RAGLEY BIG WIG build

[Larryvaan]

Hi,

I did not find any good thread about Ragley bikes build with Bafang bbshd.
Has anyone done this? The frame seems quite good for fitting motor to frame.

Wonder what chainring could be possible also. And does the motor fit to the "bottom", or does it require shims.

[stts]

Hard to say. Looking at Google pics kinda looks like the crank tube is really small diameter. The motor may not fit inside of it. If you have this bike then you need to measure your crank tube and compare to motor dimensions. Somebody posted a great motor dimension page.

[Larryvaan]

You mean bottom bracket size?

Based on specs, it should be 73mm BSA, so it should be fit for bbshd?
Is it?

[stts]

No I'm talking about the inner diameter. It has to be about 34mm. Google pictures look to be even smaller than that. If its bigger you can put an adapter on to make it fit.

Here's the second link again. It seems to have vanished.

https://intercom.help/bafangusadirect/en/articles/4649613-bbs02-bbshd-motor-fitment-templates

[ncmired]

Welcome to the forum, and I hope you gather answers to the questions and concerns you have.

I think all of the current Ragley steel and aluminum frames have pretty standard 73mm threaded English BBs. Some of them have compressed or plate-style right "1-by" chainstays, which usually help with clearing the motor's secondary gear reduction case (i.e. how many spacers, if any, required). But, the area around the BB still holds some mystery to me, as I didn't come across any other detailed pictures - the angling-out of the chain stay, for example. Short-stayed Boost frames clearing tires much larger than, say, 2" wide would be suspect - getting riskier as the tire width increases.

This picture illustrates the motor-to-chainstay clearance conundrum, and where using a partial plate chainstay can help:

No frame designer will wander too far out of the design box if they know what's good for them, and that's probably the case with Ragley. The Bafang BBSHD motor is pretty wide and accommodates a few spacers with ease on a 73mm BB. The pedal Q is also quite wide, so crank arm to stay interference is rare. The Big Wig max tire size is listed as 2.5".

What I can see in some of the frame pictures that's not helpful, is the welded-on ISCG 05 Tabs which will have to be chopped off, and it would have been helpful if the frame had three water bottle bossed, for stronger bolt-on style battery retention.

For chainrings, two go-tos are often the Luna 2-piece Eclipse and the Lekkie 40 - both have wide-narrow cuts. 130BCD spiders are also available, and probably less costly over time as widely-available generic rings can be used.

As you're in Finland, I'm guessing you don't have any bikes/frames of this brand you can see in person. Some of us have made the leap "where no man has gone before", crossed our fingers, and winged it on some brand or another. If you choose to do so and it works out (usually does), please come back and document the build, for the next Ragley wanderer.

[Larryvaan]

Thank you for detailed response! This will help a lot.
Just to make sure, your motor is 68mm version of bbshd in the picture?

I found two images, first is Ragley mmmbop, looks like fitting fine. Ring is perhaps Lekkie 40T or 42T..


Second is Big Wig detailed image of chainstay with 30T chainring. Seems like plenty of room for bafang there.
I read somewhere that secondary gear would be same diameter as 32T chainring


I think I am going to take my changes and try the big wig frame. If it is success, I will write a report of mod.

[ncmired]

Yep, in my picture is the 68-73mm wide BBSHD. Your first picture has an original 42 tooth Lekkie (there are now two versions). Good luck on the leap, and I suspect you'll land fine. For additional battery-related mounting bosses, rivnuts work pretty well.

32-34T sounds about right for the secondary gear housing diameter - in my picture is a 36T Luna one-piece, and later I used a 30T Luna one-piece for a while - lousy chain line for most derailleur drives, but fine on a Rohloff IGH (see my signature line for build link). The fancier chainrings surround the secondary gear case and put the chain line roughly even with the case cover / main casting line - as illustrated in the PDF link stts thankfully provided.