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-   -   Boma F-1 Build & Help. (http://www.bikeforums.net/folding-bikes/935797-boma-f-1-build-help.html)

ziqpy 02-26-14 08:47 AM

Boma F-1 Build & Help.
 
My frame arrived on Monday chaps, and I'm making up a list of what is going to go on it. And hopefully get some pics as it goes, and also some input on a few bits I don't know about.
  • Boma F-1 Frame
  • SRAM Rival Groupset;
    minus brakes.
    53/39t 172.5mm crank
    11-26 cassette
  • Velocity Cliffhanger 32h Black NMSW Rims 406/28mm
  • Schwalbe Marathon Plus 1.35"
  • TRP Spyre Calipers
  • Ergonomic Drop bars
  • Hubs?

Ain't decided on seat or headset reach yet till rest done.

Main problem I'm having is with rotor size and hub choice. 100mm spacing front and told i can run 130/135 on rear.

Is rotor alignment standard on disc brakes for bicyles and unsure about what hubs to buy, as there bearing vs cup and cone?

Also how does the gearing I chosen and the crank length work out? DO have hills here and would goto Wales and other hilly areas to enjoy the countryside.

Appreciated chaps,
Damien

mconlonx 02-26-14 12:21 PM

Since this looks like a road bike build, you could go with either 140 or 160mm disks, 160 being more common and perhaps cheaper. The TRP Spyre brakes don't already come with rotors? If they come with adapters, see what size rotor they will accommodate and go from there. Personally, I'd opt for 160s.

You'll have way more choice with 135mm OLD hubs. Get 6-bolt standard hubs, not "centerlock." Rotor alignment should be standard, but I am not familiar with Boma and 130/135 convertible(?) rear introduces complication to the point that I wouldn't say for sure. Cup and cone can be sealed bearings, but they are adjustable; cartridge bearings are good or not, are replaceable. I'd not base hub choice on bearing type -- they both work.

I can't advise about gearing without having something to compare it to -- what's gearing on one of your normal size bikes which you like? Otherwise, even with the smaller wheels, I'd be tempted to go with a compact crank, 50/34 or a 11-32 cass. Maybe both. But only because I prefer lower gearing.

Good luck!

ziqpy 02-26-14 01:48 PM

I'm using a tape measure but getting aroudn 132mm on rear.

The forks have a pressed section to clear discs, and around 95mm from center.

I going with 53/39 because of the smaller wheels.

Last bike i was a specialized rockhopper.

2000 ish model

something like this ish...

http://i1095.photobucket.com/albums/...6032011095.jpg

Used to go everywhere around 16mph and deff without tail wind got 30mph outta the bugger on the flat. Fastest was 47 going downhill filtering (which you should not do at that speed)

dynaryder 02-26-14 05:41 PM

Quote:

Originally Posted by mconlonx (Post 16529350)
but I am not familiar with Boma and 130/135 convertible(?) rear

Quote:

Originally Posted by ziqpy (Post 16529705)
I'm using a tape measure but getting aroudn 132mm on rear.

Probably 132.5mm:
http://forums.roadbikereview.com/cyc...ng-265455.html

Allows 130 road or 135 MTB. Either will work,but you'll find 135 is more common so you'll have more choices.

For gearing,plug the numbers for your old bike into Sheldon's calculator,then compare to your new build. 39/26 with 20" wheels is fairly low,so you prolly won't have issues. You could always go with an 11-28 cassette if you need to get lower.

ziqpy 02-26-14 08:56 PM

Quote:

Originally Posted by dynaryder;16530371for gearing,plug the numbers for your old bike into [url="http://sheldonbrown.com/gears/"
sheldon's calculator[/url],then compare to your new build. 53/26 with 20" wheels is fairly low,so you prolly won't have issues. You could always go with an 11-28 cassette if you need to get lower.

