About time for an update, had a busy Autumn. Ive still not managed to weigh the Rockhopper nor video any runs on it, but I will given time. I have taken it for two quick little outings and on both occasions had a bit of a 'moment' when Ive been carrying a little too much speed (getting carried away with using the engine downhill), either on gravel or in the woods, and was only just able to scrub off enough speed to keep it upright. Maybe the cantis were a bit inadequate after all.
So I had a bit of a think about how I could better enhance them. I was already running cartridge M70/R pads from the later M737 XT cantis, and had sourced some 2mm inners (it was originally built with regular 1.8mm inners), but it still wasn't adequate. I still wanted it to be period appropriate (if not correct), and obviously discs were not an option. The obvious choice would be to change to M737 V brakes, but I really didn't want to mix the M730/735 bits I have with anything obviously M737. M737 is a really nice group in its own right, but for this build I wanted to keep it a bit more 'clunky'. The only choice left was Magura really, or some of the really obscure American early v-brake-alikes. Retro Paul stuff is too pricey for this build, so the search for some good older HS33s was on. It didn't take too long, I recently picked up a set of what I think are '93 silver HS33s in good condition. I used to have HS33s on my trials bike in the late 90's so am familiar with them. 20 years has since passed and not knowing the history of these I'm now waiting for a service kit so I can bleed them before fitting. I remember them being awesome back in the day, it'll be interesting to see what I make of them now, compared to modern discs. In any case, I really hope they are better than the DX cantis.
Ive made a few other changes too. The LX chainset was functionally perfect, however didn't quite match the rest of the group. Ive now changed this for a must have M730 XT chainset to match the mechs and pedals. This is now on along with a perfect UN71 bb I found in the bottom of a parts box that I never knew I had.
Having said I don't like mixing different age groups too much, I made one final change that contradicts this. I already had an 11-28 XT M737 8 speed cassette fitted, but Ive now changed this for an 11-30 version instead. This now gives me a 24-30 or 22" bottom gear, which is going to be needed when pulling the trailer loaded up the hills where I live.
One other thing I did try was to convert an old STI shifter to make a thumb throttle for the motor. I picked up an XT SL-M770-10 to butcher. Being Dynasis with the larger pull ratio I thought it would have enough cable pull, but even this could only pull half the cable needed with a full lever throw. Back to the drawing board for this for now.
Moving on slightly from this project, but linked from the spare parts it has generated, I now had a complete M550 Deore LX groupset going spare. This really needed to be hung on something and made use of so I started hunting for another quick and cheap project. In working out what I wanted, I decided that it needed to be an early 90s steel mtb again, big clearances, relatively discreet, ugly paint, but sound so as to make a reliable if undesirable bike. Retrobike sorted me out by giving this shocker a new home (frameset only): Its a 91 Diamond Back Axis in tasty splatter paint. Ive never really been a DB fan, I always turned my nose up at them back in the 90s, for no real logic to be fair. This thing arrived and I spent a full evening cleaning the bits worth keeping. The frame really surprised me with how nice it actually is. The Axis was the top model in 91 and is made from True Temper OX tubing. The quality seems good, the clearances are enormous and to my surprise the fork is a quality Spinner unit. Once 20 years worth of grease, grime and crap decal residue was removed it was also in really good condition, with no dents and barely a scratch underneath. The bike originally came with M730 series XT so would be more than a good enough match for the '91 LX group I was intending to use. Of that group, the front mech was the wrong size, so I had to find a 31.8mm replacement.
The bike is currently half built. I still need to clean up the old chain, rear hub and headset. Everything else is ready to go. Ive a feeling it might be a bit long given the 19" frame and 130mm stem, I'll sus that out once built and ridden. I must admit to half wanting to build this into another drop bar mtb as I still have the 105 levers spare from the courier, only a stem, bar and shifters would be needed. This build so far has barely cost me anything and to be honest I want to keep it that way so it will stay budget and flat bar for the time being.
