ok to drill 2 holes in frame?

[josh kayz]

Hi, I`ve converted a rockrider 6.3 to an electric bike, been using it 5,6 weeks, but theres no space in the triangle for the battery so i`ve had it under the frame ,secured by straps ,it was always temporary, i wondered do people think it would be ok to drill 2 holes under the frame, the same size as the bottle holes?they would be drilled the other side of the tube to the bottle holes, then i`ll put a long bolts/nuts throught it, i need to attach the battery to the frame somehow... i`ll add velcro straps too, the width of the lower post is 2.2cm wide ,by 5cm deep,

this is the bike

regards,Josh

 

[Ocsid]

I think I would use some form of wrap under strap fixed by the existing bottle fixings, rather than further weaken the structure of a bike never designed as a powered bike. The strap most likely made of metal, structurally probably selecting to use steel sheet.

 

[Andy-Mat]

I agree with Ocsid, bike frames/tubes have very thin walls, and you would probably crush the tube unintentionally.
I do believe (not done it myself!) that such strong points are often made using metal clamps, with thin rubber inside to protect the paint/frame, and I do believe that someone posted a web link recently where they could be bought!
If I made up my mind to do something like as you say, I would make up a double sided, wide headed, strong threaded tube, the length being the width of the bike tube. Screw it together in place and either braze on both sides (for a steel framed bike) or glue it in place with Epoxy of the strongest type (the slow setting ones!), so that the compression stresses would be handled by that tube, not the frame.
There are probably many other methods that someone else here could possibly detail as well.
Bike frames are generally very lightly built and can be crushed easily and fail.....care must be taken....
Regards
Andy

 

[josh kayz]

ok, no drilling for me lol

 

[Chris Swinb]

I am looking to do the same with my Rockrider 6.3 like yours . Have you fitting a Bafang 750W mid drive? If so what battery did you choose for the under mounting and do you foresee and water ingress issues? Great Bike but a nightmare finding parts to fit in the limited space, I would like a 48V 17.5AH Battery. Thanks Chris

 

[WheezyRider]

Hi, I`ve converted a rockrider 6.3 to an electric bike, been using it 5,6 weeks, but theres no space in the triangle for the battery so i`ve had it under the frame ,secured by straps ,it was always temporary, i wondered do people think it would be ok to drill 2 holes under the frame, the same size as the bottle holes?they would be drilled the other side of the tube to the bottle holes, then i`ll put a long bolts/nuts throught it, i need to attach the battery to the frame somehow... i`ll add velcro straps too, the width of the lower post is 2.2cm wide ,by 5cm deep,

this is the bike View attachment 33893

regards,Josh

I wouldn't want to go drilling holes in the frame. Best solution I've found is to 3D print your own mounts:

 

[cannon]

I had the same issue with a FS MTB, the link below was the inspiration for my conversion and I used the same bike too. My battery is mounted under the downtube with 3 rivnuts and two re-usable cable ties. In two years and 1800 miles there have been no mounting problems.
There are many threads on here via the search button

Self build full suspension emtb

After lurking and perusing the forum for ideas I thought I would throw my hat in with the following. I live in the middle of a very forested corner of the realm and have access to a life times worth of forestry trails for which I want to ride with a full suspension rig. I had already built a...

www.pedelecs.co.uk