Dahon Jetstream conversion

[Cyclezee]

I think I've just figured out why John was able to fit an 8 speed free-wheel, and i struggled with a 7 speed. I bet he didn't fit a disc brake. You need an extra couple of washers to line up the caliper and get the disc away from the frame.

Exactly right Dave, the Jetstream had an eZee Mk1 motor with 48v battery and CA, but standard V brake was retained, then it was shipped to a customer in Athens.

Even though it was 3 years ago, I remember that one well because TNT gave it the grand European tour before it eventually got to Greece. UK to Brussels, Brussels to Budapest, then back to Brussels, then to Athens.

 

[cwah]

So if I understand it correctly, the 180mm disc brake from bmsbattery can't be installed to the bike???

Can it work if I just buy an additional 140mm rotor??

 

[Deleted member 4366]

You need a 180mm or bigger to be sure that the caliper will be clear of the motor. Your disc-mount on the frame is side-mount. The BMS battery caliper is also side-mount, so you need a 140 to 180mm side-mount to side-mount adapter.They're not as common as side-mount to post-mount adapters and they're more expensive, so its better to get a brake with a post-mount.

 

[Alan Quay]

Executive summary: You only need to add about 10mm of spacers and a longer machine screw to go from a 140mm rotor to a 180mm.

You need a 180mm or bigger to be sure that the caliper will be clear of the motor. Your disc-mount on the frame is side-mount. The BMS battery caliper is also side-mount, so you need a 140 to 180mm side-mount to side-mount adapter.They're not as common as side-mount to post-mount adapters and they're more expensive, so its better to get a brake with a post-mount.

I did a similar thing to my bike the other day. LBS had the adapter in stock (from 140 to 180) for £12. When I went to pick it up, it was the same bracket as the 140mm, but with four 5mm spacers added (two each end). On closer inspection the spacers were those cupped washers that you get on V brakes:
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I declined to hand over my hard earned as I already had these (and longer 6mm bolts) lying around.

 

[jackhandy]

You mean to say you had the audacity to inspect what your lbs had for sale, then go off and copy it for a fraction of the cost?
Shame on you Sir! This is just what is driving small businesses to the wall.

What size bolts did you say?

 

[Deleted member 4366]

Executive summary: You only need to add about 10mm of spacers and a longer machine screw to go from a 140mm rotor to a 180mm.

Not when you have a side-mount on your frame and a side-mount caliper. All that will do is offset your caliper sideways by 20mm.

 

[Alan Quay]

Not when you have a side-mount on your frame and a side-mount caliper. All that will do is offset your caliper sideways by 20mm.

Hmm, a fair point. Worst thing is, I have one of those calipers from BMS unfitted, and sitting on my bench and I'd not noticed is was side mount.

(Slackens jaw, slaps head, gets coat)

 

[Deleted member 4366]

Join the club. I've got two of them. this ad shows what you need, but they're always expensive.
ASHIMA Disc Brake Adapter - IS Mount Caliper to Post Mount Fork (IS-PM) | eBay

 

[cwah]

I just want something simple and easy to replace. I tend to break things on my bikes lol

So new shopping list:
Juicy rear brake:
Avid elixir 3 rear disc brake | eBay

180mm adapter:
Shimano Bicycle Bike Disc Brake Post Mount to Post Mount Front Adapter 180mm | eBay

And bmsbattery 180mm disc brake I already have.

Is it all good?

 

[Deleted member 4366]

That's the wrong adapter.You need IS to post mount:
is to post adapter 180mm | eBay

 

[cwah]

ok going to get the one from your link then.

Is the avid brake ok? It finishes in 27mn and I could bid on it?

 

[Deleted member 4366]

Yes, It looks OK, but don't forget that you can get this one new for £34.
XTECH (by ZOOM) GOLD Mountain bike Hydraulic Disc Brakes !! 160mm rotors. | eBay

 

[cwah]

so I get the XTECH one + the 160mm IS to mount adaptor then:
Shimano Front IS Mount to Post Mount 160mm Bicycle Bike Disc Brake Adapter | eBay

Shall I get the bleeding kit?

 

[Deleted member 4366]

You need a 180mm disc and a 180mm adapter; however, some calipers are narrow enough to keep clear of the motor on a 160mm disc, so you need to try it first with 160mm.

 

[cwah]

but the link you sent me is with 160mm rotor???

So it's not sure it's going to fit or not??

 

[Deleted member 4366]

I thought you already had a 180mm rotor. You can use the 160mm adapter that comes with that kit, but you need longer bolts and some spacers. A 180mm adapter would be better. As I said before, it might all work with the 160mm stuff.

 

[cwah]

Thanks Dave. I purchased the disc brake for now without the adaptor. Will see if I need it.

Thanks

 

[Deleted member 4366]

When it arrives, you can test it very easily and quickly without having to install everything. Lay the disc on the motor after removing the screws. Then put the caliper on the disk in approximately the right position to see if it touches the motor. If it does, you need to install the 180mm disk, so screw it on. When you put the wheel back, you'll need spacers(washers) on the axle to keep the disc at least 3mm clear of the chain-stay (frame) otherwise the caliper won't line up with the disc.

 

[cwah]

Thanks I'll check that when I'll receive it

I noticed my BPM doesn't freewheel that well... only few turns. It gets worse when I tighten the nuts. Is it normal?

Also, did any of you tried to replace the quick release with nut?

 

[Deleted member 4366]

Have you got your gears on it yet?
Which quick release are you talking about?