UK based suppliers for Q100 motors in rims

[eHomer]

Following on from my thread about changing the motor in my Alubike:

As usual I'm drifting about all over the place with this project.

I've considered mid-drive, but I'm back on the idea of a Q100H in the front wheel again.

I hadn't realised the number of UK suppliers had increased for the BBS01 motors, so I'm wondering if there are any that will supply a Q100H already spoked up into a 700c rim ?

I've only found BMS battery in China so far, and although the built wheel option only adds a few dollars, the shipping increases by $100, so the VAT and duty jumps another $25 too.

 

[Deleted member 4366]

Time to read Sheldon Brown's wheelbuilding guide. We all had to start somewhere. You can save a lot of hassle by using BMSB spokes. Their length depends on which rim you get.

 

[eHomer]

As you know Dave, I usually manage to frighten myself out of building a wheel from scratch !

Even though I have a proper wheel truing stand and know how to use it, I've only ever re-trued wheels on it, or altered dishing.

I'd like to have a bash, and as you say there are some good guides on the Internet showing lacing and such.

What worries me is getting the right length of spoke, because of the very limited amount of leeway in threaded length etc..

I do have a very nice spare 36 hole 700c rim, that was the original front wheel for the alubike with a dynohub. Here's a photo of that set against my existing Chinese "deep rim" with the existing motor. I guess they're both "deep rims", but there's a variation in those as well, the Chinese one being 30mm, and the original German rim is 26mm.

As I wouldn't be buying a new rim from BMS because of the shipping cost, what length of spokes would I need to order for my "semi-deep" rim and the Q100H front hub motor ?

I agree they're nice and cheap at 20p each.

I'd prefer to go for the thicker 12g than the 13g if they'd fit.

As I'm staying with 36 volts and my S06S controller, I'm aiming for the Q100H 36v 350w. Would you go for the 201rpm or the 260rpm? bearing in mind I'm heavy at 100kg, but Norfolk is fairly flat.

 

[Deleted member 4366]

You have to measure the inside diameter of the rim, which is virtually impossible when it's on a wheel. I always get the rim first, measure the I/D, add on 5mm for the ERD, calculate the spoke length, then order the motor and spokes.

 

[Deleted member 4366]

I forgot to mention: Don't use 12G spokes. They're too heavy for a 700C wheel and don't have any advantage. You'd be better going the other way to 14g, which you can usually find on Ebay for not too much. There's a German supplier who's quite reasonable:

http://www.ebay.co.uk/itm/40-Spokes-Niro-with-nipples-custom-made-silver-/231103012030?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item35ced01cbe

 

[eHomer]

I've measured the wheel rim carefully, and the absolute outside diameter is 635mm. (they take 700c tyres but there's no markings on them).

The spoke holes are recessed, so I measured down into them from the outer rim with a vernier gauge, that gave me 23mm.

So my reading of the Sheldon page gives me a rim spoking diameter of 589mm (635 - (2 x 23mm))

I've checked the BMS site and I can't find a spoking diameter for their Q100H front hub, or the width offsets for dishing ?

I hear what you say about spoke gauge, and I looked at the German Ebay site but the BMS stainless spokes are $8 for 40, whereas the German ones are £16.51 with postage ?

I measured the original spoke gauge, and they are 2mm diameter, with 4mm diameter nipples.

 

[Deleted member 4366]

I have a BMS 700c rim, that had a Q100 in it., which I disassembled.
The outside diameter is 633mm - measured in two directions. The depth from the edge of the rim to the inside of the spoke hole is 19mm. You have to ass about 2mm to allow for the thickness of the head of the nipple, so the ERD is 633 - 2x19 + 2x2 = 599

I put that ERD into the spoke calculator using 108mm flange dia. and 21mm from the centre to each flange:

http://leonard.io/edd/

That shows the spoke length for 2-cross is 260.1mm. The spokes that I took out of it, which were the ones BMSB built it with are 260mm

If I use your ERD of 589mm, it gives 255mm, which isn't in the BMSB list, so you have to get them from the German guy.

 

[eHomer]

Thanks Dave.
I'll place the order.

 

[eHomer]

As an update on this project, I can now confirm that once again, Dave's advice was bang on the money, (if only I'd followed it to the letter !)

As my other thread about BMS spoke ends has said, I tried using the 13g spokes from them, rather than buying the 14g as advised.

My excuse is that the BMS spokes were so cheap, ($8 for 40) that I thought I'd give them a go, as it would be no great loss if they didn't work out.

They were very tight in the Q100 hub flange, even though they're the thinnest supplied by BMS and recommended by them for that hub. Also, at 260mm long, they were about 5mm longer than the spoke calculator result for a 2 cross build on my 700c rims, but I thought the recessed spoke holes would give me a bit more leeway there, not poking up into the inner tube through the rim tape.

I was delighted to find a photo on endless sphere posted by Amigafan2003 a year ago, clearly showing a two cross spoking pattern of a Q100 in a 700c rim, ( a Godsend !)

http://endless-sphere.com/forums/viewtopic.php?f=2&t=44592

I managed to build the wheel ok with them, but as Dave said, it was difficult and hard to true up. The spokes were so tight in the hub holes that they didn't swivel freely when setting the twist.

I finally gave up on them, and ordered some 256mm 14g stainless spokes from a UK ebay seller, at £12.95 for 36, delivered. They came the next day, and they'd actually supplied 2 extra as spares, plus 5 extra nipples, great service.

http://www.ebay.co.uk/itm/111217126025?_trksid=p2060778.m2749.l2649&var=410238674668&ssPageName=STRK:MEBIDX:IT

This time the wheel build was very satisfying, taking shape easily, following Sheldon's wheel building guide. I've now trued it up in my truing stand, and got it within a mm, side to side and up and down.

Dave shamed me into finally attempting these wheel builds from scratch, and I must say I wish I'd tried it before ! The only tricky part is the need for great accuracy in spoke length, that 4mm difference made it much easier too.

I'll finish truing it tomorrow and try the Q100 on it's maiden voyage on my alubike, and post some photos.

 

[eHomer]

I've been for a 22 mile ride with the Q100H now, so I'll put the results in a new thread.