mph @ 40 rpm


[TABLE="width: 517"]
[TR]
[TD="class: Xl65, width: 47"]11-28[/TD]
[TD="class: Xl66, width: 47"]53[/TD]
[TD="class: Xl67, width: 47"]35.90%[/TD]
[TD="class: Xl66, width: 47"]39[/TD]
[TD="width: 47"][/TD]
[TD="class: Xl65, width: 47"]11-34[/TD]
[TD="class: Xl66, width: 47"]44[/TD]
[TD="class: Xl67, width: 47"]37.50%[/TD]
[TD="class: Xl66, width: 47"]32[/TD]
[TD="class: Xl67, width: 47"]45.50%[/TD]
[TD="class: Xl66, width: 47"]22[/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]11[/TD]
[TD="class: Xl68, width: 47"]10.6[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]7.8[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]11[/TD]
[TD="class: Xl68, width: 47"]13.2[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]9.6[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]6.6[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]9.10%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]18.20%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]12[/TD]
[TD="class: Xl68, width: 47"]9.7[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]7.1[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]13[/TD]
[TD="class: Xl68, width: 47"]11.1[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]8.1[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]5.6[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]8.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]15.40%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]13[/TD]
[TD="class: Xl68, width: 47"]8.9[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]6.6[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]15[/TD]
[TD="class: Xl68, width: 47"]9.6[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]7[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]4.8[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]7.70%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]13.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]14[/TD]
[TD="class: Xl68, width: 47"]8.3[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]6.1[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]17[/TD]
[TD="class: Xl68, width: 47"]8.5[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]6.2[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]4.3[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]7.10%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]17.60%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]15[/TD]
[TD="class: Xl68, width: 47"]7.7[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]5.7[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]20[/TD]
[TD="class: Xl68, width: 47"]7.2[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]5.3[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]3.6[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]13.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]15.00%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]17[/TD]
[TD="class: Xl68, width: 47"]6.8[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]5[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]23[/TD]
[TD="class: Xl68, width: 47"]6.3[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]4.6[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]3.1[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]11.80%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]13.00%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]19[/TD]
[TD="class: Xl68, width: 47"]6.1[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]4.5[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]26[/TD]
[TD="class: Xl68, width: 47"]5.6[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]4[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]2.8[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]10.50%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]15.40%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]21[/TD]
[TD="class: Xl68, width: 47"]5.5[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]4.1[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]30[/TD]
[TD="class: Xl68, width: 47"]4.8[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]3.5[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]2.4[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]9.50%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD="class: Xl67, width: 47"]13.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]23[/TD]
[TD="class: Xl68, width: 47"]5.1[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]3.7[/TD]
[TD][/TD]
[TD="class: Xl66, width: 47"]34[/TD]
[TD="class: Xl68, width: 47"]4.3[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]3.1[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]2.1[/TD]
[/TR]
[TR]
[TD="class: Xl67, width: 47"]13.00%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: Xl70"][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD="class: Xl66, width: 47"]26[/TD]
[TD="class: Xl68, width: 47"]4.5[/TD]
[TD="class: Xl69, width: 47"][/TD]
[TD="class: Xl68, width: 47"]3.3[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[/TABLE]

[TABLE="width: 188"]
[TR]
[TD="class: xl66, width: 47"]11-32

15.80%[/TD]
[TD="width: 47"][/TD]
[TD="width: 47"][/TD]
[TD="class: xl69, width: 47"][/TD]
[/TR]
[TR]
[TD="class: xl65, width: 47"]22[/TD]
[TD="class: xl67, width: 47"]5.3[/TD]
[TD="class: xl68, width: 47"][/TD]
[TD="class: xl67, width: 47"]3.9[/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]13.60%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl69"][/TD]
[/TR]
[TR]
[TD="class: xl65, width: 47"]25[/TD]
[TD="class: xl67, width: 47"]4.6[/TD]
[TD="class: xl68, width: 47"][/TD]
[TD="class: xl67, width: 47"]3.4[/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]12.00%[/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl69"][/TD]
[/TR]
[TR]
[TD="class: xl65, width: 47"]28[/TD]
[TD="class: xl67, width: 47"]4.2[/TD]
[TD="class: xl68, width: 47"][/TD]
[TD="class: xl67, width: 47"]3.1[/TD]
[/TR]
[/TABLE]


