As title says I have just fitted cast wheels to my new (to me) R1150 GSA and thought it may be of interest to others for me to jot down my views on the bike following the conversion. I won’t document how the conversion is done because it is very simple and there is an excellent guide from gabriel gs here:
http://www.ukgser.com/forums/showthread.php?t=258055&highlight=cast+wheels.
So, My GSA was completely standard and running on Tourances when I got it. I loved the way it rode and handled but a set of cast wheels came my way cheaply enough for me to have a go with them and I bunged them on last night.
The wheels came with a Pirelli Diablo on the front and a Bridgestone 020 on the rear both with plenty of tread on.
FIRST IMPRESSIONS:
AWFUL!
From the moment I pulled off my drive it just felt wrong! It had a worrying tendency to “fall” into slow speed turns and required considerable effort on the bars to stop over steering at low speed. It felt skittish and unstable and as I pulled onto the dual carriageway close to my home it felt very light and” floaty” at the front (and no I was not on the back wheel at the time!). A couple of bar wiggling experiments showed the high speed stability was ok but didn’t inspire confidence and I am sure a bump on a slight bend could induce a tankslapper!
As I got onto some good A and B roads it started to make some sense as it seemed to steer more quickly and track its line well but still did not inspire a huge amount of confidence as it remained very skittish and twitchy and seemed to want to fall further into the bend than I was imputting. Basically it had lost all of the surefootedness that we know and love from the GS in order to gain slightly quicker steering.
Not overly happy I began thinking that I may try a different front tyre (I happen to have an old Ducati which runs the Pirellis so the old tyre could be saved as a spare for that) to see if it was a rubber issue and then had another idea…….
After pulling over and winding the rear preload down to standard (I did have it almost all of the way up to high) I continued on the ride and…..
WOW!
What a difference! The quicker steering was still there but all of the twitchy, skitty horribleness had gone! It turns beautifully, tracks lines perfectly and changes direction like its on rails! It was getting late and dark so I didn’t push too hard but I am sure the lean angles possible will be fantastic. If I hadn’t experienced it myself I would never have believed that a few (dozen) turns on a preload adjuster could make such a transformation to a bike.
My assumption is that the smaller front wheel combined with a jacked up rear end had combined to generate geometry that simply didn’t work and by backing of the rear the setup has returned to “proper” geometry?
I am well pleased with the results and will post an update once I have put some more miles on the new wheels. I am doing a 400mile day fully loaded later in the week so it will be interesting to see how the extra weight on the rear affects the new setup.
If anyone has any questions about how the bike rides on cast wheels feel free to ask and I will try and answer specifics.
Hope this is of use/interest to someone?
http://www.ukgser.com/forums/showthread.php?t=258055&highlight=cast+wheels.
So, My GSA was completely standard and running on Tourances when I got it. I loved the way it rode and handled but a set of cast wheels came my way cheaply enough for me to have a go with them and I bunged them on last night.
The wheels came with a Pirelli Diablo on the front and a Bridgestone 020 on the rear both with plenty of tread on.
FIRST IMPRESSIONS:
AWFUL!
From the moment I pulled off my drive it just felt wrong! It had a worrying tendency to “fall” into slow speed turns and required considerable effort on the bars to stop over steering at low speed. It felt skittish and unstable and as I pulled onto the dual carriageway close to my home it felt very light and” floaty” at the front (and no I was not on the back wheel at the time!). A couple of bar wiggling experiments showed the high speed stability was ok but didn’t inspire confidence and I am sure a bump on a slight bend could induce a tankslapper!
As I got onto some good A and B roads it started to make some sense as it seemed to steer more quickly and track its line well but still did not inspire a huge amount of confidence as it remained very skittish and twitchy and seemed to want to fall further into the bend than I was imputting. Basically it had lost all of the surefootedness that we know and love from the GS in order to gain slightly quicker steering.
Not overly happy I began thinking that I may try a different front tyre (I happen to have an old Ducati which runs the Pirellis so the old tyre could be saved as a spare for that) to see if it was a rubber issue and then had another idea…….
After pulling over and winding the rear preload down to standard (I did have it almost all of the way up to high) I continued on the ride and…..
WOW!
What a difference! The quicker steering was still there but all of the twitchy, skitty horribleness had gone! It turns beautifully, tracks lines perfectly and changes direction like its on rails! It was getting late and dark so I didn’t push too hard but I am sure the lean angles possible will be fantastic. If I hadn’t experienced it myself I would never have believed that a few (dozen) turns on a preload adjuster could make such a transformation to a bike.
My assumption is that the smaller front wheel combined with a jacked up rear end had combined to generate geometry that simply didn’t work and by backing of the rear the setup has returned to “proper” geometry?
I am well pleased with the results and will post an update once I have put some more miles on the new wheels. I am doing a 400mile day fully loaded later in the week so it will be interesting to see how the extra weight on the rear affects the new setup.
If anyone has any questions about how the bike rides on cast wheels feel free to ask and I will try and answer specifics.
Hope this is of use/interest to someone?
