Linked brakes and ABS

[Richard]

Hi

Having done nothing to the trike since last winter, apart from lots of riding  I have a growing urge to pull something apart soon .....

Issues: -
The traction control is a pain, it flashes up far to often when setting off in anything other than a straight line, this is because the ABS sensor is on one back wheel, and in a turn its either going a bit faster or slower than the front wheel.

The ABS on the front wheel is great, but the ABS on the back is a pain, again because only one wheel is being sensed. This nearly caught me out last week pulling into a parking space, because I was turning right the right wheel was turning slower than the front so the system reduced the effort to the back wheels to nothing, causing me to have to quickly grab the front brake.

The linked brakes are a pain, despite my previous modifications to the back brakes I am still not 100% happy with them.

Solutions: -
Make a new sensor ring for the ABS and mount it on the front of the differential, this way it will average out both back wheels. Will need to do a load of maths to work out how many slots to cut in the disk, allowing for the size of the back wheels and the differential ratio.

Remove the ABS from the back brakes - make up a new pipe linking the master cylinder directly to the back brakes, but what do I do with the ABS pump?
I assume front and rear circuits are isolated from each other in the pump, so I can leave the front as it is, but what do I do with the original rear feed and output, blank them both off, link together ?

Your thoughts please

Richard

[Martin#30]

Richard,

New sensor ring sounds like a much easier, and much better solution. Like you say though, the maths might be a bit hit and miss to get the right number of pulses in the new ring once a the differential ratio has been taken into account.

How about a second sensor ring and sensor on the other rear wheel, feed them both into a homemade box that averages the two signals and trasmits the end result to the ECU? Might be an even easier solution, plus that way, if one of the rear wheels did lock up, the ABS would still see a drop in 'averaged' pulse frequency and release the rear brake pressure to get the wheel spinning again.

Martin.

[Richard]

Hi Martin

An interesting idea, I will do some reading and see what I can find out.#
I wonder if there is a way of increasing the pressure at which the linked brakes starts bringing the front brake in when you are using the back

Richard

[jonathan]

I think that just bypassing the ABS for the rear and blanking the ports would be the best method. This has been done on a couple of bikes in the US whose owners were less than happy with the linked brakes.

[shaggs147]

Sounds like a bit of a headache. PX it for a can am spyder maybe?

[SirToU]

what rim size have you got on the back - if its 17" it will be the same surely......  can't you just buy a new ring and modify it or copy it. 

you could also compare the front ring with the rear and see of their the same size.   The only problem I see you having is whether you can mount the sensor in the correct position.

just a thought.

Neil

[100milesaway]

Only ever had 2 bikes with linked brakes, the GTR being one of them, and I disliked them both. Nothing compares to a bike with individually operated brakes.

[Richard]

I think that just bypassing the ABS for the rear and blanking the ports would be the best method. This has been done on a couple of bikes in the US whose owners were less than happy with the linked brakes.

Hi Jonathan

That's great, is there any info on this anywhere?

Sounds like a bit of a headache. PX it for a can am spyder maybe?

LOL no I will stick to this, and sort out the small issues

what rim size have you got on the back - if its 17" it will be the same surely......  can't you just buy a new ring and modify it or copy it. 

you could also compare the front ring with the rear and see of their the same size.   The only problem I see you having is whether you can mount the sensor in the correct position.

just a thought.

Neil

The back rims are 18", but low profile tyre brings the rolling size down to close to the original, its all fine in a straight line, but when turning sharp at low speeds it gets confused.

[tomp]

Never seen a 1400 trike in the US.  Harleys and Wings, over here.  If it was mine, I would do away with the linked brakes and the ABS both.  Since one steers a trike instead of counter steering it, applying the rear brake on a linked system could create a stopping/steering problem for the front end.  Since the rear brakes are normally weaker than the fronts, if it is still basicallya a modded two wheel bike, seems ABS would confuse the stopping procedure for the pilot, unless the front and rear are both acting the same when emergency braking.  My 08 has neither, and I am glad for that.  Have had linked on three BMW's and wished I hadn't on each. 

[shaggs147]

I don't think you could put an extra sensor and ring on the rear end as it would probably confuse the system with the extra input. If you aren't bothered about the abs then how about this - if the bike doesn't like having the abs disconnected completely then how about wiring the rear sensor to the front of the bike and have both sensors reading on the same ring. You'll never get a different speed reading then.

[O.C.]

Never seen a 1400 trike in the US.  Harleys and Wings, over here.  If it was mine, I would do away with the linked brakes and the ABS both.  Since one steers a trike instead of counter steering it, applying the rear brake on a linked system could create a stopping/steering problem for the front end.  Since the rear brakes are normally weaker than the fronts, if it is still basicallya a modded two wheel bike, seems ABS would confuse the stopping procedure for the pilot, unless the front and rear are both acting the same when emergency braking.  My 08 has neither, and I am glad for that.  Have had linked on three BMW's and wished I hadn't on each.

Agreed +1   

[Richard]

Never seen a 1400 trike in the US.  Harleys and Wings, over here.  If it was mine, I would do away with the linked brakes and the ABS both.  Since one steers a trike instead of counter steering it, applying the rear brake on a linked system could create a stopping/steering problem for the front end.  Since the rear brakes are normally weaker than the fronts, if it is still basicallya a modded two wheel bike, seems ABS would confuse the stopping procedure for the pilot, unless the front and rear are both acting the same when emergency braking.  My 08 has neither, and I am glad for that.  Have had linked on three BMW's and wished I hadn't on each.

Yep, the only part I would like to keep is the front ABS, it does work well.

I don't think you could put an extra sensor and ring on the rear end as it would probably confuse the system with the extra input. If you aren't bothered about the abs then how about this - if the bike doesn't like having the abs disconnected completely then how about wiring the rear sensor to the front of the bike and have both sensors reading on the same ring. You'll never get a different speed reading then.

Good idea, if I do end up losing it all

[jonathan]

This should get you started:

http://forum.cog-online.org/index.php/topic,42442.msg264690.html#msg264690
http://www.zggtr.org/index.php?topic=13110.0