Both cassettes pretty close. You can tell the difference between the 29er vs 20

Sure my rockhopper was a 26", but going on latest model. Dunno the RPM vs good speed, what do you think?

so basically do you shoe horn in a 135 hub? or squeeze the frame onto a 130?

ziqpy 02-26-14 09:31 PM

[TABLE="width: 282"]
[TR]
[TD="class: xl65, width: 47"] [/TD]
[TD="class: xl66, width: 47"]44[/TD]
[TD="class: xl67, width: 47"]37.50%[/TD]
[TD="class: xl66, width: 47"]32[/TD]
[TD="class: xl67, width: 47"]45.50%[/TD]
[TD="class: xl66, width: 47"]22[/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]11[/TD]
[TD="class: xl68, width: 47"]12.3[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]8.9[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]6.1[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]9.10%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]12[/TD]
[TD="class: xl68, width: 47"]11.2[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]8.2[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]5.6[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]16.70%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]14[/TD]
[TD="class: xl68, width: 47"]9.6[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]7[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]4.8[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]14.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]16[/TD]
[TD="class: xl68, width: 47"]8.4[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]6.1[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]4.2[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]12.50%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]18[/TD]
[TD="class: xl68, width: 47"]7.5[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]5.4[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]3.7[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]16.70%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]21[/TD]
[TD="class: xl68, width: 47"]6.4[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]4.7[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]3.2[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]14.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]24[/TD]
[TD="class: xl68, width: 47"]5.6[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]4.1[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]2.8[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]16.70%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]28[/TD]
[TD="class: xl68, width: 47"]4.8[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]3.5[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]2.4[/TD]
[/TR]
[TR]
[TD="class: xl67, width: 47"]14.30%[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD="class: xl70"] [/TD]
[/TR]
[TR]
[TD="class: xl66, width: 47"]32[/TD]
[TD="class: xl68, width: 47"]4.2[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]3.1[/TD]
[TD="class: xl69, width: 47"] [/TD]
[TD="class: xl68, width: 47"]2.1
[/TD]
[/TR]
[/TABLE]

well i found some specs for roughly the year i bought mine :D on 26x2.0"

mconlonx 02-27-14 10:31 AM

Quote:

Originally Posted by ziqpy (Post 16529705)
I'm using a tape measure but getting aroudn 132mm on rear.

The forks have a pressed section to clear discs, and around 95mm from center.

I going with 53/39 because of the smaller wheels.

Last bike i was a specialized rockhopper.

2000 ish model

something like this ish...

http://i1095.photobucket.com/albums/...6032011095.jpg

Used to go everywhere around 16mph and deff without tail wind got 30mph outta the bugger on the flat. Fastest was 47 going downhill filtering (which you should not do at that speed)

Sounds like a pretty standard d/o, so I would be so bold as to say it is built to common standards. I.e. as long as you get the right sized adapters between the calipers and frame/fork, everything will work out fine. Hubs built for disks are built to work for the same standards, so go nuts. As I said, mtn hubs at 135 will be more common than road disk hubs at 130.

I'd still be tempted to go with a 50/34 crank, but if you rarely find yourself in the three lowest gears on your mtn bike, then it's a wash, stick with the bigger crank. With the Rival groupset, you could always swap out to a mtn RD (X9) and 11-36 cass if you find you miss the lower gears.

ziqpy 02-27-14 11:42 AM

Quote:

Originally Posted by mconlonx (Post 16532056)
Sounds like a pretty standard d/o, so I would be so bold as to say it is built to common standards. I.e. as long as you get the right sized adapters between the calipers and frame/fork, everything will work out fine. Hubs built for disks are built to work for the same standards, so go nuts. As I said, mtn hubs at 135 will be more common than road disk hubs at 130.

I'd still be tempted to go with a 50/34 crank, but if you rarely find yourself in the three lowest gears on your mtn bike, then it's a wash, stick with the bigger crank. With the Rival groupset, you could always swap out to a mtn RD (X9) and 11-36 cass if you find you miss the lower gears.


i ran the compact crank numbers, and you only loose .6 mph @ 40rpm

but get closer to what a mountain bike does.

so going to stick with one of the 11-sommat cranks, and i'll recheck the numbers later. Just so I can go as fast as I can.

