So no go without the proper brake plate and shoes. Needless to say the rear was fine, the front drum is 5.5 Sherpa is 4.9 dia. We had were the older Akront rims and we liked these. Some years ago when building his M49, got a good deal on a set of Alpina wheels as the ones

That said Feetups comment rang a bell, so went to the shop to check on a slip up my son and I pulled Rear wheel to get proper 199's rear brake. Hencam, I believe you and I had a discussion some time ago regarding using a 138 Alpina I have a couple of spare front Alpina wheels and brake plates I would be willing to sell if someone wants to make this change, but I am Australia so postage to overseas would not be cheap Edited Apby andy

There is a slight weight penalty with the bigger brake drum. I can arrange a photo showing this if you like. It is hard to tell the difference visually unless both wheels are close together. The similar appearance is why I suggested it. The Alpina/Frontera/Pursang front hub does look very similar to a Sherpa T front hub, but it has a larger diameter brake drum. I like my bultaco as original as possible, but not at the expense of it working as best as possible. from your suggestion I am wondering if I have missed something as I am fairly certain my Pursang has a Frontera front wheel but cannot see any difference! The best i have my sherpa is relined hub, by shrinking cast steel liner into it, bushing the brake pivot cam hole in the plate, having original FORMA shoes relined and then machining them back to the required diameter of 125.00mm. always after other peoples useful comments and experiences. I am interested in your comment for other reasons, can you tell me please why the Alpina or Frontera front brake is better than the Sherpa? I though they were the same diameter, same shoes and same brake plate etc.

Bultaco pursang 48