieve a wheely simply by twisting a throttle probably indicates the motor power is well above the legal limit.

Not necessarily. Power is torque x rpm. If the bike is stationary, the torque can be high enough to wheelie, but the rpm is close to zero, so the power is close to zero too. That's me with my defence lawyers hat on. It's up to the prosecution to prove otherwise, for which they'd need more information than what's given so far.

 

[anotherkiwi]

kiwi? most ebikes have throttles, what you on about?!

Not legal, not fitted. I sold all mine to a forum member. Not useful on old bike or new because of superior PAS. I would like to build one of these however:

Full twist throttle, 1000W motor and enough lipo to do say 50 km at around 45 km/h. Blonde or brunette, haven't decided that bit yet...

The Mxus would wheelie quite easily in assistance level 5 and first gear and up to about third if I concentrated hard enough. I think the GSM doesn't wheelie as easily (the front wheel does get light) because of the different frame geometry despite giving Watts (and thus torques - damn I speaking like Clarkson now...) very generously on start up

 

[stevenatleven]

Interesting thread as I have converted a Kraken and it has,nt wheelied but I have lost wheel nuts off the non drive side. I think I will file the dropouts a bit deeper as suggested and fit another torque arm just in case their is a torq reaction in the axle that works the wheel nuts loose.

 

[Stu33]

thanks for all your replies, so i emailed ebc ,they did`nt reply ,so i rang later in the day and they said send photos of the wheel mounted in the frame, I thought i``d show it on here too.

1. brake side of bike
2.cassette side......

do the forks look deep enough?

3. the torque plate. adequately fixed?
4.washer
5.nut.... am i missing anything?!

the other side of the wheel just has washers and nut on,I dont have a torque plate for that side yet,ebc dont think its necessary.....though i`ll add it when I have it.

ok so i tried it using the above set up at pulling the throttle a bit and it was fine, then i put more power on the throttle...and had to pull the bike back a bit....the wheel came out again... I tried this same set up on a cheap steel frame bike, and it worked fine I was riding it for 2weeks, duno wots wrong, maybe the frames sheet, there was one other thing I noticed, when i tried to tighten the cassete side first the wheel started coming out the other side of the frame, maybe the wheels too wide?!

Stuart

 

[Nealh]

Looks like you have the 1kw D/D hub so a good fit in the drop outs will be required.
From the first pic I would say you need to file the drop outs deeper approx 3mm, it looks deep enough on the rear of the drop out but the front you can't really tell because of the angle of the shot. I suspect it is rolling on the front of the drop out because its isn't quite deep enough so the flat of the axle isn't all in. The T/A really would be better on the disc side and reversed so that the it fits rearward and not to the front, it then may be possible you might be able to use just the first piece that fits the axle and use the bolt hole to fix it to throught the rack mount hole. The T/A being forward and fixed like that isn't offering much resistance. The anti rotation washer with the tab should go on before the nut and T/A the tab is usually right angled and fits in the drop out as well.

2piece T/A on my no longer Mtrax cf frame with oxydrive. Since this torque arm fitting I now make my own one piece ones so that they are shaped to the drop out area and anchored via the disc brake or rack mount holes.


Axle set deeper in drop outs.

 

[Deleted member 4366]

A couple of mm deeper wouldn't do any harm, but you'll need to file something to avoid the rack stays. Don't forget the torque arm on the brake side.

Ypu also need to make sure that you do up the nuts nice and tight. That was probably the main thing you didn't get right before.

 

[Stu33]

thanks for the replies, d8veh, nah its not the nuts being loose,if anything i tighten them too much sometimes