The sprocket jumps on the cassette quite reasonable.

Decided to go with Hope Pro 2 EVO hubs with steel freehub, in silver.

Stainless spokes and hub silver with black nipples and rim.

dynaryder 02-27-14 06:45 PM

Quote:

Originally Posted by ziqpy (Post 16530872)
Sure my rockhopper was a 26", but going on latest model. Dunno the RPM vs good speed, what do you think?

Ballparking your numbers,I get just over the 3rd gear/small ring on my Safari,which I've used to climb some serious hills. On a much lighter bike(it's around 30lbs),I wouldn't have any issues with it,but I'm not you. If you're worried about not having a low enough gear,I'd suggest an 11-28 cassette. If you never use the lowest gear,then when it comes time to change the worn out cassette,just go with an 11-26.

Quote:

Originally Posted by ziqpy (Post 16530872)
so basically do you shoe horn in a 135 hub? or squeeze the frame onto a 130?

Yep. My Ti cross bike was 132.5;it came with a 135mm 29er rear wheel,and I just pulled the dropouts apart a bit when I put the wheel in. No issues.

thugpipe 02-27-14 11:48 PM

Well from my experiences with my road mini velo build I would recomend going with the biggest front chainring you can get, the small wheels naturally gear the bike for hills your bigger issue will be top end. I am curently running a 56t up front on my bully in a 1x10 setup with an 11-32t cassette and I am getting 35-100 gear inches which is pretty comfortable going up some very steep inclines, I can't see anyone needing an even lower gear but you do probably want the top end as high as possible. Just so it is apples to apples here is my mph@40rpm according to sheldon brown with the closest cassette he had.

[TABLE]
[TR]
[TD][TABLE]
[TR]
[TD][/TD]
[TH="bgcolor: yellow"]56[/TH]
[/TR]
[TR]
[TH="bgcolor: yellow"]11[/TH]
[TH="bgcolor: white"]12.1[/TH]
[/TR]
[TR]
[TD="align: center"]18.2 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]13[/TH]
[TH="bgcolor: white"]10.2[/TH]
[/TR]
[TR]
[TD="align: center"]15.4 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]15[/TH]
[TH="bgcolor: white"]8.8[/TH]
[/TR]
[TR]
[TD="align: center"]13.3 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]17[/TH]
[TH="bgcolor: white"]7.8[/TH]
[/TR]
[TR]
[TD="align: center"]11.8 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]19[/TH]
[TH="bgcolor: white"]7.0[/TH]
[/TR]
[TR]
[TD="align: center"]10.5 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]21[/TH]
[TH="bgcolor: white"]6.3[/TH]
[/TR]
[TR]
[TD="align: center"]9.5 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]23[/TH]
[TH="bgcolor: white"]5.8[/TH]
[/TR]
[TR]
[TD="align: center"]8.7 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]25[/TH]
[TH="bgcolor: white"]5.3[/TH]
[/TR]
[TR]
[TD="align: center"]12.0 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]28[/TH]
[TH="bgcolor: white"]4.7[/TH]
[/TR]
[TR]
[TD="align: center"]14.3 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]32[/TH]
[TH="bgcolor: white"]4.1

[/TH]
[/TR]
[/TABLE]
[/TD]
[/TR]
[/TABLE]
Also I would recomend going with the narrower aeroheat rims if you are doing 1.35 road tires, they will sit better in the rims.

I personally went with 160mm rotors on 406 wheels for my brakes and 135mm mtb hubs and they work well although I am using short pull road calipers and long pull mtb levers(speed dial7) and I have brakes to spare. you could probably afford to go with the smaller 140mm discs but the 160mm ones are easier to find in kits with the calipers.

