Anyone fitted Barbacks to BCR-how long cables?

[stivesvelo]

Just bought some barbacks (Moto CNC) for my Boxercup & find the throttle & choke cables are now too short.

Looked at all the regular suppliers on the web & no longer ones are listed, Spoke with Motorworks they have standard upper cables at 570mm & are looking to see if they can get longer ones (BMW fiche shows 600mm for high bars).

Has anyone fitted these because my bars are different to the ones shown in images of bar backs fitted to bikes in that mine have the lug to anchor them to underside of the top yoke & the ones in the images don't, which means that I can fit them with the bar backs behind the yokes or in front of them, but not much in any intermediate positions.

I'm wondering if an extra 30 mm will be enough as I guess the high bar ones are just for above the top yoke, also anyone know of a supplier?

Thanks
Rob

[big rob]

Hi, the part number for the throttle cable you need is 32 73 7 692 488. (You may also need adapter kit as shown in the link).
Google the Cable Part Number, it is available from American supplier & hopefully available in UK too.
Good luck.
http://largiader.com/articles/throttle_kit/

[SP250]

Common problem for a bars above the yoke and also barbacks when fitted. I just went to my local hydraulic hose company (Friction hydraulics in Telford) and they made me up some Stainless braid covered lines a couple of inches longer for the brakes. Throttle and choke were ok. Venhill do custom bowden cables and are excellent - just order some a bit longer than standard.

[stivesvelo]

Thanks for the replies,

I had previously raised the bars above the yokes & replaced the brake hoses a few years ago (HEL I think) & managed without changing the cables, but got it into my head the other day that the 'bar backs' would give me more comfort in my old age (72) & ordered them.

Couldn't find any available cables so ordered choke & throttle uppers from BMW today (about 11 days for them to come from Germany), whilst I wait I thought I'd have a look for instructions in the manual & online & get the impression they're a bit of a pain to change.

Being short in the leg I'm beginning to notice the weight especially on loose surfaces doing a tap dance on my tip toes & am pondering the idea of changing the fork lowers from the longer BCR ones to a pair of standard and shorter ones as I like the bike & want to enjoy it for a bit longer if I can & hope this may get my feet closer to the ground - I have Ohlins front and rear & currently have the back adjusted to the top of it's range (steers very nicely) but am thinking with lower forks I can reduce rear ride height to match & have the same ride but closer to the ground, maybe less cylinders head ground clearance but is the standard height a problem?

Am I dreaming or is it a good idea?
Rob

[SP250]

You can also check to see if you have the standard (long) or GS (short) paralever arm, as that makes and inch or so of extra ride height on the rear with the short one.

John M

[stivesvelo]

I have the short paralever arm, but if I used the longer one to reduce the rear height wouldn't it just rake out the front & slow the steering?

When I bought the bike it had Ohlins fitted & steered like a barge so while giving the bike a good service took the shocks to a suspension specialist (in Stowemarket I think) & it turned out that the rear shock had been modified to be much lower, it was service & returned to 'normal', set up according to Ohlins instructions and & steering was great with small adjustments to the preload being really effective.

If I lower the rear suspension wouldn't an equal adjustment at the front be needed to keep steering etc as before ? (minor adjustments apart). I can adjust the spring preload on the front but don't think by very much.

Rob

[SP250]

Yes
The short (GS) paralever arm raises the rear ride height and quickens the steering, the longer arm lowers the rear with the opposite effect on the steering and is what the standard R1100S came with. With an Ohlins on the rear (and front) you should have a ride height adjuster on the shock which the standard shock doesn't have and you could lower both of those at front and rear. Bear in mind you will lose cylinder head clearance when cornering, but on the road it is probably irrelevant - unless you ride like you're on a qualifyer & slicks all the time. For touring it'll be ok. The other thing to look at is if you have a steering damper fitted - you can take it off as the bike doesn't need one (used to do track days and the Ring on mine) and that will help to "speed up" the the slow feel of the steering if you do re-set the geometry back to a standard bike.

[stivesvelo]

Ah well, managed to get a bit farther.. ordered longer cables and an adaptation to the throttle cable outlet at the handlebars (they call it a repair kit) & replaced the originals, had to come from the fatherland, all a success in the end.... but what a palaver fitting them!

Re-installed the 'Bar backs' & fiddled with cable routing, I hate to think what BMW charge for a change of cables as the 2 upper cables were over £100 & you need to take 1/2 the bike to bits, you also need about 10 different tools as there are few common fastenings, they should make the design office go into the workshop & do a bit of servicing, probably happened & why we now have ride by wire! If I can work out how to I'll post some photos to accompany the explanation.

It turns out that the new choke cable was identical to the old one (BMW only have that one on their system it seems) & initially was too tight using the original routing on full lock (it goes into the cable junction box which sits below the fuel tank behind & above the alternator entering on the right side & coming from around the headstock & the choke lever on the left).

At first I thought it wouldn't fit by routing above the tank mounting rubber bung as I don't like forcing things, but after repositioning a few cable ties and forcing the fuel tank mounting to go under the cable to push it over the top of the bung', it wasn't volunteering as the outer part of the cable at this end is a bent steel tube which goes through 90 degrees facing forward & is hard against the inside face of the fuel tank & isn't a natural fit, I'm thinking of knocking a dent into the tank for a bit of clearance or seeing if it's possible to tighten up the bend in the cable a smidge as I had to force it under this part of the cable outer as it exits the cable distributor (if you've changed the cables you may know what I mean). No cable snags now & all running smoothly.

Whilst tank was off removed the front shock, gave it a clean & reduced the pre-load (noted on a piece of paper), removed rear shock, cleaned up & screwed in the foot as far as I could to compensate for reduced front & put it all back together, set up throttle balance etc. & went for a test ride, after stopping & adjusting bars & mirrors I've got to say it did feel a bit odd sat upright to start with but with no preload on the rear steering was good, I did some mixed country roads (20 miles or so) & was getting used to it need to do a few more miles to get dialled in as the front feels a little remote in comparison but looking over my shoulder at junctions is now easier.

As far as lowering the seat goes it is slightly lower but needs to be a bit more, steering is possible a little too lively (like it that way) so could reduce rear height a bit more (I have a slightly lower shock mount fitting) & adjust rear height from there with the hydraulic preload. Not a fan of the front forks on stilts of the BCR as I have short legs which are getting wobbly in my old age so will consider a set of standard front fork legs depending on how I get on.

Thought I was clever cleaning up the right bar & lubing twistgrip with PTFE spray so it's now too free & like a kangaroo, I think I'll clean it off & add some friction, mind you it adds another 10bhp!

Going to try adding some pics, but if I can't work it out will try again later.

Rob

aaah need to reduce the size, will be next week now.