About time for an update, had a busy Autumn. Ive still not managed to weigh the Rockhopper nor video any runs on it, but I will given time. I have taken it for two quick little outings and on both occasions had a bit of a 'moment' when Ive been carrying a little too much speed (getting carried away with using the engine downhill), either on gravel or in the woods, and was only just able to scrub off enough speed to keep it upright. Maybe the cantis were a bit inadequate after all.
So I had a bit of a think about how I could better enhance them. I was already running cartridge M70/R pads from the later M737 XT cantis, and had sourced some 2mm inners (it was originally built with regular 1.8mm inners), but it still wasn't adequate. I still wanted it to be period appropriate (if not correct), and obviously discs were not an option. The obvious choice would be to change to M737 V brakes, but I really didn't want to mix the M730/735 bits I have with anything obviously M737. M737 is a really nice group in its own right, but for this build I wanted to keep it a bit more 'clunky'. The only choice left was Magura really, or some of the really obscure American early v-brake-alikes. Retro Paul stuff is too pricey for this build, so the search for some good older HS33s was on. It didn't take too long, I recently picked up a set of what I think are '93 silver HS33s in good condition. I used to have HS33s on my trials bike in the late 90's so am familiar with them. 20 years has since passed and not knowing the history of these I'm now waiting for a service kit so I can bleed them before fitting. I remember them being awesome back in the day, it'll be interesting to see what I make of them now, compared to modern discs. In any case, I really hope they are better than the DX cantis.
Ive made a few other changes too. The LX chainset was functionally perfect, however didn't quite match the rest of the group. Ive now changed this for a must have M730 XT chainset to match the mechs and pedals. This is now on along with a perfect UN71 bb I found in the bottom of a parts box that I never knew I had.
Having said I don't like mixing different age groups too much, I made one final change that contradicts this. I already had an 11-28 XT M737 8 speed cassette fitted, but Ive now changed this for an 11-30 version instead. This now gives me a 24-30 or 22" bottom gear, which is going to be needed when pulling the trailer loaded up the hills where I live.
One other thing I did try was to convert an old STI shifter to make a thumb throttle for the motor. I picked up an XT SL-M770-10 to butcher. Being Dynasis with the larger pull ratio I thought it would have enough cable pull, but even this could only pull half the cable needed with a full lever throw. Back to the drawing board for this for now.
Moving on slightly from this project, but linked from the spare parts it has generated, I now had a complete M550 Deore LX groupset going spare. This really needed to be hung on something and made use of so I started hunting for another quick and cheap project. In working out what I wanted, I decided that it needed to be an early 90s steel mtb again, big clearances, relatively discreet, ugly paint, but sound so as to make a reliable if undesirable bike. Retrobike sorted me out by giving this shocker a new home (frameset only): Its a 91 Diamond Back Axis in tasty splatter paint. Ive never really been a DB fan, I always turned my nose up at them back in the 90s, for no real logic to be fair. This thing arrived and I spent a full evening cleaning the bits worth keeping. The frame really surprised me with how nice it actually is. The Axis was the top model in 91 and is made from True Temper OX tubing. The quality seems good, the clearances are enormous and to my surprise the fork is a quality Spinner unit. Once 20 years worth of grease, grime and crap decal residue was removed it was also in really good condition, with no dents and barely a scratch underneath. The bike originally came with M730 series XT so would be more than a good enough match for the '91 LX group I was intending to use. Of that group, the front mech was the wrong size, so I had to find a 31.8mm replacement.
The bike is currently half built. I still need to clean up the old chain, rear hub and headset. Everything else is ready to go. Ive a feeling it might be a bit long given the 19" frame and 130mm stem, I'll sus that out once built and ridden. I must admit to half wanting to build this into another drop bar mtb as I still have the 105 levers spare from the courier, only a stem, bar and shifters would be needed. This build so far has barely cost me anything and to be honest I want to keep it that way so it will stay budget and flat bar for the time being.