Forum

[stinkwheel]

I've currently got a disc conversion for my bullet but it's somewhat unorthadox (no idea what the hub is off, possibly a moto-guzzi, and a BMW brembo calliper). I see second hand electra or EFI model front wheels come up periodically and I'm wondering if anyone knows if they'd fit or can be easily made to fit in classic forks?



I presume I'd need to fit a "fixed" spindle from a classic model to allow it to be clamped into the forks but I was wondering if the centre spacing of the bearings on the spindle and the hub spacing between the fork legs works out or can be made to fit?



I suppose the only real sin would be if the hub + speedo drive + nuts landed up too wide to fit between the forks. I have a mate who is a dab hand with a lathe and could almost certainly sort out a custom spindle if necessary.

[Adrian]

Our hosts have a conversion kit for classic Bullet drum brake forks using the RE India (pre Euro 4 bike) disk brake front wheel, but the fork sliders have been slated by some as not to the job for the extra stresses involved and hence a bit of a safety issue, though yours seems to have survived being fitted with a Brembo.



If you want an all-RE bolt-on option you can either use the complete forks, wheel and axle off an Electra-X or Electra-EFI, or if you don't like the centrally fitted front mudguard and want some trad mudguard stays you can use a set of early (pre-2012) C5 EFI forks, these still have the leading axle as well as external threads on the fork stanchion tops and will screw straight into older Indian or even Redditch casquettes or the alloy top yokes. The C5 forks use a similar Q/D spindle to the Electra-X, though it's a little bit longer to suit the chunkier fork sliders. Electra-X and Electra-EFI front wheels were 19", early C5 front wheels were only 18", but they went back to 19" after a couple of years. 2017-on Euro 4 front ends are ABS and probably not suitable.



You might of course fit an RE front disk set-up only to find that the Brembo was better...



A.

[stinkwheel]

Thanks for the reply. Main thing is that I'm probably going to build new rims on at some point (not now, but in the future) so it would make sense to do it on a hub I know I can get a disc for. I suppose if the RE calliper is less effective than the brembo one, there is no reason I can't just continue using the brembo (which is common and I can get parts for), would just need to fabricate a brake plate withthe correct stand-off.



I've looked at the various comments on the fork leg strength but from an engineering point of view, all the lugs do is hold the brake in position, all the braking force is transmitted through the fork leg with the lug material in compression. I can't see how it would be an issue. With the drums, all the brake torque is transmitted through a small alloy block on the side of the casting of one fork leg anyway.

[stinkwheel]

Looking at the part numbers. I'd just need the fork sliders off an early electra. The stanchions and damper rod internals are the same as the bullet ones.

[John R]

I have an iron barrel 350 which started life with an SLS drum, soon acquired a TLS which worked well but needed a lot of adjusting, but I have had our hosts disc conversion for a few years. Nothing has cracked, nothing has twisted, confounding the predictions of some on this board.