Good luck on the build, can't wait to see how it goes!

thugpipe 02-28-14 02:18 PM

Ok I put in my actual cogs into sheldons calculator and it looks like your rockhopper's top end range is almost identical to my bikes range and if you wanted to get the lower end you could go with a 44t small chainring.
[TABLE]
[TR]
[TD][TABLE]
[TR]
[TD][/TD]
[TH="bgcolor: yellow"]56[/TH]
[TD="align: center"]27.3 %[/TD]
[TH="bgcolor: yellow"]44[/TH]
[/TR]
[TR]
[TH="bgcolor: yellow"]11[/TH]
[TH="bgcolor: white"]12.1[/TH]
[TD][/TD]
[TH="bgcolor: white"]9.5[/TH]
[/TR]
[TR]
[TD="align: center"]9.1 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]12[/TH]
[TH="bgcolor: white"]11.1[/TH]
[TD][/TD]
[TH="bgcolor: white"]8.7[/TH]
[/TR]
[TR]
[TD="align: center"]8.3 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]13[/TH]
[TH="bgcolor: white"]10.2[/TH]
[TD][/TD]
[TH="bgcolor: white"]8.0[/TH]
[/TR]
[TR]
[TD="align: center"]15.4 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]15[/TH]
[TH="bgcolor: white"]8.8[/TH]
[TD][/TD]
[TH="bgcolor: white"]6.9[/TH]
[/TR]
[TR]
[TD="align: center"]13.3 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]17[/TH]
[TH="bgcolor: white"]7.8[/TH]
[TD][/TD]
[TH="bgcolor: white"]6.1[/TH]
[/TR]
[TR]
[TD="align: center"]11.8 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]19[/TH]
[TH="bgcolor: white"]7.0[/TH]
[TD][/TD]
[TH="bgcolor: white"]5.5[/TH]
[/TR]
[TR]
[TD="align: center"]15.8 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]22[/TH]
[TH="bgcolor: white"]6.0[/TH]
[TD][/TD]
[TH="bgcolor: white"]4.7[/TH]
[/TR]
[TR]
[TD="align: center"]13.6 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]25[/TH]
[TH="bgcolor: white"]5.3[/TH]
[TD][/TD]
[TH="bgcolor: white"]4.2[/TH]
[/TR]
[TR]
[TD="align: center"]12.0 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]28[/TH]
[TH="bgcolor: white"]4.7[/TH]
[TD][/TD]
[TH="bgcolor: white"]3.7[/TH]
[/TR]
[TR]
[TD="align: center"]14.3 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]32[/TH]
[TH="bgcolor: white"]4.1[/TH]
[TD][/TD]
[TH="bgcolor: white"]3.3

[/TH]
[/TR]
[/TABLE]
[/TD]
[/TR]
[/TABLE]

ziqpy 03-01-14 03:30 PM

Quote:

Originally Posted by thugpipe (Post 16536122)
Ok I put in my actual cogs into sheldons calculator and it looks like your rockhopper's top end range is almost identical to my bikes range and if you wanted to get the lower end you could go with a 44t small chainring.



I need to measure as they do need ISO adapters.

sram don't do a 56/44 chainring.


with the little difference in 53/39 to 50/36, I'd go with the compact. I'm just worried about top speed, which only comes to around 21mph 80rpm


should I go with a slightly shorter crank to get rpm up?

thugpipe 03-01-14 04:12 PM

Quote:

Originally Posted by ziqpy (Post 16539252)

I need to measure as they do need ISO adapters.

sram don't do a 56/44 chainring.


with the little difference in 53/39 to 50/36, I'd go with the compact. I'm just worried about top speed, which only comes to around 21mph 80rpm


should I go with a slightly shorter crank to get rpm up?

You can get a sram or fsa TT chain ring in a 55 44 setup but it does not come stock with any cranks. You can also look up vuelta chainrings and driveline chainrings on ebay. I would not recomend going down to a 50t

In my opinion changing the crank lenght makes little to no difference for me.

ziqpy 03-02-14 04:04 PM

I don't really want to go that expense.

Looking at the gearing calculations with that site, going to go 53/39 with a 11-28 or 11-32

How do you know when you need a small or medium rear derailer?

