Posted by: Blofeld
Hello and welcome!
I honestly didn’t look at the dimensions of your device closely enough to determine if it was net positive to RAD. My idea was that the cockpit size would be increased less than if you pinned the reach (and stem size) and added headtube length. I agree that headtube spacers are net positive for cockpit size, so I think we’re on the same page here.
As to your other point, I’ll note that custom bars can be commissioned for a more conventional look and user specific angles… Have you considered offering a high-rise, negative ESL corrected handlebar? Nice looking, US machined, 0 or 10mm or 20mm stems (that play nice mounted backward) might also find a niche.
Love the experimentation, best of luck!
Thank you!
I agree that running the RR stem increases the RAD less than if you pinned the reach and stem length as fixed parameters, and then added headtube length when making a frame, or even if you achieved the height with spacers on a traditional setup. I take it that is why you mentioned no additional wheelbase with the RR stem, due to the increased front center you would achieve with the longer headtube by in a sense extending the front end down and out from below the headtube instead of up and back from above it like running spacers would do.
I did consider achieving the position of the RR stem via a custom designed riser bar run with a traditional stem. There would still be the issue of that you would majorly change the geometry with different bar rolls, and you would be more reliant on a tight grip at the stem clamp to keep it from slipping forward or back on hard hits. I even considered doing a one piece bar stem unit similar to what Peter Verdone of PVD has done, but I didn't like how the grip angles would be fixed. That would be fine if I were making them just for me, but other people will have other preferences, and those preference may change in different conditions. I don't really want to do custom orders either. I even considered doing a custom bar stem combo that would have adjustable grips that were angled from the bar. I still may do something like that someday because if the angle was made in the grips, roll adjustments wouldn't really change ESL, and alternate angle grips could be made to allow differences in backsweep. The main issue I had with that idea was making sure the left and right grips were properly mirroring each other. Ultimately, I believe that getting the height and offset mostly from the stem and a traditional bar allows the most room for fine tuning your cockpit feel without majorly modifying the performance benefits that the RR stem achieves. You can fine tune height by running spacers above or below the steerer tube clamp, or playing with higher or lower rise bars, and you can make adjustments to bar roll for comfort without majorly moving your hands forward and back like you would with a bar that achieved this geometry alone.
Nice looking US machined 15mm offset stems that play nice with being mounted backward IS my niche! You can find them here!
Click here to see the BMB RR Stem!