Thorn Raven now converted

[paulhipwood]

Hello all

Got an 8Fun kit, took most of the day to put the kit on

• Changed the carbon fork for a steel one
• Fitted battery
• Fitted controller
• Modified the mounting for the pedelec sensor
• Lashed the cables out of the way
• Fitted new brake levers

Just been out for a short ride.
IT WORKS
First impressions are that I am going to get a lot of use out of this.
There is a couple of long 10% hills will try them tomorrow.

Thanks for all the information on this forum, it made the selection and fitting of the kit fairly easy.

regards
Paul

 

[flecc]

Congratulations Paul, glad you are pleased with it. Let us have more news as you try it more, and maybe a photo?

 

[kitchenman]

Nice one Paul. Do you have a link to the kit that you bought? That would be useful.

 

[paulhipwood]

This is the one I bought
8F26F36B | 26" Electric Bike Conversion Kit | 36V 250W Motor, 36V Li-ion Water Bottle Type Battery with Panasonic cells

paul

 

[amigafan2003]

Why did you feel the need to change the carbon fork? They are fines for low powered kits - approx 750w or below.

 

[paulhipwood]

I changed the fork just to be on the safe side. The fork is fairly old and I am not too sure what forces a hub motor would impart on it.
I put on a Thorn twin plate beast of a fork.

paul

 

[amigafan2003]

Ah that's fine then - to be honest I'd have probably done the same on an old carbon fork.

New ones are much better - modern carbon forks have three times the shear rating of good steel forks - just keep an eye on them for surface damage and inspect very carefully or return to manufacturer after any impact.

 

[flecc]

Problem with carbon forks is the way they fail, suddenly. Fork failures with steel or alloy often have some degree of delay in the failure, depending on where the failure is. Every second counts in a front fork failure!

 

[eddieo]

Paul some pictures are always appreciated.....

 

[amigafan2003]

Problem with carbon forks is the way they fail, suddenly. Fork failures with steel or alloy often have some degree of delay in the failure, depending on where the failure is. Every second counts in a front fork failure!

I've seen way more steel fork failures than carbon fork failures (in fact - I can't recall ever seeing a carbon fork failure whilst working at my LBS) and some steel failures are downright scary.

The carbon misconception:-

http://isolatecyclist.bostonbiker.org/2011/02/21/carbon-bicycle-forks-cautions-facts-and-misconceptions/

Look at the steel fork in that article.

The carbon fibre fork on my bike has a lifetime warranty - you don't see lifetime warranties on steel or alloy forks very often.

 

[flecc]

All true, but there have been batches of production that have failed in the past. Naturally we've seen many more steel and alloy failures since there's loads of them about and few carbon ones, but the proportion of carbon ones that have failed has been much higher, though as you say, they are improved now.

The lifetime warranties are to restore confidence of course, steel and alloy forks could easily have them too, but it hasn't proved necessary.

 

[mike killay]

Possibly not relevant, but I gave up on my carbon fibre fishing rod because unlike GRP, it seems to bend the same and then suddenly snap, whereas GRP starts to 'groan'
Also, I have seen carbon fibre sailing dinghy masts snap, wooden masts just don't snap, alloy ones bend before snapping.

 

[eddieo]

last year saw bike frame snap in velodrome race very dramatic, when they go they go!

 

[paulhipwood]

Here is one photo, I will load some more if this works

 

[paulhipwood]

The first one shows the pedelec sensor

The second shows my replacement forks

The third shows the motor.

 

[flecc]

Thanks Paul, that looks a neat conversion.

 

[paulhipwood]

Has anyone calculated the power loss due to having to coil the spare cable around the frame.

I should imagine its extremly small but who knows?

paul

 

[NRG]

Its tiny, don't worry about it.

 

[andyh2]

Hi Paul,

How do you find those Thorn forks feel?

 

[paulhipwood]

Hello Andy

I read the bike magazines and the authors seem to be able to tell the difference between the tread pattern on the tyres.
The Thorn is now so much heavier, also I have had to move the gear change to the LH side to get the throttle lever on, so its like a different bike.

The carbon forks were very sturdy and weighed 850gm against the steel 1200gm. The biggest diference is that I feel more secure whe decending, this is purely in my mind.

regards
paul