Why would the aeroheat rims be better with a 1.35 tyre?

thugpipe 03-02-14 06:37 PM

Quote:

Originally Posted by ziqpy (Post 16541699)
I don't really want to go that expense.

Looking at the gearing calculations with that site, going to go 53/39 with a 11-28 or 11-32

How do you know when you need a small or medium rear derailer?

Why would the aeroheat rims be better with a 1.35 tyre?

The derailleur size effects the amount of chain the drive can hold and the range of gearing you can have, I generally determin the derailluer size based on the number of chainrings you have, more chainrings=longer derailleur cage. I have a short derailleur because I have a 1x10 drive so I don't need extra chain but I also wanted the extra clearence from the ground on the small wheels.

As for the rims, the aeroheat rim is 24mm wide and the Clifhanger is 28mm and that 4mm makes a big difference. A 1.35mm slick tire is pretty small and the narrower rim forces the tire into a rounder profile and leaves the rim less exposed. the cliffhanger is more of a BMX rim intended for 1.5 and larger tires although I am running high pressure 1.95 tires on the narrower Aero heat rims.

I would stick with the 53/39 then at the very least to get the larger 130mm BCD in case you want to upgrade the gearing later and if you keep an eye on ebay you could probably pick up a large chainring for cheap. got my current 56t chainring for $26 on ebay.

ziqpy 03-02-14 07:49 PM

Thx,

Can you get away with medium cage on 20"?

thugpipe 03-02-14 08:46 PM

Quote:

Originally Posted by ziqpy (Post 16542398)
Thx,

Can you get away with medium cage on 20"?

Sure you can, you might just need to be a little mindful when get close to a curb or something.

Just in case here is a link to some cheaper 55t chainring options:
http://www.ebay.co.uk/sch/i.html?_tr...at=0&_from=R40

ziqpy 03-06-14 05:54 PM

Velocity rims ordered from states.

Hope hubs and TRP Spyre (160mm) brakes ordered also.

Rims were not cheap in rim terms, hopefully worth it.

Anyone know of any good website that sell sram groupsets in europe?

thugpipe 03-06-14 09:58 PM

Have you seen this probably doesn't still apply
http://www.cxmagazine.com/recall-trp...e-caliper-2013

I'm very happy with my velocity rims

Quote:

Originally Posted by ziqpy (Post 16555404)
Velocity rims ordered from states.

Hope hubs and TRP Spyre (160mm) brakes ordered also.

Rims were not cheap in rim terms, hopefully worth it.

Anyone know of any good website that sell sram groupsets in europe?


ziqpy 03-06-14 10:06 PM

They corrected that error over Christmas period, and I seen pic of new version.

been a common fault with a mechanical even shimano.

ziqpy 03-11-14 07:26 PM

Ok so I ordered the wrong rear hub 12mm instead of a 10mm QR

On top of that, there is too much play because the front is a 9mm QR with a 10mm drop out.

I can get brass tube w/ 0.5mm sidewall. Also seen carbon fibre, so will it hold up as a spacer?

thugpipe 03-11-14 08:26 PM

So that bike has 10mm fork dropouts? That seems odd, if you are replacing the rear hub I would just return the front hub as well and get something that fits better because a shim would be a major pain in the ass. If you do a shim I would go for the brass, carbon fiber is not the best where it will get repeatedly abraded and weight savings on something like that is laughable.

ziqpy 03-12-14 10:40 AM

some MTB over sized hubs used 10mm dropouts for front forks. I will use a spacer out of brass or get something machined.

I will try the brass spacer 1st, coz it's cheap ;)

Rear hub sorted in 5min. Just swaped end caps off the hub of a new hub he had which was QR ready.

ziqpy 04-04-14 04:25 AM

http://i.imgur.com/WPRH9US.jpg

Only been 4 weeks, but my rims finally here, and missed some nice sunny days too :notamused:

Very little groupset sellers in UK for sram. trying to find one in Europe.

thugpipe 04-04-14 07:10 AM

Exciting, I remember putting my Bully together last year and getting all the parts and all the waiting but it was worth it, hang in there!

So are you building the wheels yourself or sending them out to a shop?


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