Wheel, Rotor, Caliper suggestions

[wolfram]

Hi,

I'm looking to build a custom front end on R80GS forks. looking for dual disk brembo single pot calipers and a 19" wire wheel.

I dont think there is a stock wheel - I've spent most of the day looking through microfiches on the motorworks website. The nearest i have come to is an 18" wire wheel on the R80R Mystic.

Would I be able to buy a 21" spoke wheel hub and get the 19" rim I already have (from the R80/7) laced in?

If I did that, which rotors would work? I can see there are single disk rotors that work with that hub, like the Serie Oro upgrade, but not sure if there are dual rotos that will work.

 

[Stirlingmoz]

Wouldn’t an R80ST front wheel suit your requirements ?

They are 19” and I think are plug and play in G/S fork legs.

They can take twin discs too

Pardon our interruption...

 

[wolfram]

Ah, that’s an idea. The motor works website did not offer that as a possibility. Maybe the spindle size was not compatible?

 

[Gelandestrasse]

I believe you can also use a 1981-84 RT spoke hub (2-rib) to do the same. Can be difficult to find, though.

 

[scooter paul]

Wouldn’t an R80ST front wheel suit your requirements ?

They are 19” and I think are plug and play in G/S fork legs.

They can take twin discs too

Pardon our interruption...

The R80 ST wheel fits the ST ( obviously) and the G/S forks but if you use R80/R100 GS forks you need a custom axle and spacers.

 

[Bubb]

Wolfram.
You could use ST forks, and wheel. ( or g/s forks )
Then use either one ST brake disk, or two….. as the forks have holders for two.

If you want to go this route, give me a shout as I have the forks, wheel and one disk sitting in my garage…..
Also have bottom yoke……so nearly all you need!

 

[wolfram]

Wolfram.
You could use ST forks, and wheel. ( or g/s forks )
Then use either one ST brake disk, or two….. as the forks have holders for two.

If you want to go this route, give me a shout as I have the forks, wheel and one disk sitting in my garage…..
Also have bottom yoke……so nearly all you need!

I have already purchased the later r80GS forks, as I thought they were stronger. I hadn't done my homework really! How are the spokes arranged on the ST wheel? are they centre stud or outer stud tubeless? I want to keep my early rear wheel and that is centre stud, so want the look to be the same.

I think my options are 1) stick with my forks and find a R80R, R100R, Mystic front hub, or 2) find a R80GS, R100GS hub or c) go with your ST forks, ST wheel.

If the spokes are outer stud though, id still be relacing the ST hub

its complicated isn't it! a good argument for keeping stuff stock!

 

[Bubb]

At wheels are centre of rim spokes.
You could retain the later para lever forks, use a st wheel but you need a bespoke axel and spacers making up…., details available on this very site from scooter Paul.
R100 mystic etc are spiked to outside of rim and cannot be centre spoked due to offset of holes I believe.
Best bet is a st wheel and new bespoke axel or a r100 two rib wheel hub and 19 rim… but as earlier said these are hard to find….. I believe police bikes had them with twin disks.
St wheel will accept twin disks…

 

[Gelandestrasse]

I thought we were talking about R80G/S forks on my last contribution here. If it is later R80GS then twin disc is an issue as there are only lugs for a caliper on one slider (RHS). So I am (easily) confused as to the OP's needs here.

 

[wolfram]

Hi, I've got one right hand lower fork leg - If I can understand what hub would work, my plan was to buy another and turn one around and get it machined.

Different bike and forks I know, but this builder claims to have used an R80R hub with a larger spindle and the spokes are centred on the rim. Probably more machining required! https://www.bikeexif.com/bmw-r80st-restomod-renard

Can a 21" R80GS hub take two rotors? There are more likely to be sourced than the specific R80R hub I guess as there were not many of them made by all accounts.

I'm fast re-evaluating this plan and the ST forks, hub, rotor and wheel might be the more sensible plan. I'm off to a few auto-jumbles in the next few weeks., I'll be at the Scottish motorbike show on 8th March and Stafford classic show in April. Hopefully the right set of parts can be brought together somehow!

 

[Stirlingmoz]

I don’t want to influence the route you eventually decide to take, but I do have a bare R100R / R80R front hub in the garage.

I wanted the 18” rim for another bike and have the hub left over.

They can take twin discs.

Can take photographs if you are interested.

 

[wolfram]

I don’t want to influence the route you eventually decide to take, but I do have a bare R100R / R80R front hub in the garage.

I wanted the 18” rim for another bike and have the hub left over.

They can take twin discs.

Can take photographs if you are interested.

Yes please that may be just the ticket

 

[Stirlingmoz]

Yes please that may be just the ticket

I have just followed the link in your earlier thread to that rather nice ST custom.

I’m confident the forks (and likely the yokes) on that bike are from an 85 on Monolever. The caliper location, fork brace and axle style being the giveaway.

The hub I have will fit Monolever forks using the stock axle and spacers.

I’ll take some photographs

 

[Stirlingmoz]

Just to prove the concept, here’s an R100R front wheel in Monolever forks using stock axle and spacers. The discs are R100R.

Note the forks are reversed to place the calipers behind them

 

[Stirlingmoz]

A bare R100R front wheel hub

 

[Bubb]

Pete
Think the OP does not want the cross spoked wheel rims…. So don’t think the hub can be laced to centre of the rim …
I could be wrong tho as I don’t really know what the OP is trying to build.
Still think a straight ST front end is his best bet if it’s for a road only machine…cafe racer type thing.

 

[Stirlingmoz]

Pete
Think the OP does not want the cross spoked wheel rims…. So don’t think the hub can be laced to centre of the rim …
I could be wrong tho as I don’t really know what the OP is trying to build.
Still think a straight ST front end is his best bet if it’s for a road only machine…cafe racer type thing.

I think the ST parts you have are plug and play and would match the rear wheel.

Still able to upgrade to twin discs too.

Need to catch up to grab those rocker covers.

I’m getting close to needing them

 

[Bubb]

I will dig them out and we can arrange a time/place to hand over….

 

[sidkn33]

Hi,

I'm looking to build a custom front end on R80GS forks. looking for dual disk brembo single pot calipers and a 19" wire wheel.

I dont think there is a stock wheel - I've spent most of the day looking through microfiches on the motorworks website. The nearest i have come to is an 18" wire wheel on the R80R Mystic.

Would I be able to buy a 21" spoke wheel hub and get the 19" rim I already have (from the R80/7) laced in?

If I did that, which rotors would work? I can see there are single disk rotors that work with that hub, like the Serie Oro upgrade, but not sure if there are dual rotos that will work.

If you can stomach upgraded braking but only single disc, I followed ScooterPaul's guide and had a custom axle and spacers made, along with an R1150 4 pot caliper and custom disc with GS forks, on my ST, using the original 19" wheel.
I have a 21" GS front wheel with GS disc which swaps in using the GS axle, but I wanted to keep the ST looking "right" with matching wheels, hence the custom axle and disc.

GS forks are a big improvement over ST and/or G/S and worth the effort.

 

[Bubb]

So far we know the OP has bought some forks, but we don’t know what he is trying to build…
Is it a cafe racer ( when Paralever GS forks will be too long)
Is it a street scrambler ( paralever GS forks will be fine)
Is it a desert racer ….at which point I would say he would be better with newer KTM (or similar) forks.
A “brat style” bike would be better with standard length RT /RS/ etc forks…..

We need more info before we can give a definite plan of action to assist the OP in his quest